From c078aa2fc4d8e022c3b611e07b25ff77afdf9b73 Mon Sep 17 00:00:00 2001 From: Thomas Hellstrom Date: Sun, 6 Dec 2009 21:46:26 +0100 Subject: [PATCH] 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: Thomas Hellstrom Signed-off-by: Dave Airlie --- drivers/gpu/drm/ttm/Makefile | 2 +- drivers/gpu/drm/ttm/ttm_execbuf_util.c | 117 +++++++++++++++++++++++++ include/drm/ttm/ttm_execbuf_util.h | 107 ++++++++++++++++++++++ 3 files changed, 225 insertions(+), 1 deletion(-) create mode 100644 drivers/gpu/drm/ttm/ttm_execbuf_util.c create mode 100644 include/drm/ttm/ttm_execbuf_util.h diff --git a/drivers/gpu/drm/ttm/Makefile b/drivers/gpu/drm/ttm/Makefile index 4473549bc5d2..1e138f5bae09 100644 --- a/drivers/gpu/drm/ttm/Makefile +++ b/drivers/gpu/drm/ttm/Makefile @@ -4,6 +4,6 @@ ccflags-y := -Iinclude/drm 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_object.o ttm_lock.o + ttm_object.o ttm_lock.o ttm_execbuf_util.o obj-$(CONFIG_DRM_TTM) += ttm.o diff --git a/drivers/gpu/drm/ttm/ttm_execbuf_util.c b/drivers/gpu/drm/ttm/ttm_execbuf_util.c new file mode 100644 index 000000000000..c285c2902d15 --- /dev/null +++ b/drivers/gpu/drm/ttm/ttm_execbuf_util.c @@ -0,0 +1,117 @@ +/************************************************************************** + * + * 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 +#include +#include + +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); diff --git a/include/drm/ttm/ttm_execbuf_util.h b/include/drm/ttm/ttm_execbuf_util.h new file mode 100644 index 000000000000..cd2c475da9ea --- /dev/null +++ b/include/drm/ttm/ttm_execbuf_util.h @@ -0,0 +1,107 @@ +/************************************************************************** + * + * 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 + */ + +#ifndef _TTM_EXECBUF_UTIL_H_ +#define _TTM_EXECBUF_UTIL_H_ + +#include "ttm/ttm_bo_api.h" +#include + +/** + * 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 -- 2.20.1