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 #include "pan_bo.h"
  33
  34 /* A given Gallium blend state can be encoded to the hardware in numerous,
  35  * dramatically divergent ways due to the interactions of blending with
  36  * framebuffer formats. Conceptually, there are two modes:
  37  *
  38  * - Fixed-function blending (for suitable framebuffer formats, suitable blend
  39  *   state, and suitable blend constant)
  40  *
  41  * - Blend shaders (for everything else)
  42  *
  43  * A given Gallium blend configuration will compile to exactly one
  44  * fixed-function blend state, if it compiles to any, although the constant
  45  * will vary across runs as that is tracked outside of the Gallium CSO.
  46  *
  47  * However, that same blend configuration will compile to many different blend
  48  * shaders, depending on the framebuffer formats active. The rationale is that
  49  * blend shaders override not just fixed-function blending but also
  50  * fixed-function format conversion. As such, each blend shader must be
  51  * hardcoded to a particular framebuffer format to correctly pack/unpack it. As
  52  * a concrete example, to the hardware there is no difference (!) between RG16F
  53  * and RG16UI -- both are simply 4-byte-per-pixel chunks. Thus both formats
  54  * require a blend shader (even with blending is totally disabled!), required
  55  * to do conversion as necessary (if necessary).
  56  *
  57  * All of this state is encapsulated in the panfrost_blend_state struct
  58  * (our subclass of pipe_blend_state).
  59  */
  60
  61 /* Given an initialized CSO and a particular framebuffer format, grab a
  62  * blend shader, generating and compiling it if it doesn't exist
  63  * (lazy-loading in a way). This routine, when the cache hits, should
  64  * befast, suitable for calling every draw to avoid wacky dirty
  65  * tracking paths. If the cache hits, boom, done. */
  66
  67 static struct panfrost_blend_shader *
  68 panfrost_get_blend_shader(
  69         struct panfrost_context *ctx,
  70         struct panfrost_blend_state *blend,
  71         enum pipe_format fmt,
  72         unsigned rt)
  73 {
  74         /* Prevent NULL collision issues.. */
  75         assert(fmt != 0);
  76
  77         /* Check the cache */
  78         struct hash_table_u64 *shaders = blend->rt[rt].shaders;
  79
  80         struct panfrost_blend_shader *shader =
  81                 _mesa_hash_table_u64_search(shaders, fmt);
  82
  83         if (shader)
  84                 return shader;
  85
  86         /* Cache miss. Build one instead, cache it, and go */
  87
  88         struct panfrost_blend_shader generated =
  89                 panfrost_compile_blend_shader(ctx, &blend->base, fmt);
  90
  91         shader = mem_dup(&generated, sizeof(generated));
  92         _mesa_hash_table_u64_insert(shaders, fmt, shader);
  93         return  shader;
  94 }
  95
  96 /* Create a blend CSO. Essentially, try to compile a fixed-function
  97  * expression and initialize blend shaders */
  98
  99 static void *
 100 panfrost_create_blend_state(struct pipe_context *pipe,
 101                             const struct pipe_blend_state *blend)
 102 {
 103         struct panfrost_context *ctx = pan_context(pipe);
 104         struct panfrost_blend_state *so = rzalloc(ctx, struct panfrost_blend_state);
 105         so->base = *blend;
 106
 107         /* TODO: The following features are not yet implemented */
 108         assert(!blend->logicop_enable);
 109         assert(!blend->alpha_to_coverage);
 110         assert(!blend->alpha_to_one);
 111
 112         for (unsigned c = 0; c < PIPE_MAX_COLOR_BUFS; ++c) {
 113                 struct panfrost_blend_rt *rt = &so->rt[c];
 114
 115                 /* There are two paths. First, we would like to try a
 116                  * fixed-function if we can */
 117
 118                 /* Without indep blending, the first RT settings replicate */
 119
 120                 unsigned g =
 121                         blend->independent_blend_enable ? c : 0;
 122
 123                 rt->has_fixed_function =
 124                         panfrost_make_fixed_blend_mode(
 125                                 &blend->rt[g],
 126                                 &rt->equation,
 127                                 &rt->constant_mask,
 128                                 blend->rt[g].colormask);
 129
 130                 /* Regardless if that works, we also need to initialize
 131                  * the blend shaders */
 132
 133                 rt->shaders = _mesa_hash_table_u64_create(so);
 134         }
 135
 136         return so;
 137 }
 138
 139 static void
 140 panfrost_bind_blend_state(struct pipe_context *pipe,
 141                           void *cso)
 142 {
 143         struct panfrost_context *ctx = pan_context(pipe);
 144         struct panfrost_screen *screen = pan_screen(ctx->base.screen);
 145         struct pipe_blend_state *blend = (struct pipe_blend_state *) cso;
 146         struct panfrost_blend_state *pblend = (struct panfrost_blend_state *) cso;
 147         ctx->blend = pblend;
 148
 149         if (!blend)
 150                 return;
 151
 152         if (screen->require_sfbd) {
 153                 SET_BIT(ctx->fragment_shader_core.unknown2_4, MALI_NO_DITHER, !blend->dither);
 154         }
 155
 156         /* Shader itself is not dirty, but the shader core is */
 157         ctx->dirty |= PAN_DIRTY_FS;
 158 }
 159
 160 static void
 161 panfrost_delete_blend_shader(struct hash_entry *entry)
 162 {
 163         struct panfrost_blend_shader *shader = (struct panfrost_blend_shader *)entry->data;
 164         free(shader->buffer);
 165         free(shader);
 166 }
 167
 168 static void
 169 panfrost_delete_blend_state(struct pipe_context *pipe,
 170                             void *cso)
 171 {
 172         struct panfrost_blend_state *blend = (struct panfrost_blend_state *) cso;
 173
 174         for (unsigned c = 0; c < 4; ++c) {
 175                 struct panfrost_blend_rt *rt = &blend->rt[c];
 176                 _mesa_hash_table_u64_clear(rt->shaders, panfrost_delete_blend_shader);
 177         }
 178         ralloc_free(blend);
 179 }
 180
 181 static void
 182 panfrost_set_blend_color(struct pipe_context *pipe,
 183                          const struct pipe_blend_color *blend_color)
 184 {
 185         struct panfrost_context *ctx = pan_context(pipe);
 186
 187         if (blend_color)
 188                 ctx->blend_color = *blend_color;
 189 }
 190
 191 /* Given a vec4 of constants, reduce it to just a single constant according to
 192  * the mask (if we can) */
 193
 194 static bool
 195 panfrost_blend_constant(float *out, float *in, unsigned mask)
 196 {
 197         /* If there is no components used, it automatically works. Do set a
 198          * dummy constant just to avoid reading uninitialized memory. */
 199
 200         if (!mask) {
 201                 *out = 0.0;
 202                 return true;
 203         }
 204
 205         /* Find some starter mask */
 206         unsigned first = ffs(mask) - 1;
 207         float cons = in[first];
 208         mask ^= (1 << first);
 209
 210         /* Ensure the rest are equal */
 211         while (mask) {
 212                 unsigned i = u_bit_scan(&mask);
 213
 214                 if (in[i] != cons) {
 215                         *out = 0.0;
 216                         return false;
 217                 }
 218         }
 219
 220         /* Otherwise, we're good to go */
 221         *out = cons;
 222         return true;
 223 }
 224
 225 /* Create a final blend given the context */
 226
 227 struct panfrost_blend_final
 228 panfrost_get_blend_for_context(struct panfrost_context *ctx, unsigned rti)
 229 {
 230         struct panfrost_batch *batch = panfrost_get_batch_for_fbo(ctx);
 231
 232         /* Grab the format, falling back gracefully if called invalidly (which
 233          * has to happen for no-color-attachment FBOs, for instance)  */
 234         struct pipe_framebuffer_state *fb = &ctx->pipe_framebuffer;
 235         enum pipe_format fmt = PIPE_FORMAT_R8G8B8A8_UNORM;
 236
 237         if ((fb->nr_cbufs > rti) && fb->cbufs[rti])
 238                 fmt = fb->cbufs[rti]->format;
 239
 240         /* Grab the blend state */
 241         struct panfrost_blend_state *blend = ctx->blend;
 242         assert(blend);
 243
 244         struct panfrost_blend_rt *rt = &blend->rt[rti];
 245
 246         struct panfrost_blend_final final;
 247
 248         /* First, we'll try a fixed function path */
 249         if (rt->has_fixed_function && panfrost_can_fixed_blend(fmt)) {
 250                 if (panfrost_blend_constant(
 251                             &final.equation.constant,
 252                             ctx->blend_color.color,
 253                             rt->constant_mask)) {
 254                         /* There's an equation and suitable constant, so we're good to go */
 255                         final.is_shader = false;
 256                         final.equation.equation = &rt->equation;
 257
 258                         final.no_blending =
 259                                 (rt->equation.rgb_mode == 0x122) &&
 260                                 (rt->equation.alpha_mode == 0x122) &&
 261                                 (rt->equation.color_mask == 0xf);
 262
 263                         return final;
 264                 }
 265         }
 266
 267         /* Otherwise, we need to grab a shader */
 268         struct panfrost_blend_shader *shader = panfrost_get_blend_shader(ctx, blend, fmt, rti);
 269         final.is_shader = true;
 270         final.no_blending = false;
 271         final.shader.work_count = shader->work_count;
 272         final.shader.first_tag = shader->first_tag;
 273
 274         /* Upload the shader */
 275         final.shader.bo = panfrost_batch_create_bo(batch, shader->size,
 276                                                    PAN_BO_EXECUTE,
 277                                                    PAN_BO_ACCESS_PRIVATE |
 278                                                    PAN_BO_ACCESS_READ |
 279                                                    PAN_BO_ACCESS_VERTEX_TILER |
 280                                                    PAN_BO_ACCESS_FRAGMENT);
 281         memcpy(final.shader.bo->cpu, shader->buffer, shader->size);
 282
 283         if (shader->patch_index) {
 284                 /* We have to specialize the blend shader to use constants, so
 285                  * patch in the current constants */
 286
 287                 float *patch = (float *) (final.shader.bo->cpu + shader->patch_index);
 288                 memcpy(patch, ctx->blend_color.color, sizeof(float) * 4);
 289         }
 290
 291         return final;
 292 }
 293
 294 void
 295 panfrost_blend_context_init(struct pipe_context *pipe)
 296 {
 297         pipe->create_blend_state = panfrost_create_blend_state;
 298         pipe->bind_blend_state   = panfrost_bind_blend_state;
 299         pipe->delete_blend_state = panfrost_delete_blend_state;
 300
 301         pipe->set_blend_color = panfrost_set_blend_color;
 302 }