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, 4 insertions, 2 deletions

diff --git a/src/mesa/vbo/vbo_save_draw.c b/src/mesa/vbo/vbo_save_draw.c
index 4b13cc4e5d0..89fd30e0fb1 100644
--- a/src/mesa/vbo/vbo_save_draw.c
+++ b/src/mesa/vbo/vbo_save_draw.c
@@ -225,7 +225,8 @@ vbo_save_loopback_vertex_list(struct gl_context *ctx,
       ctx->Driver.MapBufferRange(ctx, 0,
 				 list->vertex_store->bufferobj->Size,
 				 GL_MAP_READ_BIT, /* ? */
-				 list->vertex_store->bufferobj);
+				 list->vertex_store->bufferobj,
+                                 MAP_INTERNAL);
 
    vbo_loopback_vertex_list(ctx,
                             (const GLfloat *)(buffer + list->buffer_offset),
@@ -235,7 +236,8 @@ vbo_save_loopback_vertex_list(struct gl_context *ctx,
                             list->wrap_count,
                             list->vertex_size);
 
-   ctx->Driver.UnmapBuffer(ctx, list->vertex_store->bufferobj);
+   ctx->Driver.UnmapBuffer(ctx, list->vertex_store->bufferobj,
+                           MAP_INTERNAL);
 }