[PATCH 1/3] drm/ttm: allow fence to be added as shared

Alex Deucher alexdeucher at gmail.com
Wed Sep 10 13:05:47 PDT 2014


Dave any opinion on this patch set?  Are you ok with me including it
in my next drm-next pull request?  It'd be nice to get some additional
review on the ttm changes, but it shouldn't really affect any other
drivers unless they enable shared fences for concurrent buffer reads.
We'd like to get this in since it avoid unnecessary serialization of
the command stream when a buffer is read by multiple engines.

Alex

On Wed, Sep 10, 2014 at 11:26 AM, Alex Deucher <alexdeucher at gmail.com> wrote:
> On Thu, Sep 4, 2014 at 2:01 PM, Christian König <deathsimple at vodafone.de> wrote:
>> From: Christian König <christian.koenig at amd.com>
>>
>> This patch adds a new flag to the ttm_validate_buffer list to
>> add the fence as shared to the reservation object.
>>
>> Signed-off-by: Christian König <christian.koenig at amd.com>
>
> Reviewed-by: Alex Deucher <alexander.deucher at amd.com>
>
>> ---
>>  drivers/gpu/drm/qxl/qxl_release.c        |  1 +
>>  drivers/gpu/drm/radeon/radeon_cs.c       |  1 +
>>  drivers/gpu/drm/radeon/radeon_vm.c       |  3 +++
>>  drivers/gpu/drm/ttm/ttm_execbuf_util.c   | 18 +++++++++++++++---
>>  drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c  |  3 +++
>>  drivers/gpu/drm/vmwgfx/vmwgfx_resource.c |  5 +++++
>>  include/drm/ttm/ttm_execbuf_util.h       |  2 ++
>>  7 files changed, 30 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/qxl/qxl_release.c b/drivers/gpu/drm/qxl/qxl_release.c
>> index a6e19c8..446e71c 100644
>> --- a/drivers/gpu/drm/qxl/qxl_release.c
>> +++ b/drivers/gpu/drm/qxl/qxl_release.c
>> @@ -226,6 +226,7 @@ int qxl_release_list_add(struct qxl_release *release, struct qxl_bo *bo)
>>
>>         qxl_bo_ref(bo);
>>         entry->tv.bo = &bo->tbo;
>> +       entry->tv.shared = false;
>>         list_add_tail(&entry->tv.head, &release->bos);
>>         return 0;
>>  }
>> diff --git a/drivers/gpu/drm/radeon/radeon_cs.c b/drivers/gpu/drm/radeon/radeon_cs.c
>> index 6e3d1c8..cd517ab 100644
>> --- a/drivers/gpu/drm/radeon/radeon_cs.c
>> +++ b/drivers/gpu/drm/radeon/radeon_cs.c
>> @@ -183,6 +183,7 @@ static int radeon_cs_parser_relocs(struct radeon_cs_parser *p)
>>                 }
>>
>>                 p->relocs[i].tv.bo = &p->relocs[i].robj->tbo;
>> +               p->relocs[i].tv.shared = false;
>>                 p->relocs[i].handle = r->handle;
>>
>>                 radeon_cs_buckets_add(&buckets, &p->relocs[i].tv.head,
>> diff --git a/drivers/gpu/drm/radeon/radeon_vm.c b/drivers/gpu/drm/radeon/radeon_vm.c
>> index 671ee56..1cce446 100644
>> --- a/drivers/gpu/drm/radeon/radeon_vm.c
>> +++ b/drivers/gpu/drm/radeon/radeon_vm.c
>> @@ -143,6 +143,7 @@ struct radeon_cs_reloc *radeon_vm_get_bos(struct radeon_device *rdev,
>>         list[0].prefered_domains = RADEON_GEM_DOMAIN_VRAM;
>>         list[0].allowed_domains = RADEON_GEM_DOMAIN_VRAM;
>>         list[0].tv.bo = &vm->page_directory->tbo;
>> +       list[0].tv.shared = false;
>>         list[0].tiling_flags = 0;
>>         list[0].handle = 0;
>>         list_add(&list[0].tv.head, head);
>> @@ -156,6 +157,7 @@ struct radeon_cs_reloc *radeon_vm_get_bos(struct radeon_device *rdev,
>>                 list[idx].prefered_domains = RADEON_GEM_DOMAIN_VRAM;
>>                 list[idx].allowed_domains = RADEON_GEM_DOMAIN_VRAM;
>>                 list[idx].tv.bo = &list[idx].robj->tbo;
>> +               list[idx].tv.shared = false;
>>                 list[idx].tiling_flags = 0;
>>                 list[idx].handle = 0;
>>                 list_add(&list[idx++].tv.head, head);
>> @@ -395,6 +397,7 @@ static int radeon_vm_clear_bo(struct radeon_device *rdev,
>>
>>          memset(&tv, 0, sizeof(tv));
>>          tv.bo = &bo->tbo;
>> +       tv.shared = false;
>>
>>          INIT_LIST_HEAD(&head);
>>          list_add(&tv.head, &head);
>> diff --git a/drivers/gpu/drm/ttm/ttm_execbuf_util.c b/drivers/gpu/drm/ttm/ttm_execbuf_util.c
>> index adafc0f..8ce508e 100644
>> --- a/drivers/gpu/drm/ttm/ttm_execbuf_util.c
>> +++ b/drivers/gpu/drm/ttm/ttm_execbuf_util.c
>> @@ -119,8 +119,14 @@ int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket,
>>                         ret = -EBUSY;
>>                 }
>>
>> -               if (!ret)
>> -                       continue;
>> +               if (!ret) {
>> +                       if (!entry->shared)
>> +                               continue;
>> +
>> +                       ret = reservation_object_reserve_shared(bo->resv);
>> +                       if (!ret)
>> +                               continue;
>> +               }
>>
>>                 /* uh oh, we lost out, drop every reservation and try
>>                  * to only reserve this buffer, then start over if
>> @@ -136,6 +142,9 @@ int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket,
>>                         ret = 0;
>>                 }
>>
>> +               if (!ret && entry->shared)
>> +                       ret = reservation_object_reserve_shared(bo->resv);
>> +
>>                 if (unlikely(ret != 0)) {
>>                         if (ret == -EINTR)
>>                                 ret = -ERESTARTSYS;
>> @@ -183,7 +192,10 @@ void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
>>
>>         list_for_each_entry(entry, list, head) {
>>                 bo = entry->bo;
>> -               reservation_object_add_excl_fence(bo->resv, fence);
>> +               if (entry->shared)
>> +                       reservation_object_add_shared_fence(bo->resv, fence);
>> +               else
>> +                       reservation_object_add_excl_fence(bo->resv, fence);
>>                 ttm_bo_add_to_lru(bo);
>>                 __ttm_bo_unreserve(bo);
>>         }
>> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
>> index 0ceaddc..b4de3b2 100644
>> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
>> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
>> @@ -346,6 +346,7 @@ static int vmw_bo_to_validate_list(struct vmw_sw_context *sw_context,
>>                 ++sw_context->cur_val_buf;
>>                 val_buf = &vval_buf->base;
>>                 val_buf->bo = ttm_bo_reference(bo);
>> +               val_buf->shared = false;
>>                 list_add_tail(&val_buf->head, &sw_context->validate_nodes);
>>                 vval_buf->validate_as_mob = validate_as_mob;
>>         }
>> @@ -2670,9 +2671,11 @@ void __vmw_execbuf_release_pinned_bo(struct vmw_private *dev_priv,
>>         INIT_LIST_HEAD(&validate_list);
>>
>>         pinned_val.bo = ttm_bo_reference(dev_priv->pinned_bo);
>> +       pinned_val.shared = false;
>>         list_add_tail(&pinned_val.head, &validate_list);
>>
>>         query_val.bo = ttm_bo_reference(dev_priv->dummy_query_bo);
>> +       query_val.shared = false;
>>         list_add_tail(&query_val.head, &validate_list);
>>
>>         ret = ttm_eu_reserve_buffers(&ticket, &validate_list, false);
>> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
>> index ff0e03b..2658431 100644
>> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
>> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
>> @@ -133,6 +133,7 @@ static void vmw_resource_release(struct kref *kref)
>>                         struct ttm_validate_buffer val_buf;
>>
>>                         val_buf.bo = bo;
>> +                       val_buf.shared = false;
>>                         res->func->unbind(res, false, &val_buf);
>>                 }
>>                 res->backup_dirty = false;
>> @@ -1219,6 +1220,7 @@ vmw_resource_check_buffer(struct vmw_resource *res,
>>
>>         INIT_LIST_HEAD(&val_list);
>>         val_buf->bo = ttm_bo_reference(&res->backup->base);
>> +       val_buf->shared = false;
>>         list_add_tail(&val_buf->head, &val_list);
>>         ret = ttm_eu_reserve_buffers(NULL, &val_list, interruptible);
>>         if (unlikely(ret != 0))
>> @@ -1312,6 +1314,7 @@ int vmw_resource_do_evict(struct vmw_resource *res, bool interruptible)
>>         BUG_ON(!func->may_evict);
>>
>>         val_buf.bo = NULL;
>> +       val_buf.shared = false;
>>         ret = vmw_resource_check_buffer(res, interruptible, &val_buf);
>>         if (unlikely(ret != 0))
>>                 return ret;
>> @@ -1357,6 +1360,7 @@ int vmw_resource_validate(struct vmw_resource *res)
>>                 return 0;
>>
>>         val_buf.bo = NULL;
>> +       val_buf.shared = false;
>>         if (res->backup)
>>                 val_buf.bo = &res->backup->base;
>>         do {
>> @@ -1474,6 +1478,7 @@ void vmw_resource_move_notify(struct ttm_buffer_object *bo,
>>                 struct ttm_validate_buffer val_buf;
>>
>>                 val_buf.bo = bo;
>> +               val_buf.shared = false;
>>
>>                 list_for_each_entry_safe(res, n, &dma_buf->res_list, mob_head) {
>>
>> diff --git a/include/drm/ttm/ttm_execbuf_util.h b/include/drm/ttm/ttm_execbuf_util.h
>> index ff11a42..4604417 100644
>> --- a/include/drm/ttm/ttm_execbuf_util.h
>> +++ b/include/drm/ttm/ttm_execbuf_util.h
>> @@ -39,11 +39,13 @@
>>   *
>>   * @head:           list head for thread-private list.
>>   * @bo:             refcounted buffer object pointer.
>> + * @shared:         should the fence be added shared?
>>   */
>>
>>  struct ttm_validate_buffer {
>>         struct list_head head;
>>         struct ttm_buffer_object *bo;
>> +       bool shared;
>>  };
>>
>>  /**
>> --
>> 1.9.1
>>
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>> dri-devel at lists.freedesktop.org
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