mesa: allow buffers to be mapped multiple times

OpenGL allows a buffer to be mapped only once, but we also map buffers
internally, e.g. in the software primitive restart fallback, for PBOs,
vbo_get_minmax_index, etc. This has always been a problem, but it will
be a bigger problem with persistent buffer mappings, which will prevent
all Mesa functions from mapping buffers for internal purposes.

This adds a driver interface to core Mesa which supports multiple buffer
mappings and allows 2 mappings: one for the GL user and one for Mesa.

Note that Gallium supports an unlimited number of buffer and texture
mappings, so it's not really an issue for Gallium.

v2: fix unmapping in xm_dd.c, remove the GL errors there
v3: fix the intel driver (by Fredrik)

Reviewed-by: Fredrik Höglund <[email protected]>

1 files changed, 6 insertions, 4 deletions

diff --git a/src/mesa/main/texgetimage.c b/src/mesa/main/texgetimage.c
index b21aa2cf25f..fedd814e932 100644
--- a/src/mesa/main/texgetimage.c
+++ b/src/mesa/main/texgetimage.c
@@ -635,7 +635,8 @@ _mesa_get_teximage(struct gl_context *ctx,
        */
       GLubyte *buf = (GLubyte *)
          ctx->Driver.MapBufferRange(ctx, 0, ctx->Pack.BufferObj->Size,
-				    GL_MAP_WRITE_BIT, ctx->Pack.BufferObj);
+				    GL_MAP_WRITE_BIT, ctx->Pack.BufferObj,
+                                    MAP_INTERNAL);
       if (!buf) {
          /* out of memory or other unexpected error */
          _mesa_error(ctx, GL_OUT_OF_MEMORY, "glGetTexImage(map PBO failed)");
@@ -664,7 +665,7 @@ _mesa_get_teximage(struct gl_context *ctx,
    }
 
    if (_mesa_is_bufferobj(ctx->Pack.BufferObj)) {
-      ctx->Driver.UnmapBuffer(ctx, ctx->Pack.BufferObj);
+      ctx->Driver.UnmapBuffer(ctx, ctx->Pack.BufferObj, MAP_INTERNAL);
    }
 }
 
@@ -689,7 +690,8 @@ _mesa_get_compressed_teximage(struct gl_context *ctx,
       /* pack texture image into a PBO */
       GLubyte *buf = (GLubyte *)
          ctx->Driver.MapBufferRange(ctx, 0, ctx->Pack.BufferObj->Size,
-				    GL_MAP_WRITE_BIT, ctx->Pack.BufferObj);
+				    GL_MAP_WRITE_BIT, ctx->Pack.BufferObj,
+                                    MAP_INTERNAL);
       if (!buf) {
          /* out of memory or other unexpected error */
          _mesa_error(ctx, GL_OUT_OF_MEMORY,
@@ -731,7 +733,7 @@ _mesa_get_compressed_teximage(struct gl_context *ctx,
    }
 
    if (_mesa_is_bufferobj(ctx->Pack.BufferObj)) {
-      ctx->Driver.UnmapBuffer(ctx, ctx->Pack.BufferObj);
+      ctx->Driver.UnmapBuffer(ctx, ctx->Pack.BufferObj, MAP_INTERNAL);
    }
 }