radeonsi: support thread-safe shaders shared by multiple contexts

The "current" shader pointer is moved from the CSO to the context, so that
the CSO is mostly immutable.

The only drawback is that the "current" pointer isn't saved when unbinding
a shader and it must be looked up when the shader is bound again.

This is also a prerequisite for multithreaded shader compilation.

Reviewed-by: Michel Dänzer <[email protected]>

1 files changed, 17 insertions, 14 deletions

diff --git a/src/gallium/drivers/radeonsi/si_shader.h b/src/gallium/drivers/radeonsi/si_shader.h
index 54dad726d01..b1076ed9183 100644
--- a/src/gallium/drivers/radeonsi/si_shader.h
+++ b/src/gallium/drivers/radeonsi/si_shader.h
@@ -179,15 +179,18 @@ struct radeon_shader_reloc;
 
 struct si_shader;
 
+/* A shader selector is a gallium CSO and contains shader variants and
+ * binaries for one TGSI program. This can be shared by multiple contexts.
+ */
 struct si_shader_selector {
-	struct si_shader *current;
+	pipe_mutex		mutex;
+	struct si_shader	*first_variant; /* immutable after the first variant */
+	struct si_shader	*last_variant; /* mutable */
 
 	struct tgsi_token       *tokens;
 	struct pipe_stream_output_info  so;
 	struct tgsi_shader_info		info;
 
-	unsigned	num_shaders;
-
 	/* PIPE_SHADER_[VERTEX|FRAGMENT|...] */
 	unsigned	type;
 
@@ -293,24 +296,24 @@ struct si_shader {
 
 static inline struct tgsi_shader_info *si_get_vs_info(struct si_context *sctx)
 {
-	if (sctx->gs_shader)
-		return &sctx->gs_shader->info;
-	else if (sctx->tes_shader)
-		return &sctx->tes_shader->info;
-	else if (sctx->vs_shader)
-		return &sctx->vs_shader->info;
+	if (sctx->gs_shader.cso)
+		return &sctx->gs_shader.cso->info;
+	else if (sctx->tes_shader.cso)
+		return &sctx->tes_shader.cso->info;
+	else if (sctx->vs_shader.cso)
+		return &sctx->vs_shader.cso->info;
 	else
 		return NULL;
 }
 
 static inline struct si_shader* si_get_vs_state(struct si_context *sctx)
 {
-	if (sctx->gs_shader)
-		return sctx->gs_shader->current->gs_copy_shader;
-	else if (sctx->tes_shader)
-		return sctx->tes_shader->current;
+	if (sctx->gs_shader.current)
+		return sctx->gs_shader.current->gs_copy_shader;
+	else if (sctx->tes_shader.current)
+		return sctx->tes_shader.current;
 	else
-		return sctx->vs_shader->current;
+		return sctx->vs_shader.current;
 }
 
 static inline bool si_vs_exports_prim_id(struct si_shader *shader)