[PATCH] powerpc/mm: Define MAX_PHYSMEM_BITS for all 64-bit configs

The recent commit 8bc086899816 ("powerpc/mm: Only define
MAX_PHYSMEM_BITS in SPARSEMEM configurations") removed our definition
of MAX_PHYSMEM_BITS when SPARSEMEM is disabled.

This inadvertently broke some 64-bit FLATMEM using configs with eg:

  arch/powerpc/include/asm/book3s/64/mmu-hash.h:584:6: error: "MAX_PHYSMEM_BITS" is not defined, evaluates to 0
   #if (MAX_PHYSMEM_BITS > MAX_EA_BITS_PER_CONTEXT)
        ^~~~~~~~~~~~~~~~

Fix it by making sure we define MAX_PHYSMEM_BITS for all 64-bit
configs regardless of SPARSEMEM.

Fixes: 8bc086899816 ("powerpc/mm: Only define MAX_PHYSMEM_BITS in SPARSEMEM configurations")
Reported-by: Andreas Schwab <redacted>
Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/include/asm/mmu.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
index 598cdcdd1355..8ddd4a91bdc1 100644
--- a/arch/powerpc/include/asm/mmu.h
+++ b/arch/powerpc/include/asm/mmu.h

@@ -352,7 +352,7 @@ static inline bool strict_kernel_rwx_enabled(void)
 #if defined(CONFIG_SPARSEMEM_VMEMMAP) && defined(CONFIG_SPARSEMEM_EXTREME) &&	\
 	defined (CONFIG_PPC_64K_PAGES)
 #define MAX_PHYSMEM_BITS        51
-#elif defined(CONFIG_SPARSEMEM)
+#elif defined(CONFIG_PPC64)
 #define MAX_PHYSMEM_BITS        46
 #endif
 

-- 
2.20.1

Michael Ellerman [off-list ref] writes:

The recent commit 8bc086899816 ("powerpc/mm: Only define
MAX_PHYSMEM_BITS in SPARSEMEM configurations") removed our definition
of MAX_PHYSMEM_BITS when SPARSEMEM is disabled.

This inadvertently broke some 64-bit FLATMEM using configs with eg:

  arch/powerpc/include/asm/book3s/64/mmu-hash.h:584:6: error: "MAX_PHYSMEM_BITS" is not defined, evaluates to 0
   #if (MAX_PHYSMEM_BITS > MAX_EA_BITS_PER_CONTEXT)
        ^~~~~~~~~~~~~~~~

Fix it by making sure we define MAX_PHYSMEM_BITS for all 64-bit
configs regardless of SPARSEMEM.

Reviewed-by: Aneesh Kumar K.V <redacted>

But I still like the patch I posted which move this to the correct
platform header.

On Tue, 2019-04-09 at 06:03:24 UTC, Michael Ellerman wrote:

The recent commit 8bc086899816 ("powerpc/mm: Only define
MAX_PHYSMEM_BITS in SPARSEMEM configurations") removed our definition
of MAX_PHYSMEM_BITS when SPARSEMEM is disabled.

This inadvertently broke some 64-bit FLATMEM using configs with eg:

  arch/powerpc/include/asm/book3s/64/mmu-hash.h:584:6: error: "MAX_PHYSMEM_BITS" is not defined, evaluates to 0
   #if (MAX_PHYSMEM_BITS > MAX_EA_BITS_PER_CONTEXT)
        ^~~~~~~~~~~~~~~~

Fix it by making sure we define MAX_PHYSMEM_BITS for all 64-bit
configs regardless of SPARSEMEM.

Fixes: 8bc086899816 ("powerpc/mm: Only define MAX_PHYSMEM_BITS in SPARSEMEM configurations")
Reported-by: Andreas Schwab <redacted>
Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Aneesh Kumar K.V <redacted>

Applied to powerpc fixes.

https://git.kernel.org/powerpc/c/cf7cf6977f531acd5dfe55250d0ee8cb

cheers