| /* |
| * 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> |
| |
| |
| /* |
| * This data structure tracks the rectangle data, etc., associated |
| * one-to-one with a "struct file *" from opening HARDWALL_FILE. |
| * Note that the file's private data points back to this structure. |
| */ |
| struct hardwall_info { |
| struct list_head list; /* "rectangles" list */ |
| struct list_head task_head; /* head of tasks in this hardwall */ |
| 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 */ |
| int teardown_in_progress; /* are we tearing this one down? */ |
| }; |
| |
| /* Currently allocated hardwall rectangles */ |
| static LIST_HEAD(rectangles); |
| |
| /* |
| * Guard changes to the hardwall data structures. |
| * This could be finer grained (e.g. one lock for the list of hardwall |
| * rectangles, then separate embedded locks for each one's list of tasks), |
| * but there are subtle correctness issues when trying to start with |
| * a task's "hardwall" pointer and lock the correct rectangle's embedded |
| * lock in the presence of a simultaneous deactivation, so it seems |
| * easier to have a single lock, given that none of these data |
| * structures are touched very frequently during normal operation. |
| */ |
| static DEFINE_SPINLOCK(hardwall_lock); |
| |
| /* Allow disabling UDN access. */ |
| static int udn_disabled; |
| static int __init noudn(char *str) |
| { |
| pr_info("User-space UDN access is disabled\n"); |
| udn_disabled = 1; |
| return 0; |
| } |
| early_param("noudn", noudn); |
| |
| |
| /* |
| * Low-level primitives |
| */ |
| |
| /* 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 setup_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 UDN |
| * 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; |
| } |
| |
| /* Do the two given rectangles overlap on any cpu? */ |
| static int overlaps(struct hardwall_info *a, struct hardwall_info *b) |
| { |
| return a->ulhc_x + a->width > b->ulhc_x && /* A not to the left */ |
| b->ulhc_x + b->width > a->ulhc_x && /* B not to the left */ |
| a->ulhc_y + a->height > b->ulhc_y && /* A not above */ |
| b->ulhc_y + b->height > a->ulhc_y; /* B not above */ |
| } |
| |
| |
| /* |
| * 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) |
| }; |
| |
| static void enable_firewall_interrupts(void) |
| { |
| arch_local_irq_unmask_now(INT_UDN_FIREWALL); |
| } |
| |
| static void disable_firewall_interrupts(void) |
| { |
| arch_local_irq_mask_now(INT_UDN_FIREWALL); |
| } |
| |
| /* Set up hardwall on this cpu based on the passed hardwall_info. */ |
| static void hardwall_setup_ipi_func(void *info) |
| { |
| struct hardwall_info *r = info; |
| int cpu = smp_processor_id(); |
| int x = cpu % smp_width; |
| int y = cpu / smp_width; |
| 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); |
| __insn_mtspr(SPR_UDN_DIRECTION_PROTECT, bits); |
| enable_firewall_interrupts(); |
| |
| } |
| |
| /* Set up all cpus on edge of rectangle to enable/disable hardwall SPRs. */ |
| static void hardwall_setup(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_ipi_func, r, 1); |
| } |
| |
| void __kprobes do_hardwall_trap(struct pt_regs* regs, int fault_num) |
| { |
| struct hardwall_info *rect; |
| struct task_struct *p; |
| struct siginfo info; |
| int x, y; |
| int cpu = smp_processor_id(); |
| int found_processes; |
| unsigned long flags; |
| |
| struct pt_regs *old_regs = set_irq_regs(regs); |
| irq_enter(); |
| |
| /* This tile trapped a network access; find the rectangle. */ |
| x = cpu % smp_width; |
| y = cpu / smp_width; |
| spin_lock_irqsave(&hardwall_lock, flags); |
| list_for_each_entry(rect, &rectangles, list) { |
| if (contains(rect, x, y)) |
| 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 UDN is drained. |
| */ |
| BUG_ON(&rect->list == &rectangles); |
| |
| /* |
| * 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 hardwall violation %#lx" |
| " while teardown already in progress\n", |
| cpu, (long) __insn_mfspr(SPR_UDN_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 UDN |
| * 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 hardwall violation %#lx...\n", |
| cpu, (long) __insn_mfspr(SPR_UDN_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_list) { |
| BUG_ON(p->thread.hardwall != rect); |
| if (p->sighand) { |
| found_processes = 1; |
| pr_notice("hardwall: killing %d\n", p->pid); |
| spin_lock(&p->sighand->siglock); |
| __group_send_sig_info(info.si_signo, &info, p); |
| spin_unlock(&p->sighand->siglock); |
| } |
| } |
| if (!found_processes) |
| pr_notice("hardwall: no associated processes!\n"); |
| |
| done: |
| spin_unlock_irqrestore(&hardwall_lock, flags); |
| |
| /* |
| * 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(); |
| |
| irq_exit(); |
| set_irq_regs(old_regs); |
| } |
| |
| /* Allow access from user space to the UDN. */ |
| void grant_network_mpls(void) |
| { |
| __insn_mtspr(SPR_MPL_UDN_ACCESS_SET_0, 1); |
| __insn_mtspr(SPR_MPL_UDN_AVAIL_SET_0, 1); |
| __insn_mtspr(SPR_MPL_UDN_COMPLETE_SET_0, 1); |
| __insn_mtspr(SPR_MPL_UDN_TIMER_SET_0, 1); |
| #if !CHIP_HAS_REV1_XDN() |
| __insn_mtspr(SPR_MPL_UDN_REFILL_SET_0, 1); |
| __insn_mtspr(SPR_MPL_UDN_CA_SET_0, 1); |
| #endif |
| } |
| |
| /* Deny access from user space to the UDN. */ |
| void restrict_network_mpls(void) |
| { |
| __insn_mtspr(SPR_MPL_UDN_ACCESS_SET_1, 1); |
| __insn_mtspr(SPR_MPL_UDN_AVAIL_SET_1, 1); |
| __insn_mtspr(SPR_MPL_UDN_COMPLETE_SET_1, 1); |
| __insn_mtspr(SPR_MPL_UDN_TIMER_SET_1, 1); |
| #if !CHIP_HAS_REV1_XDN() |
| __insn_mtspr(SPR_MPL_UDN_REFILL_SET_1, 1); |
| __insn_mtspr(SPR_MPL_UDN_CA_SET_1, 1); |
| #endif |
| } |
| |
| |
| /* |
| * Code to create, activate, deactivate, and destroy hardwall rectangles. |
| */ |
| |
| /* Create a hardwall for the given rectangle */ |
| static struct hardwall_info *hardwall_create( |
| size_t size, const unsigned char __user *bits) |
| { |
| struct hardwall_info *iter, *rect; |
| 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 rectangle optimistically. */ |
| rect = kmalloc(sizeof(struct hardwall_info), |
| GFP_KERNEL | __GFP_ZERO); |
| if (rect == NULL) |
| return ERR_PTR(-ENOMEM); |
| INIT_LIST_HEAD(&rect->task_head); |
| |
| /* Compute the rectangle size and validate that it's plausible. */ |
| rc = setup_rectangle(rect, &mask); |
| if (rc != 0) { |
| kfree(rect); |
| return ERR_PTR(rc); |
| } |
| |
| /* Confirm it doesn't overlap and add it to the list. */ |
| spin_lock_irqsave(&hardwall_lock, flags); |
| list_for_each_entry(iter, &rectangles, list) { |
| if (overlaps(iter, rect)) { |
| spin_unlock_irqrestore(&hardwall_lock, flags); |
| kfree(rect); |
| return ERR_PTR(-EBUSY); |
| } |
| } |
| list_add_tail(&rect->list, &rectangles); |
| spin_unlock_irqrestore(&hardwall_lock, flags); |
| |
| /* Set up appropriate hardwalling on all affected cpus. */ |
| hardwall_setup(rect); |
| |
| return rect; |
| } |
| |
| /* Activate a given hardwall on this cpu for this process. */ |
| static int hardwall_activate(struct hardwall_info *rect) |
| { |
| int cpu, x, y; |
| unsigned long flags; |
| struct task_struct *p = current; |
| struct thread_struct *ts = &p->thread; |
| |
| /* Require a rectangle. */ |
| if (rect == NULL) |
| return -ENODATA; |
| |
| /* Not allowed to activate a rectangle that is being torn down. */ |
| if (rect->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 in this rectangle. */ |
| cpu = smp_processor_id(); |
| BUG_ON(cpumask_first(&p->cpus_allowed) != cpu); |
| x = cpu_x(cpu); |
| y = cpu_y(cpu); |
| if (!contains(rect, x, y)) |
| return -EINVAL; |
| |
| /* If we are already bound to this hardwall, it's a no-op. */ |
| if (ts->hardwall) { |
| BUG_ON(ts->hardwall != rect); |
| return 0; |
| } |
| |
| /* Success! This process gets to use the user networks on this cpu. */ |
| ts->hardwall = rect; |
| spin_lock_irqsave(&hardwall_lock, flags); |
| list_add(&ts->hardwall_list, &rect->task_head); |
| spin_unlock_irqrestore(&hardwall_lock, flags); |
| grant_network_mpls(); |
| printk(KERN_DEBUG "Pid %d (%s) activated for hardwall: cpu %d\n", |
| p->pid, p->comm, cpu); |
| return 0; |
| } |
| |
| /* |
| * Deactivate a task's hardwall. Must hold hardwall_lock. |
| * This method may be called from free_task(), 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 task_struct *task) |
| { |
| struct thread_struct *ts = &task->thread; |
| |
| if (cpumask_weight(&task->cpus_allowed) != 1) { |
| pr_err("pid %d (%s) releasing networks with" |
| " an affinity mask containing %d cpus!\n", |
| task->pid, task->comm, |
| cpumask_weight(&task->cpus_allowed)); |
| BUG(); |
| } |
| |
| BUG_ON(ts->hardwall == NULL); |
| ts->hardwall = NULL; |
| list_del(&ts->hardwall_list); |
| if (task == current) |
| restrict_network_mpls(); |
| } |
| |
| /* Deactivate a task's hardwall. */ |
| int hardwall_deactivate(struct task_struct *task) |
| { |
| unsigned long flags; |
| int activated; |
| |
| spin_lock_irqsave(&hardwall_lock, flags); |
| activated = (task->thread.hardwall != NULL); |
| if (activated) |
| _hardwall_deactivate(task); |
| spin_unlock_irqrestore(&hardwall_lock, flags); |
| |
| if (!activated) |
| return -EINVAL; |
| |
| printk(KERN_DEBUG "Pid %d (%s) deactivated for hardwall: cpu %d\n", |
| task->pid, task->comm, smp_processor_id()); |
| return 0; |
| } |
| |
| /* Stop a UDN switch before draining the network. */ |
| static void stop_udn_switch(void *ignored) |
| { |
| #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); |
| #endif |
| } |
| |
| /* Drain all the state from a stopped switch. */ |
| static void drain_udn_switch(void *ignored) |
| { |
| #if !CHIP_HAS_REV1_XDN() |
| 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. */ |
| 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(); |
| BUG_ON((__insn_mfspr(SPR_UDN_DATA_AVAIL) & 0xF) != 0); |
| |
| /* 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 UDN state registers at boot up and during hardwall teardown. */ |
| void reset_network_state(void) |
| { |
| #if !CHIP_HAS_REV1_XDN() |
| /* Reset UDN coordinates to their standard value */ |
| unsigned int cpu = smp_processor_id(); |
| unsigned int x = cpu % smp_width; |
| unsigned int y = cpu / smp_width; |
| #endif |
| |
| if (udn_disabled) |
| return; |
| |
| #if !CHIP_HAS_REV1_XDN() |
| __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)); |
| #endif |
| |
| /* Clear out other random registers so we have a clean slate. */ |
| __insn_mtspr(SPR_UDN_AVAIL_EN, 0); |
| __insn_mtspr(SPR_UDN_DEADLOCK_TIMEOUT, 0); |
| #if !CHIP_HAS_REV1_XDN() |
| __insn_mtspr(SPR_UDN_REFILL_EN, 0); |
| __insn_mtspr(SPR_UDN_DEMUX_QUEUE_SEL, 0); |
| __insn_mtspr(SPR_UDN_SP_FIFO_SEL, 0); |
| #endif |
| |
| /* Start the switch and demux. */ |
| #if !CHIP_HAS_REV1_XDN() |
| __insn_mtspr(SPR_UDN_SP_FREEZE, 0); |
| #endif |
| } |
| |
| /* Restart a UDN switch after draining. */ |
| static void restart_udn_switch(void *ignored) |
| { |
| reset_network_state(); |
| |
| /* Disable firewall interrupts. */ |
| __insn_mtspr(SPR_UDN_DIRECTION_PROTECT, 0); |
| disable_firewall_interrupts(); |
| } |
| |
| /* Build a struct cpumask containing all valid tiles in bounding rectangle. */ |
| static void fill_mask(struct hardwall_info *r, struct cpumask *result) |
| { |
| int x, y, cpu; |
| |
| cpumask_clear(result); |
| |
| cpu = r->ulhc_y * smp_width + r->ulhc_x; |
| for (y = 0; y < r->height; ++y, cpu += smp_width - r->width) { |
| for (x = 0; x < r->width; ++x, ++cpu) |
| cpu_online_set(cpu, result); |
| } |
| } |
| |
| /* Last reference to a hardwall is gone, so clear the network. */ |
| static void hardwall_destroy(struct hardwall_info *rect) |
| { |
| struct task_struct *task; |
| unsigned long flags; |
| struct cpumask mask; |
| |
| /* Make sure this file actually represents a rectangle. */ |
| if (rect == 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. |
| */ |
| spin_lock_irqsave(&hardwall_lock, flags); |
| list_for_each_entry(task, &rect->task_head, thread.hardwall_list) |
| _hardwall_deactivate(task); |
| spin_unlock_irqrestore(&hardwall_lock, flags); |
| |
| /* Drain the UDN. */ |
| printk(KERN_DEBUG "Clearing hardwall rectangle %dx%d %d,%d\n", |
| rect->width, rect->height, rect->ulhc_x, rect->ulhc_y); |
| fill_mask(rect, &mask); |
| on_each_cpu_mask(&mask, stop_udn_switch, NULL, 1); |
| on_each_cpu_mask(&mask, drain_udn_switch, NULL, 1); |
| |
| /* Restart switch and disable firewall. */ |
| on_each_cpu_mask(&mask, restart_udn_switch, NULL, 1); |
| |
| /* Now free the rectangle from the list. */ |
| spin_lock_irqsave(&hardwall_lock, flags); |
| BUG_ON(!list_empty(&rect->task_head)); |
| list_del(&rect->list); |
| spin_unlock_irqrestore(&hardwall_lock, flags); |
| kfree(rect); |
| } |
| |
| |
| /* |
| * Dump hardwall state via /proc; initialized in arch/tile/sys/proc.c. |
| */ |
| int proc_tile_hardwall_show(struct seq_file *sf, void *v) |
| { |
| struct hardwall_info *r; |
| |
| if (udn_disabled) { |
| seq_printf(sf, "%dx%d 0,0 pids:\n", smp_width, smp_height); |
| return 0; |
| } |
| |
| spin_lock_irq(&hardwall_lock); |
| list_for_each_entry(r, &rectangles, list) { |
| struct task_struct *p; |
| seq_printf(sf, "%dx%d %d,%d pids:", |
| r->width, r->height, r->ulhc_x, r->ulhc_y); |
| list_for_each_entry(p, &r->task_head, thread.hardwall_list) { |
| unsigned int cpu = cpumask_first(&p->cpus_allowed); |
| unsigned int x = cpu % smp_width; |
| unsigned int y = cpu / smp_width; |
| seq_printf(sf, " %d@%d,%d", p->pid, x, y); |
| } |
| seq_printf(sf, "\n"); |
| } |
| spin_unlock_irq(&hardwall_lock); |
| return 0; |
| } |
| |
| |
| /* |
| * Character device support via ioctl/close. |
| */ |
| |
| static long hardwall_ioctl(struct file *file, unsigned int a, unsigned long b) |
| { |
| struct hardwall_info *rect = file->private_data; |
| |
| if (_IOC_TYPE(a) != HARDWALL_IOCTL_BASE) |
| return -EINVAL; |
| |
| switch (_IOC_NR(a)) { |
| case _HARDWALL_CREATE: |
| if (udn_disabled) |
| return -ENOSYS; |
| if (rect != NULL) |
| return -EALREADY; |
| rect = hardwall_create(_IOC_SIZE(a), |
| (const unsigned char __user *)b); |
| if (IS_ERR(rect)) |
| return PTR_ERR(rect); |
| file->private_data = rect; |
| return 0; |
| |
| case _HARDWALL_ACTIVATE: |
| return hardwall_activate(rect); |
| |
| case _HARDWALL_DEACTIVATE: |
| if (current->thread.hardwall != rect) |
| return -EINVAL; |
| return hardwall_deactivate(current); |
| |
| 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 *rect = file->private_data; |
| struct task_struct *task, *tmp; |
| unsigned long flags; |
| |
| if (rect) { |
| /* |
| * NOTE: if multiple threads are activated on this hardwall |
| * file, the other threads will continue having access to the |
| * UDN 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. |
| */ |
| spin_lock_irqsave(&hardwall_lock, flags); |
| list_for_each_entry_safe(task, tmp, &rect->task_head, |
| thread.hardwall_list) { |
| if (task->files == owner || task->files == NULL) |
| _hardwall_deactivate(task); |
| } |
| spin_unlock_irqrestore(&hardwall_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, 1, "hardwall"); |
| if (rc < 0) |
| return rc; |
| cdev_init(&hardwall_dev, &dev_hardwall_fops); |
| rc = cdev_add(&hardwall_dev, dev, 1); |
| if (rc < 0) |
| return rc; |
| |
| return 0; |
| } |
| late_initcall(dev_hardwall_init); |