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Diffstat (limited to 'arch/tile/kernel/hardwall.c')
| -rw-r--r-- | arch/tile/kernel/hardwall.c | 1096 |
1 files changed, 1096 insertions, 0 deletions
diff --git a/arch/tile/kernel/hardwall.c b/arch/tile/kernel/hardwall.c new file mode 100644 index 000000000..2fd1694ac --- /dev/null +++ b/arch/tile/kernel/hardwall.c @@ -0,0 +1,1096 @@ +/* + * Copyright 2010 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/fs.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/rwsem.h> +#include <linux/kprobes.h> +#include <linux/sched.h> +#include <linux/hardirq.h> +#include <linux/uaccess.h> +#include <linux/smp.h> +#include <linux/cdev.h> +#include <linux/compat.h> +#include <asm/hardwall.h> +#include <asm/traps.h> +#include <asm/siginfo.h> +#include <asm/irq_regs.h> + +#include <arch/interrupts.h> +#include <arch/spr_def.h> + + +/* + * Implement a per-cpu "hardwall" resource class such as UDN or IPI. + * We use "hardwall" nomenclature throughout for historical reasons. + * The lock here controls access to the list data structure as well as + * to the items on the list. + */ +struct hardwall_type { + int index; + int is_xdn; + int is_idn; + int disabled; + const char *name; + struct list_head list; + spinlock_t lock; + struct proc_dir_entry *proc_dir; +}; + +enum hardwall_index { + HARDWALL_UDN = 0, +#ifndef __tilepro__ + HARDWALL_IDN = 1, + HARDWALL_IPI = 2, +#endif + _HARDWALL_TYPES +}; + +static struct hardwall_type hardwall_types[] = { + { /* user-space access to UDN */ + 0, + 1, + 0, + 0, + "udn", + LIST_HEAD_INIT(hardwall_types[HARDWALL_UDN].list), + __SPIN_LOCK_UNLOCKED(hardwall_types[HARDWALL_UDN].lock), + NULL + }, +#ifndef __tilepro__ + { /* user-space access to IDN */ + 1, + 1, + 1, + 1, /* disabled pending hypervisor support */ + "idn", + LIST_HEAD_INIT(hardwall_types[HARDWALL_IDN].list), + __SPIN_LOCK_UNLOCKED(hardwall_types[HARDWALL_IDN].lock), + NULL + }, + { /* access to user-space IPI */ + 2, + 0, + 0, + 0, + "ipi", + LIST_HEAD_INIT(hardwall_types[HARDWALL_IPI].list), + __SPIN_LOCK_UNLOCKED(hardwall_types[HARDWALL_IPI].lock), + NULL + }, +#endif +}; + +/* + * This data structure tracks the cpu data, etc., associated + * one-to-one with a "struct file *" from opening a hardwall device file. + * Note that the file's private data points back to this structure. + */ +struct hardwall_info { + struct list_head list; /* for hardwall_types.list */ + struct list_head task_head; /* head of tasks in this hardwall */ + struct hardwall_type *type; /* type of this resource */ + struct cpumask cpumask; /* cpus reserved */ + int id; /* integer id for this hardwall */ + int teardown_in_progress; /* are we tearing this one down? */ + + /* Remaining fields only valid for user-network resources. */ + int ulhc_x; /* upper left hand corner x coord */ + int ulhc_y; /* upper left hand corner y coord */ + int width; /* rectangle width */ + int height; /* rectangle height */ +#if CHIP_HAS_REV1_XDN() + atomic_t xdn_pending_count; /* cores in phase 1 of drain */ +#endif +}; + + +/* /proc/tile/hardwall */ +static struct proc_dir_entry *hardwall_proc_dir; + +/* Functions to manage files in /proc/tile/hardwall. */ +static void hardwall_add_proc(struct hardwall_info *); +static void hardwall_remove_proc(struct hardwall_info *); + +/* Allow disabling UDN access. */ +static int __init noudn(char *str) +{ + pr_info("User-space UDN access is disabled\n"); + hardwall_types[HARDWALL_UDN].disabled = 1; + return 0; +} +early_param("noudn", noudn); + +#ifndef __tilepro__ +/* Allow disabling IDN access. */ +static int __init noidn(char *str) +{ + pr_info("User-space IDN access is disabled\n"); + hardwall_types[HARDWALL_IDN].disabled = 1; + return 0; +} +early_param("noidn", noidn); + +/* Allow disabling IPI access. */ +static int __init noipi(char *str) +{ + pr_info("User-space IPI access is disabled\n"); + hardwall_types[HARDWALL_IPI].disabled = 1; + return 0; +} +early_param("noipi", noipi); +#endif + + +/* + * Low-level primitives for UDN/IDN + */ + +#ifdef __tilepro__ +#define mtspr_XDN(hwt, name, val) \ + do { (void)(hwt); __insn_mtspr(SPR_UDN_##name, (val)); } while (0) +#define mtspr_MPL_XDN(hwt, name, val) \ + do { (void)(hwt); __insn_mtspr(SPR_MPL_UDN_##name, (val)); } while (0) +#define mfspr_XDN(hwt, name) \ + ((void)(hwt), __insn_mfspr(SPR_UDN_##name)) +#else +#define mtspr_XDN(hwt, name, val) \ + do { \ + if ((hwt)->is_idn) \ + __insn_mtspr(SPR_IDN_##name, (val)); \ + else \ + __insn_mtspr(SPR_UDN_##name, (val)); \ + } while (0) +#define mtspr_MPL_XDN(hwt, name, val) \ + do { \ + if ((hwt)->is_idn) \ + __insn_mtspr(SPR_MPL_IDN_##name, (val)); \ + else \ + __insn_mtspr(SPR_MPL_UDN_##name, (val)); \ + } while (0) +#define mfspr_XDN(hwt, name) \ + ((hwt)->is_idn ? __insn_mfspr(SPR_IDN_##name) : __insn_mfspr(SPR_UDN_##name)) +#endif + +/* Set a CPU bit if the CPU is online. */ +#define cpu_online_set(cpu, dst) do { \ + if (cpu_online(cpu)) \ + cpumask_set_cpu(cpu, dst); \ +} while (0) + + +/* Does the given rectangle contain the given x,y coordinate? */ +static int contains(struct hardwall_info *r, int x, int y) +{ + return (x >= r->ulhc_x && x < r->ulhc_x + r->width) && + (y >= r->ulhc_y && y < r->ulhc_y + r->height); +} + +/* Compute the rectangle parameters and validate the cpumask. */ +static int check_rectangle(struct hardwall_info *r, struct cpumask *mask) +{ + int x, y, cpu, ulhc, lrhc; + + /* The first cpu is the ULHC, the last the LRHC. */ + ulhc = find_first_bit(cpumask_bits(mask), nr_cpumask_bits); + lrhc = find_last_bit(cpumask_bits(mask), nr_cpumask_bits); + + /* Compute the rectangle attributes from the cpus. */ + r->ulhc_x = cpu_x(ulhc); + r->ulhc_y = cpu_y(ulhc); + r->width = cpu_x(lrhc) - r->ulhc_x + 1; + r->height = cpu_y(lrhc) - r->ulhc_y + 1; + + /* Width and height must be positive */ + if (r->width <= 0 || r->height <= 0) + return -EINVAL; + + /* Confirm that the cpumask is exactly the rectangle. */ + for (y = 0, cpu = 0; y < smp_height; ++y) + for (x = 0; x < smp_width; ++x, ++cpu) + if (cpumask_test_cpu(cpu, mask) != contains(r, x, y)) + return -EINVAL; + + /* + * Note that offline cpus can't be drained when this user network + * rectangle eventually closes. We used to detect this + * situation and print a warning, but it annoyed users and + * they ignored it anyway, so now we just return without a + * warning. + */ + return 0; +} + +/* + * Hardware management of hardwall setup, teardown, trapping, + * and enabling/disabling PL0 access to the networks. + */ + +/* Bit field values to mask together for writes to SPR_XDN_DIRECTION_PROTECT */ +enum direction_protect { + N_PROTECT = (1 << 0), + E_PROTECT = (1 << 1), + S_PROTECT = (1 << 2), + W_PROTECT = (1 << 3), + C_PROTECT = (1 << 4), +}; + +static inline int xdn_which_interrupt(struct hardwall_type *hwt) +{ +#ifndef __tilepro__ + if (hwt->is_idn) + return INT_IDN_FIREWALL; +#endif + return INT_UDN_FIREWALL; +} + +static void enable_firewall_interrupts(struct hardwall_type *hwt) +{ + arch_local_irq_unmask_now(xdn_which_interrupt(hwt)); +} + +static void disable_firewall_interrupts(struct hardwall_type *hwt) +{ + arch_local_irq_mask_now(xdn_which_interrupt(hwt)); +} + +/* Set up hardwall on this cpu based on the passed hardwall_info. */ +static void hardwall_setup_func(void *info) +{ + struct hardwall_info *r = info; + struct hardwall_type *hwt = r->type; + + int cpu = smp_processor_id(); /* on_each_cpu disables preemption */ + int x = cpu_x(cpu); + int y = cpu_y(cpu); + int bits = 0; + if (x == r->ulhc_x) + bits |= W_PROTECT; + if (x == r->ulhc_x + r->width - 1) + bits |= E_PROTECT; + if (y == r->ulhc_y) + bits |= N_PROTECT; + if (y == r->ulhc_y + r->height - 1) + bits |= S_PROTECT; + BUG_ON(bits == 0); + mtspr_XDN(hwt, DIRECTION_PROTECT, bits); + enable_firewall_interrupts(hwt); +} + +/* Set up all cpus on edge of rectangle to enable/disable hardwall SPRs. */ +static void hardwall_protect_rectangle(struct hardwall_info *r) +{ + int x, y, cpu, delta; + struct cpumask rect_cpus; + + cpumask_clear(&rect_cpus); + + /* First include the top and bottom edges */ + cpu = r->ulhc_y * smp_width + r->ulhc_x; + delta = (r->height - 1) * smp_width; + for (x = 0; x < r->width; ++x, ++cpu) { + cpu_online_set(cpu, &rect_cpus); + cpu_online_set(cpu + delta, &rect_cpus); + } + + /* Then the left and right edges */ + cpu -= r->width; + delta = r->width - 1; + for (y = 0; y < r->height; ++y, cpu += smp_width) { + cpu_online_set(cpu, &rect_cpus); + cpu_online_set(cpu + delta, &rect_cpus); + } + + /* Then tell all the cpus to set up their protection SPR */ + on_each_cpu_mask(&rect_cpus, hardwall_setup_func, r, 1); +} + +/* Entered from INT_xDN_FIREWALL interrupt vector with irqs disabled. */ +void __kprobes do_hardwall_trap(struct pt_regs* regs, int fault_num) +{ + struct hardwall_info *rect; + struct hardwall_type *hwt; + struct task_struct *p; + struct siginfo info; + int cpu = smp_processor_id(); + int found_processes; + struct pt_regs *old_regs = set_irq_regs(regs); + + irq_enter(); + + /* Figure out which network trapped. */ + switch (fault_num) { +#ifndef __tilepro__ + case INT_IDN_FIREWALL: + hwt = &hardwall_types[HARDWALL_IDN]; + break; +#endif + case INT_UDN_FIREWALL: + hwt = &hardwall_types[HARDWALL_UDN]; + break; + default: + BUG(); + } + BUG_ON(hwt->disabled); + + /* This tile trapped a network access; find the rectangle. */ + spin_lock(&hwt->lock); + list_for_each_entry(rect, &hwt->list, list) { + if (cpumask_test_cpu(cpu, &rect->cpumask)) + break; + } + + /* + * It shouldn't be possible not to find this cpu on the + * rectangle list, since only cpus in rectangles get hardwalled. + * The hardwall is only removed after the user network is drained. + */ + BUG_ON(&rect->list == &hwt->list); + + /* + * If we already started teardown on this hardwall, don't worry; + * the abort signal has been sent and we are just waiting for things + * to quiesce. + */ + if (rect->teardown_in_progress) { + pr_notice("cpu %d: detected %s hardwall violation %#lx while teardown already in progress\n", + cpu, hwt->name, + (long)mfspr_XDN(hwt, DIRECTION_PROTECT)); + goto done; + } + + /* + * Kill off any process that is activated in this rectangle. + * We bypass security to deliver the signal, since it must be + * one of the activated processes that generated the user network + * message that caused this trap, and all the activated + * processes shared a single open file so are pretty tightly + * bound together from a security point of view to begin with. + */ + rect->teardown_in_progress = 1; + wmb(); /* Ensure visibility of rectangle before notifying processes. */ + pr_notice("cpu %d: detected %s hardwall violation %#lx...\n", + cpu, hwt->name, (long)mfspr_XDN(hwt, DIRECTION_PROTECT)); + info.si_signo = SIGILL; + info.si_errno = 0; + info.si_code = ILL_HARDWALL; + found_processes = 0; + list_for_each_entry(p, &rect->task_head, + thread.hardwall[hwt->index].list) { + BUG_ON(p->thread.hardwall[hwt->index].info != rect); + if (!(p->flags & PF_EXITING)) { + found_processes = 1; + pr_notice("hardwall: killing %d\n", p->pid); + do_send_sig_info(info.si_signo, &info, p, false); + } + } + if (!found_processes) + pr_notice("hardwall: no associated processes!\n"); + + done: + spin_unlock(&hwt->lock); + + /* + * We have to disable firewall interrupts now, or else when we + * return from this handler, we will simply re-interrupt back to + * it. However, we can't clear the protection bits, since we + * haven't yet drained the network, and that would allow packets + * to cross out of the hardwall region. + */ + disable_firewall_interrupts(hwt); + + irq_exit(); + set_irq_regs(old_regs); +} + +/* Allow access from user space to the user network. */ +void grant_hardwall_mpls(struct hardwall_type *hwt) +{ +#ifndef __tilepro__ + if (!hwt->is_xdn) { + __insn_mtspr(SPR_MPL_IPI_0_SET_0, 1); + return; + } +#endif + mtspr_MPL_XDN(hwt, ACCESS_SET_0, 1); + mtspr_MPL_XDN(hwt, AVAIL_SET_0, 1); + mtspr_MPL_XDN(hwt, COMPLETE_SET_0, 1); + mtspr_MPL_XDN(hwt, TIMER_SET_0, 1); +#if !CHIP_HAS_REV1_XDN() + mtspr_MPL_XDN(hwt, REFILL_SET_0, 1); + mtspr_MPL_XDN(hwt, CA_SET_0, 1); +#endif +} + +/* Deny access from user space to the user network. */ +void restrict_hardwall_mpls(struct hardwall_type *hwt) +{ +#ifndef __tilepro__ + if (!hwt->is_xdn) { + __insn_mtspr(SPR_MPL_IPI_0_SET_1, 1); + return; + } +#endif + mtspr_MPL_XDN(hwt, ACCESS_SET_1, 1); + mtspr_MPL_XDN(hwt, AVAIL_SET_1, 1); + mtspr_MPL_XDN(hwt, COMPLETE_SET_1, 1); + mtspr_MPL_XDN(hwt, TIMER_SET_1, 1); +#if !CHIP_HAS_REV1_XDN() + mtspr_MPL_XDN(hwt, REFILL_SET_1, 1); + mtspr_MPL_XDN(hwt, CA_SET_1, 1); +#endif +} + +/* Restrict or deny as necessary for the task we're switching to. */ +void hardwall_switch_tasks(struct task_struct *prev, + struct task_struct *next) +{ + int i; + for (i = 0; i < HARDWALL_TYPES; ++i) { + if (prev->thread.hardwall[i].info != NULL) { + if (next->thread.hardwall[i].info == NULL) + restrict_hardwall_mpls(&hardwall_types[i]); + } else if (next->thread.hardwall[i].info != NULL) { + grant_hardwall_mpls(&hardwall_types[i]); + } + } +} + +/* Does this task have the right to IPI the given cpu? */ +int hardwall_ipi_valid(int cpu) +{ +#ifdef __tilegx__ + struct hardwall_info *info = + current->thread.hardwall[HARDWALL_IPI].info; + return info && cpumask_test_cpu(cpu, &info->cpumask); +#else + return 0; +#endif +} + +/* + * Code to create, activate, deactivate, and destroy hardwall resources. + */ + +/* Create a hardwall for the given resource */ +static struct hardwall_info *hardwall_create(struct hardwall_type *hwt, + size_t size, + const unsigned char __user *bits) +{ + struct hardwall_info *iter, *info; + struct cpumask mask; + unsigned long flags; + int rc; + + /* Reject crazy sizes out of hand, a la sys_mbind(). */ + if (size > PAGE_SIZE) + return ERR_PTR(-EINVAL); + + /* Copy whatever fits into a cpumask. */ + if (copy_from_user(&mask, bits, min(sizeof(struct cpumask), size))) + return ERR_PTR(-EFAULT); + + /* + * If the size was short, clear the rest of the mask; + * otherwise validate that the rest of the user mask was zero + * (we don't try hard to be efficient when validating huge masks). + */ + if (size < sizeof(struct cpumask)) { + memset((char *)&mask + size, 0, sizeof(struct cpumask) - size); + } else if (size > sizeof(struct cpumask)) { + size_t i; + for (i = sizeof(struct cpumask); i < size; ++i) { + char c; + if (get_user(c, &bits[i])) + return ERR_PTR(-EFAULT); + if (c) + return ERR_PTR(-EINVAL); + } + } + + /* Allocate a new hardwall_info optimistically. */ + info = kmalloc(sizeof(struct hardwall_info), + GFP_KERNEL | __GFP_ZERO); + if (info == NULL) + return ERR_PTR(-ENOMEM); + INIT_LIST_HEAD(&info->task_head); + info->type = hwt; + + /* Compute the rectangle size and validate that it's plausible. */ + cpumask_copy(&info->cpumask, &mask); + info->id = find_first_bit(cpumask_bits(&mask), nr_cpumask_bits); + if (hwt->is_xdn) { + rc = check_rectangle(info, &mask); + if (rc != 0) { + kfree(info); + return ERR_PTR(rc); + } + } + + /* + * Eliminate cpus that are not part of this Linux client. + * Note that this allows for configurations that we might not want to + * support, such as one client on every even cpu, another client on + * every odd cpu. + */ + cpumask_and(&info->cpumask, &info->cpumask, cpu_online_mask); + + /* Confirm it doesn't overlap and add it to the list. */ + spin_lock_irqsave(&hwt->lock, flags); + list_for_each_entry(iter, &hwt->list, list) { + if (cpumask_intersects(&iter->cpumask, &info->cpumask)) { + spin_unlock_irqrestore(&hwt->lock, flags); + kfree(info); + return ERR_PTR(-EBUSY); + } + } + list_add_tail(&info->list, &hwt->list); + spin_unlock_irqrestore(&hwt->lock, flags); + + /* Set up appropriate hardwalling on all affected cpus. */ + if (hwt->is_xdn) + hardwall_protect_rectangle(info); + + /* Create a /proc/tile/hardwall entry. */ + hardwall_add_proc(info); + + return info; +} + +/* Activate a given hardwall on this cpu for this process. */ +static int hardwall_activate(struct hardwall_info *info) +{ + int cpu; + unsigned long flags; + struct task_struct *p = current; + struct thread_struct *ts = &p->thread; + struct hardwall_type *hwt; + + /* Require a hardwall. */ + if (info == NULL) + return -ENODATA; + + /* Not allowed to activate a hardwall that is being torn down. */ + if (info->teardown_in_progress) + return -EINVAL; + + /* + * Get our affinity; if we're not bound to this tile uniquely, + * we can't access the network registers. + */ + if (cpumask_weight(&p->cpus_allowed) != 1) + return -EPERM; + + /* Make sure we are bound to a cpu assigned to this resource. */ + cpu = smp_processor_id(); + BUG_ON(cpumask_first(&p->cpus_allowed) != cpu); + if (!cpumask_test_cpu(cpu, &info->cpumask)) + return -EINVAL; + + /* If we are already bound to this hardwall, it's a no-op. */ + hwt = info->type; + if (ts->hardwall[hwt->index].info) { + BUG_ON(ts->hardwall[hwt->index].info != info); + return 0; + } + + /* Success! This process gets to use the resource on this cpu. */ + ts->hardwall[hwt->index].info = info; + spin_lock_irqsave(&hwt->lock, flags); + list_add(&ts->hardwall[hwt->index].list, &info->task_head); + spin_unlock_irqrestore(&hwt->lock, flags); + grant_hardwall_mpls(hwt); + printk(KERN_DEBUG "Pid %d (%s) activated for %s hardwall: cpu %d\n", + p->pid, p->comm, hwt->name, cpu); + return 0; +} + +/* + * Deactivate a task's hardwall. Must hold lock for hardwall_type. + * This method may be called from exit_thread(), so we don't want to + * rely on too many fields of struct task_struct still being valid. + * We assume the cpus_allowed, pid, and comm fields are still valid. + */ +static void _hardwall_deactivate(struct hardwall_type *hwt, + struct task_struct *task) +{ + struct thread_struct *ts = &task->thread; + + if (cpumask_weight(&task->cpus_allowed) != 1) { + pr_err("pid %d (%s) releasing %s hardwall with an affinity mask containing %d cpus!\n", + task->pid, task->comm, hwt->name, + cpumask_weight(&task->cpus_allowed)); + BUG(); + } + + BUG_ON(ts->hardwall[hwt->index].info == NULL); + ts->hardwall[hwt->index].info = NULL; + list_del(&ts->hardwall[hwt->index].list); + if (task == current) + restrict_hardwall_mpls(hwt); +} + +/* Deactivate a task's hardwall. */ +static int hardwall_deactivate(struct hardwall_type *hwt, + struct task_struct *task) +{ + unsigned long flags; + int activated; + + spin_lock_irqsave(&hwt->lock, flags); + activated = (task->thread.hardwall[hwt->index].info != NULL); + if (activated) + _hardwall_deactivate(hwt, task); + spin_unlock_irqrestore(&hwt->lock, flags); + + if (!activated) + return -EINVAL; + + printk(KERN_DEBUG "Pid %d (%s) deactivated for %s hardwall: cpu %d\n", + task->pid, task->comm, hwt->name, raw_smp_processor_id()); + return 0; +} + +void hardwall_deactivate_all(struct task_struct *task) +{ + int i; + for (i = 0; i < HARDWALL_TYPES; ++i) + if (task->thread.hardwall[i].info) + hardwall_deactivate(&hardwall_types[i], task); +} + +/* Stop the switch before draining the network. */ +static void stop_xdn_switch(void *arg) +{ +#if !CHIP_HAS_REV1_XDN() + /* Freeze the switch and the demux. */ + __insn_mtspr(SPR_UDN_SP_FREEZE, + SPR_UDN_SP_FREEZE__SP_FRZ_MASK | + SPR_UDN_SP_FREEZE__DEMUX_FRZ_MASK | + SPR_UDN_SP_FREEZE__NON_DEST_EXT_MASK); +#else + /* + * Drop all packets bound for the core or off the edge. + * We rely on the normal hardwall protection setup code + * to have set the low four bits to trigger firewall interrupts, + * and shift those bits up to trigger "drop on send" semantics, + * plus adding "drop on send to core" for all switches. + * In practice it seems the switches latch the DIRECTION_PROTECT + * SPR so they won't start dropping if they're already + * delivering the last message to the core, but it doesn't + * hurt to enable it here. + */ + struct hardwall_type *hwt = arg; + unsigned long protect = mfspr_XDN(hwt, DIRECTION_PROTECT); + mtspr_XDN(hwt, DIRECTION_PROTECT, (protect | C_PROTECT) << 5); +#endif +} + +static void empty_xdn_demuxes(struct hardwall_type *hwt) +{ +#ifndef __tilepro__ + if (hwt->is_idn) { + while (__insn_mfspr(SPR_IDN_DATA_AVAIL) & (1 << 0)) + (void) __tile_idn0_receive(); + while (__insn_mfspr(SPR_IDN_DATA_AVAIL) & (1 << 1)) + (void) __tile_idn1_receive(); + return; + } +#endif + while (__insn_mfspr(SPR_UDN_DATA_AVAIL) & (1 << 0)) + (void) __tile_udn0_receive(); + while (__insn_mfspr(SPR_UDN_DATA_AVAIL) & (1 << 1)) + (void) __tile_udn1_receive(); + while (__insn_mfspr(SPR_UDN_DATA_AVAIL) & (1 << 2)) + (void) __tile_udn2_receive(); + while (__insn_mfspr(SPR_UDN_DATA_AVAIL) & (1 << 3)) + (void) __tile_udn3_receive(); +} + +/* Drain all the state from a stopped switch. */ +static void drain_xdn_switch(void *arg) +{ + struct hardwall_info *info = arg; + struct hardwall_type *hwt = info->type; + +#if CHIP_HAS_REV1_XDN() + /* + * The switches have been configured to drop any messages + * destined for cores (or off the edge of the rectangle). + * But the current message may continue to be delivered, + * so we wait until all the cores have finished any pending + * messages before we stop draining. + */ + int pending = mfspr_XDN(hwt, PENDING); + while (pending--) { + empty_xdn_demuxes(hwt); + if (hwt->is_idn) + __tile_idn_send(0); + else + __tile_udn_send(0); + } + atomic_dec(&info->xdn_pending_count); + while (atomic_read(&info->xdn_pending_count)) + empty_xdn_demuxes(hwt); +#else + int i; + int from_tile_words, ca_count; + + /* Empty out the 5 switch point fifos. */ + for (i = 0; i < 5; i++) { + int words, j; + __insn_mtspr(SPR_UDN_SP_FIFO_SEL, i); + words = __insn_mfspr(SPR_UDN_SP_STATE) & 0xF; + for (j = 0; j < words; j++) + (void) __insn_mfspr(SPR_UDN_SP_FIFO_DATA); + BUG_ON((__insn_mfspr(SPR_UDN_SP_STATE) & 0xF) != 0); + } + + /* Dump out the 3 word fifo at top. */ + from_tile_words = (__insn_mfspr(SPR_UDN_DEMUX_STATUS) >> 10) & 0x3; + for (i = 0; i < from_tile_words; i++) + (void) __insn_mfspr(SPR_UDN_DEMUX_WRITE_FIFO); + + /* Empty out demuxes. */ + empty_xdn_demuxes(hwt); + + /* Empty out catch all. */ + ca_count = __insn_mfspr(SPR_UDN_DEMUX_CA_COUNT); + for (i = 0; i < ca_count; i++) + (void) __insn_mfspr(SPR_UDN_CA_DATA); + BUG_ON(__insn_mfspr(SPR_UDN_DEMUX_CA_COUNT) != 0); + + /* Clear demux logic. */ + __insn_mtspr(SPR_UDN_DEMUX_CTL, 1); + + /* + * Write switch state; experimentation indicates that 0xc3000 + * is an idle switch point. + */ + for (i = 0; i < 5; i++) { + __insn_mtspr(SPR_UDN_SP_FIFO_SEL, i); + __insn_mtspr(SPR_UDN_SP_STATE, 0xc3000); + } +#endif +} + +/* Reset random XDN state registers at boot up and during hardwall teardown. */ +static void reset_xdn_network_state(struct hardwall_type *hwt) +{ + if (hwt->disabled) + return; + + /* Clear out other random registers so we have a clean slate. */ + mtspr_XDN(hwt, DIRECTION_PROTECT, 0); + mtspr_XDN(hwt, AVAIL_EN, 0); + mtspr_XDN(hwt, DEADLOCK_TIMEOUT, 0); + +#if !CHIP_HAS_REV1_XDN() + /* Reset UDN coordinates to their standard value */ + { + unsigned int cpu = smp_processor_id(); + unsigned int x = cpu_x(cpu); + unsigned int y = cpu_y(cpu); + __insn_mtspr(SPR_UDN_TILE_COORD, (x << 18) | (y << 7)); + } + + /* Set demux tags to predefined values and enable them. */ + __insn_mtspr(SPR_UDN_TAG_VALID, 0xf); + __insn_mtspr(SPR_UDN_TAG_0, (1 << 0)); + __insn_mtspr(SPR_UDN_TAG_1, (1 << 1)); + __insn_mtspr(SPR_UDN_TAG_2, (1 << 2)); + __insn_mtspr(SPR_UDN_TAG_3, (1 << 3)); + + /* Set other rev0 random registers to a clean state. */ + __insn_mtspr(SPR_UDN_REFILL_EN, 0); + __insn_mtspr(SPR_UDN_DEMUX_QUEUE_SEL, 0); + __insn_mtspr(SPR_UDN_SP_FIFO_SEL, 0); + + /* Start the switch and demux. */ + __insn_mtspr(SPR_UDN_SP_FREEZE, 0); +#endif +} + +void reset_network_state(void) +{ + reset_xdn_network_state(&hardwall_types[HARDWALL_UDN]); +#ifndef __tilepro__ + reset_xdn_network_state(&hardwall_types[HARDWALL_IDN]); +#endif +} + +/* Restart an XDN switch after draining. */ +static void restart_xdn_switch(void *arg) +{ + struct hardwall_type *hwt = arg; + +#if CHIP_HAS_REV1_XDN() + /* One last drain step to avoid races with injection and draining. */ + empty_xdn_demuxes(hwt); +#endif + + reset_xdn_network_state(hwt); + + /* Disable firewall interrupts. */ + disable_firewall_interrupts(hwt); +} + +/* Last reference to a hardwall is gone, so clear the network. */ +static void hardwall_destroy(struct hardwall_info *info) +{ + struct task_struct *task; + struct hardwall_type *hwt; + unsigned long flags; + + /* Make sure this file actually represents a hardwall. */ + if (info == NULL) + return; + + /* + * Deactivate any remaining tasks. It's possible to race with + * some other thread that is exiting and hasn't yet called + * deactivate (when freeing its thread_info), so we carefully + * deactivate any remaining tasks before freeing the + * hardwall_info object itself. + */ + hwt = info->type; + info->teardown_in_progress = 1; + spin_lock_irqsave(&hwt->lock, flags); + list_for_each_entry(task, &info->task_head, + thread.hardwall[hwt->index].list) + _hardwall_deactivate(hwt, task); + spin_unlock_irqrestore(&hwt->lock, flags); + + if (hwt->is_xdn) { + /* Configure the switches for draining the user network. */ + printk(KERN_DEBUG + "Clearing %s hardwall rectangle %dx%d %d,%d\n", + hwt->name, info->width, info->height, + info->ulhc_x, info->ulhc_y); + on_each_cpu_mask(&info->cpumask, stop_xdn_switch, hwt, 1); + + /* Drain the network. */ +#if CHIP_HAS_REV1_XDN() + atomic_set(&info->xdn_pending_count, + cpumask_weight(&info->cpumask)); + on_each_cpu_mask(&info->cpumask, drain_xdn_switch, info, 0); +#else + on_each_cpu_mask(&info->cpumask, drain_xdn_switch, info, 1); +#endif + + /* Restart switch and disable firewall. */ + on_each_cpu_mask(&info->cpumask, restart_xdn_switch, hwt, 1); + } + + /* Remove the /proc/tile/hardwall entry. */ + hardwall_remove_proc(info); + + /* Now free the hardwall from the list. */ + spin_lock_irqsave(&hwt->lock, flags); + BUG_ON(!list_empty(&info->task_head)); + list_del(&info->list); + spin_unlock_irqrestore(&hwt->lock, flags); + kfree(info); +} + + +static int hardwall_proc_show(struct seq_file *sf, void *v) +{ + struct hardwall_info *info = sf->private; + + seq_printf(sf, "%*pbl\n", cpumask_pr_args(&info->cpumask)); + return 0; +} + +static int hardwall_proc_open(struct inode *inode, + struct file *file) +{ + return single_open(file, hardwall_proc_show, PDE_DATA(inode)); +} + +static const struct file_operations hardwall_proc_fops = { + .open = hardwall_proc_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static void hardwall_add_proc(struct hardwall_info *info) +{ + char buf[64]; + snprintf(buf, sizeof(buf), "%d", info->id); + proc_create_data(buf, 0444, info->type->proc_dir, + &hardwall_proc_fops, info); +} + +static void hardwall_remove_proc(struct hardwall_info *info) +{ + char buf[64]; + snprintf(buf, sizeof(buf), "%d", info->id); + remove_proc_entry(buf, info->type->proc_dir); +} + +int proc_pid_hardwall(struct seq_file *m, struct pid_namespace *ns, + struct pid *pid, struct task_struct *task) +{ + int i; + int n = 0; + for (i = 0; i < HARDWALL_TYPES; ++i) { + struct hardwall_info *info = task->thread.hardwall[i].info; + if (info) + seq_printf(m, "%s: %d\n", info->type->name, info->id); + } + return n; +} + +void proc_tile_hardwall_init(struct proc_dir_entry *root) +{ + int i; + for (i = 0; i < HARDWALL_TYPES; ++i) { + struct hardwall_type *hwt = &hardwall_types[i]; + if (hwt->disabled) + continue; + if (hardwall_proc_dir == NULL) + hardwall_proc_dir = proc_mkdir("hardwall", root); + hwt->proc_dir = proc_mkdir(hwt->name, hardwall_proc_dir); + } +} + + +/* + * Character device support via ioctl/close. + */ + +static long hardwall_ioctl(struct file *file, unsigned int a, unsigned long b) +{ + struct hardwall_info *info = file->private_data; + int minor = iminor(file->f_mapping->host); + struct hardwall_type* hwt; + + if (_IOC_TYPE(a) != HARDWALL_IOCTL_BASE) + return -EINVAL; + + BUILD_BUG_ON(HARDWALL_TYPES != _HARDWALL_TYPES); + BUILD_BUG_ON(HARDWALL_TYPES != + sizeof(hardwall_types)/sizeof(hardwall_types[0])); + + if (minor < 0 || minor >= HARDWALL_TYPES) + return -EINVAL; + hwt = &hardwall_types[minor]; + WARN_ON(info && hwt != info->type); + + switch (_IOC_NR(a)) { + case _HARDWALL_CREATE: + if (hwt->disabled) + return -ENOSYS; + if (info != NULL) + return -EALREADY; + info = hardwall_create(hwt, _IOC_SIZE(a), + (const unsigned char __user *)b); + if (IS_ERR(info)) + return PTR_ERR(info); + file->private_data = info; + return 0; + + case _HARDWALL_ACTIVATE: + return hardwall_activate(info); + + case _HARDWALL_DEACTIVATE: + if (current->thread.hardwall[hwt->index].info != info) + return -EINVAL; + return hardwall_deactivate(hwt, current); + + case _HARDWALL_GET_ID: + return info ? info->id : -EINVAL; + + default: + return -EINVAL; + } +} + +#ifdef CONFIG_COMPAT +static long hardwall_compat_ioctl(struct file *file, + unsigned int a, unsigned long b) +{ + /* Sign-extend the argument so it can be used as a pointer. */ + return hardwall_ioctl(file, a, (unsigned long)compat_ptr(b)); +} +#endif + +/* The user process closed the file; revoke access to user networks. */ +static int hardwall_flush(struct file *file, fl_owner_t owner) +{ + struct hardwall_info *info = file->private_data; + struct task_struct *task, *tmp; + unsigned long flags; + + if (info) { + /* + * NOTE: if multiple threads are activated on this hardwall + * file, the other threads will continue having access to the + * user network until they are context-switched out and back + * in again. + * + * NOTE: A NULL files pointer means the task is being torn + * down, so in that case we also deactivate it. + */ + struct hardwall_type *hwt = info->type; + spin_lock_irqsave(&hwt->lock, flags); + list_for_each_entry_safe(task, tmp, &info->task_head, + thread.hardwall[hwt->index].list) { + if (task->files == owner || task->files == NULL) + _hardwall_deactivate(hwt, task); + } + spin_unlock_irqrestore(&hwt->lock, flags); + } + + return 0; +} + +/* This hardwall is gone, so destroy it. */ +static int hardwall_release(struct inode *inode, struct file *file) +{ + hardwall_destroy(file->private_data); + return 0; +} + +static const struct file_operations dev_hardwall_fops = { + .open = nonseekable_open, + .unlocked_ioctl = hardwall_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = hardwall_compat_ioctl, +#endif + .flush = hardwall_flush, + .release = hardwall_release, +}; + +static struct cdev hardwall_dev; + +static int __init dev_hardwall_init(void) +{ + int rc; + dev_t dev; + + rc = alloc_chrdev_region(&dev, 0, HARDWALL_TYPES, "hardwall"); + if (rc < 0) + return rc; + cdev_init(&hardwall_dev, &dev_hardwall_fops); + rc = cdev_add(&hardwall_dev, dev, HARDWALL_TYPES); + if (rc < 0) + return rc; + + return 0; +} +late_initcall(dev_hardwall_init); |