asahi: Check box implement NV_conditional_render

Use the freedreno lowering. It'll be slow but I don't know of any apps that
actually use this and it's required for GL 3.0.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20446>

docs/features.txt

@@ -39,7 +39,7 @@ Feature                                                 Status
 GL 3.0, GLSL 1.30 --- all DONE: freedreno, i965, nv50, nvc0, r600, radeonsi, llvmpipe, softpipe, virgl, zink, d3d12, panfrost
 
   glBindFragDataLocation, glGetFragDataLocation         DONE
-  GL_NV_conditional_render (Conditional rendering)      DONE ()
+  GL_NV_conditional_render (Conditional rendering)      DONE (asahi)
   GL_ARB_map_buffer_range (Map buffer subranges)        DONE (v3d, vc4, lima, asahi)
   GL_ARB_color_buffer_float (Clamping controls)         DONE (v3d, vc4, lima, asahi)
   GL_ARB_texture_float (Float textures, renderbuffers)  DONE (v3d, asahi)

src/gallium/drivers/asahi/agx_blit.c

@@ -68,12 +68,11 @@ agx_blitter_save(struct agx_context *ctx, struct blitter_context *blitter,
 void
 agx_blit(struct pipe_context *pipe, const struct pipe_blit_info *info)
 {
-   // if (info->render_condition_enable &&
-   //     !agx_render_condition_check(pan_context(pipe)))
-   //         return;
-
    struct agx_context *ctx = agx_context(pipe);
 
+   if (info->render_condition_enable && !agx_render_condition_check(ctx))
+      return;
+
    if (!util_blitter_is_blit_supported(ctx->blitter, info)) {
       fprintf(stderr, "\n");
       util_dump_blit_info(stderr, info);

src/gallium/drivers/asahi/agx_pipe.c

@@ -870,6 +870,9 @@ agx_clear(struct pipe_context *pctx, unsigned buffers,
    struct agx_context *ctx = agx_context(pctx);
    struct agx_batch *batch = agx_get_batch(ctx);
 
+   if (unlikely(!agx_render_condition_check(ctx)))
+      return;
+
    unsigned fastclear = buffers & ~(batch->draw | batch->load);
    unsigned slowclear = buffers & ~fastclear;
 
@@ -1239,6 +1242,8 @@ agx_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
    case PIPE_CAP_QUADS_FOLLOW_PROVOKING_VERTEX_CONVENTION:
    case PIPE_CAP_VS_INSTANCEID:
    case PIPE_CAP_VERTEX_ELEMENT_INSTANCE_DIVISOR:
+   case PIPE_CAP_CONDITIONAL_RENDER:
+   case PIPE_CAP_CONDITIONAL_RENDER_INVERTED:
       return 1;
 
    case PIPE_CAP_TEXTURE_MULTISAMPLE:

src/gallium/drivers/asahi/agx_query.c

@@ -176,6 +176,36 @@ agx_finish_batch_occlusion_queries(struct agx_batch *batch)
    }
 }
 
+static void
+agx_render_condition(struct pipe_context *pipe, struct pipe_query *query,
+                     bool condition, enum pipe_render_cond_flag mode)
+{
+   struct agx_context *ctx = agx_context(pipe);
+
+   ctx->cond_query = query;
+   ctx->cond_cond = condition;
+   ctx->cond_mode = mode;
+}
+
+bool
+agx_render_condition_check_inner(struct agx_context *ctx)
+{
+   assert(ctx->cond_query != NULL && "precondition");
+
+   perf_debug_ctx(ctx, "Implementing conditional rendering on the CPU");
+
+   union pipe_query_result res = {0};
+   bool wait = ctx->cond_mode != PIPE_RENDER_COND_NO_WAIT &&
+               ctx->cond_mode != PIPE_RENDER_COND_BY_REGION_NO_WAIT;
+
+   struct pipe_query *pq = (struct pipe_query *)ctx->cond_query;
+
+   if (agx_get_query_result(&ctx->base, pq, wait, &res))
+      return res.u64 != ctx->cond_cond;
+
+   return true;
+}
+
 void
 agx_init_query_functions(struct pipe_context *pctx)
 {
@@ -185,6 +215,7 @@ agx_init_query_functions(struct pipe_context *pctx)
    pctx->end_query = agx_end_query;
    pctx->get_query_result = agx_get_query_result;
    pctx->set_active_query_state = agx_set_active_query_state;
+   pctx->render_condition = agx_render_condition;
 
    /* By default queries are active */
    agx_context(pctx)->active_queries = true;

src/gallium/drivers/asahi/agx_state.c

@@ -2157,12 +2157,16 @@ agx_draw_vbo(struct pipe_context *pctx, const struct pipe_draw_info *info,
              const struct pipe_draw_indirect_info *indirect,
              const struct pipe_draw_start_count_bias *draws, unsigned num_draws)
 {
+   struct agx_context *ctx = agx_context(pctx);
+
+   if (unlikely(!agx_render_condition_check(ctx)))
+      return;
+
    if (num_draws > 1) {
       util_draw_multi(pctx, info, drawid_offset, indirect, draws, num_draws);
       return;
    }
 
-   struct agx_context *ctx = agx_context(pctx);
    struct agx_batch *batch = agx_get_batch(ctx);
 
 #ifndef NDEBUG

src/gallium/drivers/asahi/agx_state.h

@@ -505,4 +505,15 @@ uint16_t agx_get_oq_index(struct agx_batch *batch, struct agx_query *query);
 
 void agx_finish_batch_occlusion_queries(struct agx_batch *batch);
 
+bool agx_render_condition_check_inner(struct agx_context *ctx);
+
+static inline bool
+agx_render_condition_check(struct agx_context *ctx)
+{
+   if (likely(!ctx->cond_query))
+      return true;
+   else
+      return agx_render_condition_check_inner(ctx);
+}
+
 #endif