pvr, pco: track and implement workaround for brn74056

Signed-off-by: Simon Perretta <simon.perretta@imgtec.com>
Acked-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/37512>

src/imagination/common/device_info/axe-1-16m.h

@@ -108,6 +108,7 @@ static const struct pvr_device_enhancements pvr_device_enhancements_33_15_11_3 =
 
 static const struct pvr_device_quirks pvr_device_quirks_33_15_11_3 = {
    .has_brn70165 = true,
+   .has_brn74056 = true,
 };
 
 static const struct pvr_device_info pvr_device_info_33_15_11_3 = {

src/imagination/common/device_info/bxs-4-64.h

@@ -125,6 +125,7 @@ static const struct pvr_device_quirks pvr_device_quirks_36_53_104_796 = {
    .has_brn70165 = true,
    .has_brn72168 = true,
    .has_brn72463 = true,
+   .has_brn74056 = true,
 };
 
 static const struct pvr_device_info pvr_device_info_36_53_104_796 = {

src/imagination/common/device_info/gx6250.h

@@ -124,6 +124,7 @@ static const struct pvr_device_quirks pvr_device_quirks_4_40_2_51 = {
    .has_brn62269 = true,
    .has_brn66011 = true,
    .has_brn70165 = true,
+   .has_brn74056 = true,
 };
 
 static const struct pvr_device_info pvr_device_info_4_40_2_51 = {

src/imagination/common/pvr_device_info.h

@@ -368,6 +368,7 @@ struct pvr_device_quirks {
    bool has_brn70165 : 1;
    bool has_brn72168 : 1;
    bool has_brn72463 : 1;
+   bool has_brn74056 : 1;
 };
 
 struct pvr_device_info {

src/imagination/pco/pco_internal.h

@@ -1766,7 +1766,7 @@ bool pco_nir_lower_fs_intrinsics(nir_shader *shader);
 bool pco_nir_lower_images(nir_shader *shader, pco_data *data);
 bool pco_nir_lower_interpolation(nir_shader *shader, pco_fs_data *fs);
 bool pco_nir_lower_io(nir_shader *shader);
-bool pco_nir_lower_tex(nir_shader *shader, pco_data *data);
+bool pco_nir_lower_tex(nir_shader *shader, pco_data *data, pco_ctx *ctx);
 bool pco_nir_lower_variables(nir_shader *shader, bool inputs, bool outputs);
 bool pco_nir_lower_vk(nir_shader *shader, pco_data *data);
 bool pco_nir_pfo(nir_shader *shader, pco_fs_data *fs);

src/imagination/pco/pco_nir.c

@@ -863,7 +863,7 @@ void pco_lower_nir(pco_ctx *ctx, nir_shader *nir, pco_data *data)
             &(nir_lower_tex_options){
                .lower_txd_cube_map = true,
             });
-   NIR_PASS(_, nir, pco_nir_lower_tex, data);
+   NIR_PASS(_, nir, pco_nir_lower_tex, data, ctx);
 
    if (nir->info.stage == MESA_SHADER_FRAGMENT) {
       if (data->fs.uses.alpha_to_coverage) {

src/imagination/pco/pco_nir_tex.c

@@ -25,6 +25,11 @@
 #include <stdbool.h>
 #include <stdio.h>
 
+struct state {
+   pco_data *data;
+   pco_ctx *ctx;
+};
+
 static inline nir_def *get_src_def(nir_tex_instr *tex,
                                    nir_tex_src_type src_type)
 {
@@ -108,8 +113,12 @@ static inline enum pco_dim to_pco_dim(enum glsl_sampler_dim dim)
    UNREACHABLE("");
 }
 
-static nir_def *
-lower_tex_query_lod(nir_builder *b, nir_def *coords, nir_def *smp_coeffs)
+static nir_def *lower_tex_query_lod(nir_builder *b,
+                                    nir_def *coords,
+                                    nir_def *smp_coeffs,
+                                    pco_smp_params *params,
+                                    pco_data *data,
+                                    pco_ctx *ctx)
 {
    nir_def *lod_dval_post_clamp =
       nir_channel(b, smp_coeffs, ROGUE_SMP_COEFF_LOD_DVAL_POST_CLAMP);
@@ -131,6 +140,17 @@ lower_tex_query_lod(nir_builder *b, nir_def *coords, nir_def *smp_coeffs)
    tfrac_post_clamp = nir_fdiv_imm(b, tfrac_post_clamp, 256.0f);
    tfrac_pre_clamp = nir_fdiv_imm(b, tfrac_pre_clamp, 256.0f);
 
+   if (PVR_HAS_QUIRK(ctx->dev_info, 74056)) {
+      lod_dval_post_clamp =
+         usclib_tex_lod_dval_post_clamp_resource_to_view_space(
+            b,
+            params->tex_state,
+            params->smp_state,
+            lod_dval_post_clamp);
+
+      data->common.uses.usclib = true;
+   }
+
    /* Calculate coord deltas. */
    nir_def *coord_deltas = nir_imm_int(b, 0);
    for (unsigned c = 0; c < coords->num_components; ++c) {
@@ -422,7 +442,9 @@ static nir_def *lower_tex_shadow(nir_builder *b,
 static nir_def *lower_tex(nir_builder *b, nir_instr *instr, void *cb_data)
 {
    nir_tex_instr *tex = nir_instr_as_tex(instr);
-   pco_data *data = cb_data;
+   struct state *state = cb_data;
+   pco_data *data = state->data;
+   pco_ctx *ctx = state->ctx;
 
    unsigned tex_desc_set;
    unsigned tex_binding;
@@ -677,7 +699,8 @@ static nir_def *lower_tex(nir_builder *b, nir_instr *instr, void *cb_data)
    case nir_texop_lod:
       params.sample_coeffs = true;
       smp = pco_emit_nir_smp(b, &params);
-      result = lower_tex_query_lod(b, float_coords, &smp->def);
+      result =
+         lower_tex_query_lod(b, float_coords, &smp->def, &params, data, ctx);
       break;
 
    case nir_texop_txf:
@@ -736,11 +759,17 @@ static bool is_tex(const nir_instr *instr, UNUSED const void *cb_data)
  *
  * \param[in,out] shader NIR shader.
  * \param[in,out] data Shader data.
+ * \param[in] ctx PCO compiler context.
  * \return True if the pass made progress.
  */
-bool pco_nir_lower_tex(nir_shader *shader, pco_data *data)
+bool pco_nir_lower_tex(nir_shader *shader, pco_data *data, pco_ctx *ctx)
 {
-   return nir_shader_lower_instructions(shader, is_tex, lower_tex, data);
+   struct state state = {
+      .data = data,
+      .ctx = ctx,
+   };
+
+   return nir_shader_lower_instructions(shader, is_tex, lower_tex, &state);
 }
 
 static enum util_format_type nir_type_to_util_type(nir_alu_type nir_type)

src/imagination/pco/usclib/tex.cl

@@ -87,3 +87,35 @@ usclib_tex_state_size(uint4 tex_state, uint num_comps, bool is_1d, bool is_array
 
    return size_comps;
 }
+
+uint
+usclib_tex_state_base_level(uint4 tex_state)
+{
+   uint32_t texstate_image_word1[] = {tex_state.z, tex_state.w};
+   struct ROGUE_TEXSTATE_IMAGE_WORD1 texstate_image_struct;
+
+   ROGUE_TEXSTATE_IMAGE_WORD1_unpack(texstate_image_word1, &texstate_image_struct);
+
+   return texstate_image_struct.baselevel;
+}
+
+bool
+usclib_smp_state_mipfilter(uint4 smp_state)
+{
+   uint32_t texstate_sampler_word0[] = {smp_state.x, smp_state.y};
+   struct ROGUE_TEXSTATE_SAMPLER_WORD0 texstate_sampler_struct;
+
+   ROGUE_TEXSTATE_SAMPLER_WORD0_unpack(texstate_sampler_word0, &texstate_sampler_struct);
+
+   return texstate_sampler_struct.mipfilter;
+}
+
+float
+usclib_tex_lod_dval_post_clamp_resource_to_view_space(uint4 tex_state, uint4 smp_state, float lod_dval_post_clamp)
+{
+   lod_dval_post_clamp -= (float)usclib_tex_state_base_level(tex_state);
+   if (!usclib_smp_state_mipfilter(smp_state))
+      lod_dval_post_clamp = floor(lod_dval_post_clamp + 0.5f);
+
+   return MAX2(lod_dval_post_clamp, 0.0f);
+}