diff options
Diffstat (limited to 'drivers/ntb/ntb_transport.c')
| -rw-r--r-- | drivers/ntb/ntb_transport.c | 1776 |
1 files changed, 1776 insertions, 0 deletions
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c new file mode 100644 index 000000000..e9bf2f47b --- /dev/null +++ b/drivers/ntb/ntb_transport.c @@ -0,0 +1,1776 @@ +/* + * This file is provided under a dual BSD/GPLv2 license. When using or + * redistributing this file, you may do so under either license. + * + * GPL LICENSE SUMMARY + * + * Copyright(c) 2012 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * BSD LICENSE + * + * Copyright(c) 2012 Intel Corporation. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copy + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Intel Corporation nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Intel PCIe NTB Linux driver + * + * Contact Information: + * Jon Mason <jon.mason@intel.com> + */ +#include <linux/debugfs.h> +#include <linux/delay.h> +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> +#include <linux/errno.h> +#include <linux/export.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/slab.h> +#include <linux/types.h> +#include "ntb_hw.h" + +#define NTB_TRANSPORT_VERSION 3 + +static unsigned int transport_mtu = 0x401E; +module_param(transport_mtu, uint, 0644); +MODULE_PARM_DESC(transport_mtu, "Maximum size of NTB transport packets"); + +static unsigned char max_num_clients; +module_param(max_num_clients, byte, 0644); +MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients"); + +static unsigned int copy_bytes = 1024; +module_param(copy_bytes, uint, 0644); +MODULE_PARM_DESC(copy_bytes, "Threshold under which NTB will use the CPU to copy instead of DMA"); + +struct ntb_queue_entry { + /* ntb_queue list reference */ + struct list_head entry; + /* pointers to data to be transfered */ + void *cb_data; + void *buf; + unsigned int len; + unsigned int flags; + + struct ntb_transport_qp *qp; + union { + struct ntb_payload_header __iomem *tx_hdr; + struct ntb_payload_header *rx_hdr; + }; + unsigned int index; +}; + +struct ntb_rx_info { + unsigned int entry; +}; + +struct ntb_transport_qp { + struct ntb_transport *transport; + struct ntb_device *ndev; + void *cb_data; + struct dma_chan *dma_chan; + + bool client_ready; + bool qp_link; + u8 qp_num; /* Only 64 QP's are allowed. 0-63 */ + + struct ntb_rx_info __iomem *rx_info; + struct ntb_rx_info *remote_rx_info; + + void (*tx_handler)(struct ntb_transport_qp *qp, void *qp_data, + void *data, int len); + struct list_head tx_free_q; + spinlock_t ntb_tx_free_q_lock; + void __iomem *tx_mw; + dma_addr_t tx_mw_phys; + unsigned int tx_index; + unsigned int tx_max_entry; + unsigned int tx_max_frame; + + void (*rx_handler)(struct ntb_transport_qp *qp, void *qp_data, + void *data, int len); + struct list_head rx_pend_q; + struct list_head rx_free_q; + spinlock_t ntb_rx_pend_q_lock; + spinlock_t ntb_rx_free_q_lock; + void *rx_buff; + unsigned int rx_index; + unsigned int rx_max_entry; + unsigned int rx_max_frame; + dma_cookie_t last_cookie; + + void (*event_handler)(void *data, int status); + struct delayed_work link_work; + struct work_struct link_cleanup; + + struct dentry *debugfs_dir; + struct dentry *debugfs_stats; + + /* Stats */ + u64 rx_bytes; + u64 rx_pkts; + u64 rx_ring_empty; + u64 rx_err_no_buf; + u64 rx_err_oflow; + u64 rx_err_ver; + u64 rx_memcpy; + u64 rx_async; + u64 tx_bytes; + u64 tx_pkts; + u64 tx_ring_full; + u64 tx_err_no_buf; + u64 tx_memcpy; + u64 tx_async; +}; + +struct ntb_transport_mw { + size_t size; + void *virt_addr; + dma_addr_t dma_addr; +}; + +struct ntb_transport_client_dev { + struct list_head entry; + struct device dev; +}; + +struct ntb_transport { + struct list_head entry; + struct list_head client_devs; + + struct ntb_device *ndev; + struct ntb_transport_mw *mw; + struct ntb_transport_qp *qps; + unsigned int max_qps; + unsigned long qp_bitmap; + bool transport_link; + struct delayed_work link_work; + struct work_struct link_cleanup; +}; + +enum { + DESC_DONE_FLAG = 1 << 0, + LINK_DOWN_FLAG = 1 << 1, +}; + +struct ntb_payload_header { + unsigned int ver; + unsigned int len; + unsigned int flags; +}; + +enum { + VERSION = 0, + QP_LINKS, + NUM_QPS, + NUM_MWS, + MW0_SZ_HIGH, + MW0_SZ_LOW, + MW1_SZ_HIGH, + MW1_SZ_LOW, + MAX_SPAD, +}; + +#define QP_TO_MW(ndev, qp) ((qp) % ntb_max_mw(ndev)) +#define NTB_QP_DEF_NUM_ENTRIES 100 +#define NTB_LINK_DOWN_TIMEOUT 10 + +static int ntb_match_bus(struct device *dev, struct device_driver *drv) +{ + return !strncmp(dev_name(dev), drv->name, strlen(drv->name)); +} + +static int ntb_client_probe(struct device *dev) +{ + const struct ntb_client *drv = container_of(dev->driver, + struct ntb_client, driver); + struct pci_dev *pdev = container_of(dev->parent, struct pci_dev, dev); + int rc = -EINVAL; + + get_device(dev); + if (drv && drv->probe) + rc = drv->probe(pdev); + if (rc) + put_device(dev); + + return rc; +} + +static int ntb_client_remove(struct device *dev) +{ + const struct ntb_client *drv = container_of(dev->driver, + struct ntb_client, driver); + struct pci_dev *pdev = container_of(dev->parent, struct pci_dev, dev); + + if (drv && drv->remove) + drv->remove(pdev); + + put_device(dev); + + return 0; +} + +static struct bus_type ntb_bus_type = { + .name = "ntb_bus", + .match = ntb_match_bus, + .probe = ntb_client_probe, + .remove = ntb_client_remove, +}; + +static LIST_HEAD(ntb_transport_list); + +static int ntb_bus_init(struct ntb_transport *nt) +{ + if (list_empty(&ntb_transport_list)) { + int rc = bus_register(&ntb_bus_type); + if (rc) + return rc; + } + + list_add(&nt->entry, &ntb_transport_list); + + return 0; +} + +static void ntb_bus_remove(struct ntb_transport *nt) +{ + struct ntb_transport_client_dev *client_dev, *cd; + + list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) { + dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n", + dev_name(&client_dev->dev)); + list_del(&client_dev->entry); + device_unregister(&client_dev->dev); + } + + list_del(&nt->entry); + + if (list_empty(&ntb_transport_list)) + bus_unregister(&ntb_bus_type); +} + +static void ntb_client_release(struct device *dev) +{ + struct ntb_transport_client_dev *client_dev; + client_dev = container_of(dev, struct ntb_transport_client_dev, dev); + + kfree(client_dev); +} + +/** + * ntb_unregister_client_dev - Unregister NTB client device + * @device_name: Name of NTB client device + * + * Unregister an NTB client device with the NTB transport layer + */ +void ntb_unregister_client_dev(char *device_name) +{ + struct ntb_transport_client_dev *client, *cd; + struct ntb_transport *nt; + + list_for_each_entry(nt, &ntb_transport_list, entry) + list_for_each_entry_safe(client, cd, &nt->client_devs, entry) + if (!strncmp(dev_name(&client->dev), device_name, + strlen(device_name))) { + list_del(&client->entry); + device_unregister(&client->dev); + } +} +EXPORT_SYMBOL_GPL(ntb_unregister_client_dev); + +/** + * ntb_register_client_dev - Register NTB client device + * @device_name: Name of NTB client device + * + * Register an NTB client device with the NTB transport layer + */ +int ntb_register_client_dev(char *device_name) +{ + struct ntb_transport_client_dev *client_dev; + struct ntb_transport *nt; + int rc, i = 0; + + if (list_empty(&ntb_transport_list)) + return -ENODEV; + + list_for_each_entry(nt, &ntb_transport_list, entry) { + struct device *dev; + + client_dev = kzalloc(sizeof(struct ntb_transport_client_dev), + GFP_KERNEL); + if (!client_dev) { + rc = -ENOMEM; + goto err; + } + + dev = &client_dev->dev; + + /* setup and register client devices */ + dev_set_name(dev, "%s%d", device_name, i); + dev->bus = &ntb_bus_type; + dev->release = ntb_client_release; + dev->parent = &ntb_query_pdev(nt->ndev)->dev; + + rc = device_register(dev); + if (rc) { + kfree(client_dev); + goto err; + } + + list_add_tail(&client_dev->entry, &nt->client_devs); + i++; + } + + return 0; + +err: + ntb_unregister_client_dev(device_name); + + return rc; +} +EXPORT_SYMBOL_GPL(ntb_register_client_dev); + +/** + * ntb_register_client - Register NTB client driver + * @drv: NTB client driver to be registered + * + * Register an NTB client driver with the NTB transport layer + * + * RETURNS: An appropriate -ERRNO error value on error, or zero for success. + */ +int ntb_register_client(struct ntb_client *drv) +{ + drv->driver.bus = &ntb_bus_type; + + if (list_empty(&ntb_transport_list)) + return -ENODEV; + + return driver_register(&drv->driver); +} +EXPORT_SYMBOL_GPL(ntb_register_client); + +/** + * ntb_unregister_client - Unregister NTB client driver + * @drv: NTB client driver to be unregistered + * + * Unregister an NTB client driver with the NTB transport layer + * + * RETURNS: An appropriate -ERRNO error value on error, or zero for success. + */ +void ntb_unregister_client(struct ntb_client *drv) +{ + driver_unregister(&drv->driver); +} +EXPORT_SYMBOL_GPL(ntb_unregister_client); + +static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count, + loff_t *offp) +{ + struct ntb_transport_qp *qp; + char *buf; + ssize_t ret, out_offset, out_count; + + out_count = 1000; + + buf = kmalloc(out_count, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + qp = filp->private_data; + out_offset = 0; + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "NTB QP stats\n"); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "rx_bytes - \t%llu\n", qp->rx_bytes); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "rx_pkts - \t%llu\n", qp->rx_pkts); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "rx_memcpy - \t%llu\n", qp->rx_memcpy); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "rx_async - \t%llu\n", qp->rx_async); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "rx_ring_empty - %llu\n", qp->rx_ring_empty); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "rx_err_no_buf - %llu\n", qp->rx_err_no_buf); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "rx_err_oflow - \t%llu\n", qp->rx_err_oflow); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "rx_err_ver - \t%llu\n", qp->rx_err_ver); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "rx_buff - \t%p\n", qp->rx_buff); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "rx_index - \t%u\n", qp->rx_index); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "rx_max_entry - \t%u\n", qp->rx_max_entry); + + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "tx_bytes - \t%llu\n", qp->tx_bytes); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "tx_pkts - \t%llu\n", qp->tx_pkts); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "tx_memcpy - \t%llu\n", qp->tx_memcpy); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "tx_async - \t%llu\n", qp->tx_async); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "tx_ring_full - \t%llu\n", qp->tx_ring_full); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "tx_err_no_buf - %llu\n", qp->tx_err_no_buf); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "tx_mw - \t%p\n", qp->tx_mw); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "tx_index - \t%u\n", qp->tx_index); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "tx_max_entry - \t%u\n", qp->tx_max_entry); + + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "\nQP Link %s\n", (qp->qp_link == NTB_LINK_UP) ? + "Up" : "Down"); + if (out_offset > out_count) + out_offset = out_count; + + ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset); + kfree(buf); + return ret; +} + +static const struct file_operations ntb_qp_debugfs_stats = { + .owner = THIS_MODULE, + .open = simple_open, + .read = debugfs_read, +}; + +static void ntb_list_add(spinlock_t *lock, struct list_head *entry, + struct list_head *list) +{ + unsigned long flags; + + spin_lock_irqsave(lock, flags); + list_add_tail(entry, list); + spin_unlock_irqrestore(lock, flags); +} + +static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock, + struct list_head *list) +{ + struct ntb_queue_entry *entry; + unsigned long flags; + + spin_lock_irqsave(lock, flags); + if (list_empty(list)) { + entry = NULL; + goto out; + } + entry = list_first_entry(list, struct ntb_queue_entry, entry); + list_del(&entry->entry); +out: + spin_unlock_irqrestore(lock, flags); + + return entry; +} + +static void ntb_transport_setup_qp_mw(struct ntb_transport *nt, + unsigned int qp_num) +{ + struct ntb_transport_qp *qp = &nt->qps[qp_num]; + unsigned int rx_size, num_qps_mw; + u8 mw_num, mw_max; + unsigned int i; + + mw_max = ntb_max_mw(nt->ndev); + mw_num = QP_TO_MW(nt->ndev, qp_num); + + WARN_ON(nt->mw[mw_num].virt_addr == NULL); + + if (nt->max_qps % mw_max && mw_num + 1 < nt->max_qps / mw_max) + num_qps_mw = nt->max_qps / mw_max + 1; + else + num_qps_mw = nt->max_qps / mw_max; + + rx_size = (unsigned int) nt->mw[mw_num].size / num_qps_mw; + qp->rx_buff = nt->mw[mw_num].virt_addr + qp_num / mw_max * rx_size; + rx_size -= sizeof(struct ntb_rx_info); + + qp->remote_rx_info = qp->rx_buff + rx_size; + + /* Due to housekeeping, there must be atleast 2 buffs */ + qp->rx_max_frame = min(transport_mtu, rx_size / 2); + qp->rx_max_entry = rx_size / qp->rx_max_frame; + qp->rx_index = 0; + + qp->remote_rx_info->entry = qp->rx_max_entry - 1; + + /* setup the hdr offsets with 0's */ + for (i = 0; i < qp->rx_max_entry; i++) { + void *offset = qp->rx_buff + qp->rx_max_frame * (i + 1) - + sizeof(struct ntb_payload_header); + memset(offset, 0, sizeof(struct ntb_payload_header)); + } + + qp->rx_pkts = 0; + qp->tx_pkts = 0; + qp->tx_index = 0; +} + +static void ntb_free_mw(struct ntb_transport *nt, int num_mw) +{ + struct ntb_transport_mw *mw = &nt->mw[num_mw]; + struct pci_dev *pdev = ntb_query_pdev(nt->ndev); + + if (!mw->virt_addr) + return; + + dma_free_coherent(&pdev->dev, mw->size, mw->virt_addr, mw->dma_addr); + mw->virt_addr = NULL; +} + +static int ntb_set_mw(struct ntb_transport *nt, int num_mw, unsigned int size) +{ + struct ntb_transport_mw *mw = &nt->mw[num_mw]; + struct pci_dev *pdev = ntb_query_pdev(nt->ndev); + + /* No need to re-setup */ + if (mw->size == ALIGN(size, 4096)) + return 0; + + if (mw->size != 0) + ntb_free_mw(nt, num_mw); + + /* Alloc memory for receiving data. Must be 4k aligned */ + mw->size = ALIGN(size, 4096); + + mw->virt_addr = dma_alloc_coherent(&pdev->dev, mw->size, &mw->dma_addr, + GFP_KERNEL); + if (!mw->virt_addr) { + mw->size = 0; + dev_err(&pdev->dev, "Unable to allocate MW buffer of size %d\n", + (int) mw->size); + return -ENOMEM; + } + + /* + * we must ensure that the memory address allocated is BAR size + * aligned in order for the XLAT register to take the value. This + * is a requirement of the hardware. It is recommended to setup CMA + * for BAR sizes equal or greater than 4MB. + */ + if (!IS_ALIGNED(mw->dma_addr, mw->size)) { + dev_err(&pdev->dev, "DMA memory %pad not aligned to BAR size\n", + &mw->dma_addr); + ntb_free_mw(nt, num_mw); + return -ENOMEM; + } + + /* Notify HW the memory location of the receive buffer */ + ntb_set_mw_addr(nt->ndev, num_mw, mw->dma_addr); + + return 0; +} + +static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp) +{ + struct ntb_transport *nt = qp->transport; + struct pci_dev *pdev = ntb_query_pdev(nt->ndev); + + if (qp->qp_link == NTB_LINK_DOWN) { + cancel_delayed_work_sync(&qp->link_work); + return; + } + + if (qp->event_handler) + qp->event_handler(qp->cb_data, NTB_LINK_DOWN); + + dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num); + qp->qp_link = NTB_LINK_DOWN; +} + +static void ntb_qp_link_cleanup_work(struct work_struct *work) +{ + struct ntb_transport_qp *qp = container_of(work, + struct ntb_transport_qp, + link_cleanup); + struct ntb_transport *nt = qp->transport; + + ntb_qp_link_cleanup(qp); + + if (nt->transport_link == NTB_LINK_UP) + schedule_delayed_work(&qp->link_work, + msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT)); +} + +static void ntb_qp_link_down(struct ntb_transport_qp *qp) +{ + schedule_work(&qp->link_cleanup); +} + +static void ntb_transport_link_cleanup(struct ntb_transport *nt) +{ + int i; + + /* Pass along the info to any clients */ + for (i = 0; i < nt->max_qps; i++) + if (!test_bit(i, &nt->qp_bitmap)) + ntb_qp_link_cleanup(&nt->qps[i]); + + if (nt->transport_link == NTB_LINK_DOWN) + cancel_delayed_work_sync(&nt->link_work); + else + nt->transport_link = NTB_LINK_DOWN; + + /* The scratchpad registers keep the values if the remote side + * goes down, blast them now to give them a sane value the next + * time they are accessed + */ + for (i = 0; i < MAX_SPAD; i++) + ntb_write_local_spad(nt->ndev, i, 0); +} + +static void ntb_transport_link_cleanup_work(struct work_struct *work) +{ + struct ntb_transport *nt = container_of(work, struct ntb_transport, + link_cleanup); + + ntb_transport_link_cleanup(nt); +} + +static void ntb_transport_event_callback(void *data, enum ntb_hw_event event) +{ + struct ntb_transport *nt = data; + + switch (event) { + case NTB_EVENT_HW_LINK_UP: + schedule_delayed_work(&nt->link_work, 0); + break; + case NTB_EVENT_HW_LINK_DOWN: + schedule_work(&nt->link_cleanup); + break; + default: + BUG(); + } +} + +static void ntb_transport_link_work(struct work_struct *work) +{ + struct ntb_transport *nt = container_of(work, struct ntb_transport, + link_work.work); + struct ntb_device *ndev = nt->ndev; + struct pci_dev *pdev = ntb_query_pdev(ndev); + u32 val; + int rc, i; + + /* send the local info, in the opposite order of the way we read it */ + for (i = 0; i < ntb_max_mw(ndev); i++) { + rc = ntb_write_remote_spad(ndev, MW0_SZ_HIGH + (i * 2), + ntb_get_mw_size(ndev, i) >> 32); + if (rc) { + dev_err(&pdev->dev, "Error writing %u to remote spad %d\n", + (u32)(ntb_get_mw_size(ndev, i) >> 32), + MW0_SZ_HIGH + (i * 2)); + goto out; + } + + rc = ntb_write_remote_spad(ndev, MW0_SZ_LOW + (i * 2), + (u32) ntb_get_mw_size(ndev, i)); + if (rc) { + dev_err(&pdev->dev, "Error writing %u to remote spad %d\n", + (u32) ntb_get_mw_size(ndev, i), + MW0_SZ_LOW + (i * 2)); + goto out; + } + } + + rc = ntb_write_remote_spad(ndev, NUM_MWS, ntb_max_mw(ndev)); + if (rc) { + dev_err(&pdev->dev, "Error writing %x to remote spad %d\n", + ntb_max_mw(ndev), NUM_MWS); + goto out; + } + + rc = ntb_write_remote_spad(ndev, NUM_QPS, nt->max_qps); + if (rc) { + dev_err(&pdev->dev, "Error writing %x to remote spad %d\n", + nt->max_qps, NUM_QPS); + goto out; + } + + rc = ntb_write_remote_spad(ndev, VERSION, NTB_TRANSPORT_VERSION); + if (rc) { + dev_err(&pdev->dev, "Error writing %x to remote spad %d\n", + NTB_TRANSPORT_VERSION, VERSION); + goto out; + } + + /* Query the remote side for its info */ + rc = ntb_read_remote_spad(ndev, VERSION, &val); + if (rc) { + dev_err(&pdev->dev, "Error reading remote spad %d\n", VERSION); + goto out; + } + + if (val != NTB_TRANSPORT_VERSION) + goto out; + dev_dbg(&pdev->dev, "Remote version = %d\n", val); + + rc = ntb_read_remote_spad(ndev, NUM_QPS, &val); + if (rc) { + dev_err(&pdev->dev, "Error reading remote spad %d\n", NUM_QPS); + goto out; + } + + if (val != nt->max_qps) + goto out; + dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val); + + rc = ntb_read_remote_spad(ndev, NUM_MWS, &val); + if (rc) { + dev_err(&pdev->dev, "Error reading remote spad %d\n", NUM_MWS); + goto out; + } + + if (val != ntb_max_mw(ndev)) + goto out; + dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val); + + for (i = 0; i < ntb_max_mw(ndev); i++) { + u64 val64; + + rc = ntb_read_remote_spad(ndev, MW0_SZ_HIGH + (i * 2), &val); + if (rc) { + dev_err(&pdev->dev, "Error reading remote spad %d\n", + MW0_SZ_HIGH + (i * 2)); + goto out1; + } + + val64 = (u64) val << 32; + + rc = ntb_read_remote_spad(ndev, MW0_SZ_LOW + (i * 2), &val); + if (rc) { + dev_err(&pdev->dev, "Error reading remote spad %d\n", + MW0_SZ_LOW + (i * 2)); + goto out1; + } + + val64 |= val; + + dev_dbg(&pdev->dev, "Remote MW%d size = %llu\n", i, val64); + + rc = ntb_set_mw(nt, i, val64); + if (rc) + goto out1; + } + + nt->transport_link = NTB_LINK_UP; + + for (i = 0; i < nt->max_qps; i++) { + struct ntb_transport_qp *qp = &nt->qps[i]; + + ntb_transport_setup_qp_mw(nt, i); + + if (qp->client_ready == NTB_LINK_UP) + schedule_delayed_work(&qp->link_work, 0); + } + + return; + +out1: + for (i = 0; i < ntb_max_mw(ndev); i++) + ntb_free_mw(nt, i); +out: + if (ntb_hw_link_status(ndev)) + schedule_delayed_work(&nt->link_work, + msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT)); +} + +static void ntb_qp_link_work(struct work_struct *work) +{ + struct ntb_transport_qp *qp = container_of(work, + struct ntb_transport_qp, + link_work.work); + struct pci_dev *pdev = ntb_query_pdev(qp->ndev); + struct ntb_transport *nt = qp->transport; + int rc, val; + + WARN_ON(nt->transport_link != NTB_LINK_UP); + + rc = ntb_read_local_spad(nt->ndev, QP_LINKS, &val); + if (rc) { + dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS); + return; + } + + rc = ntb_write_remote_spad(nt->ndev, QP_LINKS, val | 1 << qp->qp_num); + if (rc) + dev_err(&pdev->dev, "Error writing %x to remote spad %d\n", + val | 1 << qp->qp_num, QP_LINKS); + + /* query remote spad for qp ready bits */ + rc = ntb_read_remote_spad(nt->ndev, QP_LINKS, &val); + if (rc) + dev_err(&pdev->dev, "Error reading remote spad %d\n", QP_LINKS); + + dev_dbg(&pdev->dev, "Remote QP link status = %x\n", val); + + /* See if the remote side is up */ + if (1 << qp->qp_num & val) { + qp->qp_link = NTB_LINK_UP; + + dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num); + if (qp->event_handler) + qp->event_handler(qp->cb_data, NTB_LINK_UP); + } else if (nt->transport_link == NTB_LINK_UP) + schedule_delayed_work(&qp->link_work, + msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT)); +} + +static int ntb_transport_init_queue(struct ntb_transport *nt, + unsigned int qp_num) +{ + struct ntb_transport_qp *qp; + unsigned int num_qps_mw, tx_size; + u8 mw_num, mw_max; + u64 qp_offset; + + mw_max = ntb_max_mw(nt->ndev); + mw_num = QP_TO_MW(nt->ndev, qp_num); + + qp = &nt->qps[qp_num]; + qp->qp_num = qp_num; + qp->transport = nt; + qp->ndev = nt->ndev; + qp->qp_link = NTB_LINK_DOWN; + qp->client_ready = NTB_LINK_DOWN; + qp->event_handler = NULL; + + if (nt->max_qps % mw_max && mw_num + 1 < nt->max_qps / mw_max) + num_qps_mw = nt->max_qps / mw_max + 1; + else + num_qps_mw = nt->max_qps / mw_max; + + tx_size = (unsigned int) ntb_get_mw_size(qp->ndev, mw_num) / num_qps_mw; + qp_offset = qp_num / mw_max * tx_size; + qp->tx_mw = ntb_get_mw_vbase(nt->ndev, mw_num) + qp_offset; + if (!qp->tx_mw) + return -EINVAL; + + qp->tx_mw_phys = ntb_get_mw_base(qp->ndev, mw_num) + qp_offset; + if (!qp->tx_mw_phys) + return -EINVAL; + + tx_size -= sizeof(struct ntb_rx_info); + qp->rx_info = qp->tx_mw + tx_size; + + /* Due to housekeeping, there must be atleast 2 buffs */ + qp->tx_max_frame = min(transport_mtu, tx_size / 2); + qp->tx_max_entry = tx_size / qp->tx_max_frame; + + if (ntb_query_debugfs(nt->ndev)) { + char debugfs_name[4]; + + snprintf(debugfs_name, 4, "qp%d", qp_num); + qp->debugfs_dir = debugfs_create_dir(debugfs_name, + ntb_query_debugfs(nt->ndev)); + + qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR, + qp->debugfs_dir, qp, + &ntb_qp_debugfs_stats); + } + + INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work); + INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup_work); + + spin_lock_init(&qp->ntb_rx_pend_q_lock); + spin_lock_init(&qp->ntb_rx_free_q_lock); + spin_lock_init(&qp->ntb_tx_free_q_lock); + + INIT_LIST_HEAD(&qp->rx_pend_q); + INIT_LIST_HEAD(&qp->rx_free_q); + INIT_LIST_HEAD(&qp->tx_free_q); + + return 0; +} + +int ntb_transport_init(struct pci_dev *pdev) +{ + struct ntb_transport *nt; + int rc, i; + + nt = kzalloc(sizeof(struct ntb_transport), GFP_KERNEL); + if (!nt) + return -ENOMEM; + + nt->ndev = ntb_register_transport(pdev, nt); + if (!nt->ndev) { + rc = -EIO; + goto err; + } + + nt->mw = kcalloc(ntb_max_mw(nt->ndev), sizeof(struct ntb_transport_mw), + GFP_KERNEL); + if (!nt->mw) { + rc = -ENOMEM; + goto err1; + } + + if (max_num_clients) + nt->max_qps = min(ntb_max_cbs(nt->ndev), max_num_clients); + else + nt->max_qps = min(ntb_max_cbs(nt->ndev), ntb_max_mw(nt->ndev)); + + nt->qps = kcalloc(nt->max_qps, sizeof(struct ntb_transport_qp), + GFP_KERNEL); + if (!nt->qps) { + rc = -ENOMEM; + goto err2; + } + + nt->qp_bitmap = ((u64) 1 << nt->max_qps) - 1; + + for (i = 0; i < nt->max_qps; i++) { + rc = ntb_transport_init_queue(nt, i); + if (rc) + goto err3; + } + + INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work); + INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work); + + rc = ntb_register_event_callback(nt->ndev, + ntb_transport_event_callback); + if (rc) + goto err3; + + INIT_LIST_HEAD(&nt->client_devs); + rc = ntb_bus_init(nt); + if (rc) + goto err4; + + if (ntb_hw_link_status(nt->ndev)) + schedule_delayed_work(&nt->link_work, 0); + + return 0; + +err4: + ntb_unregister_event_callback(nt->ndev); +err3: + kfree(nt->qps); +err2: + kfree(nt->mw); +err1: + ntb_unregister_transport(nt->ndev); +err: + kfree(nt); + return rc; +} + +void ntb_transport_free(void *transport) +{ + struct ntb_transport *nt = transport; + struct ntb_device *ndev = nt->ndev; + int i; + + ntb_transport_link_cleanup(nt); + + /* verify that all the qp's are freed */ + for (i = 0; i < nt->max_qps; i++) { + if (!test_bit(i, &nt->qp_bitmap)) + ntb_transport_free_queue(&nt->qps[i]); + debugfs_remove_recursive(nt->qps[i].debugfs_dir); + } + + ntb_bus_remove(nt); + + cancel_delayed_work_sync(&nt->link_work); + + ntb_unregister_event_callback(ndev); + + for (i = 0; i < ntb_max_mw(ndev); i++) + ntb_free_mw(nt, i); + + kfree(nt->qps); + kfree(nt->mw); + ntb_unregister_transport(ndev); + kfree(nt); +} + +static void ntb_rx_copy_callback(void *data) +{ + struct ntb_queue_entry *entry = data; + struct ntb_transport_qp *qp = entry->qp; + void *cb_data = entry->cb_data; + unsigned int len = entry->len; + struct ntb_payload_header *hdr = entry->rx_hdr; + + /* Ensure that the data is fully copied out before clearing the flag */ + wmb(); + hdr->flags = 0; + + iowrite32(entry->index, &qp->rx_info->entry); + + ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q); + + if (qp->rx_handler && qp->client_ready == NTB_LINK_UP) + qp->rx_handler(qp, qp->cb_data, cb_data, len); +} + +static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset) +{ + void *buf = entry->buf; + size_t len = entry->len; + + memcpy(buf, offset, len); + + ntb_rx_copy_callback(entry); +} + +static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset, + size_t len) +{ + struct dma_async_tx_descriptor *txd; + struct ntb_transport_qp *qp = entry->qp; + struct dma_chan *chan = qp->dma_chan; + struct dma_device *device; + size_t pay_off, buff_off; + struct dmaengine_unmap_data *unmap; + dma_cookie_t cookie; + void *buf = entry->buf; + + entry->len = len; + + if (!chan) + goto err; + + if (len < copy_bytes) + goto err_wait; + + device = chan->device; + pay_off = (size_t) offset & ~PAGE_MASK; + buff_off = (size_t) buf & ~PAGE_MASK; + + if (!is_dma_copy_aligned(device, pay_off, buff_off, len)) + goto err_wait; + + unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT); + if (!unmap) + goto err_wait; + + unmap->len = len; + unmap->addr[0] = dma_map_page(device->dev, virt_to_page(offset), + pay_off, len, DMA_TO_DEVICE); + if (dma_mapping_error(device->dev, unmap->addr[0])) + goto err_get_unmap; + + unmap->to_cnt = 1; + + unmap->addr[1] = dma_map_page(device->dev, virt_to_page(buf), + buff_off, len, DMA_FROM_DEVICE); + if (dma_mapping_error(device->dev, unmap->addr[1])) + goto err_get_unmap; + + unmap->from_cnt = 1; + + txd = device->device_prep_dma_memcpy(chan, unmap->addr[1], + unmap->addr[0], len, + DMA_PREP_INTERRUPT); + if (!txd) + goto err_get_unmap; + + txd->callback = ntb_rx_copy_callback; + txd->callback_param = entry; + dma_set_unmap(txd, unmap); + + cookie = dmaengine_submit(txd); + if (dma_submit_error(cookie)) + goto err_set_unmap; + + dmaengine_unmap_put(unmap); + + qp->last_cookie = cookie; + + qp->rx_async++; + + return; + +err_set_unmap: + dmaengine_unmap_put(unmap); +err_get_unmap: + dmaengine_unmap_put(unmap); +err_wait: + /* If the callbacks come out of order, the writing of the index to the + * last completed will be out of order. This may result in the + * receive stalling forever. + */ + dma_sync_wait(chan, qp->last_cookie); +err: + ntb_memcpy_rx(entry, offset); + qp->rx_memcpy++; +} + +static int ntb_process_rxc(struct ntb_transport_qp *qp) +{ + struct ntb_payload_header *hdr; + struct ntb_queue_entry *entry; + void *offset; + + offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index; + hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header); + + entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q); + if (!entry) { + dev_dbg(&ntb_query_pdev(qp->ndev)->dev, + "no buffer - HDR ver %u, len %d, flags %x\n", + hdr->ver, hdr->len, hdr->flags); + qp->rx_err_no_buf++; + return -ENOMEM; + } + + if (!(hdr->flags & DESC_DONE_FLAG)) { + ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry, + &qp->rx_pend_q); + qp->rx_ring_empty++; + return -EAGAIN; + } + + if (hdr->ver != (u32) qp->rx_pkts) { + dev_dbg(&ntb_query_pdev(qp->ndev)->dev, + "qp %d: version mismatch, expected %llu - got %u\n", + qp->qp_num, qp->rx_pkts, hdr->ver); + ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry, + &qp->rx_pend_q); + qp->rx_err_ver++; + return -EIO; + } + + if (hdr->flags & LINK_DOWN_FLAG) { + ntb_qp_link_down(qp); + + goto err; + } + + dev_dbg(&ntb_query_pdev(qp->ndev)->dev, + "rx offset %u, ver %u - %d payload received, buf size %d\n", + qp->rx_index, hdr->ver, hdr->len, entry->len); + + qp->rx_bytes += hdr->len; + qp->rx_pkts++; + + if (hdr->len > entry->len) { + qp->rx_err_oflow++; + dev_dbg(&ntb_query_pdev(qp->ndev)->dev, + "RX overflow! Wanted %d got %d\n", + hdr->len, entry->len); + + goto err; + } + + entry->index = qp->rx_index; + entry->rx_hdr = hdr; + + ntb_async_rx(entry, offset, hdr->len); + +out: + qp->rx_index++; + qp->rx_index %= qp->rx_max_entry; + + return 0; + +err: + ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry, &qp->rx_pend_q); + /* Ensure that the data is fully copied out before clearing the flag */ + wmb(); + hdr->flags = 0; + iowrite32(qp->rx_index, &qp->rx_info->entry); + + goto out; +} + +static int ntb_transport_rxc_db(void *data, int db_num) +{ + struct ntb_transport_qp *qp = data; + int rc, i; + + dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%s: doorbell %d received\n", + __func__, db_num); + + /* Limit the number of packets processed in a single interrupt to + * provide fairness to others + */ + for (i = 0; i < qp->rx_max_entry; i++) { + rc = ntb_process_rxc(qp); + if (rc) + break; + } + + if (qp->dma_chan) + dma_async_issue_pending(qp->dma_chan); + + return i; +} + +static void ntb_tx_copy_callback(void *data) +{ + struct ntb_queue_entry *entry = data; + struct ntb_transport_qp *qp = entry->qp; + struct ntb_payload_header __iomem *hdr = entry->tx_hdr; + + /* Ensure that the data is fully copied out before setting the flags */ + wmb(); + iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags); + + ntb_ring_doorbell(qp->ndev, qp->qp_num); + + /* The entry length can only be zero if the packet is intended to be a + * "link down" or similar. Since no payload is being sent in these + * cases, there is nothing to add to the completion queue. + */ + if (entry->len > 0) { + qp->tx_bytes += entry->len; + + if (qp->tx_handler) + qp->tx_handler(qp, qp->cb_data, entry->cb_data, + entry->len); + } + + ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q); +} + +static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset) +{ + memcpy_toio(offset, entry->buf, entry->len); + + ntb_tx_copy_callback(entry); +} + +static void ntb_async_tx(struct ntb_transport_qp *qp, + struct ntb_queue_entry *entry) +{ + struct ntb_payload_header __iomem *hdr; + struct dma_async_tx_descriptor *txd; + struct dma_chan *chan = qp->dma_chan; + struct dma_device *device; + size_t dest_off, buff_off; + struct dmaengine_unmap_data *unmap; + dma_addr_t dest; + dma_cookie_t cookie; + void __iomem *offset; + size_t len = entry->len; + void *buf = entry->buf; + + offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index; + hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header); + entry->tx_hdr = hdr; + + iowrite32(entry->len, &hdr->len); + iowrite32((u32) qp->tx_pkts, &hdr->ver); + + if (!chan) + goto err; + + if (len < copy_bytes) + goto err; + + device = chan->device; + dest = qp->tx_mw_phys + qp->tx_max_frame * qp->tx_index; + buff_off = (size_t) buf & ~PAGE_MASK; + dest_off = (size_t) dest & ~PAGE_MASK; + + if (!is_dma_copy_aligned(device, buff_off, dest_off, len)) + goto err; + + unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT); + if (!unmap) + goto err; + + unmap->len = len; + unmap->addr[0] = dma_map_page(device->dev, virt_to_page(buf), + buff_off, len, DMA_TO_DEVICE); + if (dma_mapping_error(device->dev, unmap->addr[0])) + goto err_get_unmap; + + unmap->to_cnt = 1; + + txd = device->device_prep_dma_memcpy(chan, dest, unmap->addr[0], len, + DMA_PREP_INTERRUPT); + if (!txd) + goto err_get_unmap; + + txd->callback = ntb_tx_copy_callback; + txd->callback_param = entry; + dma_set_unmap(txd, unmap); + + cookie = dmaengine_submit(txd); + if (dma_submit_error(cookie)) + goto err_set_unmap; + + dmaengine_unmap_put(unmap); + + dma_async_issue_pending(chan); + qp->tx_async++; + + return; +err_set_unmap: + dmaengine_unmap_put(unmap); +err_get_unmap: + dmaengine_unmap_put(unmap); +err: + ntb_memcpy_tx(entry, offset); + qp->tx_memcpy++; +} + +static int ntb_process_tx(struct ntb_transport_qp *qp, + struct ntb_queue_entry *entry) +{ + dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%lld - tx %u, entry len %d flags %x buff %p\n", + qp->tx_pkts, qp->tx_index, entry->len, entry->flags, + entry->buf); + if (qp->tx_index == qp->remote_rx_info->entry) { + qp->tx_ring_full++; + return -EAGAIN; + } + + if (entry->len > qp->tx_max_frame - sizeof(struct ntb_payload_header)) { + if (qp->tx_handler) + qp->tx_handler(qp->cb_data, qp, NULL, -EIO); + + ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, + &qp->tx_free_q); + return 0; + } + + ntb_async_tx(qp, entry); + + qp->tx_index++; + qp->tx_index %= qp->tx_max_entry; + + qp->tx_pkts++; + + return 0; +} + +static void ntb_send_link_down(struct ntb_transport_qp *qp) +{ + struct pci_dev *pdev = ntb_query_pdev(qp->ndev); + struct ntb_queue_entry *entry; + int i, rc; + + if (qp->qp_link == NTB_LINK_DOWN) + return; + + qp->qp_link = NTB_LINK_DOWN; + dev_info(&pdev->dev, "qp %d: Link Down\n", qp->qp_num); + + for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) { + entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q); + if (entry) + break; + msleep(100); + } + + if (!entry) + return; + + entry->cb_data = NULL; + entry->buf = NULL; + entry->len = 0; + entry->flags = LINK_DOWN_FLAG; + + rc = ntb_process_tx(qp, entry); + if (rc) + dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n", + qp->qp_num); +} + +/** + * ntb_transport_create_queue - Create a new NTB transport layer queue + * @rx_handler: receive callback function + * @tx_handler: transmit callback function + * @event_handler: event callback function + * + * Create a new NTB transport layer queue and provide the queue with a callback + * routine for both transmit and receive. The receive callback routine will be + * used to pass up data when the transport has received it on the queue. The + * transmit callback routine will be called when the transport has completed the + * transmission of the data on the queue and the data is ready to be freed. + * + * RETURNS: pointer to newly created ntb_queue, NULL on error. + */ +struct ntb_transport_qp * +ntb_transport_create_queue(void *data, struct pci_dev *pdev, + const struct ntb_queue_handlers *handlers) +{ + struct ntb_queue_entry *entry; + struct ntb_transport_qp *qp; + struct ntb_transport *nt; + unsigned int free_queue; + int rc, i; + + nt = ntb_find_transport(pdev); + if (!nt) + goto err; + + free_queue = ffs(nt->qp_bitmap); + if (!free_queue) + goto err; + + /* decrement free_queue to make it zero based */ + free_queue--; + + clear_bit(free_queue, &nt->qp_bitmap); + + qp = &nt->qps[free_queue]; + qp->cb_data = data; + qp->rx_handler = handlers->rx_handler; + qp->tx_handler = handlers->tx_handler; + qp->event_handler = handlers->event_handler; + + dmaengine_get(); + qp->dma_chan = dma_find_channel(DMA_MEMCPY); + if (!qp->dma_chan) { + dmaengine_put(); + dev_info(&pdev->dev, "Unable to allocate DMA channel, using CPU instead\n"); + } + + for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) { + entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC); + if (!entry) + goto err1; + + entry->qp = qp; + ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, + &qp->rx_free_q); + } + + for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) { + entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC); + if (!entry) + goto err2; + + entry->qp = qp; + ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, + &qp->tx_free_q); + } + + rc = ntb_register_db_callback(qp->ndev, free_queue, qp, + ntb_transport_rxc_db); + if (rc) + goto err2; + + dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num); + + return qp; + +err2: + while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q))) + kfree(entry); +err1: + while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q))) + kfree(entry); + if (qp->dma_chan) + dmaengine_put(); + set_bit(free_queue, &nt->qp_bitmap); +err: + return NULL; +} +EXPORT_SYMBOL_GPL(ntb_transport_create_queue); + +/** + * ntb_transport_free_queue - Frees NTB transport queue + * @qp: NTB queue to be freed + * + * Frees NTB transport queue + */ +void ntb_transport_free_queue(struct ntb_transport_qp *qp) +{ + struct pci_dev *pdev; + struct ntb_queue_entry *entry; + + if (!qp) + return; + + pdev = ntb_query_pdev(qp->ndev); + + if (qp->dma_chan) { + struct dma_chan *chan = qp->dma_chan; + /* Putting the dma_chan to NULL will force any new traffic to be + * processed by the CPU instead of the DAM engine + */ + qp->dma_chan = NULL; + + /* Try to be nice and wait for any queued DMA engine + * transactions to process before smashing it with a rock + */ + dma_sync_wait(chan, qp->last_cookie); + dmaengine_terminate_all(chan); + dmaengine_put(); + } + + ntb_unregister_db_callback(qp->ndev, qp->qp_num); + + cancel_delayed_work_sync(&qp->link_work); + + while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q))) + kfree(entry); + + while ((entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q))) { + dev_warn(&pdev->dev, "Freeing item from a non-empty queue\n"); + kfree(entry); + } + + while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q))) + kfree(entry); + + set_bit(qp->qp_num, &qp->transport->qp_bitmap); + + dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num); +} +EXPORT_SYMBOL_GPL(ntb_transport_free_queue); + +/** + * ntb_transport_rx_remove - Dequeues enqueued rx packet + * @qp: NTB queue to be freed + * @len: pointer to variable to write enqueued buffers length + * + * Dequeues unused buffers from receive queue. Should only be used during + * shutdown of qp. + * + * RETURNS: NULL error value on error, or void* for success. + */ +void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len) +{ + struct ntb_queue_entry *entry; + void *buf; + + if (!qp || qp->client_ready == NTB_LINK_UP) + return NULL; + + entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q); + if (!entry) + return NULL; + + buf = entry->cb_data; + *len = entry->len; + + ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q); + + return buf; +} +EXPORT_SYMBOL_GPL(ntb_transport_rx_remove); + +/** + * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry + * @qp: NTB transport layer queue the entry is to be enqueued on + * @cb: per buffer pointer for callback function to use + * @data: pointer to data buffer that incoming packets will be copied into + * @len: length of the data buffer + * + * Enqueue a new receive buffer onto the transport queue into which a NTB + * payload can be received into. + * + * RETURNS: An appropriate -ERRNO error value on error, or zero for success. + */ +int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data, + unsigned int len) +{ + struct ntb_queue_entry *entry; + + if (!qp) + return -EINVAL; + + entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q); + if (!entry) + return -ENOMEM; + + entry->cb_data = cb; + entry->buf = data; + entry->len = len; + + ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry, &qp->rx_pend_q); + + return 0; +} +EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue); + +/** + * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry + * @qp: NTB transport layer queue the entry is to be enqueued on + * @cb: per buffer pointer for callback function to use + * @data: pointer to data buffer that will be sent + * @len: length of the data buffer + * + * Enqueue a new transmit buffer onto the transport queue from which a NTB + * payload will be transmitted. This assumes that a lock is being held to + * serialize access to the qp. + * + * RETURNS: An appropriate -ERRNO error value on error, or zero for success. + */ +int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data, + unsigned int len) +{ + struct ntb_queue_entry *entry; + int rc; + + if (!qp || qp->qp_link != NTB_LINK_UP || !len) + return -EINVAL; + + entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q); + if (!entry) { + qp->tx_err_no_buf++; + return -ENOMEM; + } + + entry->cb_data = cb; + entry->buf = data; + entry->len = len; + entry->flags = 0; + + rc = ntb_process_tx(qp, entry); + if (rc) + ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, + &qp->tx_free_q); + + return rc; +} +EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue); + +/** + * ntb_transport_link_up - Notify NTB transport of client readiness to use queue + * @qp: NTB transport layer queue to be enabled + * + * Notify NTB transport layer of client readiness to use queue + */ +void ntb_transport_link_up(struct ntb_transport_qp *qp) +{ + if (!qp) + return; + + qp->client_ready = NTB_LINK_UP; + + if (qp->transport->transport_link == NTB_LINK_UP) + schedule_delayed_work(&qp->link_work, 0); +} +EXPORT_SYMBOL_GPL(ntb_transport_link_up); + +/** + * ntb_transport_link_down - Notify NTB transport to no longer enqueue data + * @qp: NTB transport layer queue to be disabled + * + * Notify NTB transport layer of client's desire to no longer receive data on + * transport queue specified. It is the client's responsibility to ensure all + * entries on queue are purged or otherwise handled appropriately. + */ +void ntb_transport_link_down(struct ntb_transport_qp *qp) +{ + struct pci_dev *pdev; + int rc, val; + + if (!qp) + return; + + pdev = ntb_query_pdev(qp->ndev); + qp->client_ready = NTB_LINK_DOWN; + + rc = ntb_read_local_spad(qp->ndev, QP_LINKS, &val); + if (rc) { + dev_err(&pdev->dev, "Error reading spad %d\n", QP_LINKS); + return; + } + + rc = ntb_write_remote_spad(qp->ndev, QP_LINKS, + val & ~(1 << qp->qp_num)); + if (rc) + dev_err(&pdev->dev, "Error writing %x to remote spad %d\n", + val & ~(1 << qp->qp_num), QP_LINKS); + + if (qp->qp_link == NTB_LINK_UP) + ntb_send_link_down(qp); + else + cancel_delayed_work_sync(&qp->link_work); +} +EXPORT_SYMBOL_GPL(ntb_transport_link_down); + +/** + * ntb_transport_link_query - Query transport link state + * @qp: NTB transport layer queue to be queried + * + * Query connectivity to the remote system of the NTB transport queue + * + * RETURNS: true for link up or false for link down + */ +bool ntb_transport_link_query(struct ntb_transport_qp *qp) +{ + if (!qp) + return false; + + return qp->qp_link == NTB_LINK_UP; +} +EXPORT_SYMBOL_GPL(ntb_transport_link_query); + +/** + * ntb_transport_qp_num - Query the qp number + * @qp: NTB transport layer queue to be queried + * + * Query qp number of the NTB transport queue + * + * RETURNS: a zero based number specifying the qp number + */ +unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp) +{ + if (!qp) + return 0; + + return qp->qp_num; +} +EXPORT_SYMBOL_GPL(ntb_transport_qp_num); + +/** + * ntb_transport_max_size - Query the max payload size of a qp + * @qp: NTB transport layer queue to be queried + * + * Query the maximum payload size permissible on the given qp + * + * RETURNS: the max payload size of a qp + */ +unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp) +{ + unsigned int max; + + if (!qp) + return 0; + + if (!qp->dma_chan) + return qp->tx_max_frame - sizeof(struct ntb_payload_header); + + /* If DMA engine usage is possible, try to find the max size for that */ + max = qp->tx_max_frame - sizeof(struct ntb_payload_header); + max -= max % (1 << qp->dma_chan->device->copy_align); + + return max; +} +EXPORT_SYMBOL_GPL(ntb_transport_max_size); |