etnaviv: Add support for conditional rendering

The hardware doesn't support native conditional rendering, so it is
implemented by software.

Code borrowed from Freedreno and Panfrost.

Signed-off-by: Christian Gmeiner <cgmeiner@igalia.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23392>

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, asahi
 
   glBindFragDataLocation, glGetFragDataLocation         DONE
-  GL_NV_conditional_render (Conditional rendering)      DONE (v3d)
+  GL_NV_conditional_render (Conditional rendering)      DONE (v3d, etnaviv/HALTI0)
   GL_ARB_map_buffer_range (Map buffer subranges)        DONE (v3d, vc4, lima)
   GL_ARB_color_buffer_float (Clamping controls)         DONE (v3d, vc4, lima)
   GL_ARB_texture_float (Float textures, renderbuffers)  DONE (v3d)

src/gallium/drivers/etnaviv/etnaviv_blt.c

@@ -360,6 +360,9 @@ etna_clear_blt(struct pipe_context *pctx, unsigned buffers, const struct pipe_sc
 {
    struct etna_context *ctx = etna_context(pctx);
 
+   if (!etna_render_condition_check(pctx))
+      return;
+
    etna_set_state(ctx->stream, VIVS_GL_FLUSH_CACHE, 0x00000c23);
    etna_set_state(ctx->stream, VIVS_TS_FLUSH_CACHE, VIVS_TS_FLUSH_CACHE_FLUSH);
 

src/gallium/drivers/etnaviv/etnaviv_clear_blit.c

@@ -47,7 +47,7 @@
 
 /* Save current state for blitter operation */
 void
-etna_blit_save_state(struct etna_context *ctx)
+etna_blit_save_state(struct etna_context *ctx, bool render_cond)
 {
    util_blitter_save_fragment_constant_buffer_slot(ctx->blitter,
                                                    ctx->constant_buffer[PIPE_SHADER_FRAGMENT].cb);
@@ -68,6 +68,10 @@ etna_blit_save_state(struct etna_context *ctx)
    util_blitter_save_fragment_sampler_views(ctx->blitter,
          ctx->num_fragment_sampler_views, ctx->sampler_view);
 
+   if (!render_cond)
+      util_blitter_save_render_condition(ctx->blitter,
+            ctx->cond_query, ctx->cond_cond, ctx->cond_mode);
+
    if (DBG_ENABLED(ETNA_DBG_DEQP))
       util_blitter_save_so_targets(ctx->blitter, 0, NULL);
 }
@@ -100,6 +104,8 @@ etna_blit(struct pipe_context *pctx, const struct pipe_blit_info *blit_info)
    struct etna_context *ctx = etna_context(pctx);
    struct pipe_blit_info info = *blit_info;
 
+   if (info.render_condition_enable && !etna_render_condition_check(pctx))
+      return;
 
    if (ctx->blit(pctx, &info))
       goto success;
@@ -119,7 +125,7 @@ etna_blit(struct pipe_context *pctx, const struct pipe_blit_info *blit_info)
       return;
    }
 
-   etna_blit_save_state(ctx);
+   etna_blit_save_state(ctx, info.render_condition_enable);
    util_blitter_blit(ctx->blitter, &info);
 
 success:
@@ -137,7 +143,7 @@ etna_clear_render_target(struct pipe_context *pctx, struct pipe_surface *dst,
 
    /* XXX could fall back to RS when target area is full screen / resolveable
     * and no TS. */
-   etna_blit_save_state(ctx);
+   etna_blit_save_state(ctx, false);
    util_blitter_clear_render_target(ctx->blitter, dst, color, dstx, dsty, width, height);
 }
 
@@ -151,7 +157,7 @@ etna_clear_depth_stencil(struct pipe_context *pctx, struct pipe_surface *dst,
 
    /* XXX could fall back to RS when target area is full screen / resolveable
     * and no TS. */
-   etna_blit_save_state(ctx);
+   etna_blit_save_state(ctx, false);
    util_blitter_clear_depth_stencil(ctx->blitter, dst, clear_flags, depth,
                                     stencil, dstx, dsty, width, height);
 }
@@ -166,7 +172,7 @@ etna_resource_copy_region(struct pipe_context *pctx, struct pipe_resource *dst,
 
    if (src->target != PIPE_BUFFER && dst->target != PIPE_BUFFER &&
        util_blitter_is_copy_supported(ctx->blitter, dst, src)) {
-      etna_blit_save_state(ctx);
+      etna_blit_save_state(ctx, false);
       util_blitter_copy_texture(ctx->blitter, dst, dst_level, dstx, dsty, dstz,
                                 src, src_level, src_box);
    } else {

src/gallium/drivers/etnaviv/etnaviv_clear_blit.h

@@ -48,7 +48,7 @@ etna_copy_resource_box(struct pipe_context *pctx, struct pipe_resource *dst,
                        struct pipe_box *box);
 
 void
-etna_blit_save_state(struct etna_context *ctx);
+etna_blit_save_state(struct etna_context *ctx, bool render_cond);
 
 uint64_t
 etna_clear_blit_pack_rgba(enum pipe_format format, const union pipe_color_union *color);

src/gallium/drivers/etnaviv/etnaviv_context.c

@@ -248,6 +248,9 @@ etna_draw_vbo(struct pipe_context *pctx, const struct pipe_draw_info *info,
                 u_decomposed_prim(info->mode) == MESA_PRIM_TRIANGLES))
       return;
 
+   if (!etna_render_condition_check(pctx))
+      return;
+
    int prims = u_decomposed_prims_for_vertices(info->mode, draws[0].count);
    if (unlikely(prims <= 0)) {
       DBG("Invalid draw primitive mode=%i or no primitives to be drawn", info->mode);
@@ -664,3 +667,22 @@ fail:
 
    return NULL;
 }
+
+bool
+etna_render_condition_check(struct pipe_context *pctx)
+{
+   struct etna_context *ctx = etna_context(pctx);
+
+   if (!ctx->cond_query)
+      return true;
+
+   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;
+
+   if (pctx->get_query_result(pctx, ctx->cond_query, wait, &res))
+      return (bool)res.u64 != ctx->cond_cond;
+
+   return true;
+}

src/gallium/drivers/etnaviv/etnaviv_context.h

@@ -199,6 +199,11 @@ struct etna_context {
    struct set *flush_resources;
 
    bool is_noop;
+
+   /* conditional rendering */
+   struct pipe_query *cond_query;
+   bool cond_cond; /* inverted rendering condition */
+   uint cond_mode;
 };
 
 static inline struct etna_context *
@@ -224,4 +229,7 @@ void
 etna_flush(struct pipe_context *pctx, struct pipe_fence_handle **fence,
            enum pipe_flush_flags flags, bool internal);
 
+bool
+etna_render_condition_check(struct pipe_context *pctx);
+
 #endif

src/gallium/drivers/etnaviv/etnaviv_query.c

@@ -119,6 +119,17 @@ etna_get_driver_query_group_info(struct pipe_screen *pscreen, unsigned index,
    return etna_pm_get_driver_query_group_info(pscreen, index, info);
 }
 
+static void
+etna_render_condition(struct pipe_context *pctx, struct pipe_query *pq,
+                      bool condition, enum pipe_render_cond_flag mode)
+{
+   struct etna_context *ctx = etna_context(pctx);
+
+   ctx->cond_query = pq;
+   ctx->cond_cond = condition;
+   ctx->cond_mode = mode;
+}
+
 static void
 etna_set_active_query_state(struct pipe_context *pctx, bool enable)
 {
@@ -149,4 +160,5 @@ etna_query_context_init(struct pipe_context *pctx)
    pctx->end_query = etna_end_query;
    pctx->get_query_result = etna_get_query_result;
    pctx->set_active_query_state = etna_set_active_query_state;
+   pctx->render_condition = etna_render_condition;
 }

src/gallium/drivers/etnaviv/etnaviv_rs.c

@@ -431,6 +431,9 @@ etna_clear_rs(struct pipe_context *pctx, unsigned buffers, const struct pipe_sci
 {
    struct etna_context *ctx = etna_context(pctx);
 
+   if (!etna_render_condition_check(pctx))
+      return;
+
    /* Flush color and depth cache before clearing anything.
     * This is especially important when coming from another surface, as
     * otherwise it may clear part of the old surface instead. */

src/gallium/drivers/etnaviv/etnaviv_screen.c

@@ -241,6 +241,8 @@ etna_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
 
    /* Queries. */
    case PIPE_CAP_OCCLUSION_QUERY:
+   case PIPE_CAP_CONDITIONAL_RENDER:
+   case PIPE_CAP_CONDITIONAL_RENDER_INVERTED:
       return VIV_FEATURE(screen, chipMinorFeatures1, HALTI0);
 
    /* Preferences */