b692076420
This fixes a crash when a resource cannot be mapped to the CPU's address space because it's too big. This puts a global pipe_context in r600_screen, which is guarded by a mutex, so that we can use pipe_context when there isn't one around. Hopefully our multi-context support is solid. Reviewed-by: Alex Deucher <alexander.deucher@amd.com> NOTE: This is a candidate for the 9.1 branch.