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, 3 insertions, 2 deletions

diff --git a/src/mesa/main/dlist.c b/src/mesa/main/dlist.c
index 08943c9f9b0..0f4c89b8d20 100644
--- a/src/mesa/main/dlist.c
+++ b/src/mesa/main/dlist.c
@@ -914,7 +914,8 @@ unpack_image(struct gl_context *ctx, GLuint dimensions,
 
       map = (GLubyte *)
          ctx->Driver.MapBufferRange(ctx, 0, unpack->BufferObj->Size,
-				    GL_MAP_READ_BIT, unpack->BufferObj);
+				    GL_MAP_READ_BIT, unpack->BufferObj,
+                                    MAP_INTERNAL);
       if (!map) {
          /* unable to map src buffer! */
          _mesa_error(ctx, GL_INVALID_OPERATION, "unable to map PBO");
@@ -928,7 +929,7 @@ unpack_image(struct gl_context *ctx, GLuint dimensions,
          image = _mesa_unpack_image(dimensions, width, height, depth,
                                     format, type, src, unpack);
 
-      ctx->Driver.UnmapBuffer(ctx, unpack->BufferObj);
+      ctx->Driver.UnmapBuffer(ctx, unpack->BufferObj, MAP_INTERNAL);
 
       if (!image) {
          _mesa_error(ctx, GL_OUT_OF_MEMORY, "display list construction");