pan/bi: Add texture operator descriptor

Used to encode all the different texture modes.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7081>

src/panfrost/bifrost/bifrost.h

@@ -402,4 +402,140 @@ static const struct bifrost_reg_ctrl_23 bifrost_reg_ctrl_lut[32] = {
         [BIFROST_IDLE]      = { BIFROST_OP_IDLE,     BIFROST_OP_IDLE,     true },
 };
 
+/* Texture operator descriptors in various states. Usually packed in the
+ * compiler and stored as a constant */
+
+enum bifrost_index {
+        /* Both texture/sampler index immediate */
+        BIFROST_INDEX_IMMEDIATE_SHARED = 0,
+
+        /* Sampler index immediate, texture index from staging */
+        BIFROST_INDEX_IMMEDIATE_SAMPLER = 1,
+
+        /* Texture index immediate, sampler index from staging */
+        BIFROST_INDEX_IMMEDIATE_TEXTURE = 2,
+
+        /* Both indices from (separate) staging registers */
+        BIFROST_INDEX_REGISTER = 3,
+};
+
+enum bifrost_tex_op {
+        /* Given explicit derivatives, compute a gradient descriptor */
+        BIFROST_TEX_OP_GRDESC_DER = 4,
+
+        /* Given implicit derivatives (texture coordinates in a fragment
+         * shader), compute a gradient descriptor */
+        BIFROST_TEX_OP_GRDESC = 5,
+
+        /* Fetch a texel. Takes a staging register with LOD level / face index
+         * packed 16:16 */
+        BIFROST_TEX_OP_FETCH = 6,
+
+        /* Filtered texture */
+        BIFROST_TEX_OP_TEX = 7,
+};
+
+enum bifrost_lod_mode {
+        /* Takes two staging registers forming a 64-bit gradient descriptor
+         * (computed by a previous GRDESC or GRDESC_DER operation) */
+        BIFROST_LOD_MODE_GRDESC = 3,
+
+        /* Take a staging register with 8:8 fixed-point in bottom 16-bits
+         * specifying an explicit LOD */
+        BIFROST_LOD_MODE_EXPLICIT = 4,
+
+        /* Takes a staging register with bottom 16-bits as 8:8 fixed-point LOD
+         * bias and top 16-bit as 8:8 fixed-point lower bound (generally left
+         * zero), added and clamped to a computed LOD */
+        BIFROST_LOD_MODE_BIAS = 5,
+
+        /* Set LOD to zero */
+        BIFROST_LOD_MODE_ZERO = 6,
+
+        /* Compute LOD */
+        BIFROST_LOD_MODE_COMPUTE = 7,
+};
+
+enum bifrost_texture_format {
+        /* 16-bit floating point, with optional clamping */
+        BIFROST_TEXTURE_FORMAT_F16 = 0,
+        BIFROST_TEXTURE_FORMAT_F16_POS = 1,
+        BIFROST_TEXTURE_FORMAT_F16_PM1 = 2,
+        BIFROST_TEXTURE_FORMAT_F16_1 = 3,
+
+        /* 32-bit floating point, with optional clamping */
+        BIFROST_TEXTURE_FORMAT_F32 = 4,
+        BIFROST_TEXTURE_FORMAT_F32_POS = 5,
+        BIFROST_TEXTURE_FORMAT_F32_PM1 = 6,
+        BIFROST_TEXTURE_FORMAT_F32_1 = 7,
+};
+
+enum bifrost_texture_format_full {
+        /* Transclude bifrost_texture_format from above */
+
+        /* Integers, unclamped */
+        BIFROST_TEXTURE_FORMAT_U16 = 12,
+        BIFROST_TEXTURE_FORMAT_S16 = 13,
+        BIFROST_TEXTURE_FORMAT_U32 = 14,
+        BIFROST_TEXTURE_FORMAT_S32 = 15,
+};
+
+enum bifrost_texture_fetch {
+        /* Default texelFetch */
+        BIFROST_TEXTURE_FETCH_TEXEL = 1,
+
+        /* Deprecated, fetches 4x U32 of a U8 x 4 texture. Do not use. */
+        BIFROST_TEXTURE_FETCH_GATHER4_RGBA = 3,
+
+        /* Gathers */
+        BIFROST_TEXTURE_FETCH_GATHER4_R = 4,
+        BIFROST_TEXTURE_FETCH_GATHER4_G = 5,
+        BIFROST_TEXTURE_FETCH_GATHER4_B = 6,
+        BIFROST_TEXTURE_FETCH_GATHER4_A = 7
+};
+
+struct bifrost_texture_operation {
+        /* If immediate_indices is set:
+         *     - immediate sampler index
+         *     - index used as texture index
+         * Otherwise:
+         *      - bifrost_single_index in lower 2 bits
+         *      - 0x3 in upper 2 bits (single-texturing)
+         */
+        unsigned sampler_index_or_mode : 4;
+        unsigned index : 7;
+        bool immediate_indices : 1;
+        enum bifrost_tex_op op : 3;
+
+        /* If set for TEX/FETCH, loads texel offsets and multisample index from
+         * a staging register containing offset_x:offset_y:offset_z:ms_index
+         * packed 8:8:8:8. Offsets must be in [-31, +31]. If set for
+         * GRDESC(_DER), disable LOD bias. */
+        bool offset_or_bias_disable : 1;
+
+        /* If set for TEX/FETCH, loads fp32 shadow comparison value from a
+         * staging register. Implies fetch_component = gather4_r. If set for
+         * GRDESC(_DER), disables LOD clamping. */
+        bool shadow_or_clamp_disable : 1;
+
+        /* If set, loads an uint32 array index from a staging register. */
+        bool array : 1;
+
+        /* Texture dimension, or 0 for a cubemap */
+        unsigned dimension : 2;
+
+        /* Method to compute LOD value */
+        enum bifrost_lod_mode lod_mode : 3;
+
+        /* Reserved */
+        unsigned zero : 1;
+
+        /* Register format for the result or for a FETCH, the
+         * bifrost_texture_fetch component specification */
+        enum bifrost_texture_format_full format_or_fetch : 4;
+
+        /* Write mask for the result */
+        unsigned mask : 4;
+} __attribute__((packed));
+
 #endif