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         struct pipe_blend_state *blend = (struct pipe_blend_state *) cso;
 150         struct panfrost_blend_state *pblend = (struct panfrost_blend_state *) cso;
 151         ctx->blend = pblend;
 152
 153         if (!blend)
 154                 return;
 155 }
 156
 157 static void
 158 panfrost_delete_blend_shader(struct hash_entry *entry)
 159 {
 160         struct panfrost_blend_shader *shader = (struct panfrost_blend_shader *)entry->data;
 161         free(shader->buffer);
 162         free(shader);
 163 }
 164
 165 static void
 166 panfrost_delete_blend_state(struct pipe_context *pipe,
 167                             void *cso)
 168 {
 169         struct panfrost_blend_state *blend = (struct panfrost_blend_state *) cso;
 170
 171         for (unsigned c = 0; c < PIPE_MAX_COLOR_BUFS; ++c) {
 172                 struct panfrost_blend_rt *rt = &blend->rt[c];
 173                 _mesa_hash_table_u64_clear(rt->shaders, panfrost_delete_blend_shader);
 174         }
 175         ralloc_free(blend);
 176 }
 177
 178 static void
 179 panfrost_set_blend_color(struct pipe_context *pipe,
 180                          const struct pipe_blend_color *blend_color)
 181 {
 182         struct panfrost_context *ctx = pan_context(pipe);
 183
 184         if (blend_color)
 185                 ctx->blend_color = *blend_color;
 186 }
 187
 188 /* Given a vec4 of constants, reduce it to just a single constant according to
 189  * the mask (if we can) */
 190
 191 static bool
 192 panfrost_blend_constant(float *out, float *in, unsigned mask)
 193 {
 194         /* If there is no components used, it automatically works */
 195
 196         if (!mask)
 197                 return true;
 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                         return false;
 210         }
 211
 212         /* Otherwise, we're good to go */
 213         *out = cons;
 214         return true;
 215 }
 216
 217 /* Create a final blend given the context */
 218
 219 struct panfrost_blend_final
 220 panfrost_get_blend_for_context(struct panfrost_context *ctx, unsigned rti)
 221 {
 222         struct panfrost_batch *batch = panfrost_get_batch_for_fbo(ctx);
 223         struct pipe_framebuffer_state *fb = &ctx->pipe_framebuffer;
 224         enum pipe_format fmt = fb->cbufs[rti]->format;
 225
 226         /* Grab the blend state */
 227         struct panfrost_blend_state *blend = ctx->blend;
 228         struct panfrost_blend_rt *rt = &blend->rt[rti];
 229
 230         /* First, we'll try fixed function, matching equationn and constant */
 231         if (rt->has_fixed_function && panfrost_can_fixed_blend(fmt)) {
 232                 float constant = 0.0;
 233
 234                 if (panfrost_blend_constant(
 235                             &constant,
 236                             ctx->blend_color.color,
 237                             rt->constant_mask)) {
 238                         struct panfrost_blend_final final = {
 239                                 .equation = {
 240                                         .equation = rt->equation,
 241                                         .constant = constant
 242                                 },
 243                                 .load_dest = rt->load_dest,
 244                                 .opaque = rt->opaque,
 245                                 .no_colour = rt->no_colour
 246                         };
 247
 248                         return final;
 249                 }
 250         }
 251
 252         /* Otherwise, we need to grab a shader */
 253         struct panfrost_blend_shader *shader = panfrost_get_blend_shader(ctx, blend, fmt, rti);
 254
 255         struct panfrost_bo *bo = panfrost_batch_create_bo(batch, shader->size,
 256                    PAN_BO_EXECUTE,
 257                    PAN_BO_ACCESS_PRIVATE |
 258                    PAN_BO_ACCESS_READ |
 259                    PAN_BO_ACCESS_FRAGMENT);
 260
 261         memcpy(bo->cpu, shader->buffer, shader->size);
 262
 263         if (shader->patch_index) {
 264                 /* We have to specialize the blend shader to use constants, so
 265                  * patch in the current constants */
 266
 267                 float *patch = (float *) (bo->cpu + shader->patch_index);
 268                 memcpy(patch, ctx->blend_color.color, sizeof(float) * 4);
 269         }
 270
 271         struct panfrost_blend_final final = {
 272                 .is_shader = true,
 273                 .shader = {
 274                         .work_count = shader->work_count,
 275                         .first_tag = shader->first_tag,
 276                         .gpu = bo->gpu,
 277                 },
 278                 .load_dest = rt->load_dest,
 279         };
 280
 281         return final;
 282 }
 283
 284 void
 285 panfrost_blend_context_init(struct pipe_context *pipe)
 286 {
 287         pipe->create_blend_state = panfrost_create_blend_state;
 288         pipe->bind_blend_state   = panfrost_bind_blend_state;
 289         pipe->delete_blend_state = panfrost_delete_blend_state;
 290
 291         pipe->set_blend_color = panfrost_set_blend_color;
 292 }