virgl: ARB_texture_barrier support

Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>

docs/features.txt

@@ -219,7 +219,7 @@ GL 4.5, GLSL 4.50 -- all DONE: nvc0, radeonsi
   GL_ARB_direct_state_access                            DONE (all drivers)
   GL_ARB_get_texture_sub_image                          DONE (all drivers)
   GL_ARB_shader_texture_image_samples                   DONE (i965, nv50, r600, virgl)
-  GL_ARB_texture_barrier                                DONE (freedreno, i965, nv50, r600)
+  GL_ARB_texture_barrier                                DONE (freedreno, i965, nv50, r600, virgl)
   GL_KHR_context_flush_control                          DONE (all - but needs GLX/EGL extension to be useful)
   GL_KHR_robustness                                     DONE (i965)
   GL_EXT_shader_integer_mix                             DONE (all drivers that support GLSL)

src/gallium/drivers/virgl/virgl_context.c

@@ -805,9 +805,14 @@ static void virgl_set_sampler_views(struct pipe_context *ctx,
 }
 
 static void
-virgl_texture_barrier(struct pipe_context *pctx, unsigned flags)
+virgl_texture_barrier(struct pipe_context *ctx, unsigned flags)
 {
-   /* stub */
+   struct virgl_context *vctx = virgl_context(ctx);
+   struct virgl_screen *rs = virgl_screen(ctx->screen);
+
+   if (!(rs->caps.caps.v2.capability_bits & VIRGL_CAP_TEXTURE_BARRIER))
+      return;
+   virgl_encode_texture_barrier(vctx, flags);
 }
 
 static void virgl_destroy_sampler_view(struct pipe_context *ctx,

src/gallium/drivers/virgl/virgl_encode.c

@@ -1009,3 +1009,11 @@ int virgl_encode_launch_grid(struct virgl_context *ctx,
    virgl_encoder_write_dword(ctx->cbuf, grid_info->indirect_offset);
    return 0;
 }
+
+int virgl_encode_texture_barrier(struct virgl_context *ctx,
+                                 unsigned flags)
+{
+   virgl_encoder_write_cmd_dword(ctx, VIRGL_CMD0(VIRGL_CCMD_TEXTURE_BARRIER, 0, 1));
+   virgl_encoder_write_dword(ctx->cbuf, flags);
+   return 0;
+}

src/gallium/drivers/virgl/virgl_encode.h

@@ -272,4 +272,6 @@ int virgl_encode_memory_barrier(struct virgl_context *ctx,
                                 unsigned flags);
 int virgl_encode_launch_grid(struct virgl_context *ctx,
                              const struct pipe_grid_info *grid_info);
+int virgl_encode_texture_barrier(struct virgl_context *ctx,
+                                 unsigned flags);
 #endif

src/gallium/drivers/virgl/virgl_hw.h

@@ -229,6 +229,7 @@ enum virgl_formats {
 #define VIRGL_CAP_ROBUST_BUFFER_ACCESS (1 << 9)
 #define VIRGL_CAP_TGSI_FBFETCH         (1 << 10)
 #define VIRGL_CAP_SHADER_CLOCK         (1 << 11)
+#define VIRGL_CAP_TEXTURE_BARRIER      (1 << 12)
 
 /* virgl bind flags - these are compatible with mesa 10.5 gallium.
  * but are fixed, no other should be passed to virgl either.

src/gallium/drivers/virgl/virgl_protocol.h

@@ -91,6 +91,7 @@ enum virgl_context_cmd {
    VIRGL_CCMD_MEMORY_BARRIER,
    VIRGL_CCMD_LAUNCH_GRID,
    VIRGL_CCMD_SET_FRAMEBUFFER_STATE_NO_ATTACH,
+   VIRGL_CCMD_TEXTURE_BARRIER,
 };
 
 /*
@@ -539,4 +540,8 @@ enum virgl_context_cmd {
 #define VIRGL_SET_FRAMEBUFFER_STATE_NO_ATTACH_LAYERS(x) (x & 0xffff)
 #define VIRGL_SET_FRAMEBUFFER_STATE_NO_ATTACH_SAMPLES(x) ((x >> 16) & 0xff)
 
+/* texture barrier */
+#define VIRGL_TEXTURE_BARRIER_SIZE 1
+#define VIRGL_TEXTURE_BARRIER_FLAGS 1
+
 #endif

src/gallium/drivers/virgl/virgl_screen.c

@@ -124,7 +124,7 @@ virgl_get_param(struct pipe_screen *screen, enum pipe_cap param)
    case PIPE_CAP_CONDITIONAL_RENDER:
       return vscreen->caps.caps.v1.bset.conditional_render;
    case PIPE_CAP_TEXTURE_BARRIER:
-      return 0;
+      return vscreen->caps.caps.v2.capability_bits & VIRGL_CAP_TEXTURE_BARRIER;
    case PIPE_CAP_VERTEX_COLOR_UNCLAMPED:
       return 1;
    case PIPE_CAP_FRAGMENT_COLOR_CLAMPED: