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 <fredrik@kde.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/mesa/vbo/vbo_exec_api.c b/src/mesa/vbo/vbo_exec_api.c
index 9858bad..74aec12 100644
--- a/src/mesa/vbo/vbo_exec_api.c
+++ b/src/mesa/vbo/vbo_exec_api.c
@@ -1118,8 +1118,8 @@ void vbo_exec_vtx_destroy( struct vbo_exec_context *exec )
 
    /* Free the vertex buffer.  Unmap first if needed.
     */
-   if (_mesa_bufferobj_mapped(exec->vtx.bufferobj)) {
-      ctx->Driver.UnmapBuffer(ctx, exec->vtx.bufferobj);
+   if (_mesa_bufferobj_mapped(exec->vtx.bufferobj, MAP_INTERNAL)) {
+      ctx->Driver.UnmapBuffer(ctx, exec->vtx.bufferobj, MAP_INTERNAL);
    }
    _mesa_reference_buffer_object(ctx, &exec->vtx.bufferobj, NULL);
 }