[PATCH] drm/ttm: move cpu_writers handling into vmwgfx
Thomas Hellstrom
thellstrom at vmware.com
Wed Jun 12 15:27:46 UTC 2019
Hi, Christian,
This looks OK, although there are a couple of minor alterations needed
in the vmwgfx driver:
- We should operate on vmw_buffer_objects rather than on
user_buffer_objects.
- vmw_user_bo_verify_synccpu should move to the validate code.
I can take care of that if it's ok with you.
Thanks,
Thomas
On Fri, 2019-06-07 at 16:47 +0200, Christian König wrote:
> This feature is only used by vmwgfx and superflous for everybody
> else.
>
> Signed-off-by: Christian König <christian.koenig at amd.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 | 35 ++++++++++++++++++++
> ----
> drivers/gpu/drm/vmwgfx/vmwgfx_drv.h | 2 ++
> drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c | 8 ++++++
> drivers/gpu/drm/vmwgfx/vmwgfx_resource.c | 4 +++
> include/drm/ttm/ttm_bo_api.h | 31 ---------------------
> 8 files changed, 45 insertions(+), 70 deletions(-)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_bo.c
> b/drivers/gpu/drm/ttm/ttm_bo.c
> index c7de667d482a..4ec055ffd6a7 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));
> @@ -1308,7 +1307,6 @@ 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);
> @@ -1814,31 +1812,6 @@ 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 895d77d799e4..6f43f1f0de7c 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.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 957ec375a4ba..80fa52b36d5c 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)) {
> - reservation_object_unlock(bo->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 5d5c2bce01f3..457861c5047f 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
> @@ -565,7 +565,7 @@ 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");
> @@ -681,12 +681,12 @@ 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 = reservation_object_wait_timeout_rcu
> @@ -699,15 +699,20 @@ 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;
> }
> @@ -731,6 +736,26 @@ static int vmw_user_bo_synccpu_release(uint32_t
> handle,
> return 0;
> }
>
> +/**
> + * vmw_user_bo_verify_synccpu - Verify if grab for CPU access exists
> + *
> + * @list: list of ttm_validate_buffer objects
> + *
> + * Return:
> + * -EBUSY if a CPU grab is found, 0 otherwise.
> + */
> +int vmw_user_bo_verify_synccpu(struct list_head *list)
> +{
> + struct ttm_validate_buffer *entry;
> +
> + list_for_each_entry(entry, list, head) {
> + struct vmw_buffer_object *bo = vmw_buffer_object(entry-
> >bo);
> +
> + if (unlikely(atomic_read(&bo->cpu_writers) > 0))
> + return -EBUSY;
> + }
> + return 0;
> +}
>
> /**
> * vmw_user_bo_synccpu_ioctl - ioctl function implementing the
> synccpu
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
> b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
> index 96983c47fb40..b3988c957f0e 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
> @@ -90,6 +90,7 @@ 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 */
> @@ -749,6 +750,7 @@ extern int vmw_bo_init(struct vmw_private
> *dev_priv,
> void (*bo_free)(struct ttm_buffer_object *bo));
> extern int vmw_user_bo_verify_access(struct ttm_buffer_object *bo,
> struct ttm_object_file *tfile);
> +extern int vmw_user_bo_verify_synccpu(struct list_head *list);
> extern int vmw_user_bo_alloc(struct vmw_private *dev_priv,
> struct ttm_object_file *tfile,
> uint32_t size,
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
> b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
> index 2ff7ba04d8c8..271217f6e3a3 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
> @@ -3719,6 +3719,10 @@ int vmw_execbuf_process(struct drm_file
> *file_priv,
> if (unlikely(ret != 0))
> goto out_err_nores;
>
> + ret = vmw_user_bo_verify_synccpu(&val_ctx.bo_list);
> + if (unlikely(ret != 0))
> + goto out_err;
> +
> ret = vmw_validation_bo_validate(&val_ctx, true);
> if (unlikely(ret != 0))
> goto out_err;
> @@ -3918,6 +3922,10 @@ void __vmw_execbuf_release_pinned_bo(struct
> vmw_private *dev_priv,
> if (ret)
> goto out_no_reserve;
>
> + ret = vmw_user_bo_verify_synccpu(&val_ctx.bo_list);
> + if (unlikely(ret != 0))
> + goto out_no_emit;
> +
> if (dev_priv->query_cid_valid) {
> BUG_ON(fence != NULL);
> ret = vmw_fifo_emit_dummy_query(dev_priv, dev_priv-
> >query_cid);
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
> b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
> index 1d38a8b2f2ec..c55da6f0ff03 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
> @@ -469,6 +469,10 @@ vmw_resource_check_buffer(struct ww_acquire_ctx
> *ticket,
> if (unlikely(ret != 0))
> goto out_no_reserve;
>
> + ret = vmw_user_bo_verify_synccpu(&val_list);
> + if (unlikely(ret != 0))
> + goto out_no_validate;
> +
> if (res->func->needs_backup && list_empty(&res->mob_head))
> return 0;
>
> diff --git a/include/drm/ttm/ttm_bo_api.h
> b/include/drm/ttm/ttm_bo_api.h
> index 49d9cdfc58f2..e358e965d4c0 100644
> --- a/include/drm/ttm/ttm_bo_api.h
> +++ b/include/drm/ttm/ttm_bo_api.h
> @@ -145,7 +145,6 @@ 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.
> @@ -195,11 +194,6 @@ 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.
> @@ -443,31 +437,6 @@ 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
> *
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