src/gallium/drivers/panfrost/pan_blend_cso.c

   1 /*
   2  * Copyright (C) 2019 Collabora, Ltd.
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  21  * SOFTWARE.
  22  *
  23  * Authors (Collabora):
  24  *   Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
  25  *
  26  */
  27
  28 #include <stdio.h>
  29 #include "util/u_memory.h"
  30 #include "gallium/auxiliary/util/u_blend.h"
  31 #include "pan_blend_shaders.h"
  32 #include "pan_blending.h"
  33 #include "pan_bo.h"
  34 #include "panfrost-quirks.h"
  35
  36 /* A given Gallium blend state can be encoded to the hardware in numerous,
  37  * dramatically divergent ways due to the interactions of blending with
  38  * framebuffer formats. Conceptually, there are two modes:
  39  *
  40  * - Fixed-function blending (for suitable framebuffer formats, suitable blend
  41  *   state, and suitable blend constant)
  42  *
  43  * - Blend shaders (for everything else)
  44  *
  45  * A given Gallium blend configuration will compile to exactly one
  46  * fixed-function blend state, if it compiles to any, although the constant
  47  * will vary across runs as that is tracked outside of the Gallium CSO.
  48  *
  49  * However, that same blend configuration will compile to many different blend
  50  * shaders, depending on the framebuffer formats active. The rationale is that
  51  * blend shaders override not just fixed-function blending but also
  52  * fixed-function format conversion. As such, each blend shader must be
  53  * hardcoded to a particular framebuffer format to correctly pack/unpack it. As
  54  * a concrete example, to the hardware there is no difference (!) between RG16F
  55  * and RG16UI -- both are simply 4-byte-per-pixel chunks. Thus both formats
  56  * require a blend shader (even with blending is totally disabled!), required
  57  * to do conversion as necessary (if necessary).
  58  *
  59  * All of this state is encapsulated in the panfrost_blend_state struct
  60  * (our subclass of pipe_blend_state).
  61  */
  62
  63 /* Given an initialized CSO and a particular framebuffer format, grab a
  64  * blend shader, generating and compiling it if it doesn't exist
  65  * (lazy-loading in a way). This routine, when the cache hits, should
  66  * befast, suitable for calling every draw to avoid wacky dirty
  67  * tracking paths. If the cache hits, boom, done. */
  68
  69 struct panfrost_blend_shader *
  70 panfrost_get_blend_shader(
  71         struct panfrost_context *ctx,
  72         struct panfrost_blend_state *blend,
  73         enum pipe_format fmt,
  74         unsigned rt)
  75 {
  76         /* Prevent NULL collision issues.. */
  77         assert(fmt != 0);
  78
  79         /* Check the cache. Key by the RT and format */
  80         struct hash_table_u64 *shaders = blend->rt[rt].shaders;
  81         unsigned key = (fmt << 3) | rt;
  82
  83         struct panfrost_blend_shader *shader =
  84                 _mesa_hash_table_u64_search(shaders, key);
  85
  86         if (shader)
  87                 return shader;
  88
  89         /* Cache miss. Build one instead, cache it, and go */
  90
  91         struct panfrost_blend_shader generated =
  92                 panfrost_compile_blend_shader(ctx, &blend->base, fmt, rt);
  93
  94         shader = mem_dup(&generated, sizeof(generated));
  95         _mesa_hash_table_u64_insert(shaders, key, shader);
  96         return  shader;
  97 }
  98
  99 /* Create a blend CSO. Essentially, try to compile a fixed-function
 100  * expression and initialize blend shaders */
 101
 102 static void *
 103 panfrost_create_blend_state(struct pipe_context *pipe,
 104                             const struct pipe_blend_state *blend)
 105 {
 106         struct panfrost_context *ctx = pan_context(pipe);
 107         struct panfrost_blend_state *so = rzalloc(ctx, struct panfrost_blend_state);
 108         so->base = *blend;
 109
 110         /* TODO: The following features are not yet implemented */
 111         assert(!blend->alpha_to_one);
 112
 113         for (unsigned c = 0; c < PIPE_MAX_COLOR_BUFS; ++c) {
 114                 unsigned g = blend->independent_blend_enable ? c : 0;
 115                 struct pipe_rt_blend_state pipe = blend->rt[g];
 116
 117                 struct panfrost_blend_rt *rt = &so->rt[c];
 118                 rt->shaders = _mesa_hash_table_u64_create(so);
 119
 120                 /* Logic ops are always shader */
 121                 if (blend->logicop_enable) {
 122                         rt->load_dest = true;
 123                         continue;
 124                 }
 125
 126                 rt->has_fixed_function =
 127                                 panfrost_make_fixed_blend_mode(
 128                                         pipe,
 129                                         &rt->equation,
 130                                         &rt->constant_mask);
 131
 132                 if (rt->has_fixed_function)
 133                         rt->opaque = (rt->equation.opaque[0] == 0xf0122122);
 134
 135                 rt->load_dest = util_blend_uses_dest(pipe)
 136                         || pipe.colormask != 0xF;
 137
 138                 rt->no_colour = pipe.colormask == 0x0;
 139         }
 140
 141         return so;
 142 }
 143
 144 static void
 145 panfrost_bind_blend_state(struct pipe_context *pipe,
 146                           void *cso)
 147 {
 148         struct panfrost_context *ctx = pan_context(pipe);
 149         ctx->blend = (struct panfrost_blend_state *) cso;
 150 }
 151
 152 static void
 153 panfrost_delete_blend_shader(struct hash_entry *entry)
 154 {
 155         struct panfrost_blend_shader *shader = (struct panfrost_blend_shader *)entry->data;
 156         free(shader->buffer);
 157         free(shader);
 158 }
 159
 160 static void
 161 panfrost_delete_blend_state(struct pipe_context *pipe,
 162                             void *cso)
 163 {
 164         struct panfrost_blend_state *blend = (struct panfrost_blend_state *) cso;
 165
 166         for (unsigned c = 0; c < PIPE_MAX_COLOR_BUFS; ++c) {
 167                 struct panfrost_blend_rt *rt = &blend->rt[c];
 168                 _mesa_hash_table_u64_clear(rt->shaders, panfrost_delete_blend_shader);
 169         }
 170         ralloc_free(blend);
 171 }
 172
 173 static void
 174 panfrost_set_blend_color(struct pipe_context *pipe,
 175                          const struct pipe_blend_color *blend_color)
 176 {
 177         struct panfrost_context *ctx = pan_context(pipe);
 178
 179         if (blend_color)
 180                 ctx->blend_color = *blend_color;
 181 }
 182
 183 /* Given a vec4 of constants, reduce it to just a single constant according to
 184  * the mask (if we can) */
 185
 186 static bool
 187 panfrost_blend_constant(float *out, float *in, unsigned mask)
 188 {
 189         /* If there is no components used, it automatically works */
 190
 191         if (!mask)
 192                 return true;
 193
 194         /* Find some starter mask */
 195         unsigned first = ffs(mask) - 1;
 196         float cons = in[first];
 197         mask ^= (1 << first);
 198
 199         /* Ensure the rest are equal */
 200         while (mask) {
 201                 unsigned i = u_bit_scan(&mask);
 202
 203                 if (in[i] != cons)
 204                         return false;
 205         }
 206
 207         /* Otherwise, we're good to go */
 208         *out = cons;
 209         return true;
 210 }
 211
 212 /* Create a final blend given the context */
 213
 214 struct panfrost_blend_final
 215 panfrost_get_blend_for_context(struct panfrost_context *ctx, unsigned rti)
 216 {
 217         struct panfrost_batch *batch = panfrost_get_batch_for_fbo(ctx);
 218         struct pipe_framebuffer_state *fb = &ctx->pipe_framebuffer;
 219         enum pipe_format fmt = fb->cbufs[rti]->format;
 220
 221         /* Grab the blend state */
 222         struct panfrost_blend_state *blend = ctx->blend;
 223         struct panfrost_blend_rt *rt = &blend->rt[rti];
 224
 225         /* First, we'll try fixed function, matching equationn and constant */
 226         if (rt->has_fixed_function && panfrost_can_fixed_blend(fmt)) {
 227                 float constant = 0.0;
 228
 229                 if (panfrost_blend_constant(
 230                             &constant,
 231                             ctx->blend_color.color,
 232                             rt->constant_mask)) {
 233                         struct panfrost_blend_final final = {
 234                                 .equation = {
 235                                         .equation = rt->equation,
 236                                         .constant = constant
 237                                 },
 238                                 .load_dest = rt->load_dest,
 239                                 .opaque = rt->opaque,
 240                                 .no_colour = rt->no_colour
 241                         };
 242
 243                         return final;
 244                 }
 245         }
 246
 247         /* Otherwise, we need to grab a shader */
 248         struct panfrost_blend_shader *shader = panfrost_get_blend_shader(ctx, blend, fmt, rti);
 249
 250         struct panfrost_bo *bo = panfrost_batch_create_bo(batch, shader->size,
 251                    PAN_BO_EXECUTE,
 252                    PAN_BO_ACCESS_PRIVATE |
 253                    PAN_BO_ACCESS_READ |
 254                    PAN_BO_ACCESS_FRAGMENT);
 255
 256         memcpy(bo->cpu, shader->buffer, shader->size);
 257
 258         if (shader->patch_index) {
 259                 /* We have to specialize the blend shader to use constants, so
 260                  * patch in the current constants */
 261
 262                 float *patch = (float *) (bo->cpu + shader->patch_index);
 263                 memcpy(patch, ctx->blend_color.color, sizeof(float) * 4);
 264         }
 265
 266         struct panfrost_blend_final final = {
 267                 .is_shader = true,
 268                 .shader = {
 269                         .work_count = shader->work_count,
 270                         .first_tag = shader->first_tag,
 271                         .gpu = bo->gpu,
 272                 },
 273                 .load_dest = rt->load_dest,
 274         };
 275
 276         return final;
 277 }
 278
 279 void
 280 panfrost_blend_context_init(struct pipe_context *pipe)
 281 {
 282         pipe->create_blend_state = panfrost_create_blend_state;
 283         pipe->bind_blend_state   = panfrost_bind_blend_state;
 284         pipe->delete_blend_state = panfrost_delete_blend_state;
 285
 286         pipe->set_blend_color = panfrost_set_blend_color;
 287 }