Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 248 insertions, 0 deletions

diff --git a/include/drm/ttm/ttm_lock.h b/include/drm/ttm/ttm_lock.h
new file mode 100644
index 000000000..0c3af9836
--- /dev/null
+++ b/include/drm/ttm/ttm_lock.h
@@ -0,0 +1,248 @@
+/**************************************************************************
+ *
+ * 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 <linux/wait.h>
+#include <linux/atomic.h>
+
+#include "ttm_object.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