On Fri, 2019-02-08 at 13:01 +0000, Christophe Leroy wrote:

On 02/08/2019 12:34 PM, Michael Ellerman wrote:

quoted

In commit 7820856a4fcd ("powerpc/mm/book3e/64: Remove unsupported
64Kpage size from 64bit booke") we dropped the 64K page size support
from the 64-bit nohash (Book3E) code.

But we didn't update the dependencies of the PPC_64K_PAGES option,
meaning a randconfig can still trigger this code and cause a build
breakage, eg:
   arch/powerpc/include/asm/nohash/64/pgtable.h:14:2: error: #error "Page
size not supported"
   arch/powerpc/include/asm/nohash/mmu-book3e.h:275:2: error: #error
Unsupported page size

So remove PPC_BOOK3E_64 from the dependencies. This also means we
don't need to worry about PPC_FSL_BOOK3E, because that was just trying
to prevent the PPC_BOOK3E_64=y && PPC_FSL_BOOK3E=y case.

Does it means some cleanup could be done, for instance:

arch/powerpc/include/asm/nohash/64/pgalloc.h:#ifndef CONFIG_PPC_64K_PAGES
arch/powerpc/include/asm/nohash/64/pgalloc.h:#endif /* 
CONFIG_PPC_64K_PAGES */
arch/powerpc/include/asm/nohash/64/pgtable.h:#ifdef CONFIG_PPC_64K_PAGES
arch/powerpc/include/asm/nohash/64/slice.h:#ifdef CONFIG_PPC_64K_PAGES
arch/powerpc/include/asm/nohash/64/slice.h:#else /* CONFIG_PPC_64K_PAGES */
arch/powerpc/include/asm/nohash/64/slice.h:#endif /* 
!CONFIG_PPC_64K_PAGES */
arch/powerpc/include/asm/nohash/pte-book3e.h:#ifdef CONFIG_PPC_64K_PAGES

arch/powerpc/mm/tlb_low_64e.S:#ifdef CONFIG_PPC_64K_PAGES
arch/powerpc/mm/tlb_low_64e.S:#ifndef CONFIG_PPC_64K_PAGES
arch/powerpc/mm/tlb_low_64e.S:#endif /* CONFIG_PPC_64K_PAGES */
arch/powerpc/mm/tlb_low_64e.S:#ifdef CONFIG_PPC_64K_PAGES
arch/powerpc/mm/tlb_low_64e.S:#ifdef CONFIG_PPC_64K_PAGES
arch/powerpc/mm/tlb_low_64e.S:#ifndef CONFIG_PPC_64K_PAGES
arch/powerpc/mm/tlb_low_64e.S:#endif /* CONFIG_PPC_64K_PAGES */
arch/powerpc/mm/tlb_low_64e.S:#ifndef CONFIG_PPC_64K_PAGES
arch/powerpc/mm/tlb_low_64e.S:#endif /* CONFIG_PPC_64K_PAGES */
arch/powerpc/mm/tlb_low_64e.S:#ifndef CONFIG_PPC_64K_PAGES
arch/powerpc/mm/tlb_low_64e.S:#ifdef CONFIG_PPC_64K_PAGES

More generally, if fsl is the only supported book3e platform and that's not
expected to change, everything in tlb_low_64e.S except the bolted and e6500
variants could go away.

-Scott