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 "pan_blend_shaders.h"
  31 #include "pan_blending.h"
  32
  33 /* A given Gallium blend state can be encoded to the hardware in numerous,
  34  * dramatically divergent ways due to the interactions of blending with
  35  * framebuffer formats. Conceptually, there are two modes:
  36  *
  37  * - Fixed-function blending (for suitable framebuffer formats, suitable blend
  38  *   state, and suitable blend constant)
  39  *
  40  * - Blend shaders (for everything else)
  41  *
  42  * A given Gallium blend configuration will compile to exactly one
  43  * fixed-function blend state, if it compiles to any, although the constant
  44  * will vary across runs as that is tracked outside of the Gallium CSO.
  45  *
  46  * However, that same blend configuration will compile to many different blend
  47  * shaders, depending on the framebuffer formats active. The rationale is that
  48  * blend shaders override not just fixed-function blending but also
  49  * fixed-function format conversion. As such, each blend shader must be
  50  * hardcoded to a particular framebuffer format to correctly pack/unpack it. As
  51  * a concrete example, to the hardware there is no difference (!) between RG16F
  52  * and RG16UI -- both are simply 4-byte-per-pixel chunks. Thus both formats
  53  * require a blend shader (even with blending is totally disabled!), required
  54  * to do conversion as necessary (if necessary).
  55  *
  56  * All of this state is encapsulated in the panfrost_blend_state struct
  57  * (our subclass of pipe_blend_state).
  58  */
  59
  60 /* Given an initialized CSO and a particular framebuffer format, grab a
  61  * blend shader, generating and compiling it if it doesn't exist
  62  * (lazy-loading in a way). This routine, when the cache hits, should
  63  * befast, suitable for calling every draw to avoid wacky dirty
  64  * tracking paths. If the cache hits, boom, done. */
  65
  66 static struct panfrost_blend_shader *
  67 panfrost_get_blend_shader(
  68         struct panfrost_context *ctx,
  69         struct panfrost_blend_state *blend,
  70         enum pipe_format fmt,
  71         unsigned rt)
  72 {
  73         /* Prevent NULL collision issues.. */
  74         assert(fmt != 0);
  75
  76         /* Check the cache */
  77         struct hash_table_u64 *shaders = blend->rt[rt].shaders;
  78
  79         struct panfrost_blend_shader *shader =
  80                 _mesa_hash_table_u64_search(shaders, fmt);
  81
  82         if (shader)
  83                 return shader;
  84
  85         /* Cache miss. Build one instead, cache it, and go */
  86
  87         struct panfrost_blend_shader generated =
  88                 panfrost_compile_blend_shader(ctx, &blend->base, fmt);
  89
  90         shader = mem_dup(&generated, sizeof(generated));
  91         _mesa_hash_table_u64_insert(shaders, fmt, shader);
  92         return  shader;
  93 }
  94
  95 /* Create a blend CSO. Essentially, try to compile a fixed-function
  96  * expression and initialize blend shaders */
  97
  98 static void *
  99 panfrost_create_blend_state(struct pipe_context *pipe,
 100                             const struct pipe_blend_state *blend)
 101 {
 102         struct panfrost_context *ctx = pan_context(pipe);
 103         struct panfrost_blend_state *so = rzalloc(ctx, struct panfrost_blend_state);
 104         so->base = *blend;
 105
 106         /* TODO: The following features are not yet implemented */
 107         assert(!blend->logicop_enable);
 108         assert(!blend->alpha_to_coverage);
 109         assert(!blend->alpha_to_one);
 110
 111         for (unsigned c = 0; c < 4; ++c) {
 112                 struct panfrost_blend_rt *rt = &so->rt[c];
 113
 114                 /* There are two paths. First, we would like to try a
 115                  * fixed-function if we can */
 116
 117                 rt->has_fixed_function =
 118                         panfrost_make_fixed_blend_mode(
 119                                 &blend->rt[c],
 120                                 &rt->equation,
 121                                 &rt->constant_mask,
 122                                 blend->rt[c].colormask);
 123
 124                 /* Regardless if that works, we also need to initialize
 125                  * the blend shaders */
 126
 127                 rt->shaders = _mesa_hash_table_u64_create(so);
 128         }
 129
 130         return so;
 131 }
 132
 133 static void
 134 panfrost_bind_blend_state(struct pipe_context *pipe,
 135                           void *cso)
 136 {
 137         struct panfrost_context *ctx = pan_context(pipe);
 138         struct panfrost_screen *screen = pan_screen(ctx->base.screen);
 139         struct pipe_blend_state *blend = (struct pipe_blend_state *) cso;
 140         struct panfrost_blend_state *pblend = (struct panfrost_blend_state *) cso;
 141         ctx->blend = pblend;
 142
 143         if (!blend)
 144                 return;
 145
 146         if (screen->require_sfbd) {
 147                 SET_BIT(ctx->fragment_shader_core.unknown2_4, MALI_NO_DITHER, !blend->dither);
 148         }
 149
 150         /* Shader itself is not dirty, but the shader core is */
 151         ctx->dirty |= PAN_DIRTY_FS;
 152 }
 153
 154 static void
 155 panfrost_delete_blend_shader(struct hash_entry *entry)
 156 {
 157         struct panfrost_blend_shader *shader = (struct panfrost_blend_shader *)entry->data;
 158         free(shader->buffer);
 159         free(shader);
 160 }
 161
 162 static void
 163 panfrost_delete_blend_state(struct pipe_context *pipe,
 164                             void *cso)
 165 {
 166         struct panfrost_blend_state *blend = (struct panfrost_blend_state *) cso;
 167
 168         for (unsigned c = 0; c < 4; ++c) {
 169                 struct panfrost_blend_rt *rt = &blend->rt[c];
 170                 _mesa_hash_table_u64_clear(rt->shaders, panfrost_delete_blend_shader);
 171         }
 172         ralloc_free(blend);
 173 }
 174
 175 static void
 176 panfrost_set_blend_color(struct pipe_context *pipe,
 177                          const struct pipe_blend_color *blend_color)
 178 {
 179         struct panfrost_context *ctx = pan_context(pipe);
 180
 181         if (blend_color)
 182                 ctx->blend_color = *blend_color;
 183 }
 184
 185 /* Given a vec4 of constants, reduce it to just a single constant according to
 186  * the mask (if we can) */
 187
 188 static bool
 189 panfrost_blend_constant(float *out, float *in, unsigned mask)
 190 {
 191         /* If there is no components used, it automatically works. Do set a
 192          * dummy constant just to avoid reading uninitialized memory. */
 193
 194         if (!mask) {
 195                 *out = 0.0;
 196                 return true;
 197         }
 198
 199         /* Find some starter mask */
 200         unsigned first = ffs(mask) - 1;
 201         float cons = in[first];
 202         mask ^= (1 << first);
 203
 204         /* Ensure the rest are equal */
 205         while (mask) {
 206                 unsigned i = u_bit_scan(&mask);
 207
 208                 if (in[i] != cons) {
 209                         *out = 0.0;
 210                         return false;
 211                 }
 212         }
 213
 214         /* Otherwise, we're good to go */
 215         *out = cons;
 216         return true;
 217 }
 218
 219 /* Create a final blend given the context */
 220
 221 struct panfrost_blend_final
 222 panfrost_get_blend_for_context(struct panfrost_context *ctx, unsigned rti)
 223 {
 224         struct panfrost_screen *screen = pan_screen(ctx->base.screen);
 225         struct panfrost_job *job = panfrost_get_job_for_fbo(ctx);
 226
 227         /* Grab the format, falling back gracefully if called invalidly (which
 228          * has to happen for no-color-attachment FBOs, for instance)  */
 229         struct pipe_framebuffer_state *fb = &ctx->pipe_framebuffer;
 230         enum pipe_format fmt = PIPE_FORMAT_R8G8B8A8_UNORM;
 231
 232         if ((fb->nr_cbufs > rti) && fb->cbufs[rti])
 233                 fmt = fb->cbufs[rti]->format;
 234
 235         /* Grab the blend state */
 236         struct panfrost_blend_state *blend = ctx->blend;
 237         assert(blend);
 238
 239         struct panfrost_blend_rt *rt = &blend->rt[rti];
 240
 241         struct panfrost_blend_final final;
 242
 243         /* First, we'll try a fixed function path */
 244         if (rt->has_fixed_function && panfrost_can_fixed_blend(fmt)) {
 245                 if (panfrost_blend_constant(
 246                             &final.equation.constant,
 247                             ctx->blend_color.color,
 248                             rt->constant_mask)) {
 249                         /* There's an equation and suitable constant, so we're good to go */
 250                         final.is_shader = false;
 251                         final.equation.equation = &rt->equation;
 252                         return final;
 253                 }
 254         }
 255
 256         /* Otherwise, we need to grab a shader */
 257         struct panfrost_blend_shader *shader = panfrost_get_blend_shader(ctx, blend, fmt, rti);
 258         final.is_shader = true;
 259         final.shader.work_count = shader->work_count;
 260         final.shader.first_tag = shader->first_tag;
 261
 262         /* Upload the shader */
 263         final.shader.bo = panfrost_drm_create_bo(screen, shader->size, PAN_ALLOCATE_EXECUTE);
 264         memcpy(final.shader.bo->cpu, shader->buffer, shader->size);
 265
 266         /* Pass BO ownership to job */
 267         panfrost_job_add_bo(job, final.shader.bo);
 268         panfrost_bo_unreference(ctx->base.screen, final.shader.bo);
 269
 270         if (shader->patch_index) {
 271                 /* We have to specialize the blend shader to use constants, so
 272                  * patch in the current constants */
 273
 274                 float *patch = (float *) (final.shader.bo->cpu + shader->patch_index);
 275                 memcpy(patch, ctx->blend_color.color, sizeof(float) * 4);
 276         }
 277
 278         return final;
 279 }
 280
 281 void
 282 panfrost_blend_context_init(struct pipe_context *pipe)
 283 {
 284         pipe->create_blend_state = panfrost_create_blend_state;
 285         pipe->bind_blend_state   = panfrost_bind_blend_state;
 286         pipe->delete_blend_state = panfrost_delete_blend_state;
 287
 288         pipe->set_blend_color = panfrost_set_blend_color;
 289 }