[Mesa-dev] [PATCH 08/13] i915g: add winsys function to create tiled buffers

[Jakob Bornecrantz]

On Fri, Nov 19, 2010 at 11:38 PM, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> Different kernels have different restrictions for tiled buffers.
> Hence use the libdrm abstraction to calculate the necessary
> stride and height alignment requirements.
>
> Not yet used.
>
> Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>

I discussed this a bit with Daniel on IRC just writing it down so
other people can join in.

> ---
>  src/gallium/drivers/i915/i915_winsys.h        |    8 +++++
>  src/gallium/winsys/i915/drm/i915_drm_buffer.c |   35 ++++++++++++++++++++++++-
>  src/gallium/winsys/i915/sw/i915_sw_buffer.c   |   27 +++++++++++++++++++
>  src/gallium/winsys/i915/sw/i915_sw_winsys.h   |    2 +
>  4 files changed, 71 insertions(+), 1 deletions(-)
>
> diff --git a/src/gallium/drivers/i915/i915_winsys.h b/src/gallium/drivers/i915/i915_winsys.h
> index 1058a0e..a071c5e 100644
> --- a/src/gallium/drivers/i915/i915_winsys.h
> +++ b/src/gallium/drivers/i915/i915_winsys.h
> @@ -133,6 +133,14 @@ struct i915_winsys {
>                        unsigned size);
>
>    /**
> +    * Create a tiled buffer.
> +    */
> +   struct i915_winsys_buffer *
> +      (*buffer_create_tiled)(struct i915_winsys *iws,
> +                       unsigned x, unsigned y,
> +                      unsigned *tiling, unsigned *stride);

Looking ahead in the patch series there I see there is no need to pass
x and y should probably be renamed total_nbocksy or just nblocksy.

But in the future if you need more information for getting correct
tiling information don't be afraid to pass down the texture format and
stride expressed in nblocksx.

Also as mentioned in earlier emails use the tile enum for the
arguments descriptor.

> +
> +   /**
>     * Creates a buffer from a handle.
>     * Used to implement pipe_screen::resource_from_handle.
>     * Also provides the stride information needed for the
> diff --git a/src/gallium/winsys/i915/drm/i915_drm_buffer.c b/src/gallium/winsys/i915/drm/i915_drm_buffer.c
> index ffc1772..be87d28 100644
> --- a/src/gallium/winsys/i915/drm/i915_drm_buffer.c
> +++ b/src/gallium/winsys/i915/drm/i915_drm_buffer.c
> @@ -11,7 +11,6 @@ i915_drm_buffer_create(struct i915_winsys *iws,
>  {
>    struct i915_drm_buffer *buf = CALLOC_STRUCT(i915_drm_buffer);
>    struct i915_drm_winsys *idws = i915_drm_winsys(iws);
> -   char *name;
>
>    if (!buf)
>       return NULL;
> @@ -35,6 +34,39 @@ err:
>  }
>
>  static struct i915_winsys_buffer *
> +i915_drm_buffer_create_tiled(struct i915_winsys *iws,
> +                            unsigned x, unsigned y,
> +                            unsigned *tiling, unsigned *stride)
> +{
> +   struct i915_drm_buffer *buf = CALLOC_STRUCT(i915_drm_buffer);
> +   struct i915_drm_winsys *idws = i915_drm_winsys(iws);
> +   unsigned long pitch = *stride;
> +   uint32_t tiling_mode = *tiling;
> +
> +   if (!buf)
> +      return NULL;
> +
> +   buf->magic = 0xDEAD1337;
> +   buf->flinked = FALSE;
> +   buf->flink = 0;
> +
> +   buf->bo = drm_intel_bo_alloc_tiled(idws->gem_manager, "i915 gallium buffer",
> +                                     x, y, 1, &tiling_mode, &pitch, 0);
> +
> +   if (!buf->bo)
> +      goto err;
> +
> +   *stride = pitch;
> +   *tiling = tiling_mode;
> +   return (struct i915_winsys_buffer *)buf;
> +
> +err:
> +   assert(0);
> +   FREE(buf);
> +   return NULL;
> +}
> +
> +static struct i915_winsys_buffer *
>  i915_drm_buffer_from_handle(struct i915_winsys *iws,
>                              struct winsys_handle *whandle,
>                              unsigned *stride)
> @@ -179,6 +211,7 @@ void
>  i915_drm_winsys_init_buffer_functions(struct i915_drm_winsys *idws)
>  {
>    idws->base.buffer_create = i915_drm_buffer_create;
> +   idws->base.buffer_create_tiled = i915_drm_buffer_create_tiled;
>    idws->base.buffer_from_handle = i915_drm_buffer_from_handle;
>    idws->base.buffer_get_handle = i915_drm_buffer_get_handle;
>    idws->base.buffer_set_fence_reg = i915_drm_buffer_set_fence_reg;
> diff --git a/src/gallium/winsys/i915/sw/i915_sw_buffer.c b/src/gallium/winsys/i915/sw/i915_sw_buffer.c
> index a1c2deb..be8b9cb 100644
> --- a/src/gallium/winsys/i915/sw/i915_sw_buffer.c
> +++ b/src/gallium/winsys/i915/sw/i915_sw_buffer.c
> @@ -26,6 +26,32 @@ err:
>    return NULL;
>  }
>
> +static struct i915_winsys_buffer *
> +i915_sw_buffer_create_tiled(struct i915_winsys *iws,
> +                      unsigned x, unsigned y, unsigned *tiling, unsigned *stride)
> +{
> +   struct i915_sw_buffer *buf = CALLOC_STRUCT(i915_sw_buffer);
> +
> +   if (!buf)
> +      return NULL;
> +
> +   buf->magic = 0xDEAD1337;
> +   buf->name = "i915 gallium buffer";
> +   buf->ptr = CALLOC(*stride * y, 1);
> +   buf->tiling = *tiling;
> +   buf->stride = *stride;
> +
> +   if (!buf->ptr)
> +      goto err;
> +
> +   return (struct i915_winsys_buffer *)buf;
> +
> +err:
> +   assert(0);
> +   FREE(buf);
> +   return NULL;
> +}
> +
>  static int
>  i915_sw_buffer_set_fence_reg(struct i915_winsys *iws,
>                                struct i915_winsys_buffer *buffer,
> @@ -94,6 +120,7 @@ void
>  i915_sw_winsys_init_buffer_functions(struct i915_sw_winsys *isws)
>  {
>    isws->base.buffer_create = i915_sw_buffer_create;
> +   isws->base.buffer_create_tiled = i915_sw_buffer_create_tiled;
>    isws->base.buffer_set_fence_reg = i915_sw_buffer_set_fence_reg;
>    isws->base.buffer_map = i915_sw_buffer_map;
>    isws->base.buffer_unmap = i915_sw_buffer_unmap;
> diff --git a/src/gallium/winsys/i915/sw/i915_sw_winsys.h b/src/gallium/winsys/i915/sw/i915_sw_winsys.h
> index 666ea34..7d6e8fd 100644
> --- a/src/gallium/winsys/i915/sw/i915_sw_winsys.h
> +++ b/src/gallium/winsys/i915/sw/i915_sw_winsys.h
> @@ -44,6 +44,8 @@ struct i915_sw_buffer {
>    unsigned map_count;
>    enum i915_winsys_buffer_tile tile;
>    const char *name;
> +   unsigned tiling;

Just reuse the tile field instead of creating a new one?

> +   unsigned stride;
>  };
>
>  static INLINE struct i915_sw_buffer *
> --
> 1.7.1