Commit c078aa2f authored by Thomas Hellstrom's avatar Thomas Hellstrom Committed by Dave Airlie

drm/ttm: Add TTM execbuf utilities.

Utilities to reserve, unreserve and fence a list of TTM
buffer objects in a deadlock-safe manner.

Used by the vmwgfx driver.
Signed-off-by: default avatarThomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
parent 4aff1013
...@@ -4,6 +4,6 @@ ...@@ -4,6 +4,6 @@
ccflags-y := -Iinclude/drm ccflags-y := -Iinclude/drm
ttm-y := ttm_agp_backend.o ttm_memory.o ttm_tt.o ttm_bo.o \ ttm-y := ttm_agp_backend.o ttm_memory.o ttm_tt.o ttm_bo.o \
ttm_bo_util.o ttm_bo_vm.o ttm_module.o ttm_global.o \ ttm_bo_util.o ttm_bo_vm.o ttm_module.o ttm_global.o \
ttm_object.o ttm_lock.o ttm_object.o ttm_lock.o ttm_execbuf_util.o
obj-$(CONFIG_DRM_TTM) += ttm.o obj-$(CONFIG_DRM_TTM) += ttm.o
/**************************************************************************
*
* Copyright (c) 2006-2009 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.
*
**************************************************************************/
#include "ttm/ttm_execbuf_util.h"
#include "ttm/ttm_bo_driver.h"
#include "ttm/ttm_placement.h"
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/module.h>
void ttm_eu_backoff_reservation(struct list_head *list)
{
struct ttm_validate_buffer *entry;
list_for_each_entry(entry, list, head) {
struct ttm_buffer_object *bo = entry->bo;
if (!entry->reserved)
continue;
entry->reserved = false;
ttm_bo_unreserve(bo);
}
}
EXPORT_SYMBOL(ttm_eu_backoff_reservation);
/*
* Reserve buffers for validation.
*
* If a buffer in the list is marked for CPU access, we back off and
* wait for that buffer to become free for GPU access.
*
* If a buffer is reserved for another validation, the validator with
* the highest validation sequence backs off and waits for that buffer
* to become unreserved. This prevents deadlocks when validating multiple
* buffers in different orders.
*/
int ttm_eu_reserve_buffers(struct list_head *list, uint32_t val_seq)
{
struct ttm_validate_buffer *entry;
int ret;
retry:
list_for_each_entry(entry, list, head) {
struct ttm_buffer_object *bo = entry->bo;
entry->reserved = false;
ret = ttm_bo_reserve(bo, true, false, true, val_seq);
if (ret != 0) {
ttm_eu_backoff_reservation(list);
if (ret == -EAGAIN) {
ret = ttm_bo_wait_unreserved(bo, true);
if (unlikely(ret != 0))
return ret;
goto retry;
} else
return ret;
}
entry->reserved = true;
if (unlikely(atomic_read(&bo->cpu_writers) > 0)) {
ttm_eu_backoff_reservation(list);
ret = ttm_bo_wait_cpu(bo, false);
if (ret)
return ret;
goto retry;
}
}
return 0;
}
EXPORT_SYMBOL(ttm_eu_reserve_buffers);
void ttm_eu_fence_buffer_objects(struct list_head *list, void *sync_obj)
{
struct ttm_validate_buffer *entry;
list_for_each_entry(entry, list, head) {
struct ttm_buffer_object *bo = entry->bo;
struct ttm_bo_driver *driver = bo->bdev->driver;
void *old_sync_obj;
spin_lock(&bo->lock);
old_sync_obj = bo->sync_obj;
bo->sync_obj = driver->sync_obj_ref(sync_obj);
bo->sync_obj_arg = entry->new_sync_obj_arg;
spin_unlock(&bo->lock);
ttm_bo_unreserve(bo);
entry->reserved = false;
if (old_sync_obj)
driver->sync_obj_unref(&old_sync_obj);
}
}
EXPORT_SYMBOL(ttm_eu_fence_buffer_objects);
/**************************************************************************
*
* Copyright (c) 2006-2009 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>
*/
#ifndef _TTM_EXECBUF_UTIL_H_
#define _TTM_EXECBUF_UTIL_H_
#include "ttm/ttm_bo_api.h"
#include <linux/list.h>
/**
* struct ttm_validate_buffer
*
* @head: list head for thread-private list.
* @bo: refcounted buffer object pointer.
* @new_sync_obj_arg: New sync_obj_arg for @bo, to be used once
* adding a new sync object.
* @reservied: Indicates whether @bo has been reserved for validation.
*/
struct ttm_validate_buffer {
struct list_head head;
struct ttm_buffer_object *bo;
void *new_sync_obj_arg;
bool reserved;
};
/**
* function ttm_eu_backoff_reservation
*
* @list: thread private list of ttm_validate_buffer structs.
*
* Undoes all buffer validation reservations for bos pointed to by
* the list entries.
*/
extern void ttm_eu_backoff_reservation(struct list_head *list);
/**
* function ttm_eu_reserve_buffers
*
* @list: thread private list of ttm_validate_buffer structs.
* @val_seq: A unique sequence number.
*
* Tries to reserve bos pointed to by the list entries for validation.
* If the function returns 0, all buffers are marked as "unfenced",
* taken off the lru lists and are not synced for write CPU usage.
*
* If the function detects a deadlock due to multiple threads trying to
* reserve the same buffers in reverse order, all threads except one will
* back off and retry. This function may sleep while waiting for
* CPU write reservations to be cleared, and for other threads to
* unreserve their buffers.
*
* This function may return -ERESTART or -EAGAIN if the calling process
* receives a signal while waiting. In that case, no buffers on the list
* will be reserved upon return.
*
* Buffers reserved by this function should be unreserved by
* a call to either ttm_eu_backoff_reservation() or
* ttm_eu_fence_buffer_objects() when command submission is complete or
* has failed.
*/
extern int ttm_eu_reserve_buffers(struct list_head *list, uint32_t val_seq);
/**
* function ttm_eu_fence_buffer_objects.
*
* @list: thread private list of ttm_validate_buffer structs.
* @sync_obj: The new sync object for the buffers.
*
* This function should be called when command submission is complete, and
* it will add a new sync object to bos pointed to by entries on @list.
* It also unreserves all buffers, putting them on lru lists.
*
*/
extern void ttm_eu_fence_buffer_objects(struct list_head *list, void *sync_obj);
#endif
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