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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /drivers/gpu/drm/vmwgfx/ttm_lock.c | |
parent | Initial commit. (diff) | |
download | linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip |
Adding upstream version 5.10.209.upstream/5.10.209
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/gpu/drm/vmwgfx/ttm_lock.c')
-rw-r--r-- | drivers/gpu/drm/vmwgfx/ttm_lock.c | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/drivers/gpu/drm/vmwgfx/ttm_lock.c b/drivers/gpu/drm/vmwgfx/ttm_lock.c new file mode 100644 index 000000000..5971c72e6 --- /dev/null +++ b/drivers/gpu/drm/vmwgfx/ttm_lock.c @@ -0,0 +1,194 @@ +/* SPDX-License-Identifier: GPL-2.0 OR MIT */ +/************************************************************************** + * + * 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 <linux/atomic.h> +#include <linux/errno.h> +#include <linux/wait.h> +#include <linux/sched/signal.h> +#include "ttm_lock.h" +#include "ttm_object.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; +} + +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); +} + +static bool __ttm_read_lock(struct ttm_lock *lock) +{ + bool locked = false; + + spin_lock(&lock->lock); + 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; +} + +static bool __ttm_read_trylock(struct ttm_lock *lock, bool *locked) +{ + bool block = true; + + *locked = false; + + spin_lock(&lock->lock); + 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); +} + +static bool __ttm_write_lock(struct ttm_lock *lock) +{ + bool locked = false; + + spin_lock(&lock->lock); + 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_write_lock(lock)); + + return ret; +} + +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)); +} |