diff options
Diffstat (limited to 'drivers/net/ethernet/tile')
| -rw-r--r-- | drivers/net/ethernet/tile/Kconfig | 18 | ||||
| -rw-r--r-- | drivers/net/ethernet/tile/Makefile | 10 | ||||
| -rw-r--r-- | drivers/net/ethernet/tile/tilegx.c | 2281 | ||||
| -rw-r--r-- | drivers/net/ethernet/tile/tilepro.c | 2423 |
4 files changed, 4732 insertions, 0 deletions
diff --git a/drivers/net/ethernet/tile/Kconfig b/drivers/net/ethernet/tile/Kconfig new file mode 100644 index 000000000..f59a6c265 --- /dev/null +++ b/drivers/net/ethernet/tile/Kconfig @@ -0,0 +1,18 @@ +# +# Tilera network device configuration +# + +config TILE_NET + tristate "Tilera GBE/XGBE network driver support" + depends on TILE + default y + select CRC32 + select TILE_GXIO_MPIPE if TILEGX + select HIGH_RES_TIMERS if TILEGX + select PTP_1588_CLOCK if TILEGX + ---help--- + This is a standard Linux network device driver for the + on-chip Tilera Gigabit Ethernet and XAUI interfaces. + + To compile this driver as a module, choose M here: the module + will be called tile_net. diff --git a/drivers/net/ethernet/tile/Makefile b/drivers/net/ethernet/tile/Makefile new file mode 100644 index 000000000..0ef9eefd3 --- /dev/null +++ b/drivers/net/ethernet/tile/Makefile @@ -0,0 +1,10 @@ +# +# Makefile for the TILE on-chip networking support. +# + +obj-$(CONFIG_TILE_NET) += tile_net.o +ifdef CONFIG_TILEGX +tile_net-y := tilegx.o +else +tile_net-y := tilepro.o +endif diff --git a/drivers/net/ethernet/tile/tilegx.c b/drivers/net/ethernet/tile/tilegx.c new file mode 100644 index 000000000..a3f761000 --- /dev/null +++ b/drivers/net/ethernet/tile/tilegx.c @@ -0,0 +1,2281 @@ +/* + * Copyright 2012 Tilera Corporation. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, version 2. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for + * more details. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/moduleparam.h> +#include <linux/sched.h> +#include <linux/kernel.h> /* printk() */ +#include <linux/slab.h> /* kmalloc() */ +#include <linux/errno.h> /* error codes */ +#include <linux/types.h> /* size_t */ +#include <linux/interrupt.h> +#include <linux/in.h> +#include <linux/irq.h> +#include <linux/netdevice.h> /* struct device, and other headers */ +#include <linux/etherdevice.h> /* eth_type_trans */ +#include <linux/skbuff.h> +#include <linux/ioctl.h> +#include <linux/cdev.h> +#include <linux/hugetlb.h> +#include <linux/in6.h> +#include <linux/timer.h> +#include <linux/hrtimer.h> +#include <linux/ktime.h> +#include <linux/io.h> +#include <linux/ctype.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <linux/tcp.h> +#include <linux/net_tstamp.h> +#include <linux/ptp_clock_kernel.h> + +#include <asm/checksum.h> +#include <asm/homecache.h> +#include <gxio/mpipe.h> +#include <arch/sim.h> + +/* Default transmit lockup timeout period, in jiffies. */ +#define TILE_NET_TIMEOUT (5 * HZ) + +/* The maximum number of distinct channels (idesc.channel is 5 bits). */ +#define TILE_NET_CHANNELS 32 + +/* Maximum number of idescs to handle per "poll". */ +#define TILE_NET_BATCH 128 + +/* Maximum number of packets to handle per "poll". */ +#define TILE_NET_WEIGHT 64 + +/* Number of entries in each iqueue. */ +#define IQUEUE_ENTRIES 512 + +/* Number of entries in each equeue. */ +#define EQUEUE_ENTRIES 2048 + +/* Total header bytes per equeue slot. Must be big enough for 2 bytes + * of NET_IP_ALIGN alignment, plus 14 bytes (?) of L2 header, plus up to + * 60 bytes of actual TCP header. We round up to align to cache lines. + */ +#define HEADER_BYTES 128 + +/* Maximum completions per cpu per device (must be a power of two). + * ISSUE: What is the right number here? If this is too small, then + * egress might block waiting for free space in a completions array. + * ISSUE: At the least, allocate these only for initialized echannels. + */ +#define TILE_NET_MAX_COMPS 64 + +#define MAX_FRAGS (MAX_SKB_FRAGS + 1) + +/* The "kinds" of buffer stacks (small/large/jumbo). */ +#define MAX_KINDS 3 + +/* Size of completions data to allocate. + * ISSUE: Probably more than needed since we don't use all the channels. + */ +#define COMPS_SIZE (TILE_NET_CHANNELS * sizeof(struct tile_net_comps)) + +/* Size of NotifRing data to allocate. */ +#define NOTIF_RING_SIZE (IQUEUE_ENTRIES * sizeof(gxio_mpipe_idesc_t)) + +/* Timeout to wake the per-device TX timer after we stop the queue. + * We don't want the timeout too short (adds overhead, and might end + * up causing stop/wake/stop/wake cycles) or too long (affects performance). + * For the 10 Gb NIC, 30 usec means roughly 30+ 1500-byte packets. + */ +#define TX_TIMER_DELAY_USEC 30 + +/* Timeout to wake the per-cpu egress timer to free completions. */ +#define EGRESS_TIMER_DELAY_USEC 1000 + +MODULE_AUTHOR("Tilera Corporation"); +MODULE_LICENSE("GPL"); + +/* A "packet fragment" (a chunk of memory). */ +struct frag { + void *buf; + size_t length; +}; + +/* A single completion. */ +struct tile_net_comp { + /* The "complete_count" when the completion will be complete. */ + s64 when; + /* The buffer to be freed when the completion is complete. */ + struct sk_buff *skb; +}; + +/* The completions for a given cpu and echannel. */ +struct tile_net_comps { + /* The completions. */ + struct tile_net_comp comp_queue[TILE_NET_MAX_COMPS]; + /* The number of completions used. */ + unsigned long comp_next; + /* The number of completions freed. */ + unsigned long comp_last; +}; + +/* The transmit wake timer for a given cpu and echannel. */ +struct tile_net_tx_wake { + int tx_queue_idx; + struct hrtimer timer; + struct net_device *dev; +}; + +/* Info for a specific cpu. */ +struct tile_net_info { + /* Our cpu. */ + int my_cpu; + /* A timer for handling egress completions. */ + struct hrtimer egress_timer; + /* True if "egress_timer" is scheduled. */ + bool egress_timer_scheduled; + struct info_mpipe { + /* Packet queue. */ + gxio_mpipe_iqueue_t iqueue; + /* The NAPI struct. */ + struct napi_struct napi; + /* Number of buffers (by kind) which must still be provided. */ + unsigned int num_needed_buffers[MAX_KINDS]; + /* instance id. */ + int instance; + /* True if iqueue is valid. */ + bool has_iqueue; + /* NAPI flags. */ + bool napi_added; + bool napi_enabled; + /* Comps for each egress channel. */ + struct tile_net_comps *comps_for_echannel[TILE_NET_CHANNELS]; + /* Transmit wake timer for each egress channel. */ + struct tile_net_tx_wake tx_wake[TILE_NET_CHANNELS]; + } mpipe[NR_MPIPE_MAX]; +}; + +/* Info for egress on a particular egress channel. */ +struct tile_net_egress { + /* The "equeue". */ + gxio_mpipe_equeue_t *equeue; + /* The headers for TSO. */ + unsigned char *headers; +}; + +/* Info for a specific device. */ +struct tile_net_priv { + /* Our network device. */ + struct net_device *dev; + /* The primary link. */ + gxio_mpipe_link_t link; + /* The primary channel, if open, else -1. */ + int channel; + /* The "loopify" egress link, if needed. */ + gxio_mpipe_link_t loopify_link; + /* The "loopify" egress channel, if open, else -1. */ + int loopify_channel; + /* The egress channel (channel or loopify_channel). */ + int echannel; + /* mPIPE instance, 0 or 1. */ + int instance; + /* The timestamp config. */ + struct hwtstamp_config stamp_cfg; +}; + +static struct mpipe_data { + /* The ingress irq. */ + int ingress_irq; + + /* The "context" for all devices. */ + gxio_mpipe_context_t context; + + /* Egress info, indexed by "priv->echannel" + * (lazily created as needed). + */ + struct tile_net_egress + egress_for_echannel[TILE_NET_CHANNELS]; + + /* Devices currently associated with each channel. + * NOTE: The array entry can become NULL after ifconfig down, but + * we do not free the underlying net_device structures, so it is + * safe to use a pointer after reading it from this array. + */ + struct net_device + *tile_net_devs_for_channel[TILE_NET_CHANNELS]; + + /* The actual memory allocated for the buffer stacks. */ + void *buffer_stack_vas[MAX_KINDS]; + + /* The amount of memory allocated for each buffer stack. */ + size_t buffer_stack_bytes[MAX_KINDS]; + + /* The first buffer stack index + * (small = +0, large = +1, jumbo = +2). + */ + int first_buffer_stack; + + /* The buckets. */ + int first_bucket; + int num_buckets; + + /* PTP-specific data. */ + struct ptp_clock *ptp_clock; + struct ptp_clock_info caps; + + /* Lock for ptp accessors. */ + struct mutex ptp_lock; + +} mpipe_data[NR_MPIPE_MAX] = { + [0 ... (NR_MPIPE_MAX - 1)] { + .ingress_irq = -1, + .first_buffer_stack = -1, + .first_bucket = -1, + .num_buckets = 1 + } +}; + +/* A mutex for "tile_net_devs_for_channel". */ +static DEFINE_MUTEX(tile_net_devs_for_channel_mutex); + +/* The per-cpu info. */ +static DEFINE_PER_CPU(struct tile_net_info, per_cpu_info); + + +/* The buffer size enums for each buffer stack. + * See arch/tile/include/gxio/mpipe.h for the set of possible values. + * We avoid the "10384" size because it can induce "false chaining" + * on "cut-through" jumbo packets. + */ +static gxio_mpipe_buffer_size_enum_t buffer_size_enums[MAX_KINDS] = { + GXIO_MPIPE_BUFFER_SIZE_128, + GXIO_MPIPE_BUFFER_SIZE_1664, + GXIO_MPIPE_BUFFER_SIZE_16384 +}; + +/* Text value of tile_net.cpus if passed as a module parameter. */ +static char *network_cpus_string; + +/* The actual cpus in "network_cpus". */ +static struct cpumask network_cpus_map; + +/* If "tile_net.loopify=LINK" was specified, this is "LINK". */ +static char *loopify_link_name; + +/* If "tile_net.custom" was specified, this is true. */ +static bool custom_flag; + +/* If "tile_net.jumbo=NUM" was specified, this is "NUM". */ +static uint jumbo_num; + +/* Obtain mpipe instance from struct tile_net_priv given struct net_device. */ +static inline int mpipe_instance(struct net_device *dev) +{ + struct tile_net_priv *priv = netdev_priv(dev); + return priv->instance; +} + +/* The "tile_net.cpus" argument specifies the cpus that are dedicated + * to handle ingress packets. + * + * The parameter should be in the form "tile_net.cpus=m-n[,x-y]", where + * m, n, x, y are integer numbers that represent the cpus that can be + * neither a dedicated cpu nor a dataplane cpu. + */ +static bool network_cpus_init(void) +{ + int rc; + + if (network_cpus_string == NULL) + return false; + + rc = cpulist_parse_crop(network_cpus_string, &network_cpus_map); + if (rc != 0) { + pr_warn("tile_net.cpus=%s: malformed cpu list\n", + network_cpus_string); + return false; + } + + /* Remove dedicated cpus. */ + cpumask_and(&network_cpus_map, &network_cpus_map, cpu_possible_mask); + + if (cpumask_empty(&network_cpus_map)) { + pr_warn("Ignoring empty tile_net.cpus='%s'.\n", + network_cpus_string); + return false; + } + + pr_info("Linux network CPUs: %*pbl\n", + cpumask_pr_args(&network_cpus_map)); + return true; +} + +module_param_named(cpus, network_cpus_string, charp, 0444); +MODULE_PARM_DESC(cpus, "cpulist of cores that handle network interrupts"); + +/* The "tile_net.loopify=LINK" argument causes the named device to + * actually use "loop0" for ingress, and "loop1" for egress. This + * allows an app to sit between the actual link and linux, passing + * (some) packets along to linux, and forwarding (some) packets sent + * out by linux. + */ +module_param_named(loopify, loopify_link_name, charp, 0444); +MODULE_PARM_DESC(loopify, "name the device to use loop0/1 for ingress/egress"); + +/* The "tile_net.custom" argument causes us to ignore the "conventional" + * classifier metadata, in particular, the "l2_offset". + */ +module_param_named(custom, custom_flag, bool, 0444); +MODULE_PARM_DESC(custom, "indicates a (heavily) customized classifier"); + +/* The "tile_net.jumbo" argument causes us to support "jumbo" packets, + * and to allocate the given number of "jumbo" buffers. + */ +module_param_named(jumbo, jumbo_num, uint, 0444); +MODULE_PARM_DESC(jumbo, "the number of buffers to support jumbo packets"); + +/* Atomically update a statistics field. + * Note that on TILE-Gx, this operation is fire-and-forget on the + * issuing core (single-cycle dispatch) and takes only a few cycles + * longer than a regular store when the request reaches the home cache. + * No expensive bus management overhead is required. + */ +static void tile_net_stats_add(unsigned long value, unsigned long *field) +{ + BUILD_BUG_ON(sizeof(atomic_long_t) != sizeof(unsigned long)); + atomic_long_add(value, (atomic_long_t *)field); +} + +/* Allocate and push a buffer. */ +static bool tile_net_provide_buffer(int instance, int kind) +{ + struct mpipe_data *md = &mpipe_data[instance]; + gxio_mpipe_buffer_size_enum_t bse = buffer_size_enums[kind]; + size_t bs = gxio_mpipe_buffer_size_enum_to_buffer_size(bse); + const unsigned long buffer_alignment = 128; + struct sk_buff *skb; + int len; + + len = sizeof(struct sk_buff **) + buffer_alignment + bs; + skb = dev_alloc_skb(len); + if (skb == NULL) + return false; + + /* Make room for a back-pointer to 'skb' and guarantee alignment. */ + skb_reserve(skb, sizeof(struct sk_buff **)); + skb_reserve(skb, -(long)skb->data & (buffer_alignment - 1)); + + /* Save a back-pointer to 'skb'. */ + *(struct sk_buff **)(skb->data - sizeof(struct sk_buff **)) = skb; + + /* Make sure "skb" and the back-pointer have been flushed. */ + wmb(); + + gxio_mpipe_push_buffer(&md->context, md->first_buffer_stack + kind, + (void *)va_to_tile_io_addr(skb->data)); + + return true; +} + +/* Convert a raw mpipe buffer to its matching skb pointer. */ +static struct sk_buff *mpipe_buf_to_skb(void *va) +{ + /* Acquire the associated "skb". */ + struct sk_buff **skb_ptr = va - sizeof(*skb_ptr); + struct sk_buff *skb = *skb_ptr; + + /* Paranoia. */ + if (skb->data != va) { + /* Panic here since there's a reasonable chance + * that corrupt buffers means generic memory + * corruption, with unpredictable system effects. + */ + panic("Corrupt linux buffer! va=%p, skb=%p, skb->data=%p", + va, skb, skb->data); + } + + return skb; +} + +static void tile_net_pop_all_buffers(int instance, int stack) +{ + struct mpipe_data *md = &mpipe_data[instance]; + + for (;;) { + tile_io_addr_t addr = + (tile_io_addr_t)gxio_mpipe_pop_buffer(&md->context, + stack); + if (addr == 0) + break; + dev_kfree_skb_irq(mpipe_buf_to_skb(tile_io_addr_to_va(addr))); + } +} + +/* Provide linux buffers to mPIPE. */ +static void tile_net_provide_needed_buffers(void) +{ + struct tile_net_info *info = this_cpu_ptr(&per_cpu_info); + int instance, kind; + for (instance = 0; instance < NR_MPIPE_MAX && + info->mpipe[instance].has_iqueue; instance++) { + for (kind = 0; kind < MAX_KINDS; kind++) { + while (info->mpipe[instance].num_needed_buffers[kind] + != 0) { + if (!tile_net_provide_buffer(instance, kind)) { + pr_notice("Tile %d still needs" + " some buffers\n", + info->my_cpu); + return; + } + info->mpipe[instance]. + num_needed_buffers[kind]--; + } + } + } +} + +/* Get RX timestamp, and store it in the skb. */ +static void tile_rx_timestamp(struct tile_net_priv *priv, struct sk_buff *skb, + gxio_mpipe_idesc_t *idesc) +{ + if (unlikely(priv->stamp_cfg.rx_filter != HWTSTAMP_FILTER_NONE)) { + struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); + memset(shhwtstamps, 0, sizeof(*shhwtstamps)); + shhwtstamps->hwtstamp = ktime_set(idesc->time_stamp_sec, + idesc->time_stamp_ns); + } +} + +/* Get TX timestamp, and store it in the skb. */ +static void tile_tx_timestamp(struct sk_buff *skb, int instance) +{ + struct skb_shared_info *shtx = skb_shinfo(skb); + if (unlikely((shtx->tx_flags & SKBTX_HW_TSTAMP) != 0)) { + struct mpipe_data *md = &mpipe_data[instance]; + struct skb_shared_hwtstamps shhwtstamps; + struct timespec ts; + + shtx->tx_flags |= SKBTX_IN_PROGRESS; + gxio_mpipe_get_timestamp(&md->context, &ts); + memset(&shhwtstamps, 0, sizeof(shhwtstamps)); + shhwtstamps.hwtstamp = ktime_set(ts.tv_sec, ts.tv_nsec); + skb_tstamp_tx(skb, &shhwtstamps); + } +} + +/* Use ioctl() to enable or disable TX or RX timestamping. */ +static int tile_hwtstamp_set(struct net_device *dev, struct ifreq *rq) +{ + struct hwtstamp_config config; + struct tile_net_priv *priv = netdev_priv(dev); + + if (copy_from_user(&config, rq->ifr_data, sizeof(config))) + return -EFAULT; + + if (config.flags) /* reserved for future extensions */ + return -EINVAL; + + switch (config.tx_type) { + case HWTSTAMP_TX_OFF: + case HWTSTAMP_TX_ON: + break; + default: + return -ERANGE; + } + + switch (config.rx_filter) { + case HWTSTAMP_FILTER_NONE: + break; + case HWTSTAMP_FILTER_ALL: + case HWTSTAMP_FILTER_SOME: + case HWTSTAMP_FILTER_PTP_V1_L4_EVENT: + case HWTSTAMP_FILTER_PTP_V1_L4_SYNC: + case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ: + case HWTSTAMP_FILTER_PTP_V2_L4_EVENT: + case HWTSTAMP_FILTER_PTP_V2_L4_SYNC: + case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ: + case HWTSTAMP_FILTER_PTP_V2_L2_EVENT: + case HWTSTAMP_FILTER_PTP_V2_L2_SYNC: + case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ: + case HWTSTAMP_FILTER_PTP_V2_EVENT: + case HWTSTAMP_FILTER_PTP_V2_SYNC: + case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ: + config.rx_filter = HWTSTAMP_FILTER_ALL; + break; + default: + return -ERANGE; + } + + if (copy_to_user(rq->ifr_data, &config, sizeof(config))) + return -EFAULT; + + priv->stamp_cfg = config; + return 0; +} + +static int tile_hwtstamp_get(struct net_device *dev, struct ifreq *rq) +{ + struct tile_net_priv *priv = netdev_priv(dev); + + if (copy_to_user(rq->ifr_data, &priv->stamp_cfg, + sizeof(priv->stamp_cfg))) + return -EFAULT; + + return 0; +} + +static inline bool filter_packet(struct net_device *dev, void *buf) +{ + /* Filter packets received before we're up. */ + if (dev == NULL || !(dev->flags & IFF_UP)) + return true; + + /* Filter out packets that aren't for us. */ + if (!(dev->flags & IFF_PROMISC) && + !is_multicast_ether_addr(buf) && + !ether_addr_equal(dev->dev_addr, buf)) + return true; + + return false; +} + +static void tile_net_receive_skb(struct net_device *dev, struct sk_buff *skb, + gxio_mpipe_idesc_t *idesc, unsigned long len) +{ + struct tile_net_info *info = this_cpu_ptr(&per_cpu_info); + struct tile_net_priv *priv = netdev_priv(dev); + int instance = priv->instance; + + /* Encode the actual packet length. */ + skb_put(skb, len); + + skb->protocol = eth_type_trans(skb, dev); + + /* Acknowledge "good" hardware checksums. */ + if (idesc->cs && idesc->csum_seed_val == 0xFFFF) + skb->ip_summed = CHECKSUM_UNNECESSARY; + + /* Get RX timestamp from idesc. */ + tile_rx_timestamp(priv, skb, idesc); + + napi_gro_receive(&info->mpipe[instance].napi, skb); + + /* Update stats. */ + tile_net_stats_add(1, &dev->stats.rx_packets); + tile_net_stats_add(len, &dev->stats.rx_bytes); + + /* Need a new buffer. */ + if (idesc->size == buffer_size_enums[0]) + info->mpipe[instance].num_needed_buffers[0]++; + else if (idesc->size == buffer_size_enums[1]) + info->mpipe[instance].num_needed_buffers[1]++; + else + info->mpipe[instance].num_needed_buffers[2]++; +} + +/* Handle a packet. Return true if "processed", false if "filtered". */ +static bool tile_net_handle_packet(int instance, gxio_mpipe_idesc_t *idesc) +{ + struct tile_net_info *info = this_cpu_ptr(&per_cpu_info); + struct mpipe_data *md = &mpipe_data[instance]; + struct net_device *dev = md->tile_net_devs_for_channel[idesc->channel]; + uint8_t l2_offset; + void *va; + void *buf; + unsigned long len; + bool filter; + + /* Drop packets for which no buffer was available (which can + * happen under heavy load), or for which the me/tr/ce flags + * are set (which can happen for jumbo cut-through packets, + * or with a customized classifier). + */ + if (idesc->be || idesc->me || idesc->tr || idesc->ce) { + if (dev) + tile_net_stats_add(1, &dev->stats.rx_errors); + goto drop; + } + + /* Get the "l2_offset", if allowed. */ + l2_offset = custom_flag ? 0 : gxio_mpipe_idesc_get_l2_offset(idesc); + + /* Get the VA (including NET_IP_ALIGN bytes of "headroom"). */ + va = tile_io_addr_to_va((unsigned long)idesc->va); + + /* Get the actual packet start/length. */ + buf = va + l2_offset; + len = idesc->l2_size - l2_offset; + + /* Point "va" at the raw buffer. */ + va -= NET_IP_ALIGN; + + filter = filter_packet(dev, buf); + if (filter) { + if (dev) + tile_net_stats_add(1, &dev->stats.rx_dropped); +drop: + gxio_mpipe_iqueue_drop(&info->mpipe[instance].iqueue, idesc); + } else { + struct sk_buff *skb = mpipe_buf_to_skb(va); + + /* Skip headroom, and any custom header. */ + skb_reserve(skb, NET_IP_ALIGN + l2_offset); + + tile_net_receive_skb(dev, skb, idesc, len); + } + + gxio_mpipe_iqueue_consume(&info->mpipe[instance].iqueue, idesc); + return !filter; +} + +/* Handle some packets for the current CPU. + * + * This function handles up to TILE_NET_BATCH idescs per call. + * + * ISSUE: Since we do not provide new buffers until this function is + * complete, we must initially provide enough buffers for each network + * cpu to fill its iqueue and also its batched idescs. + * + * ISSUE: The "rotting packet" race condition occurs if a packet + * arrives after the queue appears to be empty, and before the + * hypervisor interrupt is re-enabled. + */ +static int tile_net_poll(struct napi_struct *napi, int budget) +{ + struct tile_net_info *info = this_cpu_ptr(&per_cpu_info); + unsigned int work = 0; + gxio_mpipe_idesc_t *idesc; + int instance, i, n; + struct mpipe_data *md; + struct info_mpipe *info_mpipe = + container_of(napi, struct info_mpipe, napi); + + if (budget <= 0) + goto done; + + instance = info_mpipe->instance; + while ((n = gxio_mpipe_iqueue_try_peek( + &info_mpipe->iqueue, + &idesc)) > 0) { + for (i = 0; i < n; i++) { + if (i == TILE_NET_BATCH) + goto done; + if (tile_net_handle_packet(instance, + idesc + i)) { + if (++work >= budget) + goto done; + } + } + } + + /* There are no packets left. */ + napi_complete(&info_mpipe->napi); + + md = &mpipe_data[instance]; + /* Re-enable hypervisor interrupts. */ + gxio_mpipe_enable_notif_ring_interrupt( + &md->context, info->mpipe[instance].iqueue.ring); + + /* HACK: Avoid the "rotting packet" problem. */ + if (gxio_mpipe_iqueue_try_peek(&info_mpipe->iqueue, &idesc) > 0) + napi_schedule(&info_mpipe->napi); + + /* ISSUE: Handle completions? */ + +done: + tile_net_provide_needed_buffers(); + + return work; +} + +/* Handle an ingress interrupt from an instance on the current cpu. */ +static irqreturn_t tile_net_handle_ingress_irq(int irq, void *id) +{ + struct tile_net_info *info = this_cpu_ptr(&per_cpu_info); + napi_schedule(&info->mpipe[(uint64_t)id].napi); + return IRQ_HANDLED; +} + +/* Free some completions. This must be called with interrupts blocked. */ +static int tile_net_free_comps(gxio_mpipe_equeue_t *equeue, + struct tile_net_comps *comps, + int limit, bool force_update) +{ + int n = 0; + while (comps->comp_last < comps->comp_next) { + unsigned int cid = comps->comp_last % TILE_NET_MAX_COMPS; + struct tile_net_comp *comp = &comps->comp_queue[cid]; + if (!gxio_mpipe_equeue_is_complete(equeue, comp->when, + force_update || n == 0)) + break; + dev_kfree_skb_irq(comp->skb); + comps->comp_last++; + if (++n == limit) + break; + } + return n; +} + +/* Add a completion. This must be called with interrupts blocked. + * tile_net_equeue_try_reserve() will have ensured a free completion entry. + */ +static void add_comp(gxio_mpipe_equeue_t *equeue, + struct tile_net_comps *comps, + uint64_t when, struct sk_buff *skb) +{ + int cid = comps->comp_next % TILE_NET_MAX_COMPS; + comps->comp_queue[cid].when = when; + comps->comp_queue[cid].skb = skb; + comps->comp_next++; +} + +static void tile_net_schedule_tx_wake_timer(struct net_device *dev, + int tx_queue_idx) +{ + struct tile_net_info *info = &per_cpu(per_cpu_info, tx_queue_idx); + struct tile_net_priv *priv = netdev_priv(dev); + int instance = priv->instance; + struct tile_net_tx_wake *tx_wake = + &info->mpipe[instance].tx_wake[priv->echannel]; + + hrtimer_start(&tx_wake->timer, + ktime_set(0, TX_TIMER_DELAY_USEC * 1000UL), + HRTIMER_MODE_REL_PINNED); +} + +static enum hrtimer_restart tile_net_handle_tx_wake_timer(struct hrtimer *t) +{ + struct tile_net_tx_wake *tx_wake = + container_of(t, struct tile_net_tx_wake, timer); + netif_wake_subqueue(tx_wake->dev, tx_wake->tx_queue_idx); + return HRTIMER_NORESTART; +} + +/* Make sure the egress timer is scheduled. */ +static void tile_net_schedule_egress_timer(void) +{ + struct tile_net_info *info = this_cpu_ptr(&per_cpu_info); + + if (!info->egress_timer_scheduled) { + hrtimer_start(&info->egress_timer, + ktime_set(0, EGRESS_TIMER_DELAY_USEC * 1000UL), + HRTIMER_MODE_REL_PINNED); + info->egress_timer_scheduled = true; + } +} + +/* The "function" for "info->egress_timer". + * + * This timer will reschedule itself as long as there are any pending + * completions expected for this tile. + */ +static enum hrtimer_restart tile_net_handle_egress_timer(struct hrtimer *t) +{ + struct tile_net_info *info = this_cpu_ptr(&per_cpu_info); + unsigned long irqflags; + bool pending = false; + int i, instance; + + local_irq_save(irqflags); + + /* The timer is no longer scheduled. */ + info->egress_timer_scheduled = false; + + /* Free all possible comps for this tile. */ + for (instance = 0; instance < NR_MPIPE_MAX && + info->mpipe[instance].has_iqueue; instance++) { + for (i = 0; i < TILE_NET_CHANNELS; i++) { + struct tile_net_egress *egress = + &mpipe_data[instance].egress_for_echannel[i]; + struct tile_net_comps *comps = + info->mpipe[instance].comps_for_echannel[i]; + if (!egress || comps->comp_last >= comps->comp_next) + continue; + tile_net_free_comps(egress->equeue, comps, -1, true); + pending = pending || + (comps->comp_last < comps->comp_next); + } + } + + /* Reschedule timer if needed. */ + if (pending) + tile_net_schedule_egress_timer(); + + local_irq_restore(irqflags); + + return HRTIMER_NORESTART; +} + +/* PTP clock operations. */ + +static int ptp_mpipe_adjfreq(struct ptp_clock_info *ptp, s32 ppb) +{ + int ret = 0; + struct mpipe_data *md = container_of(ptp, struct mpipe_data, caps); + mutex_lock(&md->ptp_lock); + if (gxio_mpipe_adjust_timestamp_freq(&md->context, ppb)) + ret = -EINVAL; + mutex_unlock(&md->ptp_lock); + return ret; +} + +static int ptp_mpipe_adjtime(struct ptp_clock_info *ptp, s64 delta) +{ + int ret = 0; + struct mpipe_data *md = container_of(ptp, struct mpipe_data, caps); + mutex_lock(&md->ptp_lock); + if (gxio_mpipe_adjust_timestamp(&md->context, delta)) + ret = -EBUSY; + mutex_unlock(&md->ptp_lock); + return ret; +} + +static int ptp_mpipe_gettime(struct ptp_clock_info *ptp, + struct timespec64 *ts) +{ + int ret = 0; + struct mpipe_data *md = container_of(ptp, struct mpipe_data, caps); + mutex_lock(&md->ptp_lock); + if (gxio_mpipe_get_timestamp(&md->context, ts)) + ret = -EBUSY; + mutex_unlock(&md->ptp_lock); + return ret; +} + +static int ptp_mpipe_settime(struct ptp_clock_info *ptp, + const struct timespec64 *ts) +{ + int ret = 0; + struct mpipe_data *md = container_of(ptp, struct mpipe_data, caps); + mutex_lock(&md->ptp_lock); + if (gxio_mpipe_set_timestamp(&md->context, ts)) + ret = -EBUSY; + mutex_unlock(&md->ptp_lock); + return ret; +} + +static int ptp_mpipe_enable(struct ptp_clock_info *ptp, + struct ptp_clock_request *request, int on) +{ + return -EOPNOTSUPP; +} + +static struct ptp_clock_info ptp_mpipe_caps = { + .owner = THIS_MODULE, + .name = "mPIPE clock", + .max_adj = 999999999, + .n_ext_ts = 0, + .n_pins = 0, + .pps = 0, + .adjfreq = ptp_mpipe_adjfreq, + .adjtime = ptp_mpipe_adjtime, + .gettime64 = ptp_mpipe_gettime, + .settime64 = ptp_mpipe_settime, + .enable = ptp_mpipe_enable, +}; + +/* Sync mPIPE's timestamp up with Linux system time and register PTP clock. */ +static void register_ptp_clock(struct net_device *dev, struct mpipe_data *md) +{ + struct timespec ts; + + getnstimeofday(&ts); + gxio_mpipe_set_timestamp(&md->context, &ts); + + mutex_init(&md->ptp_lock); + md->caps = ptp_mpipe_caps; + md->ptp_clock = ptp_clock_register(&md->caps, NULL); + if (IS_ERR(md->ptp_clock)) + netdev_err(dev, "ptp_clock_register failed %ld\n", + PTR_ERR(md->ptp_clock)); +} + +/* Initialize PTP fields in a new device. */ +static void init_ptp_dev(struct tile_net_priv *priv) +{ + priv->stamp_cfg.rx_filter = HWTSTAMP_FILTER_NONE; + priv->stamp_cfg.tx_type = HWTSTAMP_TX_OFF; +} + +/* Helper functions for "tile_net_update()". */ +static void enable_ingress_irq(void *irq) +{ + enable_percpu_irq((long)irq, 0); +} + +static void disable_ingress_irq(void *irq) +{ + disable_percpu_irq((long)irq); +} + +/* Helper function for tile_net_open() and tile_net_stop(). + * Always called under tile_net_devs_for_channel_mutex. + */ +static int tile_net_update(struct net_device *dev) +{ + static gxio_mpipe_rules_t rules; /* too big to fit on the stack */ + bool saw_channel = false; + int instance = mpipe_instance(dev); + struct mpipe_data *md = &mpipe_data[instance]; + int channel; + int rc; + int cpu; + + saw_channel = false; + gxio_mpipe_rules_init(&rules, &md->context); + + for (channel = 0; channel < TILE_NET_CHANNELS; channel++) { + if (md->tile_net_devs_for_channel[channel] == NULL) + continue; + if (!saw_channel) { + saw_channel = true; + gxio_mpipe_rules_begin(&rules, md->first_bucket, + md->num_buckets, NULL); + gxio_mpipe_rules_set_headroom(&rules, NET_IP_ALIGN); + } + gxio_mpipe_rules_add_channel(&rules, channel); + } + + /* NOTE: This can fail if there is no classifier. + * ISSUE: Can anything else cause it to fail? + */ + rc = gxio_mpipe_rules_commit(&rules); + if (rc != 0) { + netdev_warn(dev, "gxio_mpipe_rules_commit: mpipe[%d] %d\n", + instance, rc); + return -EIO; + } + + /* Update all cpus, sequentially (to protect "netif_napi_add()"). + * We use on_each_cpu to handle the IPI mask or unmask. + */ + if (!saw_channel) + on_each_cpu(disable_ingress_irq, + (void *)(long)(md->ingress_irq), 1); + for_each_online_cpu(cpu) { + struct tile_net_info *info = &per_cpu(per_cpu_info, cpu); + + if (!info->mpipe[instance].has_iqueue) + continue; + if (saw_channel) { + if (!info->mpipe[instance].napi_added) { + netif_napi_add(dev, &info->mpipe[instance].napi, + tile_net_poll, TILE_NET_WEIGHT); + info->mpipe[instance].napi_added = true; + } + if (!info->mpipe[instance].napi_enabled) { + napi_enable(&info->mpipe[instance].napi); + info->mpipe[instance].napi_enabled = true; + } + } else { + if (info->mpipe[instance].napi_enabled) { + napi_disable(&info->mpipe[instance].napi); + info->mpipe[instance].napi_enabled = false; + } + /* FIXME: Drain the iqueue. */ + } + } + if (saw_channel) + on_each_cpu(enable_ingress_irq, + (void *)(long)(md->ingress_irq), 1); + + /* HACK: Allow packets to flow in the simulator. */ + if (saw_channel) + sim_enable_mpipe_links(instance, -1); + + return 0; +} + +/* Initialize a buffer stack. */ +static int create_buffer_stack(struct net_device *dev, + int kind, size_t num_buffers) +{ + pte_t hash_pte = pte_set_home((pte_t) { 0 }, PAGE_HOME_HASH); + int instance = mpipe_instance(dev); + struct mpipe_data *md = &mpipe_data[instance]; + size_t needed = gxio_mpipe_calc_buffer_stack_bytes(num_buffers); + int stack_idx = md->first_buffer_stack + kind; + void *va; + int i, rc; + + /* Round up to 64KB and then use alloc_pages() so we get the + * required 64KB alignment. + */ + md->buffer_stack_bytes[kind] = + ALIGN(needed, 64 * 1024); + + va = alloc_pages_exact(md->buffer_stack_bytes[kind], GFP_KERNEL); + if (va == NULL) { + netdev_err(dev, + "Could not alloc %zd bytes for buffer stack %d\n", + md->buffer_stack_bytes[kind], kind); + return -ENOMEM; + } + + /* Initialize the buffer stack. */ + rc = gxio_mpipe_init_buffer_stack(&md->context, stack_idx, + buffer_size_enums[kind], va, + md->buffer_stack_bytes[kind], 0); + if (rc != 0) { + netdev_err(dev, "gxio_mpipe_init_buffer_stack: mpipe[%d] %d\n", + instance, rc); + free_pages_exact(va, md->buffer_stack_bytes[kind]); + return rc; + } + + md->buffer_stack_vas[kind] = va; + + rc = gxio_mpipe_register_client_memory(&md->context, stack_idx, + hash_pte, 0); + if (rc != 0) { + netdev_err(dev, + "gxio_mpipe_register_client_memory: mpipe[%d] %d\n", + instance, rc); + return rc; + } + + /* Provide initial buffers. */ + for (i = 0; i < num_buffers; i++) { + if (!tile_net_provide_buffer(instance, kind)) { + netdev_err(dev, "Cannot allocate initial sk_bufs!\n"); + return -ENOMEM; + } + } + + return 0; +} + +/* Allocate and initialize mpipe buffer stacks, and register them in + * the mPIPE TLBs, for small, large, and (possibly) jumbo packet sizes. + * This routine supports tile_net_init_mpipe(), below. + */ +static int init_buffer_stacks(struct net_device *dev, + int network_cpus_count) +{ + int num_kinds = MAX_KINDS - (jumbo_num == 0); + size_t num_buffers; + int rc; + int instance = mpipe_instance(dev); + struct mpipe_data *md = &mpipe_data[instance]; + + /* Allocate the buffer stacks. */ + rc = gxio_mpipe_alloc_buffer_stacks(&md->context, num_kinds, 0, 0); + if (rc < 0) { + netdev_err(dev, + "gxio_mpipe_alloc_buffer_stacks: mpipe[%d] %d\n", + instance, rc); + return rc; + } + md->first_buffer_stack = rc; + + /* Enough small/large buffers to (normally) avoid buffer errors. */ + num_buffers = + network_cpus_count * (IQUEUE_ENTRIES + TILE_NET_BATCH); + + /* Allocate the small memory stack. */ + if (rc >= 0) + rc = create_buffer_stack(dev, 0, num_buffers); + + /* Allocate the large buffer stack. */ + if (rc >= 0) + rc = create_buffer_stack(dev, 1, num_buffers); + + /* Allocate the jumbo buffer stack if needed. */ + if (rc >= 0 && jumbo_num != 0) + rc = create_buffer_stack(dev, 2, jumbo_num); + + return rc; +} + +/* Allocate per-cpu resources (memory for completions and idescs). + * This routine supports tile_net_init_mpipe(), below. + */ +static int alloc_percpu_mpipe_resources(struct net_device *dev, + int cpu, int ring) +{ + struct tile_net_info *info = &per_cpu(per_cpu_info, cpu); + int order, i, rc; + int instance = mpipe_instance(dev); + struct mpipe_data *md = &mpipe_data[instance]; + struct page *page; + void *addr; + + /* Allocate the "comps". */ + order = get_order(COMPS_SIZE); + page = homecache_alloc_pages(GFP_KERNEL, order, cpu); + if (page == NULL) { + netdev_err(dev, "Failed to alloc %zd bytes comps memory\n", + COMPS_SIZE); + return -ENOMEM; + } + addr = pfn_to_kaddr(page_to_pfn(page)); + memset(addr, 0, COMPS_SIZE); + for (i = 0; i < TILE_NET_CHANNELS; i++) + info->mpipe[instance].comps_for_echannel[i] = + addr + i * sizeof(struct tile_net_comps); + + /* If this is a network cpu, create an iqueue. */ + if (cpumask_test_cpu(cpu, &network_cpus_map)) { + order = get_order(NOTIF_RING_SIZE); + page = homecache_alloc_pages(GFP_KERNEL, order, cpu); + if (page == NULL) { + netdev_err(dev, + "Failed to alloc %zd bytes iqueue memory\n", + NOTIF_RING_SIZE); + return -ENOMEM; + } + addr = pfn_to_kaddr(page_to_pfn(page)); + rc = gxio_mpipe_iqueue_init(&info->mpipe[instance].iqueue, + &md->context, ring++, addr, + NOTIF_RING_SIZE, 0); + if (rc < 0) { + netdev_err(dev, + "gxio_mpipe_iqueue_init failed: %d\n", rc); + return rc; + } + info->mpipe[instance].has_iqueue = true; + } + + return ring; +} + +/* Initialize NotifGroup and buckets. + * This routine supports tile_net_init_mpipe(), below. + */ +static int init_notif_group_and_buckets(struct net_device *dev, + int ring, int network_cpus_count) +{ + int group, rc; + int instance = mpipe_instance(dev); + struct mpipe_data *md = &mpipe_data[instance]; + + /* Allocate one NotifGroup. */ + rc = gxio_mpipe_alloc_notif_groups(&md->context, 1, 0, 0); + if (rc < 0) { + netdev_err(dev, "gxio_mpipe_alloc_notif_groups: mpipe[%d] %d\n", + instance, rc); + return rc; + } + group = rc; + + /* Initialize global num_buckets value. */ + if (network_cpus_count > 4) + md->num_buckets = 256; + else if (network_cpus_count > 1) + md->num_buckets = 16; + + /* Allocate some buckets, and set global first_bucket value. */ + rc = gxio_mpipe_alloc_buckets(&md->context, md->num_buckets, 0, 0); + if (rc < 0) { + netdev_err(dev, "gxio_mpipe_alloc_buckets: mpipe[%d] %d\n", + instance, rc); + return rc; + } + md->first_bucket = rc; + + /* Init group and buckets. */ + rc = gxio_mpipe_init_notif_group_and_buckets( + &md->context, group, ring, network_cpus_count, + md->first_bucket, md->num_buckets, + GXIO_MPIPE_BUCKET_STICKY_FLOW_LOCALITY); + if (rc != 0) { + netdev_err(dev, "gxio_mpipe_init_notif_group_and_buckets: " + "mpipe[%d] %d\n", instance, rc); + return rc; + } + + return 0; +} + +/* Create an irq and register it, then activate the irq and request + * interrupts on all cores. Note that "ingress_irq" being initialized + * is how we know not to call tile_net_init_mpipe() again. + * This routine supports tile_net_init_mpipe(), below. + */ +static int tile_net_setup_interrupts(struct net_device *dev) +{ + int cpu, rc, irq; + int instance = mpipe_instance(dev); + struct mpipe_data *md = &mpipe_data[instance]; + + irq = md->ingress_irq; + if (irq < 0) { + irq = irq_alloc_hwirq(-1); + if (!irq) { + netdev_err(dev, + "create_irq failed: mpipe[%d] %d\n", + instance, irq); + return irq; + } + tile_irq_activate(irq, TILE_IRQ_PERCPU); + + rc = request_irq(irq, tile_net_handle_ingress_irq, + 0, "tile_net", (void *)((uint64_t)instance)); + + if (rc != 0) { + netdev_err(dev, "request_irq failed: mpipe[%d] %d\n", + instance, rc); + irq_free_hwirq(irq); + return rc; + } + md->ingress_irq = irq; + } + + for_each_online_cpu(cpu) { + struct tile_net_info *info = &per_cpu(per_cpu_info, cpu); + if (info->mpipe[instance].has_iqueue) { + gxio_mpipe_request_notif_ring_interrupt(&md->context, + cpu_x(cpu), cpu_y(cpu), KERNEL_PL, irq, + info->mpipe[instance].iqueue.ring); + } + } + + return 0; +} + +/* Undo any state set up partially by a failed call to tile_net_init_mpipe. */ +static void tile_net_init_mpipe_fail(int instance) +{ + int kind, cpu; + struct mpipe_data *md = &mpipe_data[instance]; + + /* Do cleanups that require the mpipe context first. */ + for (kind = 0; kind < MAX_KINDS; kind++) { + if (md->buffer_stack_vas[kind] != NULL) { + tile_net_pop_all_buffers(instance, + md->first_buffer_stack + + kind); + } + } + + /* Destroy mpipe context so the hardware no longer owns any memory. */ + gxio_mpipe_destroy(&md->context); + + for_each_online_cpu(cpu) { + struct tile_net_info *info = &per_cpu(per_cpu_info, cpu); + free_pages( + (unsigned long)( + info->mpipe[instance].comps_for_echannel[0]), + get_order(COMPS_SIZE)); + info->mpipe[instance].comps_for_echannel[0] = NULL; + free_pages((unsigned long)(info->mpipe[instance].iqueue.idescs), + get_order(NOTIF_RING_SIZE)); + info->mpipe[instance].iqueue.idescs = NULL; + } + + for (kind = 0; kind < MAX_KINDS; kind++) { + if (md->buffer_stack_vas[kind] != NULL) { + free_pages_exact(md->buffer_stack_vas[kind], + md->buffer_stack_bytes[kind]); + md->buffer_stack_vas[kind] = NULL; + } + } + + md->first_buffer_stack = -1; + md->first_bucket = -1; +} + +/* The first time any tilegx network device is opened, we initialize + * the global mpipe state. If this step fails, we fail to open the + * device, but if it succeeds, we never need to do it again, and since + * tile_net can't be unloaded, we never undo it. + * + * Note that some resources in this path (buffer stack indices, + * bindings from init_buffer_stack, etc.) are hypervisor resources + * that are freed implicitly by gxio_mpipe_destroy(). + */ +static int tile_net_init_mpipe(struct net_device *dev) +{ + int rc; + int cpu; + int first_ring, ring; + int instance = mpipe_instance(dev); + struct mpipe_data *md = &mpipe_data[instance]; + int network_cpus_count = cpumask_weight(&network_cpus_map); + + if (!hash_default) { + netdev_err(dev, "Networking requires hash_default!\n"); + return -EIO; + } + + rc = gxio_mpipe_init(&md->context, instance); + if (rc != 0) { + netdev_err(dev, "gxio_mpipe_init: mpipe[%d] %d\n", + instance, rc); + return -EIO; + } + + /* Set up the buffer stacks. */ + rc = init_buffer_stacks(dev, network_cpus_count); + if (rc != 0) + goto fail; + + /* Allocate one NotifRing for each network cpu. */ + rc = gxio_mpipe_alloc_notif_rings(&md->context, + network_cpus_count, 0, 0); + if (rc < 0) { + netdev_err(dev, "gxio_mpipe_alloc_notif_rings failed %d\n", + rc); + goto fail; + } + + /* Init NotifRings per-cpu. */ + first_ring = rc; + ring = first_ring; + for_each_online_cpu(cpu) { + rc = alloc_percpu_mpipe_resources(dev, cpu, ring); + if (rc < 0) + goto fail; + ring = rc; + } + + /* Initialize NotifGroup and buckets. */ + rc = init_notif_group_and_buckets(dev, first_ring, network_cpus_count); + if (rc != 0) + goto fail; + + /* Create and enable interrupts. */ + rc = tile_net_setup_interrupts(dev); + if (rc != 0) + goto fail; + + /* Register PTP clock and set mPIPE timestamp, if configured. */ + register_ptp_clock(dev, md); + + return 0; + +fail: + tile_net_init_mpipe_fail(instance); + return rc; +} + +/* Create persistent egress info for a given egress channel. + * Note that this may be shared between, say, "gbe0" and "xgbe0". + * ISSUE: Defer header allocation until TSO is actually needed? + */ +static int tile_net_init_egress(struct net_device *dev, int echannel) +{ + static int ering = -1; + struct page *headers_page, *edescs_page, *equeue_page; + gxio_mpipe_edesc_t *edescs; + gxio_mpipe_equeue_t *equeue; + unsigned char *headers; + int headers_order, edescs_order, equeue_order; + size_t edescs_size; + int rc = -ENOMEM; + int instance = mpipe_instance(dev); + struct mpipe_data *md = &mpipe_data[instance]; + + /* Only initialize once. */ + if (md->egress_for_echannel[echannel].equeue != NULL) + return 0; + + /* Allocate memory for the "headers". */ + headers_order = get_order(EQUEUE_ENTRIES * HEADER_BYTES); + headers_page = alloc_pages(GFP_KERNEL, headers_order); + if (headers_page == NULL) { + netdev_warn(dev, + "Could not alloc %zd bytes for TSO headers.\n", + PAGE_SIZE << headers_order); + goto fail; + } + headers = pfn_to_kaddr(page_to_pfn(headers_page)); + + /* Allocate memory for the "edescs". */ + edescs_size = EQUEUE_ENTRIES * sizeof(*edescs); + edescs_order = get_order(edescs_size); + edescs_page = alloc_pages(GFP_KERNEL, edescs_order); + if (edescs_page == NULL) { + netdev_warn(dev, + "Could not alloc %zd bytes for eDMA ring.\n", + edescs_size); + goto fail_headers; + } + edescs = pfn_to_kaddr(page_to_pfn(edescs_page)); + + /* Allocate memory for the "equeue". */ + equeue_order = get_order(sizeof(*equeue)); + equeue_page = alloc_pages(GFP_KERNEL, equeue_order); + if (equeue_page == NULL) { + netdev_warn(dev, + "Could not alloc %zd bytes for equeue info.\n", + PAGE_SIZE << equeue_order); + goto fail_edescs; + } + equeue = pfn_to_kaddr(page_to_pfn(equeue_page)); + + /* Allocate an edma ring (using a one entry "free list"). */ + if (ering < 0) { + rc = gxio_mpipe_alloc_edma_rings(&md->context, 1, 0, 0); + if (rc < 0) { + netdev_warn(dev, "gxio_mpipe_alloc_edma_rings: " + "mpipe[%d] %d\n", instance, rc); + goto fail_equeue; + } + ering = rc; + } + + /* Initialize the equeue. */ + rc = gxio_mpipe_equeue_init(equeue, &md->context, ering, echannel, + edescs, edescs_size, 0); + if (rc != 0) { + netdev_err(dev, "gxio_mpipe_equeue_init: mpipe[%d] %d\n", + instance, rc); + goto fail_equeue; + } + + /* Don't reuse the ering later. */ + ering = -1; + + if (jumbo_num != 0) { + /* Make sure "jumbo" packets can be egressed safely. */ + if (gxio_mpipe_equeue_set_snf_size(equeue, 10368) < 0) { + /* ISSUE: There is no "gxio_mpipe_equeue_destroy()". */ + netdev_warn(dev, "Jumbo packets may not be egressed" + " properly on channel %d\n", echannel); + } + } + + /* Done. */ + md->egress_for_echannel[echannel].equeue = equeue; + md->egress_for_echannel[echannel].headers = headers; + return 0; + +fail_equeue: + __free_pages(equeue_page, equeue_order); + +fail_edescs: + __free_pages(edescs_page, edescs_order); + +fail_headers: + __free_pages(headers_page, headers_order); + +fail: + return rc; +} + +/* Return channel number for a newly-opened link. */ +static int tile_net_link_open(struct net_device *dev, gxio_mpipe_link_t *link, + const char *link_name) +{ + int instance = mpipe_instance(dev); + struct mpipe_data *md = &mpipe_data[instance]; + int rc = gxio_mpipe_link_open(link, &md->context, link_name, 0); + if (rc < 0) { + netdev_err(dev, "Failed to open '%s', mpipe[%d], %d\n", + link_name, instance, rc); + return rc; + } + if (jumbo_num != 0) { + u32 attr = GXIO_MPIPE_LINK_RECEIVE_JUMBO; + rc = gxio_mpipe_link_set_attr(link, attr, 1); + if (rc != 0) { + netdev_err(dev, + "Cannot receive jumbo packets on '%s'\n", + link_name); + gxio_mpipe_link_close(link); + return rc; + } + } + rc = gxio_mpipe_link_channel(link); + if (rc < 0 || rc >= TILE_NET_CHANNELS) { + netdev_err(dev, "gxio_mpipe_link_channel bad value: %d\n", rc); + gxio_mpipe_link_close(link); + return -EINVAL; + } + return rc; +} + +/* Help the kernel activate the given network interface. */ +static int tile_net_open(struct net_device *dev) +{ + struct tile_net_priv *priv = netdev_priv(dev); + int cpu, rc, instance; + + mutex_lock(&tile_net_devs_for_channel_mutex); + + /* Get the instance info. */ + rc = gxio_mpipe_link_instance(dev->name); + if (rc < 0 || rc >= NR_MPIPE_MAX) { + mutex_unlock(&tile_net_devs_for_channel_mutex); + return -EIO; + } + + priv->instance = rc; + instance = rc; + if (!mpipe_data[rc].context.mmio_fast_base) { + /* Do one-time initialization per instance the first time + * any device is opened. + */ + rc = tile_net_init_mpipe(dev); + if (rc != 0) + goto fail; + } + + /* Determine if this is the "loopify" device. */ + if (unlikely((loopify_link_name != NULL) && + !strcmp(dev->name, loopify_link_name))) { + rc = tile_net_link_open(dev, &priv->link, "loop0"); + if (rc < 0) + goto fail; + priv->channel = rc; + rc = tile_net_link_open(dev, &priv->loopify_link, "loop1"); + if (rc < 0) + goto fail; + priv->loopify_channel = rc; + priv->echannel = rc; + } else { + rc = tile_net_link_open(dev, &priv->link, dev->name); + if (rc < 0) + goto fail; + priv->channel = rc; + priv->echannel = rc; + } + + /* Initialize egress info (if needed). Once ever, per echannel. */ + rc = tile_net_init_egress(dev, priv->echannel); + if (rc != 0) + goto fail; + + mpipe_data[instance].tile_net_devs_for_channel[priv->channel] = dev; + + rc = tile_net_update(dev); + if (rc != 0) + goto fail; + + mutex_unlock(&tile_net_devs_for_channel_mutex); + + /* Initialize the transmit wake timer for this device for each cpu. */ + for_each_online_cpu(cpu) { + struct tile_net_info *info = &per_cpu(per_cpu_info, cpu); + struct tile_net_tx_wake *tx_wake = + &info->mpipe[instance].tx_wake[priv->echannel]; + + hrtimer_init(&tx_wake->timer, CLOCK_MONOTONIC, + HRTIMER_MODE_REL); + tx_wake->tx_queue_idx = cpu; + tx_wake->timer.function = tile_net_handle_tx_wake_timer; + tx_wake->dev = dev; + } + + for_each_online_cpu(cpu) + netif_start_subqueue(dev, cpu); + netif_carrier_on(dev); + return 0; + +fail: + if (priv->loopify_channel >= 0) { + if (gxio_mpipe_link_close(&priv->loopify_link) != 0) + netdev_warn(dev, "Failed to close loopify link!\n"); + priv->loopify_channel = -1; + } + if (priv->channel >= 0) { + if (gxio_mpipe_link_close(&priv->link) != 0) + netdev_warn(dev, "Failed to close link!\n"); + priv->channel = -1; + } + priv->echannel = -1; + mpipe_data[instance].tile_net_devs_for_channel[priv->channel] = NULL; + mutex_unlock(&tile_net_devs_for_channel_mutex); + + /* Don't return raw gxio error codes to generic Linux. */ + return (rc > -512) ? rc : -EIO; +} + +/* Help the kernel deactivate the given network interface. */ +static int tile_net_stop(struct net_device *dev) +{ + struct tile_net_priv *priv = netdev_priv(dev); + int cpu; + int instance = priv->instance; + struct mpipe_data *md = &mpipe_data[instance]; + + for_each_online_cpu(cpu) { + struct tile_net_info *info = &per_cpu(per_cpu_info, cpu); + struct tile_net_tx_wake *tx_wake = + &info->mpipe[instance].tx_wake[priv->echannel]; + + hrtimer_cancel(&tx_wake->timer); + netif_stop_subqueue(dev, cpu); + } + + mutex_lock(&tile_net_devs_for_channel_mutex); + md->tile_net_devs_for_channel[priv->channel] = NULL; + (void)tile_net_update(dev); + if (priv->loopify_channel >= 0) { + if (gxio_mpipe_link_close(&priv->loopify_link) != 0) + netdev_warn(dev, "Failed to close loopify link!\n"); + priv->loopify_channel = -1; + } + if (priv->channel >= 0) { + if (gxio_mpipe_link_close(&priv->link) != 0) + netdev_warn(dev, "Failed to close link!\n"); + priv->channel = -1; + } + priv->echannel = -1; + mutex_unlock(&tile_net_devs_for_channel_mutex); + + return 0; +} + +/* Determine the VA for a fragment. */ +static inline void *tile_net_frag_buf(skb_frag_t *f) +{ + unsigned long pfn = page_to_pfn(skb_frag_page(f)); + return pfn_to_kaddr(pfn) + f->page_offset; +} + +/* Acquire a completion entry and an egress slot, or if we can't, + * stop the queue and schedule the tx_wake timer. + */ +static s64 tile_net_equeue_try_reserve(struct net_device *dev, + int tx_queue_idx, + struct tile_net_comps *comps, + gxio_mpipe_equeue_t *equeue, + int num_edescs) +{ + /* Try to acquire a completion entry. */ + if (comps->comp_next - comps->comp_last < TILE_NET_MAX_COMPS - 1 || + tile_net_free_comps(equeue, comps, 32, false) != 0) { + + /* Try to acquire an egress slot. */ + s64 slot = gxio_mpipe_equeue_try_reserve(equeue, num_edescs); + if (slot >= 0) + return slot; + + /* Freeing some completions gives the equeue time to drain. */ + tile_net_free_comps(equeue, comps, TILE_NET_MAX_COMPS, false); + + slot = gxio_mpipe_equeue_try_reserve(equeue, num_edescs); + if (slot >= 0) + return slot; + } + + /* Still nothing; give up and stop the queue for a short while. */ + netif_stop_subqueue(dev, tx_queue_idx); + tile_net_schedule_tx_wake_timer(dev, tx_queue_idx); + return -1; +} + +/* Determine how many edesc's are needed for TSO. + * + * Sometimes, if "sendfile()" requires copying, we will be called with + * "data" containing the header and payload, with "frags" being empty. + * Sometimes, for example when using NFS over TCP, a single segment can + * span 3 fragments. This requires special care. + */ +static int tso_count_edescs(struct sk_buff *skb) +{ + struct skb_shared_info *sh = skb_shinfo(skb); + unsigned int sh_len = skb_transport_offset(skb) + tcp_hdrlen(skb); + unsigned int data_len = skb->len - sh_len; + unsigned int p_len = sh->gso_size; + long f_id = -1; /* id of the current fragment */ + long f_size = skb_headlen(skb) - sh_len; /* current fragment size */ + long f_used = 0; /* bytes used from the current fragment */ + long n; /* size of the current piece of payload */ + int num_edescs = 0; + int segment; + + for (segment = 0; segment < sh->gso_segs; segment++) { + + unsigned int p_used = 0; + + /* One edesc for header and for each piece of the payload. */ + for (num_edescs++; p_used < p_len; num_edescs++) { + + /* Advance as needed. */ + while (f_used >= f_size) { + f_id++; + f_size = skb_frag_size(&sh->frags[f_id]); + f_used = 0; + } + + /* Use bytes from the current fragment. */ + n = p_len - p_used; + if (n > f_size - f_used) + n = f_size - f_used; + f_used += n; + p_used += n; + } + + /* The last segment may be less than gso_size. */ + data_len -= p_len; + if (data_len < p_len) + p_len = data_len; + } + + return num_edescs; +} + +/* Prepare modified copies of the skbuff headers. */ +static void tso_headers_prepare(struct sk_buff *skb, unsigned char *headers, + s64 slot) +{ + struct skb_shared_info *sh = skb_shinfo(skb); + struct iphdr *ih; + struct ipv6hdr *ih6; + struct tcphdr *th; + unsigned int sh_len = skb_transport_offset(skb) + tcp_hdrlen(skb); + unsigned int data_len = skb->len - sh_len; + unsigned char *data = skb->data; + unsigned int ih_off, th_off, p_len; + unsigned int isum_seed, tsum_seed, seq; + unsigned int uninitialized_var(id); + int is_ipv6; + long f_id = -1; /* id of the current fragment */ + long f_size = skb_headlen(skb) - sh_len; /* current fragment size */ + long f_used = 0; /* bytes used from the current fragment */ + long n; /* size of the current piece of payload */ + int segment; + + /* Locate original headers and compute various lengths. */ + is_ipv6 = skb_is_gso_v6(skb); + if (is_ipv6) { + ih6 = ipv6_hdr(skb); + ih_off = skb_network_offset(skb); + } else { + ih = ip_hdr(skb); + ih_off = skb_network_offset(skb); + isum_seed = ((0xFFFF - ih->check) + + (0xFFFF - ih->tot_len) + + (0xFFFF - ih->id)); + id = ntohs(ih->id); + } + + th = tcp_hdr(skb); + th_off = skb_transport_offset(skb); + p_len = sh->gso_size; + + tsum_seed = th->check + (0xFFFF ^ htons(skb->len)); + seq = ntohl(th->seq); + + /* Prepare all the headers. */ + for (segment = 0; segment < sh->gso_segs; segment++) { + unsigned char *buf; + unsigned int p_used = 0; + + /* Copy to the header memory for this segment. */ + buf = headers + (slot % EQUEUE_ENTRIES) * HEADER_BYTES + + NET_IP_ALIGN; + memcpy(buf, data, sh_len); + + /* Update copied ip header. */ + if (is_ipv6) { + ih6 = (struct ipv6hdr *)(buf + ih_off); + ih6->payload_len = htons(sh_len + p_len - ih_off - + sizeof(*ih6)); + } else { + ih = (struct iphdr *)(buf + ih_off); + ih->tot_len = htons(sh_len + p_len - ih_off); + ih->id = htons(id++); + ih->check = csum_long(isum_seed + ih->tot_len + + ih->id) ^ 0xffff; + } + + /* Update copied tcp header. */ + th = (struct tcphdr *)(buf + th_off); + th->seq = htonl(seq); + th->check = csum_long(tsum_seed + htons(sh_len + p_len)); + if (segment != sh->gso_segs - 1) { + th->fin = 0; + th->psh = 0; + } + + /* Skip past the header. */ + slot++; + + /* Skip past the payload. */ + while (p_used < p_len) { + + /* Advance as needed. */ + while (f_used >= f_size) { + f_id++; + f_size = skb_frag_size(&sh->frags[f_id]); + f_used = 0; + } + + /* Use bytes from the current fragment. */ + n = p_len - p_used; + if (n > f_size - f_used) + n = f_size - f_used; + f_used += n; + p_used += n; + + slot++; + } + + seq += p_len; + + /* The last segment may be less than gso_size. */ + data_len -= p_len; + if (data_len < p_len) + p_len = data_len; + } + + /* Flush the headers so they are ready for hardware DMA. */ + wmb(); +} + +/* Pass all the data to mpipe for egress. */ +static void tso_egress(struct net_device *dev, gxio_mpipe_equeue_t *equeue, + struct sk_buff *skb, unsigned char *headers, s64 slot) +{ + struct skb_shared_info *sh = skb_shinfo(skb); + int instance = mpipe_instance(dev); + struct mpipe_data *md = &mpipe_data[instance]; + unsigned int sh_len = skb_transport_offset(skb) + tcp_hdrlen(skb); + unsigned int data_len = skb->len - sh_len; + unsigned int p_len = sh->gso_size; + gxio_mpipe_edesc_t edesc_head = { { 0 } }; + gxio_mpipe_edesc_t edesc_body = { { 0 } }; + long f_id = -1; /* id of the current fragment */ + long f_size = skb_headlen(skb) - sh_len; /* current fragment size */ + long f_used = 0; /* bytes used from the current fragment */ + void *f_data = skb->data + sh_len; + long n; /* size of the current piece of payload */ + unsigned long tx_packets = 0, tx_bytes = 0; + unsigned int csum_start; + int segment; + + /* Prepare to egress the headers: set up header edesc. */ + csum_start = skb_checksum_start_offset(skb); + edesc_head.csum = 1; + edesc_head.csum_start = csum_start; + edesc_head.csum_dest = csum_start + skb->csum_offset; + edesc_head.xfer_size = sh_len; + + /* This is only used to specify the TLB. */ + edesc_head.stack_idx = md->first_buffer_stack; + edesc_body.stack_idx = md->first_buffer_stack; + + /* Egress all the edescs. */ + for (segment = 0; segment < sh->gso_segs; segment++) { + unsigned char *buf; + unsigned int p_used = 0; + + /* Egress the header. */ + buf = headers + (slot % EQUEUE_ENTRIES) * HEADER_BYTES + + NET_IP_ALIGN; + edesc_head.va = va_to_tile_io_addr(buf); + gxio_mpipe_equeue_put_at(equeue, edesc_head, slot); + slot++; + + /* Egress the payload. */ + while (p_used < p_len) { + void *va; + + /* Advance as needed. */ + while (f_used >= f_size) { + f_id++; + f_size = skb_frag_size(&sh->frags[f_id]); + f_data = tile_net_frag_buf(&sh->frags[f_id]); + f_used = 0; + } + + va = f_data + f_used; + + /* Use bytes from the current fragment. */ + n = p_len - p_used; + if (n > f_size - f_used) + n = f_size - f_used; + f_used += n; + p_used += n; + + /* Egress a piece of the payload. */ + edesc_body.va = va_to_tile_io_addr(va); + edesc_body.xfer_size = n; + edesc_body.bound = !(p_used < p_len); + gxio_mpipe_equeue_put_at(equeue, edesc_body, slot); + slot++; + } + + tx_packets++; + tx_bytes += sh_len + p_len; + + /* The last segment may be less than gso_size. */ + data_len -= p_len; + if (data_len < p_len) + p_len = data_len; + } + + /* Update stats. */ + tile_net_stats_add(tx_packets, &dev->stats.tx_packets); + tile_net_stats_add(tx_bytes, &dev->stats.tx_bytes); +} + +/* Do "TSO" handling for egress. + * + * Normally drivers set NETIF_F_TSO only to support hardware TSO; + * otherwise the stack uses scatter-gather to implement GSO in software. + * On our testing, enabling GSO support (via NETIF_F_SG) drops network + * performance down to around 7.5 Gbps on the 10G interfaces, although + * also dropping cpu utilization way down, to under 8%. But + * implementing "TSO" in the driver brings performance back up to line + * rate, while dropping cpu usage even further, to less than 4%. In + * practice, profiling of GSO shows that skb_segment() is what causes + * the performance overheads; we benefit in the driver from using + * preallocated memory to duplicate the TCP/IP headers. + */ +static int tile_net_tx_tso(struct sk_buff *skb, struct net_device *dev) +{ + struct tile_net_info *info = this_cpu_ptr(&per_cpu_info); + struct tile_net_priv *priv = netdev_priv(dev); + int channel = priv->echannel; + int instance = priv->instance; + struct mpipe_data *md = &mpipe_data[instance]; + struct tile_net_egress *egress = &md->egress_for_echannel[channel]; + struct tile_net_comps *comps = + info->mpipe[instance].comps_for_echannel[channel]; + gxio_mpipe_equeue_t *equeue = egress->equeue; + unsigned long irqflags; + int num_edescs; + s64 slot; + + /* Determine how many mpipe edesc's are needed. */ + num_edescs = tso_count_edescs(skb); + + local_irq_save(irqflags); + + /* Try to acquire a completion entry and an egress slot. */ + slot = tile_net_equeue_try_reserve(dev, skb->queue_mapping, comps, + equeue, num_edescs); + if (slot < 0) { + local_irq_restore(irqflags); + return NETDEV_TX_BUSY; + } + + /* Set up copies of header data properly. */ + tso_headers_prepare(skb, egress->headers, slot); + + /* Actually pass the data to the network hardware. */ + tso_egress(dev, equeue, skb, egress->headers, slot); + + /* Add a completion record. */ + add_comp(equeue, comps, slot + num_edescs - 1, skb); + + local_irq_restore(irqflags); + + /* Make sure the egress timer is scheduled. */ + tile_net_schedule_egress_timer(); + + return NETDEV_TX_OK; +} + +/* Analyze the body and frags for a transmit request. */ +static unsigned int tile_net_tx_frags(struct frag *frags, + struct sk_buff *skb, + void *b_data, unsigned int b_len) +{ + unsigned int i, n = 0; + + struct skb_shared_info *sh = skb_shinfo(skb); + + if (b_len != 0) { + frags[n].buf = b_data; + frags[n++].length = b_len; + } + + for (i = 0; i < sh->nr_frags; i++) { + skb_frag_t *f = &sh->frags[i]; + frags[n].buf = tile_net_frag_buf(f); + frags[n++].length = skb_frag_size(f); + } + + return n; +} + +/* Help the kernel transmit a packet. */ +static int tile_net_tx(struct sk_buff *skb, struct net_device *dev) +{ + struct tile_net_info *info = this_cpu_ptr(&per_cpu_info); + struct tile_net_priv *priv = netdev_priv(dev); + int instance = priv->instance; + struct mpipe_data *md = &mpipe_data[instance]; + struct tile_net_egress *egress = + &md->egress_for_echannel[priv->echannel]; + gxio_mpipe_equeue_t *equeue = egress->equeue; + struct tile_net_comps *comps = + info->mpipe[instance].comps_for_echannel[priv->echannel]; + unsigned int len = skb->len; + unsigned char *data = skb->data; + unsigned int num_edescs; + struct frag frags[MAX_FRAGS]; + gxio_mpipe_edesc_t edescs[MAX_FRAGS]; + unsigned long irqflags; + gxio_mpipe_edesc_t edesc = { { 0 } }; + unsigned int i; + s64 slot; + + if (skb_is_gso(skb)) + return tile_net_tx_tso(skb, dev); + + num_edescs = tile_net_tx_frags(frags, skb, data, skb_headlen(skb)); + + /* This is only used to specify the TLB. */ + edesc.stack_idx = md->first_buffer_stack; + + /* Prepare the edescs. */ + for (i = 0; i < num_edescs; i++) { + edesc.xfer_size = frags[i].length; + edesc.va = va_to_tile_io_addr(frags[i].buf); + edescs[i] = edesc; + } + + /* Mark the final edesc. */ + edescs[num_edescs - 1].bound = 1; + + /* Add checksum info to the initial edesc, if needed. */ + if (skb->ip_summed == CHECKSUM_PARTIAL) { + unsigned int csum_start = skb_checksum_start_offset(skb); + edescs[0].csum = 1; + edescs[0].csum_start = csum_start; + edescs[0].csum_dest = csum_start + skb->csum_offset; + } + + local_irq_save(irqflags); + + /* Try to acquire a completion entry and an egress slot. */ + slot = tile_net_equeue_try_reserve(dev, skb->queue_mapping, comps, + equeue, num_edescs); + if (slot < 0) { + local_irq_restore(irqflags); + return NETDEV_TX_BUSY; + } + + for (i = 0; i < num_edescs; i++) + gxio_mpipe_equeue_put_at(equeue, edescs[i], slot++); + + /* Store TX timestamp if needed. */ + tile_tx_timestamp(skb, instance); + + /* Add a completion record. */ + add_comp(equeue, comps, slot - 1, skb); + + /* NOTE: Use ETH_ZLEN for short packets (e.g. 42 < 60). */ + tile_net_stats_add(1, &dev->stats.tx_packets); + tile_net_stats_add(max_t(unsigned int, len, ETH_ZLEN), + &dev->stats.tx_bytes); + + local_irq_restore(irqflags); + + /* Make sure the egress timer is scheduled. */ + tile_net_schedule_egress_timer(); + + return NETDEV_TX_OK; +} + +/* Return subqueue id on this core (one per core). */ +static u16 tile_net_select_queue(struct net_device *dev, struct sk_buff *skb, + void *accel_priv, select_queue_fallback_t fallback) +{ + return smp_processor_id(); +} + +/* Deal with a transmit timeout. */ +static void tile_net_tx_timeout(struct net_device *dev) +{ + int cpu; + + for_each_online_cpu(cpu) + netif_wake_subqueue(dev, cpu); +} + +/* Ioctl commands. */ +static int tile_net_ioctl(struct net_device *dev, struct ifreq *rq, int cmd) +{ + if (cmd == SIOCSHWTSTAMP) + return tile_hwtstamp_set(dev, rq); + if (cmd == SIOCGHWTSTAMP) + return tile_hwtstamp_get(dev, rq); + + return -EOPNOTSUPP; +} + +/* Change the MTU. */ +static int tile_net_change_mtu(struct net_device *dev, int new_mtu) +{ + if (new_mtu < 68) + return -EINVAL; + if (new_mtu > ((jumbo_num != 0) ? 9000 : 1500)) + return -EINVAL; + dev->mtu = new_mtu; + return 0; +} + +/* Change the Ethernet address of the NIC. + * + * The hypervisor driver does not support changing MAC address. However, + * the hardware does not do anything with the MAC address, so the address + * which gets used on outgoing packets, and which is accepted on incoming + * packets, is completely up to us. + * + * Returns 0 on success, negative on failure. + */ +static int tile_net_set_mac_address(struct net_device *dev, void *p) +{ + struct sockaddr *addr = p; + + if (!is_valid_ether_addr(addr->sa_data)) + return -EINVAL; + memcpy(dev->dev_addr, addr->sa_data, dev->addr_len); + return 0; +} + +#ifdef CONFIG_NET_POLL_CONTROLLER +/* Polling 'interrupt' - used by things like netconsole to send skbs + * without having to re-enable interrupts. It's not called while + * the interrupt routine is executing. + */ +static void tile_net_netpoll(struct net_device *dev) +{ + int instance = mpipe_instance(dev); + struct tile_net_info *info = this_cpu_ptr(&per_cpu_info); + struct mpipe_data *md = &mpipe_data[instance]; + + disable_percpu_irq(md->ingress_irq); + napi_schedule(&info->mpipe[instance].napi); + enable_percpu_irq(md->ingress_irq, 0); +} +#endif + +static const struct net_device_ops tile_net_ops = { + .ndo_open = tile_net_open, + .ndo_stop = tile_net_stop, + .ndo_start_xmit = tile_net_tx, + .ndo_select_queue = tile_net_select_queue, + .ndo_do_ioctl = tile_net_ioctl, + .ndo_change_mtu = tile_net_change_mtu, + .ndo_tx_timeout = tile_net_tx_timeout, + .ndo_set_mac_address = tile_net_set_mac_address, +#ifdef CONFIG_NET_POLL_CONTROLLER + .ndo_poll_controller = tile_net_netpoll, +#endif +}; + +/* The setup function. + * + * This uses ether_setup() to assign various fields in dev, including + * setting IFF_BROADCAST and IFF_MULTICAST, then sets some extra fields. + */ +static void tile_net_setup(struct net_device *dev) +{ + netdev_features_t features = 0; + + ether_setup(dev); + dev->netdev_ops = &tile_net_ops; + dev->watchdog_timeo = TILE_NET_TIMEOUT; + dev->mtu = 1500; + + features |= NETIF_F_HW_CSUM; + features |= NETIF_F_SG; + features |= NETIF_F_TSO; + features |= NETIF_F_TSO6; + + dev->hw_features |= features; + dev->vlan_features |= features; + dev->features |= features; +} + +/* Allocate the device structure, register the device, and obtain the + * MAC address from the hypervisor. + */ +static void tile_net_dev_init(const char *name, const uint8_t *mac) +{ + int ret; + struct net_device *dev; + struct tile_net_priv *priv; + + /* HACK: Ignore "loop" links. */ + if (strncmp(name, "loop", 4) == 0) + return; + + /* Allocate the device structure. Normally, "name" is a + * template, instantiated by register_netdev(), but not for us. + */ + dev = alloc_netdev_mqs(sizeof(*priv), name, NET_NAME_UNKNOWN, + tile_net_setup, NR_CPUS, 1); + if (!dev) { + pr_err("alloc_netdev_mqs(%s) failed\n", name); + return; + } + + /* Initialize "priv". */ + priv = netdev_priv(dev); + priv->dev = dev; + priv->channel = -1; + priv->loopify_channel = -1; + priv->echannel = -1; + init_ptp_dev(priv); + + /* Get the MAC address and set it in the device struct; this must + * be done before the device is opened. If the MAC is all zeroes, + * we use a random address, since we're probably on the simulator. + */ + if (!is_zero_ether_addr(mac)) + ether_addr_copy(dev->dev_addr, mac); + else + eth_hw_addr_random(dev); + + /* Register the network device. */ + ret = register_netdev(dev); + if (ret) { + netdev_err(dev, "register_netdev failed %d\n", ret); + free_netdev(dev); + return; + } +} + +/* Per-cpu module initialization. */ +static void tile_net_init_module_percpu(void *unused) +{ + struct tile_net_info *info = this_cpu_ptr(&per_cpu_info); + int my_cpu = smp_processor_id(); + int instance; + + for (instance = 0; instance < NR_MPIPE_MAX; instance++) { + info->mpipe[instance].has_iqueue = false; + info->mpipe[instance].instance = instance; + } + info->my_cpu = my_cpu; + + /* Initialize the egress timer. */ + hrtimer_init(&info->egress_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + info->egress_timer.function = tile_net_handle_egress_timer; +} + +/* Module initialization. */ +static int __init tile_net_init_module(void) +{ + int i; + char name[GXIO_MPIPE_LINK_NAME_LEN]; + uint8_t mac[6]; + + pr_info("Tilera Network Driver\n"); + + BUILD_BUG_ON(NR_MPIPE_MAX != 2); + + mutex_init(&tile_net_devs_for_channel_mutex); + + /* Initialize each CPU. */ + on_each_cpu(tile_net_init_module_percpu, NULL, 1); + + /* Find out what devices we have, and initialize them. */ + for (i = 0; gxio_mpipe_link_enumerate_mac(i, name, mac) >= 0; i++) + tile_net_dev_init(name, mac); + + if (!network_cpus_init()) + network_cpus_map = *cpu_online_mask; + + return 0; +} + +module_init(tile_net_init_module); diff --git a/drivers/net/ethernet/tile/tilepro.c b/drivers/net/ethernet/tile/tilepro.c new file mode 100644 index 000000000..3d8f60d96 --- /dev/null +++ b/drivers/net/ethernet/tile/tilepro.c @@ -0,0 +1,2423 @@ +/* + * Copyright 2011 Tilera Corporation. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, version 2. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for + * more details. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/moduleparam.h> +#include <linux/sched.h> +#include <linux/kernel.h> /* printk() */ +#include <linux/slab.h> /* kmalloc() */ +#include <linux/errno.h> /* error codes */ +#include <linux/types.h> /* size_t */ +#include <linux/interrupt.h> +#include <linux/in.h> +#include <linux/netdevice.h> /* struct device, and other headers */ +#include <linux/etherdevice.h> /* eth_type_trans */ +#include <linux/skbuff.h> +#include <linux/ioctl.h> +#include <linux/cdev.h> +#include <linux/hugetlb.h> +#include <linux/in6.h> +#include <linux/timer.h> +#include <linux/io.h> +#include <linux/u64_stats_sync.h> +#include <asm/checksum.h> +#include <asm/homecache.h> + +#include <hv/drv_xgbe_intf.h> +#include <hv/drv_xgbe_impl.h> +#include <hv/hypervisor.h> +#include <hv/netio_intf.h> + +/* For TSO */ +#include <linux/ip.h> +#include <linux/tcp.h> + + +/* + * First, "tile_net_init_module()" initializes all four "devices" which + * can be used by linux. + * + * Then, "ifconfig DEVICE up" calls "tile_net_open()", which analyzes + * the network cpus, then uses "tile_net_open_aux()" to initialize + * LIPP/LEPP, and then uses "tile_net_open_inner()" to register all + * the tiles, provide buffers to LIPP, allow ingress to start, and + * turn on hypervisor interrupt handling (and NAPI) on all tiles. + * + * If registration fails due to the link being down, then "retry_work" + * is used to keep calling "tile_net_open_inner()" until it succeeds. + * + * If "ifconfig DEVICE down" is called, it uses "tile_net_stop()" to + * stop egress, drain the LIPP buffers, unregister all the tiles, stop + * LIPP/LEPP, and wipe the LEPP queue. + * + * We start out with the ingress interrupt enabled on each CPU. When + * this interrupt fires, we disable it, and call "napi_schedule()". + * This will cause "tile_net_poll()" to be called, which will pull + * packets from the netio queue, filtering them out, or passing them + * to "netif_receive_skb()". If our budget is exhausted, we will + * return, knowing we will be called again later. Otherwise, we + * reenable the ingress interrupt, and call "napi_complete()". + * + * HACK: Since disabling the ingress interrupt is not reliable, we + * ignore the interrupt if the global "active" flag is false. + * + * + * NOTE: The use of "native_driver" ensures that EPP exists, and that + * we are using "LIPP" and "LEPP". + * + * NOTE: Failing to free completions for an arbitrarily long time + * (which is defined to be illegal) does in fact cause bizarre + * problems. The "egress_timer" helps prevent this from happening. + */ + + +/* HACK: Allow use of "jumbo" packets. */ +/* This should be 1500 if "jumbo" is not set in LIPP. */ +/* This should be at most 10226 (10240 - 14) if "jumbo" is set in LIPP. */ +/* ISSUE: This has not been thoroughly tested (except at 1500). */ +#define TILE_NET_MTU 1500 + +/* HACK: Define this to verify incoming packets. */ +/* #define TILE_NET_VERIFY_INGRESS */ + +/* Use 3000 to enable the Linux Traffic Control (QoS) layer, else 0. */ +#define TILE_NET_TX_QUEUE_LEN 0 + +/* Define to dump packets (prints out the whole packet on tx and rx). */ +/* #define TILE_NET_DUMP_PACKETS */ + +/* Define to enable debug spew (all PDEBUG's are enabled). */ +/* #define TILE_NET_DEBUG */ + + +/* Define to activate paranoia checks. */ +/* #define TILE_NET_PARANOIA */ + +/* Default transmit lockup timeout period, in jiffies. */ +#define TILE_NET_TIMEOUT (5 * HZ) + +/* Default retry interval for bringing up the NetIO interface, in jiffies. */ +#define TILE_NET_RETRY_INTERVAL (5 * HZ) + +/* Number of ports (xgbe0, xgbe1, gbe0, gbe1). */ +#define TILE_NET_DEVS 4 + + + +/* Paranoia. */ +#if NET_IP_ALIGN != LIPP_PACKET_PADDING +#error "NET_IP_ALIGN must match LIPP_PACKET_PADDING." +#endif + + +/* Debug print. */ +#ifdef TILE_NET_DEBUG +#define PDEBUG(fmt, args...) net_printk(fmt, ## args) +#else +#define PDEBUG(fmt, args...) +#endif + + +MODULE_AUTHOR("Tilera"); +MODULE_LICENSE("GPL"); + + +/* + * Queue of incoming packets for a specific cpu and device. + * + * Includes a pointer to the "system" data, and the actual "user" data. + */ +struct tile_netio_queue { + netio_queue_impl_t *__system_part; + netio_queue_user_impl_t __user_part; + +}; + + +/* + * Statistics counters for a specific cpu and device. + */ +struct tile_net_stats_t { + struct u64_stats_sync syncp; + u64 rx_packets; /* total packets received */ + u64 tx_packets; /* total packets transmitted */ + u64 rx_bytes; /* total bytes received */ + u64 tx_bytes; /* total bytes transmitted */ + u64 rx_errors; /* packets truncated or marked bad by hw */ + u64 rx_dropped; /* packets not for us or intf not up */ +}; + + +/* + * Info for a specific cpu and device. + * + * ISSUE: There is a "dev" pointer in "napi" as well. + */ +struct tile_net_cpu { + /* The NAPI struct. */ + struct napi_struct napi; + /* Packet queue. */ + struct tile_netio_queue queue; + /* Statistics. */ + struct tile_net_stats_t stats; + /* True iff NAPI is enabled. */ + bool napi_enabled; + /* True if this tile has successfully registered with the IPP. */ + bool registered; + /* True if the link was down last time we tried to register. */ + bool link_down; + /* True if "egress_timer" is scheduled. */ + bool egress_timer_scheduled; + /* Number of small sk_buffs which must still be provided. */ + unsigned int num_needed_small_buffers; + /* Number of large sk_buffs which must still be provided. */ + unsigned int num_needed_large_buffers; + /* A timer for handling egress completions. */ + struct timer_list egress_timer; +}; + + +/* + * Info for a specific device. + */ +struct tile_net_priv { + /* Our network device. */ + struct net_device *dev; + /* Pages making up the egress queue. */ + struct page *eq_pages; + /* Address of the actual egress queue. */ + lepp_queue_t *eq; + /* Protects "eq". */ + spinlock_t eq_lock; + /* The hypervisor handle for this interface. */ + int hv_devhdl; + /* The intr bit mask that IDs this device. */ + u32 intr_id; + /* True iff "tile_net_open_aux()" has succeeded. */ + bool partly_opened; + /* True iff the device is "active". */ + bool active; + /* Effective network cpus. */ + struct cpumask network_cpus_map; + /* Number of network cpus. */ + int network_cpus_count; + /* Credits per network cpu. */ + int network_cpus_credits; + /* For NetIO bringup retries. */ + struct delayed_work retry_work; + /* Quick access to per cpu data. */ + struct tile_net_cpu *cpu[NR_CPUS]; +}; + +/* Log2 of the number of small pages needed for the egress queue. */ +#define EQ_ORDER get_order(sizeof(lepp_queue_t)) +/* Size of the egress queue's pages. */ +#define EQ_SIZE (1 << (PAGE_SHIFT + EQ_ORDER)) + +/* + * The actual devices (xgbe0, xgbe1, gbe0, gbe1). + */ +static struct net_device *tile_net_devs[TILE_NET_DEVS]; + +/* + * The "tile_net_cpu" structures for each device. + */ +static DEFINE_PER_CPU(struct tile_net_cpu, hv_xgbe0); +static DEFINE_PER_CPU(struct tile_net_cpu, hv_xgbe1); +static DEFINE_PER_CPU(struct tile_net_cpu, hv_gbe0); +static DEFINE_PER_CPU(struct tile_net_cpu, hv_gbe1); + + +/* + * True if "network_cpus" was specified. + */ +static bool network_cpus_used; + +/* + * The actual cpus in "network_cpus". + */ +static struct cpumask network_cpus_map; + + + +#ifdef TILE_NET_DEBUG +/* + * printk with extra stuff. + * + * We print the CPU we're running in brackets. + */ +static void net_printk(char *fmt, ...) +{ + int i; + int len; + va_list args; + static char buf[256]; + + len = sprintf(buf, "tile_net[%2.2d]: ", smp_processor_id()); + va_start(args, fmt); + i = vscnprintf(buf + len, sizeof(buf) - len - 1, fmt, args); + va_end(args); + buf[255] = '\0'; + pr_notice(buf); +} +#endif + + +#ifdef TILE_NET_DUMP_PACKETS +/* + * Dump a packet. + */ +static void dump_packet(unsigned char *data, unsigned long length, char *s) +{ + int my_cpu = smp_processor_id(); + + unsigned long i; + char buf[128]; + + static unsigned int count; + + pr_info("dump_packet(data %p, length 0x%lx s %s count 0x%x)\n", + data, length, s, count++); + + pr_info("\n"); + + for (i = 0; i < length; i++) { + if ((i & 0xf) == 0) + sprintf(buf, "[%02d] %8.8lx:", my_cpu, i); + sprintf(buf + strlen(buf), " %2.2x", data[i]); + if ((i & 0xf) == 0xf || i == length - 1) { + strcat(buf, "\n"); + pr_info("%s", buf); + } + } +} +#endif + + +/* + * Provide support for the __netio_fastio1() swint + * (see <hv/drv_xgbe_intf.h> for how it is used). + * + * The fastio swint2 call may clobber all the caller-saved registers. + * It rarely clobbers memory, but we allow for the possibility in + * the signature just to be on the safe side. + * + * Also, gcc doesn't seem to allow an input operand to be + * clobbered, so we fake it with dummy outputs. + * + * This function can't be static because of the way it is declared + * in the netio header. + */ +inline int __netio_fastio1(u32 fastio_index, u32 arg0) +{ + long result, clobber_r1, clobber_r10; + asm volatile("swint2" + : "=R00" (result), + "=R01" (clobber_r1), "=R10" (clobber_r10) + : "R10" (fastio_index), "R01" (arg0) + : "memory", "r2", "r3", "r4", + "r5", "r6", "r7", "r8", "r9", + "r11", "r12", "r13", "r14", + "r15", "r16", "r17", "r18", "r19", + "r20", "r21", "r22", "r23", "r24", + "r25", "r26", "r27", "r28", "r29"); + return result; +} + + +static void tile_net_return_credit(struct tile_net_cpu *info) +{ + struct tile_netio_queue *queue = &info->queue; + netio_queue_user_impl_t *qup = &queue->__user_part; + + /* Return four credits after every fourth packet. */ + if (--qup->__receive_credit_remaining == 0) { + u32 interval = qup->__receive_credit_interval; + qup->__receive_credit_remaining = interval; + __netio_fastio_return_credits(qup->__fastio_index, interval); + } +} + + + +/* + * Provide a linux buffer to LIPP. + */ +static void tile_net_provide_linux_buffer(struct tile_net_cpu *info, + void *va, bool small) +{ + struct tile_netio_queue *queue = &info->queue; + + /* Convert "va" and "small" to "linux_buffer_t". */ + unsigned int buffer = ((unsigned int)(__pa(va) >> 7) << 1) + small; + + __netio_fastio_free_buffer(queue->__user_part.__fastio_index, buffer); +} + + +/* + * Provide a linux buffer for LIPP. + * + * Note that the ACTUAL allocation for each buffer is a "struct sk_buff", + * plus a chunk of memory that includes not only the requested bytes, but + * also NET_SKB_PAD bytes of initial padding, and a "struct skb_shared_info". + * + * Note that "struct skb_shared_info" is 88 bytes with 64K pages and + * 268 bytes with 4K pages (since the frags[] array needs 18 entries). + * + * Without jumbo packets, the maximum packet size will be 1536 bytes, + * and we use 2 bytes (NET_IP_ALIGN) of padding. ISSUE: If we told + * the hardware to clip at 1518 bytes instead of 1536 bytes, then we + * could save an entire cache line, but in practice, we don't need it. + * + * Since CPAs are 38 bits, and we can only encode the high 31 bits in + * a "linux_buffer_t", the low 7 bits must be zero, and thus, we must + * align the actual "va" mod 128. + * + * We assume that the underlying "head" will be aligned mod 64. Note + * that in practice, we have seen "head" NOT aligned mod 128 even when + * using 2048 byte allocations, which is surprising. + * + * If "head" WAS always aligned mod 128, we could change LIPP to + * assume that the low SIX bits are zero, and the 7th bit is one, that + * is, align the actual "va" mod 128 plus 64, which would be "free". + * + * For now, the actual "head" pointer points at NET_SKB_PAD bytes of + * padding, plus 28 or 92 bytes of extra padding, plus the sk_buff + * pointer, plus the NET_IP_ALIGN padding, plus 126 or 1536 bytes for + * the actual packet, plus 62 bytes of empty padding, plus some + * padding and the "struct skb_shared_info". + * + * With 64K pages, a large buffer thus needs 32+92+4+2+1536+62+88 + * bytes, or 1816 bytes, which fits comfortably into 2048 bytes. + * + * With 64K pages, a small buffer thus needs 32+92+4+2+126+88 + * bytes, or 344 bytes, which means we are wasting 64+ bytes, and + * could presumably increase the size of small buffers. + * + * With 4K pages, a large buffer thus needs 32+92+4+2+1536+62+268 + * bytes, or 1996 bytes, which fits comfortably into 2048 bytes. + * + * With 4K pages, a small buffer thus needs 32+92+4+2+126+268 + * bytes, or 524 bytes, which is annoyingly wasteful. + * + * Maybe we should increase LIPP_SMALL_PACKET_SIZE to 192? + * + * ISSUE: Maybe we should increase "NET_SKB_PAD" to 64? + */ +static bool tile_net_provide_needed_buffer(struct tile_net_cpu *info, + bool small) +{ +#if TILE_NET_MTU <= 1536 + /* Without "jumbo", 2 + 1536 should be sufficient. */ + unsigned int large_size = NET_IP_ALIGN + 1536; +#else + /* ISSUE: This has not been tested. */ + unsigned int large_size = NET_IP_ALIGN + TILE_NET_MTU + 100; +#endif + + /* Avoid "false sharing" with last cache line. */ + /* ISSUE: This is already done by "netdev_alloc_skb()". */ + unsigned int len = + (((small ? LIPP_SMALL_PACKET_SIZE : large_size) + + CHIP_L2_LINE_SIZE() - 1) & -CHIP_L2_LINE_SIZE()); + + unsigned int padding = 128 - NET_SKB_PAD; + unsigned int align; + + struct sk_buff *skb; + void *va; + + struct sk_buff **skb_ptr; + + /* Request 96 extra bytes for alignment purposes. */ + skb = netdev_alloc_skb(info->napi.dev, len + padding); + if (skb == NULL) + return false; + + /* Skip 32 or 96 bytes to align "data" mod 128. */ + align = -(long)skb->data & (128 - 1); + BUG_ON(align > padding); + skb_reserve(skb, align); + + /* This address is given to IPP. */ + va = skb->data; + + /* Buffers must not span a huge page. */ + BUG_ON(((((long)va & ~HPAGE_MASK) + len) & HPAGE_MASK) != 0); + +#ifdef TILE_NET_PARANOIA +#if CHIP_HAS_CBOX_HOME_MAP() + if (hash_default) { + HV_PTE pte = *virt_to_pte(current->mm, (unsigned long)va); + if (hv_pte_get_mode(pte) != HV_PTE_MODE_CACHE_HASH_L3) + panic("Non-HFH ingress buffer! VA=%p Mode=%d PTE=%llx", + va, hv_pte_get_mode(pte), hv_pte_val(pte)); + } +#endif +#endif + + /* Invalidate the packet buffer. */ + if (!hash_default) + __inv_buffer(va, len); + + /* Skip two bytes to satisfy LIPP assumptions. */ + /* Note that this aligns IP on a 16 byte boundary. */ + /* ISSUE: Do this when the packet arrives? */ + skb_reserve(skb, NET_IP_ALIGN); + + /* Save a back-pointer to 'skb'. */ + skb_ptr = va - sizeof(*skb_ptr); + *skb_ptr = skb; + + /* Make sure "skb_ptr" has been flushed. */ + __insn_mf(); + + /* Provide the new buffer. */ + tile_net_provide_linux_buffer(info, va, small); + + return true; +} + + +/* + * Provide linux buffers for LIPP. + */ +static void tile_net_provide_needed_buffers(struct tile_net_cpu *info) +{ + while (info->num_needed_small_buffers != 0) { + if (!tile_net_provide_needed_buffer(info, true)) + goto oops; + info->num_needed_small_buffers--; + } + + while (info->num_needed_large_buffers != 0) { + if (!tile_net_provide_needed_buffer(info, false)) + goto oops; + info->num_needed_large_buffers--; + } + + return; + +oops: + + /* Add a description to the page allocation failure dump. */ + pr_notice("Could not provide a linux buffer to LIPP.\n"); +} + + +/* + * Grab some LEPP completions, and store them in "comps", of size + * "comps_size", and return the number of completions which were + * stored, so the caller can free them. + */ +static unsigned int tile_net_lepp_grab_comps(lepp_queue_t *eq, + struct sk_buff *comps[], + unsigned int comps_size, + unsigned int min_size) +{ + unsigned int n = 0; + + unsigned int comp_head = eq->comp_head; + unsigned int comp_busy = eq->comp_busy; + + while (comp_head != comp_busy && n < comps_size) { + comps[n++] = eq->comps[comp_head]; + LEPP_QINC(comp_head); + } + + if (n < min_size) + return 0; + + eq->comp_head = comp_head; + + return n; +} + + +/* + * Free some comps, and return true iff there are still some pending. + */ +static bool tile_net_lepp_free_comps(struct net_device *dev, bool all) +{ + struct tile_net_priv *priv = netdev_priv(dev); + + lepp_queue_t *eq = priv->eq; + + struct sk_buff *olds[64]; + unsigned int wanted = 64; + unsigned int i, n; + bool pending; + + spin_lock(&priv->eq_lock); + + if (all) + eq->comp_busy = eq->comp_tail; + + n = tile_net_lepp_grab_comps(eq, olds, wanted, 0); + + pending = (eq->comp_head != eq->comp_tail); + + spin_unlock(&priv->eq_lock); + + for (i = 0; i < n; i++) + kfree_skb(olds[i]); + + return pending; +} + + +/* + * Make sure the egress timer is scheduled. + * + * Note that we use "schedule if not scheduled" logic instead of the more + * obvious "reschedule" logic, because "reschedule" is fairly expensive. + */ +static void tile_net_schedule_egress_timer(struct tile_net_cpu *info) +{ + if (!info->egress_timer_scheduled) { + mod_timer_pinned(&info->egress_timer, jiffies + 1); + info->egress_timer_scheduled = true; + } +} + + +/* + * The "function" for "info->egress_timer". + * + * This timer will reschedule itself as long as there are any pending + * completions expected (on behalf of any tile). + * + * ISSUE: Realistically, will the timer ever stop scheduling itself? + * + * ISSUE: This timer is almost never actually needed, so just use a global + * timer that can run on any tile. + * + * ISSUE: Maybe instead track number of expected completions, and free + * only that many, resetting to zero if "pending" is ever false. + */ +static void tile_net_handle_egress_timer(unsigned long arg) +{ + struct tile_net_cpu *info = (struct tile_net_cpu *)arg; + struct net_device *dev = info->napi.dev; + + /* The timer is no longer scheduled. */ + info->egress_timer_scheduled = false; + + /* Free comps, and reschedule timer if more are pending. */ + if (tile_net_lepp_free_comps(dev, false)) + tile_net_schedule_egress_timer(info); +} + + +static void tile_net_discard_aux(struct tile_net_cpu *info, int index) +{ + struct tile_netio_queue *queue = &info->queue; + netio_queue_impl_t *qsp = queue->__system_part; + netio_queue_user_impl_t *qup = &queue->__user_part; + + int index2_aux = index + sizeof(netio_pkt_t); + int index2 = + ((index2_aux == + qsp->__packet_receive_queue.__last_packet_plus_one) ? + 0 : index2_aux); + + netio_pkt_t *pkt = (netio_pkt_t *)((unsigned long) &qsp[1] + index); + + /* Extract the "linux_buffer_t". */ + unsigned int buffer = pkt->__packet.word; + + /* Convert "linux_buffer_t" to "va". */ + void *va = __va((phys_addr_t)(buffer >> 1) << 7); + + /* Acquire the associated "skb". */ + struct sk_buff **skb_ptr = va - sizeof(*skb_ptr); + struct sk_buff *skb = *skb_ptr; + + kfree_skb(skb); + + /* Consume this packet. */ + qup->__packet_receive_read = index2; +} + + +/* + * Like "tile_net_poll()", but just discard packets. + */ +static void tile_net_discard_packets(struct net_device *dev) +{ + struct tile_net_priv *priv = netdev_priv(dev); + int my_cpu = smp_processor_id(); + struct tile_net_cpu *info = priv->cpu[my_cpu]; + struct tile_netio_queue *queue = &info->queue; + netio_queue_impl_t *qsp = queue->__system_part; + netio_queue_user_impl_t *qup = &queue->__user_part; + + while (qup->__packet_receive_read != + qsp->__packet_receive_queue.__packet_write) { + int index = qup->__packet_receive_read; + tile_net_discard_aux(info, index); + } +} + + +/* + * Handle the next packet. Return true if "processed", false if "filtered". + */ +static bool tile_net_poll_aux(struct tile_net_cpu *info, int index) +{ + struct net_device *dev = info->napi.dev; + + struct tile_netio_queue *queue = &info->queue; + netio_queue_impl_t *qsp = queue->__system_part; + netio_queue_user_impl_t *qup = &queue->__user_part; + struct tile_net_stats_t *stats = &info->stats; + + int filter; + + int index2_aux = index + sizeof(netio_pkt_t); + int index2 = + ((index2_aux == + qsp->__packet_receive_queue.__last_packet_plus_one) ? + 0 : index2_aux); + + netio_pkt_t *pkt = (netio_pkt_t *)((unsigned long) &qsp[1] + index); + + netio_pkt_metadata_t *metadata = NETIO_PKT_METADATA(pkt); + netio_pkt_status_t pkt_status = NETIO_PKT_STATUS_M(metadata, pkt); + + /* Extract the packet size. FIXME: Shouldn't the second line */ + /* get subtracted? Mostly moot, since it should be "zero". */ + unsigned long len = + (NETIO_PKT_CUSTOM_LENGTH(pkt) + + NET_IP_ALIGN - NETIO_PACKET_PADDING); + + /* Extract the "linux_buffer_t". */ + unsigned int buffer = pkt->__packet.word; + + /* Extract "small" (vs "large"). */ + bool small = ((buffer & 1) != 0); + + /* Convert "linux_buffer_t" to "va". */ + void *va = __va((phys_addr_t)(buffer >> 1) << 7); + + /* Extract the packet data pointer. */ + /* Compare to "NETIO_PKT_CUSTOM_DATA(pkt)". */ + unsigned char *buf = va + NET_IP_ALIGN; + + /* Invalidate the packet buffer. */ + if (!hash_default) + __inv_buffer(buf, len); + + /* ISSUE: Is this needed? */ + dev->last_rx = jiffies; + +#ifdef TILE_NET_DUMP_PACKETS + dump_packet(buf, len, "rx"); +#endif /* TILE_NET_DUMP_PACKETS */ + +#ifdef TILE_NET_VERIFY_INGRESS + if (pkt_status == NETIO_PKT_STATUS_OVERSIZE && len >= 64) { + dump_packet(buf, len, "rx"); + panic("Unexpected OVERSIZE."); + } +#endif + + filter = 0; + + if (pkt_status == NETIO_PKT_STATUS_BAD) { + /* Handle CRC error and hardware truncation. */ + filter = 2; + } else if (!(dev->flags & IFF_UP)) { + /* Filter packets received before we're up. */ + filter = 1; + } else if (NETIO_PKT_ETHERTYPE_RECOGNIZED_M(metadata, pkt) && + pkt_status == NETIO_PKT_STATUS_UNDERSIZE) { + /* Filter "truncated" packets. */ + filter = 2; + } else if (!(dev->flags & IFF_PROMISC)) { + if (!is_multicast_ether_addr(buf)) { + /* Filter packets not for our address. */ + const u8 *mine = dev->dev_addr; + filter = !ether_addr_equal(mine, buf); + } + } + + u64_stats_update_begin(&stats->syncp); + + if (filter != 0) { + + if (filter == 1) + stats->rx_dropped++; + else + stats->rx_errors++; + + tile_net_provide_linux_buffer(info, va, small); + + } else { + + /* Acquire the associated "skb". */ + struct sk_buff **skb_ptr = va - sizeof(*skb_ptr); + struct sk_buff *skb = *skb_ptr; + + /* Paranoia. */ + if (skb->data != buf) + panic("Corrupt linux buffer from LIPP! " + "VA=%p, skb=%p, skb->data=%p\n", + va, skb, skb->data); + + /* Encode the actual packet length. */ + skb_put(skb, len); + + /* NOTE: This call also sets "skb->dev = dev". */ + skb->protocol = eth_type_trans(skb, dev); + + /* Avoid recomputing "good" TCP/UDP checksums. */ + if (NETIO_PKT_L4_CSUM_CORRECT_M(metadata, pkt)) + skb->ip_summed = CHECKSUM_UNNECESSARY; + + netif_receive_skb(skb); + + stats->rx_packets++; + stats->rx_bytes += len; + } + + u64_stats_update_end(&stats->syncp); + + /* ISSUE: It would be nice to defer this until the packet has */ + /* actually been processed. */ + tile_net_return_credit(info); + + /* Consume this packet. */ + qup->__packet_receive_read = index2; + + return !filter; +} + + +/* + * Handle some packets for the given device on the current CPU. + * + * If "tile_net_stop()" is called on some other tile while this + * function is running, we will return, hopefully before that + * other tile asks us to call "napi_disable()". + * + * The "rotting packet" race condition occurs if a packet arrives + * during the extremely narrow window between the queue appearing to + * be empty, and the ingress interrupt being re-enabled. This happens + * a LOT under heavy network load. + */ +static int tile_net_poll(struct napi_struct *napi, int budget) +{ + struct net_device *dev = napi->dev; + struct tile_net_priv *priv = netdev_priv(dev); + int my_cpu = smp_processor_id(); + struct tile_net_cpu *info = priv->cpu[my_cpu]; + struct tile_netio_queue *queue = &info->queue; + netio_queue_impl_t *qsp = queue->__system_part; + netio_queue_user_impl_t *qup = &queue->__user_part; + + unsigned int work = 0; + + if (budget <= 0) + goto done; + + while (priv->active) { + int index = qup->__packet_receive_read; + if (index == qsp->__packet_receive_queue.__packet_write) + break; + + if (tile_net_poll_aux(info, index)) { + if (++work >= budget) + goto done; + } + } + + napi_complete(&info->napi); + + if (!priv->active) + goto done; + + /* Re-enable the ingress interrupt. */ + enable_percpu_irq(priv->intr_id, 0); + + /* HACK: Avoid the "rotting packet" problem (see above). */ + if (qup->__packet_receive_read != + qsp->__packet_receive_queue.__packet_write) { + /* ISSUE: Sometimes this returns zero, presumably */ + /* because an interrupt was handled for this tile. */ + (void)napi_reschedule(&info->napi); + } + +done: + + if (priv->active) + tile_net_provide_needed_buffers(info); + + return work; +} + + +/* + * Handle an ingress interrupt for the given device on the current cpu. + * + * ISSUE: Sometimes this gets called after "disable_percpu_irq()" has + * been called! This is probably due to "pending hypervisor downcalls". + * + * ISSUE: Is there any race condition between the "napi_schedule()" here + * and the "napi_complete()" call above? + */ +static irqreturn_t tile_net_handle_ingress_interrupt(int irq, void *dev_ptr) +{ + struct net_device *dev = (struct net_device *)dev_ptr; + struct tile_net_priv *priv = netdev_priv(dev); + int my_cpu = smp_processor_id(); + struct tile_net_cpu *info = priv->cpu[my_cpu]; + + /* Disable the ingress interrupt. */ + disable_percpu_irq(priv->intr_id); + + /* Ignore unwanted interrupts. */ + if (!priv->active) + return IRQ_HANDLED; + + /* ISSUE: Sometimes "info->napi_enabled" is false here. */ + + napi_schedule(&info->napi); + + return IRQ_HANDLED; +} + + +/* + * One time initialization per interface. + */ +static int tile_net_open_aux(struct net_device *dev) +{ + struct tile_net_priv *priv = netdev_priv(dev); + + int ret; + int dummy; + unsigned int epp_lotar; + + /* + * Find out where EPP memory should be homed. + */ + ret = hv_dev_pread(priv->hv_devhdl, 0, + (HV_VirtAddr)&epp_lotar, sizeof(epp_lotar), + NETIO_EPP_SHM_OFF); + if (ret < 0) { + pr_err("could not read epp_shm_queue lotar.\n"); + return -EIO; + } + + /* + * Home the page on the EPP. + */ + { + int epp_home = hv_lotar_to_cpu(epp_lotar); + homecache_change_page_home(priv->eq_pages, EQ_ORDER, epp_home); + } + + /* + * Register the EPP shared memory queue. + */ + { + netio_ipp_address_t ea = { + .va = 0, + .pa = __pa(priv->eq), + .pte = hv_pte(0), + .size = EQ_SIZE, + }; + ea.pte = hv_pte_set_lotar(ea.pte, epp_lotar); + ea.pte = hv_pte_set_mode(ea.pte, HV_PTE_MODE_CACHE_TILE_L3); + ret = hv_dev_pwrite(priv->hv_devhdl, 0, + (HV_VirtAddr)&ea, + sizeof(ea), + NETIO_EPP_SHM_OFF); + if (ret < 0) + return -EIO; + } + + /* + * Start LIPP/LEPP. + */ + if (hv_dev_pwrite(priv->hv_devhdl, 0, (HV_VirtAddr)&dummy, + sizeof(dummy), NETIO_IPP_START_SHIM_OFF) < 0) { + pr_warn("Failed to start LIPP/LEPP\n"); + return -EIO; + } + + return 0; +} + + +/* + * Register with hypervisor on the current CPU. + * + * Strangely, this function does important things even if it "fails", + * which is especially common if the link is not up yet. Hopefully + * these things are all "harmless" if done twice! + */ +static void tile_net_register(void *dev_ptr) +{ + struct net_device *dev = (struct net_device *)dev_ptr; + struct tile_net_priv *priv = netdev_priv(dev); + int my_cpu = smp_processor_id(); + struct tile_net_cpu *info; + + struct tile_netio_queue *queue; + + /* Only network cpus can receive packets. */ + int queue_id = + cpumask_test_cpu(my_cpu, &priv->network_cpus_map) ? 0 : 255; + + netio_input_config_t config = { + .flags = 0, + .num_receive_packets = priv->network_cpus_credits, + .queue_id = queue_id + }; + + int ret = 0; + netio_queue_impl_t *queuep; + + PDEBUG("tile_net_register(queue_id %d)\n", queue_id); + + if (!strcmp(dev->name, "xgbe0")) + info = this_cpu_ptr(&hv_xgbe0); + else if (!strcmp(dev->name, "xgbe1")) + info = this_cpu_ptr(&hv_xgbe1); + else if (!strcmp(dev->name, "gbe0")) + info = this_cpu_ptr(&hv_gbe0); + else if (!strcmp(dev->name, "gbe1")) + info = this_cpu_ptr(&hv_gbe1); + else + BUG(); + + /* Initialize the egress timer. */ + init_timer(&info->egress_timer); + info->egress_timer.data = (long)info; + info->egress_timer.function = tile_net_handle_egress_timer; + + u64_stats_init(&info->stats.syncp); + + priv->cpu[my_cpu] = info; + + /* + * Register ourselves with LIPP. This does a lot of stuff, + * including invoking the LIPP registration code. + */ + ret = hv_dev_pwrite(priv->hv_devhdl, 0, + (HV_VirtAddr)&config, + sizeof(netio_input_config_t), + NETIO_IPP_INPUT_REGISTER_OFF); + PDEBUG("hv_dev_pwrite(NETIO_IPP_INPUT_REGISTER_OFF) returned %d\n", + ret); + if (ret < 0) { + if (ret != NETIO_LINK_DOWN) { + printk(KERN_DEBUG "hv_dev_pwrite " + "NETIO_IPP_INPUT_REGISTER_OFF failure %d\n", + ret); + } + info->link_down = (ret == NETIO_LINK_DOWN); + return; + } + + /* + * Get the pointer to our queue's system part. + */ + + ret = hv_dev_pread(priv->hv_devhdl, 0, + (HV_VirtAddr)&queuep, + sizeof(netio_queue_impl_t *), + NETIO_IPP_INPUT_REGISTER_OFF); + PDEBUG("hv_dev_pread(NETIO_IPP_INPUT_REGISTER_OFF) returned %d\n", + ret); + PDEBUG("queuep %p\n", queuep); + if (ret <= 0) { + /* ISSUE: Shouldn't this be a fatal error? */ + pr_err("hv_dev_pread NETIO_IPP_INPUT_REGISTER_OFF failure\n"); + return; + } + + queue = &info->queue; + + queue->__system_part = queuep; + + memset(&queue->__user_part, 0, sizeof(netio_queue_user_impl_t)); + + /* This is traditionally "config.num_receive_packets / 2". */ + queue->__user_part.__receive_credit_interval = 4; + queue->__user_part.__receive_credit_remaining = + queue->__user_part.__receive_credit_interval; + + /* + * Get a fastio index from the hypervisor. + * ISSUE: Shouldn't this check the result? + */ + ret = hv_dev_pread(priv->hv_devhdl, 0, + (HV_VirtAddr)&queue->__user_part.__fastio_index, + sizeof(queue->__user_part.__fastio_index), + NETIO_IPP_GET_FASTIO_OFF); + PDEBUG("hv_dev_pread(NETIO_IPP_GET_FASTIO_OFF) returned %d\n", ret); + + /* Now we are registered. */ + info->registered = true; +} + + +/* + * Deregister with hypervisor on the current CPU. + * + * This simply discards all our credits, so no more packets will be + * delivered to this tile. There may still be packets in our queue. + * + * Also, disable the ingress interrupt. + */ +static void tile_net_deregister(void *dev_ptr) +{ + struct net_device *dev = (struct net_device *)dev_ptr; + struct tile_net_priv *priv = netdev_priv(dev); + int my_cpu = smp_processor_id(); + struct tile_net_cpu *info = priv->cpu[my_cpu]; + + /* Disable the ingress interrupt. */ + disable_percpu_irq(priv->intr_id); + + /* Do nothing else if not registered. */ + if (info == NULL || !info->registered) + return; + + { + struct tile_netio_queue *queue = &info->queue; + netio_queue_user_impl_t *qup = &queue->__user_part; + + /* Discard all our credits. */ + __netio_fastio_return_credits(qup->__fastio_index, -1); + } +} + + +/* + * Unregister with hypervisor on the current CPU. + * + * Also, disable the ingress interrupt. + */ +static void tile_net_unregister(void *dev_ptr) +{ + struct net_device *dev = (struct net_device *)dev_ptr; + struct tile_net_priv *priv = netdev_priv(dev); + int my_cpu = smp_processor_id(); + struct tile_net_cpu *info = priv->cpu[my_cpu]; + + int ret; + int dummy = 0; + + /* Disable the ingress interrupt. */ + disable_percpu_irq(priv->intr_id); + + /* Do nothing else if not registered. */ + if (info == NULL || !info->registered) + return; + + /* Unregister ourselves with LIPP/LEPP. */ + ret = hv_dev_pwrite(priv->hv_devhdl, 0, (HV_VirtAddr)&dummy, + sizeof(dummy), NETIO_IPP_INPUT_UNREGISTER_OFF); + if (ret < 0) + panic("Failed to unregister with LIPP/LEPP!\n"); + + /* Discard all packets still in our NetIO queue. */ + tile_net_discard_packets(dev); + + /* Reset state. */ + info->num_needed_small_buffers = 0; + info->num_needed_large_buffers = 0; + + /* Cancel egress timer. */ + del_timer(&info->egress_timer); + info->egress_timer_scheduled = false; +} + + +/* + * Helper function for "tile_net_stop()". + * + * Also used to handle registration failure in "tile_net_open_inner()", + * when the various extra steps in "tile_net_stop()" are not necessary. + */ +static void tile_net_stop_aux(struct net_device *dev) +{ + struct tile_net_priv *priv = netdev_priv(dev); + int i; + + int dummy = 0; + + /* + * Unregister all tiles, so LIPP will stop delivering packets. + * Also, delete all the "napi" objects (sequentially, to protect + * "dev->napi_list"). + */ + on_each_cpu(tile_net_unregister, (void *)dev, 1); + for_each_online_cpu(i) { + struct tile_net_cpu *info = priv->cpu[i]; + if (info != NULL && info->registered) { + netif_napi_del(&info->napi); + info->registered = false; + } + } + + /* Stop LIPP/LEPP. */ + if (hv_dev_pwrite(priv->hv_devhdl, 0, (HV_VirtAddr)&dummy, + sizeof(dummy), NETIO_IPP_STOP_SHIM_OFF) < 0) + panic("Failed to stop LIPP/LEPP!\n"); + + priv->partly_opened = false; +} + + +/* + * Disable NAPI for the given device on the current cpu. + */ +static void tile_net_stop_disable(void *dev_ptr) +{ + struct net_device *dev = (struct net_device *)dev_ptr; + struct tile_net_priv *priv = netdev_priv(dev); + int my_cpu = smp_processor_id(); + struct tile_net_cpu *info = priv->cpu[my_cpu]; + + /* Disable NAPI if needed. */ + if (info != NULL && info->napi_enabled) { + napi_disable(&info->napi); + info->napi_enabled = false; + } +} + + +/* + * Enable NAPI and the ingress interrupt for the given device + * on the current cpu. + * + * ISSUE: Only do this for "network cpus"? + */ +static void tile_net_open_enable(void *dev_ptr) +{ + struct net_device *dev = (struct net_device *)dev_ptr; + struct tile_net_priv *priv = netdev_priv(dev); + int my_cpu = smp_processor_id(); + struct tile_net_cpu *info = priv->cpu[my_cpu]; + + /* Enable NAPI. */ + napi_enable(&info->napi); + info->napi_enabled = true; + + /* Enable the ingress interrupt. */ + enable_percpu_irq(priv->intr_id, 0); +} + + +/* + * tile_net_open_inner does most of the work of bringing up the interface. + * It's called from tile_net_open(), and also from tile_net_retry_open(). + * The return value is 0 if the interface was brought up, < 0 if + * tile_net_open() should return the return value as an error, and > 0 if + * tile_net_open() should return success and schedule a work item to + * periodically retry the bringup. + */ +static int tile_net_open_inner(struct net_device *dev) +{ + struct tile_net_priv *priv = netdev_priv(dev); + int my_cpu = smp_processor_id(); + struct tile_net_cpu *info; + struct tile_netio_queue *queue; + int result = 0; + int i; + int dummy = 0; + + /* + * First try to register just on the local CPU, and handle any + * semi-expected "link down" failure specially. Note that we + * do NOT call "tile_net_stop_aux()", unlike below. + */ + tile_net_register(dev); + info = priv->cpu[my_cpu]; + if (!info->registered) { + if (info->link_down) + return 1; + return -EAGAIN; + } + + /* + * Now register everywhere else. If any registration fails, + * even for "link down" (which might not be possible), we + * clean up using "tile_net_stop_aux()". Also, add all the + * "napi" objects (sequentially, to protect "dev->napi_list"). + * ISSUE: Only use "netif_napi_add()" for "network cpus"? + */ + smp_call_function(tile_net_register, (void *)dev, 1); + for_each_online_cpu(i) { + struct tile_net_cpu *info = priv->cpu[i]; + if (info->registered) + netif_napi_add(dev, &info->napi, tile_net_poll, 64); + else + result = -EAGAIN; + } + if (result != 0) { + tile_net_stop_aux(dev); + return result; + } + + queue = &info->queue; + + if (priv->intr_id == 0) { + unsigned int irq; + + /* + * Acquire the irq allocated by the hypervisor. Every + * queue gets the same irq. The "__intr_id" field is + * "1 << irq", so we use "__ffs()" to extract "irq". + */ + priv->intr_id = queue->__system_part->__intr_id; + BUG_ON(priv->intr_id == 0); + irq = __ffs(priv->intr_id); + + /* + * Register the ingress interrupt handler for this + * device, permanently. + * + * We used to call "free_irq()" in "tile_net_stop()", + * and then re-register the handler here every time, + * but that caused DNP errors in "handle_IRQ_event()" + * because "desc->action" was NULL. See bug 9143. + */ + tile_irq_activate(irq, TILE_IRQ_PERCPU); + BUG_ON(request_irq(irq, tile_net_handle_ingress_interrupt, + 0, dev->name, (void *)dev) != 0); + } + + { + /* Allocate initial buffers. */ + + int max_buffers = + priv->network_cpus_count * priv->network_cpus_credits; + + info->num_needed_small_buffers = + min(LIPP_SMALL_BUFFERS, max_buffers); + + info->num_needed_large_buffers = + min(LIPP_LARGE_BUFFERS, max_buffers); + + tile_net_provide_needed_buffers(info); + + if (info->num_needed_small_buffers != 0 || + info->num_needed_large_buffers != 0) + panic("Insufficient memory for buffer stack!"); + } + + /* We are about to be active. */ + priv->active = true; + + /* Make sure "active" is visible to all tiles. */ + mb(); + + /* On each tile, enable NAPI and the ingress interrupt. */ + on_each_cpu(tile_net_open_enable, (void *)dev, 1); + + /* Start LIPP/LEPP and activate "ingress" at the shim. */ + if (hv_dev_pwrite(priv->hv_devhdl, 0, (HV_VirtAddr)&dummy, + sizeof(dummy), NETIO_IPP_INPUT_INIT_OFF) < 0) + panic("Failed to activate the LIPP Shim!\n"); + + /* Start our transmit queue. */ + netif_start_queue(dev); + + return 0; +} + + +/* + * Called periodically to retry bringing up the NetIO interface, + * if it doesn't come up cleanly during tile_net_open(). + */ +static void tile_net_open_retry(struct work_struct *w) +{ + struct delayed_work *dw = + container_of(w, struct delayed_work, work); + + struct tile_net_priv *priv = + container_of(dw, struct tile_net_priv, retry_work); + + /* + * Try to bring the NetIO interface up. If it fails, reschedule + * ourselves to try again later; otherwise, tell Linux we now have + * a working link. ISSUE: What if the return value is negative? + */ + if (tile_net_open_inner(priv->dev) != 0) + schedule_delayed_work(&priv->retry_work, + TILE_NET_RETRY_INTERVAL); + else + netif_carrier_on(priv->dev); +} + + +/* + * Called when a network interface is made active. + * + * Returns 0 on success, negative value on failure. + * + * The open entry point is called when a network interface is made + * active by the system (IFF_UP). At this point all resources needed + * for transmit and receive operations are allocated, the interrupt + * handler is registered with the OS (if needed), the watchdog timer + * is started, and the stack is notified that the interface is ready. + * + * If the actual link is not available yet, then we tell Linux that + * we have no carrier, and we keep checking until the link comes up. + */ +static int tile_net_open(struct net_device *dev) +{ + int ret = 0; + struct tile_net_priv *priv = netdev_priv(dev); + + /* + * We rely on priv->partly_opened to tell us if this is the + * first time this interface is being brought up. If it is + * set, the IPP was already initialized and should not be + * initialized again. + */ + if (!priv->partly_opened) { + + int count; + int credits; + + /* Initialize LIPP/LEPP, and start the Shim. */ + ret = tile_net_open_aux(dev); + if (ret < 0) { + pr_err("tile_net_open_aux failed: %d\n", ret); + return ret; + } + + /* Analyze the network cpus. */ + + if (network_cpus_used) + cpumask_copy(&priv->network_cpus_map, + &network_cpus_map); + else + cpumask_copy(&priv->network_cpus_map, cpu_online_mask); + + + count = cpumask_weight(&priv->network_cpus_map); + + /* Limit credits to available buffers, and apply min. */ + credits = max(16, (LIPP_LARGE_BUFFERS / count) & ~1); + + /* Apply "GBE" max limit. */ + /* ISSUE: Use higher limit for XGBE? */ + credits = min(NETIO_MAX_RECEIVE_PKTS, credits); + + priv->network_cpus_count = count; + priv->network_cpus_credits = credits; + +#ifdef TILE_NET_DEBUG + pr_info("Using %d network cpus, with %d credits each\n", + priv->network_cpus_count, priv->network_cpus_credits); +#endif + + priv->partly_opened = true; + + } else { + /* FIXME: Is this possible? */ + /* printk("Already partly opened.\n"); */ + } + + /* + * Attempt to bring up the link. + */ + ret = tile_net_open_inner(dev); + if (ret <= 0) { + if (ret == 0) + netif_carrier_on(dev); + return ret; + } + + /* + * We were unable to bring up the NetIO interface, but we want to + * try again in a little bit. Tell Linux that we have no carrier + * so it doesn't try to use the interface before the link comes up + * and then remember to try again later. + */ + netif_carrier_off(dev); + schedule_delayed_work(&priv->retry_work, TILE_NET_RETRY_INTERVAL); + + return 0; +} + + +static int tile_net_drain_lipp_buffers(struct tile_net_priv *priv) +{ + int n = 0; + + /* Drain all the LIPP buffers. */ + while (true) { + unsigned int buffer; + + /* NOTE: This should never fail. */ + if (hv_dev_pread(priv->hv_devhdl, 0, (HV_VirtAddr)&buffer, + sizeof(buffer), NETIO_IPP_DRAIN_OFF) < 0) + break; + + /* Stop when done. */ + if (buffer == 0) + break; + + { + /* Convert "linux_buffer_t" to "va". */ + void *va = __va((phys_addr_t)(buffer >> 1) << 7); + + /* Acquire the associated "skb". */ + struct sk_buff **skb_ptr = va - sizeof(*skb_ptr); + struct sk_buff *skb = *skb_ptr; + + kfree_skb(skb); + } + + n++; + } + + return n; +} + + +/* + * Disables a network interface. + * + * Returns 0, this is not allowed to fail. + * + * The close entry point is called when an interface is de-activated + * by the OS. The hardware is still under the drivers control, but + * needs to be disabled. A global MAC reset is issued to stop the + * hardware, and all transmit and receive resources are freed. + * + * ISSUE: How closely does "netif_running(dev)" mirror "priv->active"? + * + * Before we are called by "__dev_close()", "netif_running()" will + * have been cleared, so no NEW calls to "tile_net_poll()" will be + * made by "netpoll_poll_dev()". + * + * Often, this can cause some tiles to still have packets in their + * queues, so we must call "tile_net_discard_packets()" later. + * + * Note that some other tile may still be INSIDE "tile_net_poll()", + * and in fact, many will be, if there is heavy network load. + * + * Calling "on_each_cpu(tile_net_stop_disable, (void *)dev, 1)" when + * any tile is still "napi_schedule()"'d will induce a horrible crash + * when "msleep()" is called. This includes tiles which are inside + * "tile_net_poll()" which have not yet called "napi_complete()". + * + * So, we must first try to wait long enough for other tiles to finish + * with any current "tile_net_poll()" call, and, hopefully, to clear + * the "scheduled" flag. ISSUE: It is unclear what happens to tiles + * which have called "napi_schedule()" but which had not yet tried to + * call "tile_net_poll()", or which exhausted their budget inside + * "tile_net_poll()" just before this function was called. + */ +static int tile_net_stop(struct net_device *dev) +{ + struct tile_net_priv *priv = netdev_priv(dev); + + PDEBUG("tile_net_stop()\n"); + + /* Start discarding packets. */ + priv->active = false; + + /* Make sure "active" is visible to all tiles. */ + mb(); + + /* + * On each tile, make sure no NEW packets get delivered, and + * disable the ingress interrupt. + * + * Note that the ingress interrupt can fire AFTER this, + * presumably due to packets which were recently delivered, + * but it will have no effect. + */ + on_each_cpu(tile_net_deregister, (void *)dev, 1); + + /* Optimistically drain LIPP buffers. */ + (void)tile_net_drain_lipp_buffers(priv); + + /* ISSUE: Only needed if not yet fully open. */ + cancel_delayed_work_sync(&priv->retry_work); + + /* Can't transmit any more. */ + netif_stop_queue(dev); + + /* Disable NAPI on each tile. */ + on_each_cpu(tile_net_stop_disable, (void *)dev, 1); + + /* + * Drain any remaining LIPP buffers. NOTE: This "printk()" + * has never been observed, but in theory it could happen. + */ + if (tile_net_drain_lipp_buffers(priv) != 0) + printk("Had to drain some extra LIPP buffers!\n"); + + /* Stop LIPP/LEPP. */ + tile_net_stop_aux(dev); + + /* + * ISSUE: It appears that, in practice anyway, by the time we + * get here, there are no pending completions, but just in case, + * we free (all of) them anyway. + */ + while (tile_net_lepp_free_comps(dev, true)) + /* loop */; + + /* Wipe the EPP queue, and wait till the stores hit the EPP. */ + memset(priv->eq, 0, sizeof(lepp_queue_t)); + mb(); + + return 0; +} + + +/* + * Prepare the "frags" info for the resulting LEPP command. + * + * If needed, flush the memory used by the frags. + */ +static unsigned int tile_net_tx_frags(lepp_frag_t *frags, + struct sk_buff *skb, + void *b_data, unsigned int b_len) +{ + unsigned int i, n = 0; + + struct skb_shared_info *sh = skb_shinfo(skb); + + phys_addr_t cpa; + + if (b_len != 0) { + + if (!hash_default) + finv_buffer_remote(b_data, b_len, 0); + + cpa = __pa(b_data); + frags[n].cpa_lo = cpa; + frags[n].cpa_hi = cpa >> 32; + frags[n].length = b_len; + frags[n].hash_for_home = hash_default; + n++; + } + + for (i = 0; i < sh->nr_frags; i++) { + + skb_frag_t *f = &sh->frags[i]; + unsigned long pfn = page_to_pfn(skb_frag_page(f)); + + /* FIXME: Compute "hash_for_home" properly. */ + /* ISSUE: The hypervisor checks CHIP_HAS_REV1_DMA_PACKETS(). */ + int hash_for_home = hash_default; + + /* FIXME: Hmmm. */ + if (!hash_default) { + void *va = pfn_to_kaddr(pfn) + f->page_offset; + BUG_ON(PageHighMem(skb_frag_page(f))); + finv_buffer_remote(va, skb_frag_size(f), 0); + } + + cpa = ((phys_addr_t)pfn << PAGE_SHIFT) + f->page_offset; + frags[n].cpa_lo = cpa; + frags[n].cpa_hi = cpa >> 32; + frags[n].length = skb_frag_size(f); + frags[n].hash_for_home = hash_for_home; + n++; + } + + return n; +} + + +/* + * This function takes "skb", consisting of a header template and a + * payload, and hands it to LEPP, to emit as one or more segments, + * each consisting of a possibly modified header, plus a piece of the + * payload, via a process known as "tcp segmentation offload". + * + * Usually, "data" will contain the header template, of size "sh_len", + * and "sh->frags" will contain "skb->data_len" bytes of payload, and + * there will be "sh->gso_segs" segments. + * + * Sometimes, if "sendfile()" requires copying, we will be called with + * "data" containing the header and payload, with "frags" being empty. + * + * Sometimes, for example when using NFS over TCP, a single segment can + * span 3 fragments, which must be handled carefully in LEPP. + * + * See "emulate_large_send_offload()" for some reference code, which + * does not handle checksumming. + * + * ISSUE: How do we make sure that high memory DMA does not migrate? + */ +static int tile_net_tx_tso(struct sk_buff *skb, struct net_device *dev) +{ + struct tile_net_priv *priv = netdev_priv(dev); + int my_cpu = smp_processor_id(); + struct tile_net_cpu *info = priv->cpu[my_cpu]; + struct tile_net_stats_t *stats = &info->stats; + + struct skb_shared_info *sh = skb_shinfo(skb); + + unsigned char *data = skb->data; + + /* The ip header follows the ethernet header. */ + struct iphdr *ih = ip_hdr(skb); + unsigned int ih_len = ih->ihl * 4; + + /* Note that "nh == ih", by definition. */ + unsigned char *nh = skb_network_header(skb); + unsigned int eh_len = nh - data; + + /* The tcp header follows the ip header. */ + struct tcphdr *th = (struct tcphdr *)(nh + ih_len); + unsigned int th_len = th->doff * 4; + + /* The total number of header bytes. */ + /* NOTE: This may be less than skb_headlen(skb). */ + unsigned int sh_len = eh_len + ih_len + th_len; + + /* The number of payload bytes at "skb->data + sh_len". */ + /* This is non-zero for sendfile() without HIGHDMA. */ + unsigned int b_len = skb_headlen(skb) - sh_len; + + /* The total number of payload bytes. */ + unsigned int d_len = b_len + skb->data_len; + + /* The maximum payload size. */ + unsigned int p_len = sh->gso_size; + + /* The total number of segments. */ + unsigned int num_segs = sh->gso_segs; + + /* The temporary copy of the command. */ + u32 cmd_body[(LEPP_MAX_CMD_SIZE + 3) / 4]; + lepp_tso_cmd_t *cmd = (lepp_tso_cmd_t *)cmd_body; + + /* Analyze the "frags". */ + unsigned int num_frags = + tile_net_tx_frags(cmd->frags, skb, data + sh_len, b_len); + + /* The size of the command, including frags and header. */ + size_t cmd_size = LEPP_TSO_CMD_SIZE(num_frags, sh_len); + + /* The command header. */ + lepp_tso_cmd_t cmd_init = { + .tso = true, + .header_size = sh_len, + .ip_offset = eh_len, + .tcp_offset = eh_len + ih_len, + .payload_size = p_len, + .num_frags = num_frags, + }; + + unsigned long irqflags; + + lepp_queue_t *eq = priv->eq; + + struct sk_buff *olds[8]; + unsigned int wanted = 8; + unsigned int i, nolds = 0; + + unsigned int cmd_head, cmd_tail, cmd_next; + unsigned int comp_tail; + + + /* Paranoia. */ + BUG_ON(skb->protocol != htons(ETH_P_IP)); + BUG_ON(ih->protocol != IPPROTO_TCP); + BUG_ON(skb->ip_summed != CHECKSUM_PARTIAL); + BUG_ON(num_frags > LEPP_MAX_FRAGS); + /*--BUG_ON(num_segs != (d_len + (p_len - 1)) / p_len); */ + BUG_ON(num_segs <= 1); + + + /* Finish preparing the command. */ + + /* Copy the command header. */ + *cmd = cmd_init; + + /* Copy the "header". */ + memcpy(&cmd->frags[num_frags], data, sh_len); + + + /* Prefetch and wait, to minimize time spent holding the spinlock. */ + prefetch_L1(&eq->comp_tail); + prefetch_L1(&eq->cmd_tail); + mb(); + + + /* Enqueue the command. */ + + spin_lock_irqsave(&priv->eq_lock, irqflags); + + /* Handle completions if needed to make room. */ + /* NOTE: Return NETDEV_TX_BUSY if there is still no room. */ + if (lepp_num_free_comp_slots(eq) == 0) { + nolds = tile_net_lepp_grab_comps(eq, olds, wanted, 0); + if (nolds == 0) { +busy: + spin_unlock_irqrestore(&priv->eq_lock, irqflags); + return NETDEV_TX_BUSY; + } + } + + cmd_head = eq->cmd_head; + cmd_tail = eq->cmd_tail; + + /* Prepare to advance, detecting full queue. */ + /* NOTE: Return NETDEV_TX_BUSY if the queue is full. */ + cmd_next = cmd_tail + cmd_size; + if (cmd_tail < cmd_head && cmd_next >= cmd_head) + goto busy; + if (cmd_next > LEPP_CMD_LIMIT) { + cmd_next = 0; + if (cmd_next == cmd_head) + goto busy; + } + + /* Copy the command. */ + memcpy(&eq->cmds[cmd_tail], cmd, cmd_size); + + /* Advance. */ + cmd_tail = cmd_next; + + /* Record "skb" for eventual freeing. */ + comp_tail = eq->comp_tail; + eq->comps[comp_tail] = skb; + LEPP_QINC(comp_tail); + eq->comp_tail = comp_tail; + + /* Flush before allowing LEPP to handle the command. */ + /* ISSUE: Is this the optimal location for the flush? */ + __insn_mf(); + + eq->cmd_tail = cmd_tail; + + /* NOTE: Using "4" here is more efficient than "0" or "2", */ + /* and, strangely, more efficient than pre-checking the number */ + /* of available completions, and comparing it to 4. */ + if (nolds == 0) + nolds = tile_net_lepp_grab_comps(eq, olds, wanted, 4); + + spin_unlock_irqrestore(&priv->eq_lock, irqflags); + + /* Handle completions. */ + for (i = 0; i < nolds; i++) + dev_consume_skb_any(olds[i]); + + /* Update stats. */ + u64_stats_update_begin(&stats->syncp); + stats->tx_packets += num_segs; + stats->tx_bytes += (num_segs * sh_len) + d_len; + u64_stats_update_end(&stats->syncp); + + /* Make sure the egress timer is scheduled. */ + tile_net_schedule_egress_timer(info); + + return NETDEV_TX_OK; +} + + +/* + * Transmit a packet (called by the kernel via "hard_start_xmit" hook). + */ +static int tile_net_tx(struct sk_buff *skb, struct net_device *dev) +{ + struct tile_net_priv *priv = netdev_priv(dev); + int my_cpu = smp_processor_id(); + struct tile_net_cpu *info = priv->cpu[my_cpu]; + struct tile_net_stats_t *stats = &info->stats; + + unsigned long irqflags; + + struct skb_shared_info *sh = skb_shinfo(skb); + + unsigned int len = skb->len; + unsigned char *data = skb->data; + + unsigned int csum_start = skb_checksum_start_offset(skb); + + lepp_frag_t frags[1 + MAX_SKB_FRAGS]; + + unsigned int num_frags; + + lepp_queue_t *eq = priv->eq; + + struct sk_buff *olds[8]; + unsigned int wanted = 8; + unsigned int i, nolds = 0; + + unsigned int cmd_size = sizeof(lepp_cmd_t); + + unsigned int cmd_head, cmd_tail, cmd_next; + unsigned int comp_tail; + + lepp_cmd_t cmds[1 + MAX_SKB_FRAGS]; + + + /* + * This is paranoia, since we think that if the link doesn't come + * up, telling Linux we have no carrier will keep it from trying + * to transmit. If it does, though, we can't execute this routine, + * since data structures we depend on aren't set up yet. + */ + if (!info->registered) + return NETDEV_TX_BUSY; + + + /* Save the timestamp. */ + dev->trans_start = jiffies; + + +#ifdef TILE_NET_PARANOIA +#if CHIP_HAS_CBOX_HOME_MAP() + if (hash_default) { + HV_PTE pte = *virt_to_pte(current->mm, (unsigned long)data); + if (hv_pte_get_mode(pte) != HV_PTE_MODE_CACHE_HASH_L3) + panic("Non-HFH egress buffer! VA=%p Mode=%d PTE=%llx", + data, hv_pte_get_mode(pte), hv_pte_val(pte)); + } +#endif +#endif + + +#ifdef TILE_NET_DUMP_PACKETS + /* ISSUE: Does not dump the "frags". */ + dump_packet(data, skb_headlen(skb), "tx"); +#endif /* TILE_NET_DUMP_PACKETS */ + + + if (sh->gso_size != 0) + return tile_net_tx_tso(skb, dev); + + + /* Prepare the commands. */ + + num_frags = tile_net_tx_frags(frags, skb, data, skb_headlen(skb)); + + for (i = 0; i < num_frags; i++) { + + bool final = (i == num_frags - 1); + + lepp_cmd_t cmd = { + .cpa_lo = frags[i].cpa_lo, + .cpa_hi = frags[i].cpa_hi, + .length = frags[i].length, + .hash_for_home = frags[i].hash_for_home, + .send_completion = final, + .end_of_packet = final + }; + + if (i == 0 && skb->ip_summed == CHECKSUM_PARTIAL) { + cmd.compute_checksum = 1; + cmd.checksum_data.bits.start_byte = csum_start; + cmd.checksum_data.bits.count = len - csum_start; + cmd.checksum_data.bits.destination_byte = + csum_start + skb->csum_offset; + } + + cmds[i] = cmd; + } + + + /* Prefetch and wait, to minimize time spent holding the spinlock. */ + prefetch_L1(&eq->comp_tail); + prefetch_L1(&eq->cmd_tail); + mb(); + + + /* Enqueue the commands. */ + + spin_lock_irqsave(&priv->eq_lock, irqflags); + + /* Handle completions if needed to make room. */ + /* NOTE: Return NETDEV_TX_BUSY if there is still no room. */ + if (lepp_num_free_comp_slots(eq) == 0) { + nolds = tile_net_lepp_grab_comps(eq, olds, wanted, 0); + if (nolds == 0) { +busy: + spin_unlock_irqrestore(&priv->eq_lock, irqflags); + return NETDEV_TX_BUSY; + } + } + + cmd_head = eq->cmd_head; + cmd_tail = eq->cmd_tail; + + /* Copy the commands, or fail. */ + /* NOTE: Return NETDEV_TX_BUSY if the queue is full. */ + for (i = 0; i < num_frags; i++) { + + /* Prepare to advance, detecting full queue. */ + cmd_next = cmd_tail + cmd_size; + if (cmd_tail < cmd_head && cmd_next >= cmd_head) + goto busy; + if (cmd_next > LEPP_CMD_LIMIT) { + cmd_next = 0; + if (cmd_next == cmd_head) + goto busy; + } + + /* Copy the command. */ + *(lepp_cmd_t *)&eq->cmds[cmd_tail] = cmds[i]; + + /* Advance. */ + cmd_tail = cmd_next; + } + + /* Record "skb" for eventual freeing. */ + comp_tail = eq->comp_tail; + eq->comps[comp_tail] = skb; + LEPP_QINC(comp_tail); + eq->comp_tail = comp_tail; + + /* Flush before allowing LEPP to handle the command. */ + /* ISSUE: Is this the optimal location for the flush? */ + __insn_mf(); + + eq->cmd_tail = cmd_tail; + + /* NOTE: Using "4" here is more efficient than "0" or "2", */ + /* and, strangely, more efficient than pre-checking the number */ + /* of available completions, and comparing it to 4. */ + if (nolds == 0) + nolds = tile_net_lepp_grab_comps(eq, olds, wanted, 4); + + spin_unlock_irqrestore(&priv->eq_lock, irqflags); + + /* Handle completions. */ + for (i = 0; i < nolds; i++) + dev_consume_skb_any(olds[i]); + + /* HACK: Track "expanded" size for short packets (e.g. 42 < 60). */ + u64_stats_update_begin(&stats->syncp); + stats->tx_packets++; + stats->tx_bytes += ((len >= ETH_ZLEN) ? len : ETH_ZLEN); + u64_stats_update_end(&stats->syncp); + + /* Make sure the egress timer is scheduled. */ + tile_net_schedule_egress_timer(info); + + return NETDEV_TX_OK; +} + + +/* + * Deal with a transmit timeout. + */ +static void tile_net_tx_timeout(struct net_device *dev) +{ + PDEBUG("tile_net_tx_timeout()\n"); + PDEBUG("Transmit timeout at %ld, latency %ld\n", jiffies, + jiffies - dev->trans_start); + + /* XXX: ISSUE: This doesn't seem useful for us. */ + netif_wake_queue(dev); +} + + +/* + * Ioctl commands. + */ +static int tile_net_ioctl(struct net_device *dev, struct ifreq *rq, int cmd) +{ + return -EOPNOTSUPP; +} + + +/* + * Get System Network Statistics. + * + * Returns the address of the device statistics structure. + */ +static struct rtnl_link_stats64 *tile_net_get_stats64(struct net_device *dev, + struct rtnl_link_stats64 *stats) +{ + struct tile_net_priv *priv = netdev_priv(dev); + u64 rx_packets = 0, tx_packets = 0; + u64 rx_bytes = 0, tx_bytes = 0; + u64 rx_errors = 0, rx_dropped = 0; + int i; + + for_each_online_cpu(i) { + struct tile_net_stats_t *cpu_stats; + u64 trx_packets, ttx_packets, trx_bytes, ttx_bytes; + u64 trx_errors, trx_dropped; + unsigned int start; + + if (priv->cpu[i] == NULL) + continue; + cpu_stats = &priv->cpu[i]->stats; + + do { + start = u64_stats_fetch_begin_irq(&cpu_stats->syncp); + trx_packets = cpu_stats->rx_packets; + ttx_packets = cpu_stats->tx_packets; + trx_bytes = cpu_stats->rx_bytes; + ttx_bytes = cpu_stats->tx_bytes; + trx_errors = cpu_stats->rx_errors; + trx_dropped = cpu_stats->rx_dropped; + } while (u64_stats_fetch_retry_irq(&cpu_stats->syncp, start)); + + rx_packets += trx_packets; + tx_packets += ttx_packets; + rx_bytes += trx_bytes; + tx_bytes += ttx_bytes; + rx_errors += trx_errors; + rx_dropped += trx_dropped; + } + + stats->rx_packets = rx_packets; + stats->tx_packets = tx_packets; + stats->rx_bytes = rx_bytes; + stats->tx_bytes = tx_bytes; + stats->rx_errors = rx_errors; + stats->rx_dropped = rx_dropped; + + return stats; +} + + +/* + * Change the "mtu". + * + * The "change_mtu" method is usually not needed. + * If you need it, it must be like this. + */ +static int tile_net_change_mtu(struct net_device *dev, int new_mtu) +{ + PDEBUG("tile_net_change_mtu()\n"); + + /* Check ranges. */ + if ((new_mtu < 68) || (new_mtu > 1500)) + return -EINVAL; + + /* Accept the value. */ + dev->mtu = new_mtu; + + return 0; +} + + +/* + * Change the Ethernet Address of the NIC. + * + * The hypervisor driver does not support changing MAC address. However, + * the IPP does not do anything with the MAC address, so the address which + * gets used on outgoing packets, and which is accepted on incoming packets, + * is completely up to the NetIO program or kernel driver which is actually + * handling them. + * + * Returns 0 on success, negative on failure. + */ +static int tile_net_set_mac_address(struct net_device *dev, void *p) +{ + struct sockaddr *addr = p; + + if (!is_valid_ether_addr(addr->sa_data)) + return -EADDRNOTAVAIL; + + /* ISSUE: Note that "dev_addr" is now a pointer. */ + memcpy(dev->dev_addr, addr->sa_data, dev->addr_len); + + return 0; +} + + +/* + * Obtain the MAC address from the hypervisor. + * This must be done before opening the device. + */ +static int tile_net_get_mac(struct net_device *dev) +{ + struct tile_net_priv *priv = netdev_priv(dev); + + char hv_dev_name[32]; + int len; + + __netio_getset_offset_t offset = { .word = NETIO_IPP_PARAM_OFF }; + + int ret; + + /* For example, "xgbe0". */ + strcpy(hv_dev_name, dev->name); + len = strlen(hv_dev_name); + + /* For example, "xgbe/0". */ + hv_dev_name[len] = hv_dev_name[len - 1]; + hv_dev_name[len - 1] = '/'; + len++; + + /* For example, "xgbe/0/native_hash". */ + strcpy(hv_dev_name + len, hash_default ? "/native_hash" : "/native"); + + /* Get the hypervisor handle for this device. */ + priv->hv_devhdl = hv_dev_open((HV_VirtAddr)hv_dev_name, 0); + PDEBUG("hv_dev_open(%s) returned %d %p\n", + hv_dev_name, priv->hv_devhdl, &priv->hv_devhdl); + if (priv->hv_devhdl < 0) { + if (priv->hv_devhdl == HV_ENODEV) + printk(KERN_DEBUG "Ignoring unconfigured device %s\n", + hv_dev_name); + else + printk(KERN_DEBUG "hv_dev_open(%s) returned %d\n", + hv_dev_name, priv->hv_devhdl); + return -1; + } + + /* + * Read the hardware address from the hypervisor. + * ISSUE: Note that "dev_addr" is now a pointer. + */ + offset.bits.class = NETIO_PARAM; + offset.bits.addr = NETIO_PARAM_MAC; + ret = hv_dev_pread(priv->hv_devhdl, 0, + (HV_VirtAddr)dev->dev_addr, dev->addr_len, + offset.word); + PDEBUG("hv_dev_pread(NETIO_PARAM_MAC) returned %d\n", ret); + if (ret <= 0) { + printk(KERN_DEBUG "hv_dev_pread(NETIO_PARAM_MAC) %s failed\n", + dev->name); + /* + * Since the device is configured by the hypervisor but we + * can't get its MAC address, we are most likely running + * the simulator, so let's generate a random MAC address. + */ + eth_hw_addr_random(dev); + } + + return 0; +} + + +#ifdef CONFIG_NET_POLL_CONTROLLER +/* + * Polling 'interrupt' - used by things like netconsole to send skbs + * without having to re-enable interrupts. It's not called while + * the interrupt routine is executing. + */ +static void tile_net_netpoll(struct net_device *dev) +{ + struct tile_net_priv *priv = netdev_priv(dev); + disable_percpu_irq(priv->intr_id); + tile_net_handle_ingress_interrupt(priv->intr_id, dev); + enable_percpu_irq(priv->intr_id, 0); +} +#endif + + +static const struct net_device_ops tile_net_ops = { + .ndo_open = tile_net_open, + .ndo_stop = tile_net_stop, + .ndo_start_xmit = tile_net_tx, + .ndo_do_ioctl = tile_net_ioctl, + .ndo_get_stats64 = tile_net_get_stats64, + .ndo_change_mtu = tile_net_change_mtu, + .ndo_tx_timeout = tile_net_tx_timeout, + .ndo_set_mac_address = tile_net_set_mac_address, +#ifdef CONFIG_NET_POLL_CONTROLLER + .ndo_poll_controller = tile_net_netpoll, +#endif +}; + + +/* + * The setup function. + * + * This uses ether_setup() to assign various fields in dev, including + * setting IFF_BROADCAST and IFF_MULTICAST, then sets some extra fields. + */ +static void tile_net_setup(struct net_device *dev) +{ + netdev_features_t features = 0; + + ether_setup(dev); + dev->netdev_ops = &tile_net_ops; + dev->watchdog_timeo = TILE_NET_TIMEOUT; + dev->tx_queue_len = TILE_NET_TX_QUEUE_LEN; + dev->mtu = TILE_NET_MTU; + + features |= NETIF_F_HW_CSUM; + features |= NETIF_F_SG; + + /* We support TSO iff the HV supports sufficient frags. */ + if (LEPP_MAX_FRAGS >= 1 + MAX_SKB_FRAGS) + features |= NETIF_F_TSO; + + /* We can't support HIGHDMA without hash_default, since we need + * to be able to finv() with a VA if we don't have hash_default. + */ + if (hash_default) + features |= NETIF_F_HIGHDMA; + + dev->hw_features |= features; + dev->vlan_features |= features; + dev->features |= features; +} + + +/* + * Allocate the device structure, register the device, and obtain the + * MAC address from the hypervisor. + */ +static struct net_device *tile_net_dev_init(const char *name) +{ + int ret; + struct net_device *dev; + struct tile_net_priv *priv; + + /* + * Allocate the device structure. This allocates "priv", calls + * tile_net_setup(), and saves "name". Normally, "name" is a + * template, instantiated by register_netdev(), but not for us. + */ + dev = alloc_netdev(sizeof(*priv), name, NET_NAME_UNKNOWN, + tile_net_setup); + if (!dev) { + pr_err("alloc_netdev(%s) failed\n", name); + return NULL; + } + + priv = netdev_priv(dev); + + /* Initialize "priv". */ + + memset(priv, 0, sizeof(*priv)); + + /* Save "dev" for "tile_net_open_retry()". */ + priv->dev = dev; + + INIT_DELAYED_WORK(&priv->retry_work, tile_net_open_retry); + + spin_lock_init(&priv->eq_lock); + + /* Allocate "eq". */ + priv->eq_pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, EQ_ORDER); + if (!priv->eq_pages) { + free_netdev(dev); + return NULL; + } + priv->eq = page_address(priv->eq_pages); + + /* Register the network device. */ + ret = register_netdev(dev); + if (ret) { + pr_err("register_netdev %s failed %d\n", dev->name, ret); + __free_pages(priv->eq_pages, EQ_ORDER); + free_netdev(dev); + return NULL; + } + + /* Get the MAC address. */ + ret = tile_net_get_mac(dev); + if (ret < 0) { + unregister_netdev(dev); + __free_pages(priv->eq_pages, EQ_ORDER); + free_netdev(dev); + return NULL; + } + + return dev; +} + + +/* + * Module cleanup. + * + * FIXME: If compiled as a module, this module cannot be "unloaded", + * because the "ingress interrupt handler" is registered permanently. + */ +static void tile_net_cleanup(void) +{ + int i; + + for (i = 0; i < TILE_NET_DEVS; i++) { + if (tile_net_devs[i]) { + struct net_device *dev = tile_net_devs[i]; + struct tile_net_priv *priv = netdev_priv(dev); + unregister_netdev(dev); + finv_buffer_remote(priv->eq, EQ_SIZE, 0); + __free_pages(priv->eq_pages, EQ_ORDER); + free_netdev(dev); + } + } +} + + +/* + * Module initialization. + */ +static int tile_net_init_module(void) +{ + pr_info("Tilera Network Driver\n"); + + tile_net_devs[0] = tile_net_dev_init("xgbe0"); + tile_net_devs[1] = tile_net_dev_init("xgbe1"); + tile_net_devs[2] = tile_net_dev_init("gbe0"); + tile_net_devs[3] = tile_net_dev_init("gbe1"); + + return 0; +} + + +module_init(tile_net_init_module); +module_exit(tile_net_cleanup); + + +#ifndef MODULE + +/* + * The "network_cpus" boot argument specifies the cpus that are dedicated + * to handle ingress packets. + * + * The parameter should be in the form "network_cpus=m-n[,x-y]", where + * m, n, x, y are integer numbers that represent the cpus that can be + * neither a dedicated cpu nor a dataplane cpu. + */ +static int __init network_cpus_setup(char *str) +{ + int rc = cpulist_parse_crop(str, &network_cpus_map); + if (rc != 0) { + pr_warn("network_cpus=%s: malformed cpu list\n", str); + } else { + + /* Remove dedicated cpus. */ + cpumask_and(&network_cpus_map, &network_cpus_map, + cpu_possible_mask); + + + if (cpumask_empty(&network_cpus_map)) { + pr_warn("Ignoring network_cpus='%s'\n", str); + } else { + pr_info("Linux network CPUs: %*pbl\n", + cpumask_pr_args(&network_cpus_map)); + network_cpus_used = true; + } + } + + return 0; +} +__setup("network_cpus=", network_cpus_setup); + +#endif |