--- /dev/null
+/**************************************************************************
+ *
+ * Copyright (c) 2007-2009 VMware, Inc., Palo Alto, CA., USA
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ **************************************************************************/
+/*
+ * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
+ */
+
+#include "ttm/ttm_lock.h"
+#include "ttm/ttm_module.h"
+#include <asm/atomic.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+#include <linux/module.h>
+
+#define TTM_WRITE_LOCK_PENDING (1 << 0)
+#define TTM_VT_LOCK_PENDING (1 << 1)
+#define TTM_SUSPEND_LOCK_PENDING (1 << 2)
+#define TTM_VT_LOCK (1 << 3)
+#define TTM_SUSPEND_LOCK (1 << 4)
+
+void ttm_lock_init(struct ttm_lock *lock)
+{
+ spin_lock_init(&lock->lock);
+ init_waitqueue_head(&lock->queue);
+ lock->rw = 0;
+ lock->flags = 0;
+ lock->kill_takers = false;
+ lock->signal = SIGKILL;
+}
+EXPORT_SYMBOL(ttm_lock_init);
+
+void ttm_read_unlock(struct ttm_lock *lock)
+{
+ spin_lock(&lock->lock);
+ if (--lock->rw == 0)
+ wake_up_all(&lock->queue);
+ spin_unlock(&lock->lock);
+}
+EXPORT_SYMBOL(ttm_read_unlock);
+
+static bool __ttm_read_lock(struct ttm_lock *lock)
+{
+ bool locked = false;
+
+ spin_lock(&lock->lock);
+ if (unlikely(lock->kill_takers)) {
+ send_sig(lock->signal, current, 0);
+ spin_unlock(&lock->lock);
+ return false;
+ }
+ if (lock->rw >= 0 && lock->flags == 0) {
+ ++lock->rw;
+ locked = true;
+ }
+ spin_unlock(&lock->lock);
+ return locked;
+}
+
+int ttm_read_lock(struct ttm_lock *lock, bool interruptible)
+{
+ int ret = 0;
+
+ if (interruptible)
+ ret = wait_event_interruptible(lock->queue,
+ __ttm_read_lock(lock));
+ else
+ wait_event(lock->queue, __ttm_read_lock(lock));
+ return ret;
+}
+EXPORT_SYMBOL(ttm_read_lock);
+
+static bool __ttm_read_trylock(struct ttm_lock *lock, bool *locked)
+{
+ bool block = true;
+
+ *locked = false;
+
+ spin_lock(&lock->lock);
+ if (unlikely(lock->kill_takers)) {
+ send_sig(lock->signal, current, 0);
+ spin_unlock(&lock->lock);
+ return false;
+ }
+ if (lock->rw >= 0 && lock->flags == 0) {
+ ++lock->rw;
+ block = false;
+ *locked = true;
+ } else if (lock->flags == 0) {
+ block = false;
+ }
+ spin_unlock(&lock->lock);
+
+ return !block;
+}
+
+int ttm_read_trylock(struct ttm_lock *lock, bool interruptible)
+{
+ int ret = 0;
+ bool locked;
+
+ if (interruptible)
+ ret = wait_event_interruptible
+ (lock->queue, __ttm_read_trylock(lock, &locked));
+ else
+ wait_event(lock->queue, __ttm_read_trylock(lock, &locked));
+
+ if (unlikely(ret != 0)) {
+ BUG_ON(locked);
+ return ret;
+ }
+
+ return (locked) ? 0 : -EBUSY;
+}
+
+void ttm_write_unlock(struct ttm_lock *lock)
+{
+ spin_lock(&lock->lock);
+ lock->rw = 0;
+ wake_up_all(&lock->queue);
+ spin_unlock(&lock->lock);
+}
+EXPORT_SYMBOL(ttm_write_unlock);
+
+static bool __ttm_write_lock(struct ttm_lock *lock)
+{
+ bool locked = false;
+
+ spin_lock(&lock->lock);
+ if (unlikely(lock->kill_takers)) {
+ send_sig(lock->signal, current, 0);
+ spin_unlock(&lock->lock);
+ return false;
+ }
+ if (lock->rw == 0 && ((lock->flags & ~TTM_WRITE_LOCK_PENDING) == 0)) {
+ lock->rw = -1;
+ lock->flags &= ~TTM_WRITE_LOCK_PENDING;
+ locked = true;
+ } else {
+ lock->flags |= TTM_WRITE_LOCK_PENDING;
+ }
+ spin_unlock(&lock->lock);
+ return locked;
+}
+
+int ttm_write_lock(struct ttm_lock *lock, bool interruptible)
+{
+ int ret = 0;
+
+ if (interruptible) {
+ ret = wait_event_interruptible(lock->queue,
+ __ttm_write_lock(lock));
+ if (unlikely(ret != 0)) {
+ spin_lock(&lock->lock);
+ lock->flags &= ~TTM_WRITE_LOCK_PENDING;
+ wake_up_all(&lock->queue);
+ spin_unlock(&lock->lock);
+ }
+ } else
+ wait_event(lock->queue, __ttm_read_lock(lock));
+
+ return ret;
+}
+EXPORT_SYMBOL(ttm_write_lock);
+
+void ttm_write_lock_downgrade(struct ttm_lock *lock)
+{
+ spin_lock(&lock->lock);
+ lock->rw = 1;
+ wake_up_all(&lock->queue);
+ spin_unlock(&lock->lock);
+}
+
+static int __ttm_vt_unlock(struct ttm_lock *lock)
+{
+ int ret = 0;
+
+ spin_lock(&lock->lock);
+ if (unlikely(!(lock->flags & TTM_VT_LOCK)))
+ ret = -EINVAL;
+ lock->flags &= ~TTM_VT_LOCK;
+ wake_up_all(&lock->queue);
+ spin_unlock(&lock->lock);
+ printk(KERN_INFO TTM_PFX "vt unlock.\n");
+
+ return ret;
+}
+
+static void ttm_vt_lock_remove(struct ttm_base_object **p_base)
+{
+ struct ttm_base_object *base = *p_base;
+ struct ttm_lock *lock = container_of(base, struct ttm_lock, base);
+ int ret;
+
+ *p_base = NULL;
+ ret = __ttm_vt_unlock(lock);
+ BUG_ON(ret != 0);
+}
+
+static bool __ttm_vt_lock(struct ttm_lock *lock)
+{
+ bool locked = false;
+
+ spin_lock(&lock->lock);
+ if (lock->rw == 0) {
+ lock->flags &= ~TTM_VT_LOCK_PENDING;
+ lock->flags |= TTM_VT_LOCK;
+ locked = true;
+ } else {
+ lock->flags |= TTM_VT_LOCK_PENDING;
+ }
+ spin_unlock(&lock->lock);
+ return locked;
+}
+
+int ttm_vt_lock(struct ttm_lock *lock,
+ bool interruptible,
+ struct ttm_object_file *tfile)
+{
+ int ret = 0;
+
+ if (interruptible) {
+ ret = wait_event_interruptible(lock->queue,
+ __ttm_vt_lock(lock));
+ if (unlikely(ret != 0)) {
+ spin_lock(&lock->lock);
+ lock->flags &= ~TTM_VT_LOCK_PENDING;
+ wake_up_all(&lock->queue);
+ spin_unlock(&lock->lock);
+ return ret;
+ }
+ } else
+ wait_event(lock->queue, __ttm_vt_lock(lock));
+
+ /*
+ * Add a base-object, the destructor of which will
+ * make sure the lock is released if the client dies
+ * while holding it.
+ */
+
+ ret = ttm_base_object_init(tfile, &lock->base, false,
+ ttm_lock_type, &ttm_vt_lock_remove, NULL);
+ if (ret)
+ (void)__ttm_vt_unlock(lock);
+ else {
+ lock->vt_holder = tfile;
+ printk(KERN_INFO TTM_PFX "vt lock.\n");
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(ttm_vt_lock);
+
+int ttm_vt_unlock(struct ttm_lock *lock)
+{
+ return ttm_ref_object_base_unref(lock->vt_holder,
+ lock->base.hash.key, TTM_REF_USAGE);
+}
+EXPORT_SYMBOL(ttm_vt_unlock);
+
+void ttm_suspend_unlock(struct ttm_lock *lock)
+{
+ spin_lock(&lock->lock);
+ lock->flags &= ~TTM_SUSPEND_LOCK;
+ wake_up_all(&lock->queue);
+ spin_unlock(&lock->lock);
+}
+
+static bool __ttm_suspend_lock(struct ttm_lock *lock)
+{
+ bool locked = false;
+
+ spin_lock(&lock->lock);
+ if (lock->rw == 0) {
+ lock->flags &= ~TTM_SUSPEND_LOCK_PENDING;
+ lock->flags |= TTM_SUSPEND_LOCK;
+ locked = true;
+ } else {
+ lock->flags |= TTM_SUSPEND_LOCK_PENDING;
+ }
+ spin_unlock(&lock->lock);
+ return locked;
+}
+
+void ttm_suspend_lock(struct ttm_lock *lock)
+{
+ wait_event(lock->queue, __ttm_suspend_lock(lock));
+}
--- /dev/null
+/**************************************************************************
+ *
+ * Copyright (c) 2007-2009 VMware, Inc., Palo Alto, CA., USA
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ **************************************************************************/
+/*
+ * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
+ */
+
+/** @file ttm_lock.h
+ * This file implements a simple replacement for the buffer manager use
+ * of the DRM heavyweight hardware lock.
+ * The lock is a read-write lock. Taking it in read mode and write mode
+ * is relatively fast, and intended for in-kernel use only.
+ *
+ * The vt mode is used only when there is a need to block all
+ * user-space processes from validating buffers.
+ * It's allowed to leave kernel space with the vt lock held.
+ * If a user-space process dies while having the vt-lock,
+ * it will be released during the file descriptor release. The vt lock
+ * excludes write lock and read lock.
+ *
+ * The suspend mode is used to lock out all TTM users when preparing for
+ * and executing suspend operations.
+ *
+ */
+
+#ifndef _TTM_LOCK_H_
+#define _TTM_LOCK_H_
+
+#include "ttm/ttm_object.h"
+#include <linux/wait.h>
+#include <asm/atomic.h>
+
+/**
+ * struct ttm_lock
+ *
+ * @base: ttm base object used solely to release the lock if the client
+ * holding the lock dies.
+ * @queue: Queue for processes waiting for lock change-of-status.
+ * @lock: Spinlock protecting some lock members.
+ * @rw: Read-write lock counter. Protected by @lock.
+ * @flags: Lock state. Protected by @lock.
+ * @kill_takers: Boolean whether to kill takers of the lock.
+ * @signal: Signal to send when kill_takers is true.
+ */
+
+struct ttm_lock {
+ struct ttm_base_object base;
+ wait_queue_head_t queue;
+ spinlock_t lock;
+ int32_t rw;
+ uint32_t flags;
+ bool kill_takers;
+ int signal;
+ struct ttm_object_file *vt_holder;
+};
+
+
+/**
+ * ttm_lock_init
+ *
+ * @lock: Pointer to a struct ttm_lock
+ * Initializes the lock.
+ */
+extern void ttm_lock_init(struct ttm_lock *lock);
+
+/**
+ * ttm_read_unlock
+ *
+ * @lock: Pointer to a struct ttm_lock
+ *
+ * Releases a read lock.
+ */
+extern void ttm_read_unlock(struct ttm_lock *lock);
+
+/**
+ * ttm_read_lock
+ *
+ * @lock: Pointer to a struct ttm_lock
+ * @interruptible: Interruptible sleeping while waiting for a lock.
+ *
+ * Takes the lock in read mode.
+ * Returns:
+ * -ERESTARTSYS If interrupted by a signal and interruptible is true.
+ */
+extern int ttm_read_lock(struct ttm_lock *lock, bool interruptible);
+
+/**
+ * ttm_read_trylock
+ *
+ * @lock: Pointer to a struct ttm_lock
+ * @interruptible: Interruptible sleeping while waiting for a lock.
+ *
+ * Tries to take the lock in read mode. If the lock is already held
+ * in write mode, the function will return -EBUSY. If the lock is held
+ * in vt or suspend mode, the function will sleep until these modes
+ * are unlocked.
+ *
+ * Returns:
+ * -EBUSY The lock was already held in write mode.
+ * -ERESTARTSYS If interrupted by a signal and interruptible is true.
+ */
+extern int ttm_read_trylock(struct ttm_lock *lock, bool interruptible);
+
+/**
+ * ttm_write_unlock
+ *
+ * @lock: Pointer to a struct ttm_lock
+ *
+ * Releases a write lock.
+ */
+extern void ttm_write_unlock(struct ttm_lock *lock);
+
+/**
+ * ttm_write_lock
+ *
+ * @lock: Pointer to a struct ttm_lock
+ * @interruptible: Interruptible sleeping while waiting for a lock.
+ *
+ * Takes the lock in write mode.
+ * Returns:
+ * -ERESTARTSYS If interrupted by a signal and interruptible is true.
+ */
+extern int ttm_write_lock(struct ttm_lock *lock, bool interruptible);
+
+/**
+ * ttm_lock_downgrade
+ *
+ * @lock: Pointer to a struct ttm_lock
+ *
+ * Downgrades a write lock to a read lock.
+ */
+extern void ttm_lock_downgrade(struct ttm_lock *lock);
+
+/**
+ * ttm_suspend_lock
+ *
+ * @lock: Pointer to a struct ttm_lock
+ *
+ * Takes the lock in suspend mode. Excludes read and write mode.
+ */
+extern void ttm_suspend_lock(struct ttm_lock *lock);
+
+/**
+ * ttm_suspend_unlock
+ *
+ * @lock: Pointer to a struct ttm_lock
+ *
+ * Releases a suspend lock
+ */
+extern void ttm_suspend_unlock(struct ttm_lock *lock);
+
+/**
+ * ttm_vt_lock
+ *
+ * @lock: Pointer to a struct ttm_lock
+ * @interruptible: Interruptible sleeping while waiting for a lock.
+ * @tfile: Pointer to a struct ttm_object_file to register the lock with.
+ *
+ * Takes the lock in vt mode.
+ * Returns:
+ * -ERESTARTSYS If interrupted by a signal and interruptible is true.
+ * -ENOMEM: Out of memory when locking.
+ */
+extern int ttm_vt_lock(struct ttm_lock *lock, bool interruptible,
+ struct ttm_object_file *tfile);
+
+/**
+ * ttm_vt_unlock
+ *
+ * @lock: Pointer to a struct ttm_lock
+ *
+ * Releases a vt lock.
+ * Returns:
+ * -EINVAL If the lock was not held.
+ */
+extern int ttm_vt_unlock(struct ttm_lock *lock);
+
+/**
+ * ttm_write_unlock
+ *
+ * @lock: Pointer to a struct ttm_lock
+ *
+ * Releases a write lock.
+ */
+extern void ttm_write_unlock(struct ttm_lock *lock);
+
+/**
+ * ttm_write_lock
+ *
+ * @lock: Pointer to a struct ttm_lock
+ * @interruptible: Interruptible sleeping while waiting for a lock.
+ *
+ * Takes the lock in write mode.
+ * Returns:
+ * -ERESTARTSYS If interrupted by a signal and interruptible is true.
+ */
+extern int ttm_write_lock(struct ttm_lock *lock, bool interruptible);
+
+/**
+ * ttm_lock_set_kill
+ *
+ * @lock: Pointer to a struct ttm_lock
+ * @val: Boolean whether to kill processes taking the lock.
+ * @signal: Signal to send to the process taking the lock.
+ *
+ * The kill-when-taking-lock functionality is used to kill processes that keep
+ * on using the TTM functionality when its resources has been taken down, for
+ * example when the X server exits. A typical sequence would look like this:
+ * - X server takes lock in write mode.
+ * - ttm_lock_set_kill() is called with @val set to true.
+ * - As part of X server exit, TTM resources are taken down.
+ * - X server releases the lock on file release.
+ * - Another dri client wants to render, takes the lock and is killed.
+ *
+ */
+static inline void ttm_lock_set_kill(struct ttm_lock *lock, bool val,
+ int signal)
+{
+ lock->kill_takers = val;
+ if (val)
+ lock->signal = signal;
+}
+
+#endif
projects / GitHub / MotorolaMobilityLLC / kernel-slsi.git / commitdiff