From: Christian König christian.koenig@amd.com

This feature is only used by vmwgfx and superfluous for everybody else.

Signed-off-by: Christian König christian.koenig@amd.com Co-developed-by: Thomas Hellstrom thellstrom@vmware.com Signed-off-by: Thomas Hellstrom thellstrom@vmware.com Tested-by: Thomas Hellstrom thellstrom@vmware.com --- drivers/gpu/drm/ttm/ttm_bo.c | 27 ------------------ drivers/gpu/drm/ttm/ttm_bo_util.c | 1 - drivers/gpu/drm/ttm/ttm_execbuf_util.c | 7 +---- drivers/gpu/drm/vmwgfx/vmwgfx_bo.c | 17 ++++++++---- drivers/gpu/drm/vmwgfx/vmwgfx_drv.h | 3 ++ drivers/gpu/drm/vmwgfx/vmwgfx_validation.c | 3 ++ include/drm/ttm/ttm_bo_api.h | 32 ---------------------- 7 files changed, 19 insertions(+), 71 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c index 20ff56f27aa4..a1201729cc53 100644 --- a/drivers/gpu/drm/ttm/ttm_bo.c +++ b/drivers/gpu/drm/ttm/ttm_bo.c @@ -153,7 +153,6 @@ static void ttm_bo_release_list(struct kref *list_kref)

BUG_ON(kref_read(&bo->list_kref)); BUG_ON(kref_read(&bo->kref)); - BUG_ON(atomic_read(&bo->cpu_writers)); BUG_ON(bo->mem.mm_node != NULL); BUG_ON(!list_empty(&bo->lru)); BUG_ON(!list_empty(&bo->ddestroy)); @@ -1314,7 +1313,6 @@ int ttm_bo_init_reserved(struct ttm_bo_device *bdev,

kref_init(&bo->kref); kref_init(&bo->list_kref); - atomic_set(&bo->cpu_writers, 0); INIT_LIST_HEAD(&bo->lru); INIT_LIST_HEAD(&bo->ddestroy); INIT_LIST_HEAD(&bo->swap); @@ -1826,31 +1824,6 @@ int ttm_bo_wait(struct ttm_buffer_object *bo, } EXPORT_SYMBOL(ttm_bo_wait);

-int ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait) -{ - int ret = 0; - - /* - * Using ttm_bo_reserve makes sure the lru lists are updated. - */ - - ret = ttm_bo_reserve(bo, true, no_wait, NULL); - if (unlikely(ret != 0)) - return ret; - ret = ttm_bo_wait(bo, true, no_wait); - if (likely(ret == 0)) - atomic_inc(&bo->cpu_writers); - ttm_bo_unreserve(bo); - return ret; -} -EXPORT_SYMBOL(ttm_bo_synccpu_write_grab); - -void ttm_bo_synccpu_write_release(struct ttm_buffer_object *bo) -{ - atomic_dec(&bo->cpu_writers); -} -EXPORT_SYMBOL(ttm_bo_synccpu_write_release); - /** * A buffer object shrink method that tries to swap out the first * buffer object on the bo_global::swap_lru list. diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c index fe81c565e7ef..b00039dcb487 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_util.c +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c @@ -511,7 +511,6 @@ static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo, mutex_init(&fbo->base.wu_mutex); fbo->base.moving = NULL; drm_vma_node_reset(&fbo->base.base.vma_node); - atomic_set(&fbo->base.cpu_writers, 0);

kref_init(&fbo->base.list_kref); kref_init(&fbo->base.kref); diff --git a/drivers/gpu/drm/ttm/ttm_execbuf_util.c b/drivers/gpu/drm/ttm/ttm_execbuf_util.c index 131dae8f4170..0519e1b5a49c 100644 --- a/drivers/gpu/drm/ttm/ttm_execbuf_util.c +++ b/drivers/gpu/drm/ttm/ttm_execbuf_util.c @@ -113,12 +113,7 @@ int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket, struct ttm_buffer_object *bo = entry->bo;

ret = __ttm_bo_reserve(bo, intr, (ticket == NULL), ticket); - if (!ret && unlikely(atomic_read(&bo->cpu_writers) > 0)) { - dma_resv_unlock(bo->base.resv); - - ret = -EBUSY; - - } else if (ret == -EALREADY && dups) { + if (ret == -EALREADY && dups) { struct ttm_validate_buffer *safe = entry; entry = list_prev_entry(entry, head); list_del(&safe->head); diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c index aad8d8140259..74016a08d118 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c @@ -566,7 +566,7 @@ static void vmw_user_bo_ref_obj_release(struct ttm_base_object *base,

switch (ref_type) { case TTM_REF_SYNCCPU_WRITE: - ttm_bo_synccpu_write_release(&user_bo->vbo.base); + atomic_dec(&user_bo->vbo.cpu_writers); break; default: WARN_ONCE(true, "Undefined buffer object reference release.\n"); @@ -682,12 +682,12 @@ static int vmw_user_bo_synccpu_grab(struct vmw_user_buffer_object *user_bo, struct ttm_object_file *tfile, uint32_t flags) { + bool nonblock = !!(flags & drm_vmw_synccpu_dontblock); struct ttm_buffer_object *bo = &user_bo->vbo.base; bool existed; int ret;

if (flags & drm_vmw_synccpu_allow_cs) { - bool nonblock = !!(flags & drm_vmw_synccpu_dontblock); long lret;

lret = dma_resv_wait_timeout_rcu @@ -700,15 +700,22 @@ static int vmw_user_bo_synccpu_grab(struct vmw_user_buffer_object *user_bo, return 0; }

- ret = ttm_bo_synccpu_write_grab - (bo, !!(flags & drm_vmw_synccpu_dontblock)); + ret = ttm_bo_reserve(bo, true, nonblock, NULL); + if (unlikely(ret != 0)) + return ret; + + ret = ttm_bo_wait(bo, true, nonblock); + if (likely(ret == 0)) + atomic_inc(&user_bo->vbo.cpu_writers); + + ttm_bo_unreserve(bo); if (unlikely(ret != 0)) return ret;

ret = ttm_ref_object_add(tfile, &user_bo->prime.base, TTM_REF_SYNCCPU_WRITE, &existed, false); if (ret != 0 || existed) - ttm_bo_synccpu_write_release(&user_bo->vbo.base); + atomic_dec(&user_bo->vbo.cpu_writers);

return ret; } diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h index 5eb73ded8e07..c7c6f1e42340 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h @@ -102,6 +102,8 @@ struct vmw_fpriv { * @base: The TTM buffer object * @res_list: List of resources using this buffer object as a backing MOB * @pin_count: pin depth + * @cpu_writers: Number of synccpu write grabs. Protected by reservation when + * increased. May be decreased without reservation. * @dx_query_ctx: DX context if this buffer object is used as a DX query MOB * @map: Kmap object for semi-persistent mappings * @res_prios: Eviction priority counts for attached resources @@ -110,6 +112,7 @@ struct vmw_buffer_object { struct ttm_buffer_object base; struct list_head res_list; s32 pin_count; + atomic_t cpu_writers; /* Not ref-counted. Protected by binding_mutex */ struct vmw_resource *dx_query_ctx; /* Protected by reservation */ diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_validation.c b/drivers/gpu/drm/vmwgfx/vmwgfx_validation.c index f611b2290a1b..7bff3628fc54 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_validation.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_validation.c @@ -521,6 +521,9 @@ int vmw_validation_bo_validate_single(struct ttm_buffer_object *bo, }; int ret;

+ if (atomic_read(&vbo->cpu_writers)) + return -EBUSY; + if (vbo->pin_count > 0) return 0;

diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h index 43c4929a2171..08a5c1fcb20c 100644 --- a/include/drm/ttm/ttm_bo_api.h +++ b/include/drm/ttm/ttm_bo_api.h @@ -147,7 +147,6 @@ struct ttm_tt; * holds a pointer to a persistent shmem object. * @ttm: TTM structure holding system pages. * @evicted: Whether the object was evicted without user-space knowing. - * @cpu_writes: For synchronization. Number of cpu writers. * @lru: List head for the lru list. * @ddestroy: List head for the delayed destroy list. * @swap: List head for swap LRU list. @@ -198,12 +197,6 @@ struct ttm_buffer_object { struct ttm_tt *ttm; bool evicted;

- /** - * Members protected by the bo::reserved lock only when written to. - */ - - atomic_t cpu_writers; - /** * Members protected by the bdev::lru_lock. */ @@ -441,31 +434,6 @@ void ttm_bo_unlock_delayed_workqueue(struct ttm_bo_device *bdev, int resched); bool ttm_bo_eviction_valuable(struct ttm_buffer_object *bo, const struct ttm_place *place);

-/** - * ttm_bo_synccpu_write_grab - * - * @bo: The buffer object: - * @no_wait: Return immediately if buffer is busy. - * - * Synchronizes a buffer object for CPU RW access. This means - * command submission that affects the buffer will return -EBUSY - * until ttm_bo_synccpu_write_release is called. - * - * Returns - * -EBUSY if the buffer is busy and no_wait is true. - * -ERESTARTSYS if interrupted by a signal. - */ -int ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait); - -/** - * ttm_bo_synccpu_write_release: - * - * @bo : The buffer object. - * - * Releases a synccpu lock. - */ -void ttm_bo_synccpu_write_release(struct ttm_buffer_object *bo); - /** * ttm_bo_acc_size *