[PATCH] drm/fourcc: Add modifier definitions for Arm Fixed Rate Compression

Mon Jul 12 16:21:51 UTC 2021

On Thu, Jul 01, 2021 at 06:07:09PM +0100, Normunds Rieksts wrote:
> Arm Fixed Rate Compression (AFRC) is a proprietary fixed rate image
> compression protocol and format.
> It is designed to provide guaranteed bandwidth and memory footprint
> reductions in graphics and media use-cases.
> 
> This patch aims to add modifier definitions for describing
> AFRC.
> 
> Signed-off-by: Normunds Rieksts <normunds.rieksts at arm.com>

Looks good to me!

Reviewed-by: Liviu Dudau <liviu.dudau at arm.com>

Best regards,
Liviu

> ---
>  include/uapi/drm/drm_fourcc.h | 109 +++++++++++++++++++++++++++++++++-
>  1 file changed, 106 insertions(+), 3 deletions(-)
> 
> diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
> index f7156322aba5..9f4bb4a6f358 100644
> --- a/include/uapi/drm/drm_fourcc.h
> +++ b/include/uapi/drm/drm_fourcc.h
> @@ -900,9 +900,9 @@ drm_fourcc_canonicalize_nvidia_format_mod(__u64 modifier)
>  
>  /*
>   * The top 4 bits (out of the 56 bits alloted for specifying vendor specific
> - * modifiers) denote the category for modifiers. Currently we have only two
> - * categories of modifiers ie AFBC and MISC. We can have a maximum of sixteen
> - * different categories.
> + * modifiers) denote the category for modifiers. Currently we have three
> + * categories of modifiers ie AFBC, MISC and AFRC. We can have a maximum of
> + * sixteen different categories.
>   */
>  #define DRM_FORMAT_MOD_ARM_CODE(__type, __val) \
>  	fourcc_mod_code(ARM, ((__u64)(__type) << 52) | ((__val) & 0x000fffffffffffffULL))
> @@ -1017,6 +1017,109 @@ drm_fourcc_canonicalize_nvidia_format_mod(__u64 modifier)
>   */
>  #define AFBC_FORMAT_MOD_USM	(1ULL << 12)
>  
> +/*
> + * Arm Fixed-Rate Compression (AFRC) modifiers
> + *
> + * AFRC is a proprietary fixed rate image compression protocol and format,
> + * designed to provide guaranteed bandwidth and memory footprint
> + * reductions in graphics and media use-cases.
> + *
> + * AFRC buffers consist of one or more planes, with the same components
> + * and meaning as an uncompressed buffer using the same pixel format.
> + *
> + * Within each plane, the pixel/luma/chroma values are grouped into
> + * "coding unit" blocks which are individually compressed to a
> + * fixed size (in bytes). All coding units within a given plane of a buffer
> + * store the same number of values, and have the same compressed size.
> + *
> + * The coding unit size is configurable, allowing different rates of compression.
> + *
> + * The start of each AFRC buffer plane must be aligned to an alignment granule which
> + * depends on the coding unit size.
> + *
> + * Coding Unit Size   Plane Alignment
> + * ----------------   ---------------
> + * 16 bytes           1024 bytes
> + * 24 bytes           512  bytes
> + * 32 bytes           2048 bytes
> + *
> + * Coding units are grouped into paging tiles. AFRC buffer dimensions must be aligned
> + * to a multiple of the paging tile dimensions.
> + * The dimensions of each paging tile depend on whether the buffer is optimised for
> + * scanline (SCAN layout) or rotated (ROT layout) access.
> + *
> + * Layout   Paging Tile Width   Paging Tile Height
> + * ------   -----------------   ------------------
> + * SCAN     16 coding units     4 coding units
> + * ROT      8  coding units     8 coding units
> + *
> + * The dimensions of each coding unit depend on the number of components
> + * in the compressed plane and whether the buffer is optimised for
> + * scanline (SCAN layout) or rotated (ROT layout) access.
> + *
> + * Number of Components in Plane   Layout      Coding Unit Width   Coding Unit Height
> + * -----------------------------   ---------   -----------------   ------------------
> + * 1                               SCAN        16 samples          4 samples
> + * Example: 16x4 luma samples in a 'Y' plane
> + *          16x4 chroma 'V' values, in the 'V' plane of a fully-planar YUV buffer
> + * -----------------------------   ---------   -----------------   ------------------
> + * 1                               ROT         8 samples           8 samples
> + * Example: 8x8 luma samples in a 'Y' plane
> + *          8x8 chroma 'V' values, in the 'V' plane of a fully-planar YUV buffer
> + * -----------------------------   ---------   -----------------   ------------------
> + * 2                               DONT CARE   8 samples           4 samples
> + * Example: 8x4 chroma pairs in the 'UV' plane of a semi-planar YUV buffer
> + * -----------------------------   ---------   -----------------   ------------------
> + * 3                               DONT CARE   4 samples           4 samples
> + * Example: 4x4 pixels in an RGB buffer without alpha
> + * -----------------------------   ---------   -----------------   ------------------
> + * 4                               DONT CARE   4 samples           4 samples
> + * Example: 4x4 pixels in an RGB buffer with alpha
> + */
> +
> +#define DRM_FORMAT_MOD_ARM_TYPE_AFRC 0x02
> +
> +#define DRM_FORMAT_MOD_ARM_AFRC(__afrc_mode) \
> +	DRM_FORMAT_MOD_ARM_CODE(DRM_FORMAT_MOD_ARM_TYPE_AFRC, __afrc_mode)
> +
> +/*
> + * AFRC coding unit size modifier.
> + *
> + * Indicates the number of bytes used to store each compressed coding unit for
> + * one or more planes in an AFRC encoded buffer. The coding unit size for chrominance
> + * is the same for both Cb and Cr, which may be stored in separate planes.
> + *
> + * AFRC_FORMAT_MOD_CU_SIZE_P0 indicates the number of bytes used to store
> + * each compressed coding unit in the first plane of the buffer. For RGBA buffers
> + * this is the only plane, while for semi-planar and fully-planar YUV buffers,
> + * this corresponds to the luma plane.
> + *
> + * AFRC_FORMAT_MOD_CU_SIZE_P12 indicates the number of bytes used to store
> + * each compressed coding unit in the second and third planes in the buffer.
> + * For semi-planar and fully-planar YUV buffers, this corresponds to the chroma plane(s).
> + *
> + * For single-plane buffers, AFRC_FORMAT_MOD_CU_SIZE_P0 must be specified
> + * and AFRC_FORMAT_MOD_CU_SIZE_P12 must be zero.
> + * For semi-planar and fully-planar buffers, both AFRC_FORMAT_MOD_CU_SIZE_P0 and
> + * AFRC_FORMAT_MOD_CU_SIZE_P12 must be specified.
> + */
> +#define AFRC_FORMAT_MOD_CU_SIZE_MASK 0xf
> +#define AFRC_FORMAT_MOD_CU_SIZE_16 (1ULL)
> +#define AFRC_FORMAT_MOD_CU_SIZE_24 (2ULL)
> +#define AFRC_FORMAT_MOD_CU_SIZE_32 (3ULL)
> +
> +#define AFRC_FORMAT_MOD_CU_SIZE_P0(__afrc_cu_size) (__afrc_cu_size)
> +#define AFRC_FORMAT_MOD_CU_SIZE_P12(__afrc_cu_size) ((__afrc_cu_size) << 4)
> +
> +/*
> + * AFRC scanline memory layout.
> + *
> + * Indicates if the buffer uses the scanline-optimised layout
> + * for an AFRC encoded buffer, otherwise, it uses the rotation-optimised layout.
> + * The memory layout is the same for all planes.
> + */
> +#define AFRC_FORMAT_MOD_LAYOUT_SCAN (1ULL << 8)
> +
>  /*
>   * Arm 16x16 Block U-Interleaved modifier
>   *
> -- 
> 2.17.1
> 

-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
  ---------------
    ¯\_(ツ)_/¯