Subject: Re: [PATCH v3 10/31] powerpc/mm: Don't use pmd_val, pud_val and pgd_val as lvalue

From: "Aneesh Kumar K.V" <[email-masked]>
Date: Tue, 13 Oct 2015 10:53:09 +0530

Michael Ellerman <[email-masked]> writes:

> On Tue, 2015-10-13 at 00:09 +0530, Aneesh Kumar K.V wrote:
>> We convert them static inline function here as we did with pte_val in
>> the previous patch
>
> This breaks ppc40x_defconfig & 40x/ep405_defconfig with:
>
>   arch/powerpc/mm/40x_mmu.c: In function 'mmu_mapin_ram':
>   arch/powerpc/mm/40x_mmu.c:113:20: error: lvalue required as left operand of assignment
>   arch/powerpc/mm/40x_mmu.c:114:20: error: lvalue required as left operand of assignment
>   arch/powerpc/mm/40x_mmu.c:115:20: error: lvalue required as left operand of assignment
>   arch/powerpc/mm/40x_mmu.c:116:20: error: lvalue required as left operand of assignment
>   arch/powerpc/mm/40x_mmu.c:128:18: error: lvalue required as left operand of assignment
>
> Which is mainly:
>
> 	pmd_val(*pmdp++) = val;
>
>
> The obvious patch to use pmd_set() doesn't work, I think because there's no
> pmd_set() defined for 32-bit nohash?
>

How about

diff --git a/arch/powerpc/mm/40x_mmu.c b/arch/powerpc/mm/40x_mmu.c
index 5810967511d4..31a5d42df8c9 100644
--- a/arch/powerpc/mm/40x_mmu.c
+++ b/arch/powerpc/mm/40x_mmu.c
@@ -110,10 +110,10 @@ unsigned long __init mmu_mapin_ram(unsigned long top)
 		unsigned long val = p | _PMD_SIZE_16M | _PAGE_EXEC | _PAGE_HWWRITE;
 
 		pmdp = pmd_offset(pud_offset(pgd_offset_k(v), v), v);
-		pmd_val(*pmdp++) = val;
-		pmd_val(*pmdp++) = val;
-		pmd_val(*pmdp++) = val;
-		pmd_val(*pmdp++) = val;
+		*pmdp++ = __pmd(val);
+		*pmdp++ = __pmd(val);
+		*pmdp++ = __pmd(val);
+		*pmdp++ = __pmd(val);
 
 		v += LARGE_PAGE_SIZE_16M;
 		p += LARGE_PAGE_SIZE_16M;
@@ -125,7 +125,7 @@ unsigned long __init mmu_mapin_ram(unsigned long top)
 		unsigned long val = p | _PMD_SIZE_4M | _PAGE_EXEC | _PAGE_HWWRITE;
 
 		pmdp = pmd_offset(pud_offset(pgd_offset_k(v), v), v);
-		pmd_val(*pmdp) = val;
+		*pmdp = __pmd(val);
 
 		v += LARGE_PAGE_SIZE_4M;
 		p += LARGE_PAGE_SIZE_4M;