the include/asm-x86 directory and headers has been deleted in the 2.6.28-rc1, etc. kernels. the kernels build properly, and that directory is created dynamically; but the only header within that directory after the build is finished is the asm-offsets.h header. When I build a nvidia driver against that kernel, the build fails.
commit bb8985586*
(git log --stat --graph include/asm-x86/)