[Mesa-dev] [PATCH 04/14] gallium/radeon: add RADEON_FLAG_HANDLE

[Nicolai Hähnle]

On 17.09.2016 13:49, Marek Olšák wrote:
> On Tue, Sep 13, 2016 at 11:56 AM, Nicolai Hähnle <nhaehnle at gmail.com> wrote:
>> From: Nicolai Hähnle <nicolai.haehnle at amd.com>
>>
>> When passed to winsys->buffer_create, this flag will indicate that we require
>> a buffer that maps 1:1 with a kernel buffer handle.
>>
>> This is currently set for all textures, since textures can potentially be
>> exported to other processes. This is not a huge loss, since the main purpose
>> of this patch series is to deal with applications that allocate many small
>> buffers.
>>
>> A hypothetical application with tons of tiny textures might still benefit
>> from not setting this flag, but that's not a use case I'm worried about
>> just now.
>> ---
>>  src/gallium/drivers/r300/r300_texture.c       | 2 +-
>>  src/gallium/drivers/radeon/r600_texture.c     | 2 ++
>>  src/gallium/drivers/radeon/radeon_winsys.h    | 1 +
>>  src/gallium/winsys/amdgpu/drm/amdgpu_bo.c     | 3 +++
>>  src/gallium/winsys/radeon/drm/radeon_drm_bo.c | 3 +++
>>  src/gallium/winsys/radeon/drm/radeon_drm_cs.c | 2 +-
>>  6 files changed, 11 insertions(+), 2 deletions(-)
>>
>> diff --git a/src/gallium/drivers/r300/r300_texture.c b/src/gallium/drivers/r300/r300_texture.c
>> index 5f459e4..fbac07a 100644
>> --- a/src/gallium/drivers/r300/r300_texture.c
>> +++ b/src/gallium/drivers/r300/r300_texture.c
>> @@ -1107,21 +1107,21 @@ r300_texture_create_object(struct r300_screen *rscreen,
>>          tex->domain &= ~RADEON_DOMAIN_GTT;
>>      }
>>      /* Just fail if the texture is too large. */
>>      if (!tex->domain) {
>>          goto fail;
>>      }
>>
>>      /* Create the backing buffer if needed. */
>>      if (!tex->buf) {
>>          tex->buf = rws->buffer_create(rws, tex->tex.size_in_bytes, 2048,
>> -                                      tex->domain, 0);
>> +                                      tex->domain, RADEON_FLAG_HANDLE);
>>
>>          if (!tex->buf) {
>>              goto fail;
>>          }
>>      }
>>
>>      if (SCREEN_DBG_ON(rscreen, DBG_MSAA) && base->nr_samples > 1) {
>>          fprintf(stderr, "r300: %ix MSAA %s buffer created\n",
>>                  base->nr_samples,
>>                  util_format_is_depth_or_stencil(base->format) ? "depth" : "color");
>> diff --git a/src/gallium/drivers/radeon/r600_texture.c b/src/gallium/drivers/radeon/r600_texture.c
>> index 41fd94b..b6e5880 100644
>> --- a/src/gallium/drivers/radeon/r600_texture.c
>> +++ b/src/gallium/drivers/radeon/r600_texture.c
>> @@ -1105,20 +1105,22 @@ r600_texture_create_object(struct pipe_screen *screen,
>>                         rtex->dcc_offset = align64(rtex->size, rtex->surface.dcc_alignment);
>>                         rtex->size = rtex->dcc_offset + rtex->surface.dcc_size;
>>                 }
>>         }
>>
>>         /* Now create the backing buffer. */
>>         if (!buf) {
>>                 r600_init_resource_fields(rscreen, resource, rtex->size,
>>                                           rtex->surface.bo_alignment);
>>
>> +               resource->flags |= RADEON_FLAG_HANDLE;
>> +
>>                 if (!r600_alloc_resource(rscreen, resource)) {
>>                         FREE(rtex);
>>                         return NULL;
>>                 }
>>         } else {
>>                 resource->buf = buf;
>>                 resource->gpu_address = rscreen->ws->buffer_get_virtual_address(resource->buf);
>>                 resource->domains = rscreen->ws->buffer_get_initial_domain(resource->buf);
>>         }
>>
>> diff --git a/src/gallium/drivers/radeon/radeon_winsys.h b/src/gallium/drivers/radeon/radeon_winsys.h
>> index 809a203..8196358 100644
>> --- a/src/gallium/drivers/radeon/radeon_winsys.h
>> +++ b/src/gallium/drivers/radeon/radeon_winsys.h
>> @@ -45,20 +45,21 @@ enum radeon_bo_layout {
>>  enum radeon_bo_domain { /* bitfield */
>>      RADEON_DOMAIN_GTT  = 2,
>>      RADEON_DOMAIN_VRAM = 4,
>>      RADEON_DOMAIN_VRAM_GTT = RADEON_DOMAIN_VRAM | RADEON_DOMAIN_GTT
>>  };
>>
>>  enum radeon_bo_flag { /* bitfield */
>>      RADEON_FLAG_GTT_WC =        (1 << 0),
>>      RADEON_FLAG_CPU_ACCESS =    (1 << 1),
>>      RADEON_FLAG_NO_CPU_ACCESS = (1 << 2),
>> +    RADEON_FLAG_HANDLE =        (1 << 3), /* whether get_handle must be supported */
>
> But get_handle must always be supported because of inter-API interop.
> Maybe the comment should be:
>    /* get_handle must return offset=0 */
>
> Or even:
>    /* the buffer must not be suballocated */

I'll change the comment.

Nicolai

>
> Marek
>