--- /dev/null
+/*
+ * 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)
+{
+ raw_local_irq_unmask_now(INT_UDN_FIREWALL);
+}
+
+static void disable_firewall_interrupts(void)
+{
+ raw_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);
+ 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 = {
+ .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);
projects / GitHub / exynos8895 / android_kernel_samsung_universal8895.git / commitdiff