diff mbox series

[4/6] drm/vmwgfx: Remove the reservation semaphore

Message ID 20210505035740.286923-5-zackr@vmware.com (mailing list archive)
State New, archived
Headers show
Series drm/vmwgfx: SVGA v3 and arm64 support | expand

Commit Message

Zack Rusin May 5, 2021, 3:57 a.m. UTC
Now since Christian reworked TTM to always keep objects on the LRU
list unless they are pinned we shouldn't need the reservation
semaphore. It makes the driver code a lot cleaner, especially
because it was a little hard to reason when and where the
reservation semaphore needed to be held.

Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Roland Scheidegger <sroland@vmware.com>
---
 drivers/gpu/drm/vmwgfx/Makefile               |   2 +-
 drivers/gpu/drm/vmwgfx/ttm_lock.c             | 194 ----------------
 drivers/gpu/drm/vmwgfx/ttm_lock.h             | 218 ------------------
 drivers/gpu/drm/vmwgfx/vmwgfx_bo.c            |  31 ---
 drivers/gpu/drm/vmwgfx/vmwgfx_context.c       |  13 +-
 drivers/gpu/drm/vmwgfx/vmwgfx_drv.c           |  14 +-
 drivers/gpu/drm/vmwgfx/vmwgfx_drv.h           |   6 -
 drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c       |   5 -
 drivers/gpu/drm/vmwgfx/vmwgfx_fb.c            |   8 -
 drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c         |  11 -
 drivers/gpu/drm/vmwgfx/vmwgfx_kms.c           |   7 -
 drivers/gpu/drm/vmwgfx/vmwgfx_resource.c      |   4 -
 drivers/gpu/drm/vmwgfx/vmwgfx_shader.c        |   6 -
 .../gpu/drm/vmwgfx/vmwgfx_simple_resource.c   |   5 -
 drivers/gpu/drm/vmwgfx/vmwgfx_surface.c       |  17 --
 15 files changed, 6 insertions(+), 535 deletions(-)
 delete mode 100644 drivers/gpu/drm/vmwgfx/ttm_lock.c
 delete mode 100644 drivers/gpu/drm/vmwgfx/ttm_lock.h
diff mbox series

Patch

diff --git a/drivers/gpu/drm/vmwgfx/Makefile b/drivers/gpu/drm/vmwgfx/Makefile
index 9f5743013cbb..09f6dcac768b 100644
--- a/drivers/gpu/drm/vmwgfx/Makefile
+++ b/drivers/gpu/drm/vmwgfx/Makefile
@@ -9,7 +9,7 @@  vmwgfx-y := vmwgfx_execbuf.o vmwgfx_gmr.o vmwgfx_kms.o vmwgfx_drv.o \
 	    vmwgfx_cotable.o vmwgfx_so.o vmwgfx_binding.o vmwgfx_msg.o \
 	    vmwgfx_simple_resource.o vmwgfx_va.o vmwgfx_blit.o \
 	    vmwgfx_validation.o vmwgfx_page_dirty.o vmwgfx_streamoutput.o \
-	    ttm_object.o ttm_lock.o ttm_memory.o
+	    ttm_object.o ttm_memory.o
 
 vmwgfx-$(CONFIG_DRM_FBDEV_EMULATION) += vmwgfx_fb.o
 vmwgfx-$(CONFIG_TRANSPARENT_HUGEPAGE) += vmwgfx_thp.o
diff --git a/drivers/gpu/drm/vmwgfx/ttm_lock.c b/drivers/gpu/drm/vmwgfx/ttm_lock.c
deleted file mode 100644
index 5971c72e6d10..000000000000
--- a/drivers/gpu/drm/vmwgfx/ttm_lock.c
+++ /dev/null
@@ -1,194 +0,0 @@ 
-/* 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));
-}
diff --git a/drivers/gpu/drm/vmwgfx/ttm_lock.h b/drivers/gpu/drm/vmwgfx/ttm_lock.h
deleted file mode 100644
index af8b28ca546f..000000000000
--- a/drivers/gpu/drm/vmwgfx/ttm_lock.h
+++ /dev/null
@@ -1,218 +0,0 @@ 
-/**************************************************************************
- *
- * 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/atomic.h>
-#include <linux/wait.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.
- */
-
-struct ttm_lock {
-	struct ttm_base_object base;
-	wait_queue_head_t queue;
-	spinlock_t lock;
-	int32_t rw;
-	uint32_t flags;
-};
-
-
-/**
- * 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);
-
-#endif
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
index 587314d57991..4aa97387d27d 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
@@ -96,10 +96,6 @@  int vmw_bo_pin_in_placement(struct vmw_private *dev_priv,
 	int ret;
 	uint32_t new_flags;
 
-	ret = ttm_write_lock(&dev_priv->reservation_sem, interruptible);
-	if (unlikely(ret != 0))
-		return ret;
-
 	vmw_execbuf_release_pinned_bo(dev_priv);
 
 	ret = ttm_bo_reserve(bo, interruptible, false, NULL);
@@ -116,9 +112,7 @@  int vmw_bo_pin_in_placement(struct vmw_private *dev_priv,
 		vmw_bo_pin_reserved(buf, true);
 
 	ttm_bo_unreserve(bo);
-
 err:
-	ttm_write_unlock(&dev_priv->reservation_sem);
 	return ret;
 }
 
@@ -144,10 +138,6 @@  int vmw_bo_pin_in_vram_or_gmr(struct vmw_private *dev_priv,
 	int ret;
 	uint32_t new_flags;
 
-	ret = ttm_write_lock(&dev_priv->reservation_sem, interruptible);
-	if (unlikely(ret != 0))
-		return ret;
-
 	vmw_execbuf_release_pinned_bo(dev_priv);
 
 	ret = ttm_bo_reserve(bo, interruptible, false, NULL);
@@ -172,7 +162,6 @@  int vmw_bo_pin_in_vram_or_gmr(struct vmw_private *dev_priv,
 
 	ttm_bo_unreserve(bo);
 err:
-	ttm_write_unlock(&dev_priv->reservation_sem);
 	return ret;
 }
 
@@ -228,10 +217,6 @@  int vmw_bo_pin_in_start_of_vram(struct vmw_private *dev_priv,
 	placement.num_busy_placement = 1;
 	placement.busy_placement = &place;
 
-	ret = ttm_write_lock(&dev_priv->reservation_sem, interruptible);
-	if (unlikely(ret != 0))
-		return ret;
-
 	vmw_execbuf_release_pinned_bo(dev_priv);
 	ret = ttm_bo_reserve(bo, interruptible, false, NULL);
 	if (unlikely(ret != 0))
@@ -263,7 +248,6 @@  int vmw_bo_pin_in_start_of_vram(struct vmw_private *dev_priv,
 
 	ttm_bo_unreserve(bo);
 err_unlock:
-	ttm_write_unlock(&dev_priv->reservation_sem);
 
 	return ret;
 }
@@ -287,10 +271,6 @@  int vmw_bo_unpin(struct vmw_private *dev_priv,
 	struct ttm_buffer_object *bo = &buf->base;
 	int ret;
 
-	ret = ttm_read_lock(&dev_priv->reservation_sem, interruptible);
-	if (unlikely(ret != 0))
-		return ret;
-
 	ret = ttm_bo_reserve(bo, interruptible, false, NULL);
 	if (unlikely(ret != 0))
 		goto err;
@@ -300,7 +280,6 @@  int vmw_bo_unpin(struct vmw_private *dev_priv,
 	ttm_bo_unreserve(bo);
 
 err:
-	ttm_read_unlock(&dev_priv->reservation_sem);
 	return ret;
 }
 
@@ -906,10 +885,6 @@  int vmw_bo_alloc_ioctl(struct drm_device *dev, void *data,
 	uint32_t handle;
 	int ret;
 
-	ret = ttm_read_lock(&dev_priv->reservation_sem, true);
-	if (unlikely(ret != 0))
-		return ret;
-
 	ret = vmw_user_bo_alloc(dev_priv, vmw_fpriv(file_priv)->tfile,
 				req->size, false, &handle, &vbo,
 				NULL);
@@ -924,7 +899,6 @@  int vmw_bo_alloc_ioctl(struct drm_device *dev, void *data,
 	vmw_bo_unreference(&vbo);
 
 out_no_bo:
-	ttm_read_unlock(&dev_priv->reservation_sem);
 
 	return ret;
 }
@@ -1119,10 +1093,6 @@  int vmw_dumb_create(struct drm_file *file_priv,
 	args->pitch = args->width * ((args->bpp + 7) / 8);
 	args->size = args->pitch * args->height;
 
-	ret = ttm_read_lock(&dev_priv->reservation_sem, true);
-	if (unlikely(ret != 0))
-		return ret;
-
 	ret = vmw_user_bo_alloc(dev_priv, vmw_fpriv(file_priv)->tfile,
 				    args->size, false, &args->handle,
 				    &vbo, NULL);
@@ -1131,7 +1101,6 @@  int vmw_dumb_create(struct drm_file *file_priv,
 
 	vmw_bo_unreference(&vbo);
 out_no_bo:
-	ttm_read_unlock(&dev_priv->reservation_sem);
 	return ret;
 }
 
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_context.c b/drivers/gpu/drm/vmwgfx/vmwgfx_context.c
index 4a5a3e246216..3ed9914cb994 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_context.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_context.c
@@ -748,10 +748,6 @@  static int vmw_context_define(struct drm_device *dev, void *data,
 		  ((dev_priv->has_mob) ? vmw_cmdbuf_res_man_size() : 0) +
 		  + VMW_IDA_ACC_SIZE + TTM_OBJ_EXTRA_SIZE;
 
-	ret = ttm_read_lock(&dev_priv->reservation_sem, true);
-	if (unlikely(ret != 0))
-		return ret;
-
 	ret = ttm_mem_global_alloc(vmw_mem_glob(dev_priv),
 				   vmw_user_context_size,
 				   &ttm_opt_ctx);
@@ -759,7 +755,7 @@  static int vmw_context_define(struct drm_device *dev, void *data,
 		if (ret != -ERESTARTSYS)
 			DRM_ERROR("Out of graphics memory for context"
 				  " creation.\n");
-		goto out_unlock;
+		goto out_ret;
 	}
 
 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
@@ -767,7 +763,7 @@  static int vmw_context_define(struct drm_device *dev, void *data,
 		ttm_mem_global_free(vmw_mem_glob(dev_priv),
 				    vmw_user_context_size);
 		ret = -ENOMEM;
-		goto out_unlock;
+		goto out_ret;
 	}
 
 	res = &ctx->res;
@@ -780,7 +776,7 @@  static int vmw_context_define(struct drm_device *dev, void *data,
 
 	ret = vmw_context_init(dev_priv, res, vmw_user_context_free, dx);
 	if (unlikely(ret != 0))
-		goto out_unlock;
+		goto out_ret;
 
 	tmp = vmw_resource_reference(&ctx->res);
 	ret = ttm_base_object_init(tfile, &ctx->base, false, VMW_RES_CONTEXT,
@@ -794,8 +790,7 @@  static int vmw_context_define(struct drm_device *dev, void *data,
 	arg->cid = ctx->base.handle;
 out_err:
 	vmw_resource_unreference(&res);
-out_unlock:
-	ttm_read_unlock(&dev_priv->reservation_sem);
+out_ret:
 	return ret;
 }
 
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index 1b27d7f7fcfa..22a2874116c9 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -708,7 +708,6 @@  static int vmw_driver_load(struct vmw_private *dev_priv, u32 pci_id)
 
 	mutex_init(&dev_priv->cmdbuf_mutex);
 	mutex_init(&dev_priv->binding_mutex);
-	ttm_lock_init(&dev_priv->reservation_sem);
 	spin_lock_init(&dev_priv->resource_lock);
 	spin_lock_init(&dev_priv->hw_lock);
 	spin_lock_init(&dev_priv->waiter_lock);
@@ -966,6 +965,7 @@  static int vmw_driver_load(struct vmw_private *dev_priv, u32 pci_id)
 		DRM_INFO("SM4_1 support available.\n");
 	if (dev_priv->sm_type == VMW_SM_4)
 		DRM_INFO("SM4 support available.\n");
+	DRM_INFO("Running without reservation semaphore\n");
 
 	snprintf(host_log, sizeof(host_log), "vmwgfx: Module Version: %d.%d.%d",
 		VMWGFX_DRIVER_MAJOR, VMWGFX_DRIVER_MINOR,
@@ -1191,9 +1191,7 @@  static void __vmw_svga_enable(struct vmw_private *dev_priv)
  */
 void vmw_svga_enable(struct vmw_private *dev_priv)
 {
-	(void) ttm_read_lock(&dev_priv->reservation_sem, false);
 	__vmw_svga_enable(dev_priv);
-	ttm_read_unlock(&dev_priv->reservation_sem);
 }
 
 /**
@@ -1238,7 +1236,6 @@  void vmw_svga_disable(struct vmw_private *dev_priv)
 	 *
 	 */
 	vmw_kms_lost_device(&dev_priv->drm);
-	ttm_write_lock(&dev_priv->reservation_sem, false);
 	if (ttm_resource_manager_used(man)) {
 		if (ttm_resource_manager_evict_all(&dev_priv->bdev, man))
 			DRM_ERROR("Failed evicting VRAM buffers.\n");
@@ -1247,7 +1244,6 @@  void vmw_svga_disable(struct vmw_private *dev_priv)
 			  SVGA_REG_ENABLE_HIDE |
 			  SVGA_REG_ENABLE_ENABLE);
 	}
-	ttm_write_unlock(&dev_priv->reservation_sem);
 }
 
 static void vmw_remove(struct pci_dev *pdev)
@@ -1287,14 +1283,12 @@  static int vmwgfx_pm_notifier(struct notifier_block *nb, unsigned long val,
 		 * Once user-space processes have been frozen, we can release
 		 * the lock again.
 		 */
-		ttm_suspend_lock(&dev_priv->reservation_sem);
 		dev_priv->suspend_locked = true;
 		break;
 	case PM_POST_HIBERNATION:
 	case PM_POST_RESTORE:
 		if (READ_ONCE(dev_priv->suspend_locked)) {
 			dev_priv->suspend_locked = false;
-			ttm_suspend_unlock(&dev_priv->reservation_sem);
 		}
 		break;
 	default:
@@ -1353,20 +1347,16 @@  static int vmw_pm_freeze(struct device *kdev)
 	int ret;
 
 	/*
-	 * Unlock for vmw_kms_suspend.
 	 * No user-space processes should be running now.
 	 */
-	ttm_suspend_unlock(&dev_priv->reservation_sem);
 	ret = vmw_kms_suspend(&dev_priv->drm);
 	if (ret) {
-		ttm_suspend_lock(&dev_priv->reservation_sem);
 		DRM_ERROR("Failed to freeze modesetting.\n");
 		return ret;
 	}
 	if (dev_priv->enable_fb)
 		vmw_fb_off(dev_priv);
 
-	ttm_suspend_lock(&dev_priv->reservation_sem);
 	vmw_execbuf_release_pinned_bo(dev_priv);
 	vmw_resource_evict_all(dev_priv);
 	vmw_release_device_early(dev_priv);
@@ -1379,7 +1369,6 @@  static int vmw_pm_freeze(struct device *kdev)
 			vmw_fifo_resource_inc(dev_priv);
 		WARN_ON(vmw_request_device_late(dev_priv));
 		dev_priv->suspend_locked = false;
-		ttm_suspend_unlock(&dev_priv->reservation_sem);
 		if (dev_priv->suspend_state)
 			vmw_kms_resume(dev);
 		if (dev_priv->enable_fb)
@@ -1416,7 +1405,6 @@  static int vmw_pm_restore(struct device *kdev)
 
 	vmw_fence_fifo_up(dev_priv->fman);
 	dev_priv->suspend_locked = false;
-	ttm_suspend_unlock(&dev_priv->reservation_sem);
 	if (dev_priv->suspend_state)
 		vmw_kms_resume(&dev_priv->drm);
 
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
index ffddccff867b..2fb6898ceca9 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
@@ -40,7 +40,6 @@ 
 #include <drm/ttm/ttm_bo_driver.h>
 #include <drm/ttm/ttm_execbuf_util.h>
 
-#include "ttm_lock.h"
 #include "ttm_object.h"
 
 #include "vmwgfx_fence.h"
@@ -593,11 +592,6 @@  struct vmw_private {
 
 	atomic_t num_fifo_resources;
 
-	/*
-	 * Replace this with an rwsem as soon as we have down_xx_interruptible()
-	 */
-	struct ttm_lock reservation_sem;
-
 	/*
 	 * Query processing. These members
 	 * are protected by the cmdbuf mutex.
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
index ca5360efa172..3ad07657b7d2 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
@@ -4443,10 +4443,6 @@  int vmw_execbuf_ioctl(struct drm_device *dev, void *data,
 			goto out;
 	}
 
-	ret = ttm_read_lock(&dev_priv->reservation_sem, true);
-	if (unlikely(ret != 0))
-		return ret;
-
 	ret = vmw_execbuf_process(file_priv, dev_priv,
 				  (void __user *)(unsigned long)arg->commands,
 				  NULL, arg->command_size, arg->throttle_us,
@@ -4454,7 +4450,6 @@  int vmw_execbuf_ioctl(struct drm_device *dev, void *data,
 				  (void __user *)(unsigned long)arg->fence_rep,
 				  NULL, arg->flags);
 
-	ttm_read_unlock(&dev_priv->reservation_sem);
 	if (unlikely(ret != 0))
 		goto out;
 
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c b/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c
index 33f07abfc3ae..d18c6a56e3dc 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c
@@ -195,7 +195,6 @@  static void vmw_fb_dirty_flush(struct work_struct *work)
 	if (!cur_fb)
 		goto out_unlock;
 
-	(void) ttm_read_lock(&vmw_priv->reservation_sem, false);
 	(void) ttm_bo_reserve(&vbo->base, false, false, NULL);
 	virtual = vmw_bo_map_and_cache(vbo);
 	if (!virtual)
@@ -254,7 +253,6 @@  static void vmw_fb_dirty_flush(struct work_struct *work)
 
 out_unreserve:
 	ttm_bo_unreserve(&vbo->base);
-	ttm_read_unlock(&vmw_priv->reservation_sem);
 	if (w && h) {
 		WARN_ON_ONCE(par->set_fb->funcs->dirty(cur_fb, NULL, 0, 0,
 						       &clip, 1));
@@ -396,8 +394,6 @@  static int vmw_fb_create_bo(struct vmw_private *vmw_priv,
 	struct vmw_buffer_object *vmw_bo;
 	int ret;
 
-	(void) ttm_write_lock(&vmw_priv->reservation_sem, false);
-
 	vmw_bo = kmalloc(sizeof(*vmw_bo), GFP_KERNEL);
 	if (!vmw_bo) {
 		ret = -ENOMEM;
@@ -412,12 +408,8 @@  static int vmw_fb_create_bo(struct vmw_private *vmw_priv,
 		goto err_unlock; /* init frees the buffer on failure */
 
 	*out = vmw_bo;
-	ttm_write_unlock(&vmw_priv->reservation_sem);
-
-	return 0;
 
 err_unlock:
-	ttm_write_unlock(&vmw_priv->reservation_sem);
 	return ret;
 }
 
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c
index b36032964b2f..6763d0638450 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c
@@ -302,10 +302,6 @@  int vmw_present_ioctl(struct drm_device *dev, void *data,
 	}
 	vfb = vmw_framebuffer_to_vfb(fb);
 
-	ret = ttm_read_lock(&dev_priv->reservation_sem, true);
-	if (unlikely(ret != 0))
-		goto out_no_ttm_lock;
-
 	ret = vmw_user_resource_lookup_handle(dev_priv, tfile, arg->sid,
 					      user_surface_converter,
 					      &res);
@@ -322,8 +318,6 @@  int vmw_present_ioctl(struct drm_device *dev, void *data,
 	vmw_surface_unreference(&surface);
 
 out_no_surface:
-	ttm_read_unlock(&dev_priv->reservation_sem);
-out_no_ttm_lock:
 	drm_framebuffer_put(fb);
 out_no_fb:
 	drm_modeset_unlock_all(dev);
@@ -391,15 +385,10 @@  int vmw_present_readback_ioctl(struct drm_device *dev, void *data,
 		goto out_no_ttm_lock;
 	}
 
-	ret = ttm_read_lock(&dev_priv->reservation_sem, true);
-	if (unlikely(ret != 0))
-		goto out_no_ttm_lock;
-
 	ret = vmw_kms_readback(dev_priv, file_priv,
 			       vfb, user_fence_rep,
 			       clips, num_clips);
 
-	ttm_read_unlock(&dev_priv->reservation_sem);
 out_no_ttm_lock:
 	drm_framebuffer_put(fb);
 out_no_fb:
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
index abbca8b0b3c5..67f693acea5f 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
@@ -1008,12 +1008,6 @@  static int vmw_framebuffer_bo_dirty(struct drm_framebuffer *framebuffer,
 
 	drm_modeset_lock_all(&dev_priv->drm);
 
-	ret = ttm_read_lock(&dev_priv->reservation_sem, true);
-	if (unlikely(ret != 0)) {
-		drm_modeset_unlock_all(&dev_priv->drm);
-		return ret;
-	}
-
 	if (!num_clips) {
 		num_clips = 1;
 		clips = &norect;
@@ -1037,7 +1031,6 @@  static int vmw_framebuffer_bo_dirty(struct drm_framebuffer *framebuffer,
 	}
 
 	vmw_cmd_flush(dev_priv, false);
-	ttm_read_unlock(&dev_priv->reservation_sem);
 
 	drm_modeset_unlock_all(&dev_priv->drm);
 
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
index 35f02958ee2c..d5da28be938a 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
@@ -990,7 +990,6 @@  int vmw_resource_pin(struct vmw_resource *res, bool interruptible)
 	struct vmw_private *dev_priv = res->dev_priv;
 	int ret;
 
-	ttm_write_lock(&dev_priv->reservation_sem, interruptible);
 	mutex_lock(&dev_priv->cmdbuf_mutex);
 	ret = vmw_resource_reserve(res, interruptible, false);
 	if (ret)
@@ -1029,7 +1028,6 @@  int vmw_resource_pin(struct vmw_resource *res, bool interruptible)
 	vmw_resource_unreserve(res, false, false, false, NULL, 0UL);
 out_no_reserve:
 	mutex_unlock(&dev_priv->cmdbuf_mutex);
-	ttm_write_unlock(&dev_priv->reservation_sem);
 
 	return ret;
 }
@@ -1047,7 +1045,6 @@  void vmw_resource_unpin(struct vmw_resource *res)
 	struct vmw_private *dev_priv = res->dev_priv;
 	int ret;
 
-	(void) ttm_read_lock(&dev_priv->reservation_sem, false);
 	mutex_lock(&dev_priv->cmdbuf_mutex);
 
 	ret = vmw_resource_reserve(res, false, true);
@@ -1065,7 +1062,6 @@  void vmw_resource_unpin(struct vmw_resource *res)
 	vmw_resource_unreserve(res, false, false, false, NULL, 0UL);
 
 	mutex_unlock(&dev_priv->cmdbuf_mutex);
-	ttm_read_unlock(&dev_priv->reservation_sem);
 }
 
 /**
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_shader.c b/drivers/gpu/drm/vmwgfx/vmwgfx_shader.c
index a0db06564013..b391975871a5 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_shader.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_shader.c
@@ -876,15 +876,9 @@  static int vmw_shader_define(struct drm_device *dev, struct drm_file *file_priv,
 		goto out_bad_arg;
 	}
 
-	ret = ttm_read_lock(&dev_priv->reservation_sem, true);
-	if (unlikely(ret != 0))
-		goto out_bad_arg;
-
 	ret = vmw_user_shader_alloc(dev_priv, buffer, size, offset,
 				    shader_type, num_input_sig,
 				    num_output_sig, tfile, shader_handle);
-
-	ttm_read_unlock(&dev_priv->reservation_sem);
 out_bad_arg:
 	vmw_bo_unreference(&buffer);
 	return ret;
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_simple_resource.c b/drivers/gpu/drm/vmwgfx/vmwgfx_simple_resource.c
index 73e9a487e659..33b69a70cfe3 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_simple_resource.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_simple_resource.c
@@ -162,13 +162,8 @@  vmw_simple_resource_create_ioctl(struct drm_device *dev, void *data,
 	account_size = ttm_round_pot(alloc_size) + VMW_IDA_ACC_SIZE +
 		TTM_OBJ_EXTRA_SIZE;
 
-	ret = ttm_read_lock(&dev_priv->reservation_sem, true);
-	if (ret)
-		return ret;
-
 	ret = ttm_mem_global_alloc(vmw_mem_glob(dev_priv), account_size,
 				   &ctx);
-	ttm_read_unlock(&dev_priv->reservation_sem);
 	if (ret) {
 		if (ret != -ERESTARTSYS)
 			DRM_ERROR("Out of graphics memory for %s"
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
index beab3e19d8e2..4e08cd7855e3 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
@@ -779,10 +779,6 @@  int vmw_surface_define_ioctl(struct drm_device *dev, void *data,
 		return -EINVAL;
 	}
 
-	ret = ttm_read_lock(&dev_priv->reservation_sem, true);
-	if (unlikely(ret != 0))
-		return ret;
-
 	ret = ttm_mem_global_alloc(vmw_mem_glob(dev_priv),
 				   size, &ctx);
 	if (unlikely(ret != 0)) {
@@ -913,7 +909,6 @@  int vmw_surface_define_ioctl(struct drm_device *dev, void *data,
 	rep->sid = user_srf->prime.base.handle;
 	vmw_resource_unreference(&res);
 
-	ttm_read_unlock(&dev_priv->reservation_sem);
 	return 0;
 out_no_copy:
 	kfree(srf->offsets);
@@ -924,7 +919,6 @@  int vmw_surface_define_ioctl(struct drm_device *dev, void *data,
 out_no_user_srf:
 	ttm_mem_global_free(vmw_mem_glob(dev_priv), size);
 out_unlock:
-	ttm_read_unlock(&dev_priv->reservation_sem);
 	return ret;
 }
 
@@ -1542,10 +1536,6 @@  vmw_gb_surface_define_internal(struct drm_device *dev,
 	if (drm_is_primary_client(file_priv))
 		user_srf->master = drm_master_get(file_priv->master);
 
-	ret = ttm_read_lock(&dev_priv->reservation_sem, true);
-	if (unlikely(ret != 0))
-		return ret;
-
 	res = &user_srf->srf.res;
 
 	if (req->base.buffer_handle != SVGA3D_INVALID_ID) {
@@ -1627,7 +1617,6 @@  vmw_gb_surface_define_internal(struct drm_device *dev,
 	vmw_resource_unreference(&res);
 
 out_unlock:
-	ttm_read_unlock(&dev_priv->reservation_sem);
 	return ret;
 }
 
@@ -2125,10 +2114,6 @@  int vmw_gb_surface_define(struct vmw_private *dev_priv,
 	if (req->sizes != NULL)
 		return -EINVAL;
 
-	ret = ttm_read_lock(&dev_priv->reservation_sem, true);
-	if (unlikely(ret != 0))
-		return ret;
-
 	ret = ttm_mem_global_alloc(vmw_mem_glob(dev_priv),
 				   user_accounting_size, &ctx);
 	if (ret != 0) {
@@ -2192,13 +2177,11 @@  int vmw_gb_surface_define(struct vmw_private *dev_priv,
 	 */
 	ret = vmw_surface_init(dev_priv, srf, vmw_user_surface_free);
 
-	ttm_read_unlock(&dev_priv->reservation_sem);
 	return ret;
 
 out_no_user_srf:
 	ttm_mem_global_free(vmw_mem_glob(dev_priv), user_accounting_size);
 
 out_unlock:
-	ttm_read_unlock(&dev_priv->reservation_sem);
 	return ret;
 }