Re: [PATCH] powerpc/mm: use _raw variant of page table accessors

This switch few of the page table accessor to use the __raw variant
and does the cpu to big endian conversion of constants. This helps in
generating better code.

For ex: a pgd_none(pgd) check with and without fix is listed below

Without fix:
------------
   2240:	20 00 61 eb 	ld      r27,32(r1)
/* PGD level */
typedef struct { __be64 pgd; } pgd_t;
static inline unsigned long pgd_val(pgd_t x)
{
	return be64_to_cpu(x.pgd);

    2244:	22 00 66 78 	rldicl  r6,r3,32,32
    2248:	3e 40 7d 54 	rotlwi  r29,r3,8
    224c:	0e c0 7d 50 	rlwimi  r29,r3,24,0,7
    2250:	3e 40 c5 54 	rotlwi  r5,r6,8
    2254:	2e c4 7d 50 	rlwimi  r29,r3,24,16,23
    2258:	0e c0 c5 50 	rlwimi  r5,r6,24,0,7
    225c:	2e c4 c5 50 	rlwimi  r5,r6,24,16,23
    2260:	c6 07 bd 7b 	rldicr  r29,r29,32,31
    2264:	78 2b bd 7f 	or      r29,r29,r5
		if (pgd_none(pgd))
    2268:	00 00 bd 2f 	cmpdi   cr7,r29,0
    226c:	54 03 9e 41 	beq     cr7,25c0 <__get_user_pages_fast+0x500>

With fix:
---------
    2370:	20 00 61 eb 	ld      r27,32(r1)
		if (pgd_none(pgd))
    2374:	00 00 bd 2f 	cmpdi   cr7,r29,0
    2378:	a8 03 9e 41 	beq     cr7,2720 <__get_user_pages_fast+0x530>
			break;
Signed-off-by: Aneesh Kumar K.V <redacted>
---
 arch/powerpc/include/asm/book3s/64/pgtable-4k.h  |  6 +-
 arch/powerpc/include/asm/book3s/64/pgtable-64k.h |  6 +-
 arch/powerpc/include/asm/book3s/64/pgtable.h     | 99 +++++++++++++++++-------
 arch/powerpc/include/asm/pgtable-be-types.h      | 15 ++++
 4 files changed, 91 insertions(+), 35 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/pgtable-4k.h b/arch/powerpc/include/asm/book3s/64/pgtable-4k.h
index 71e9abced493..9db83b4e017d 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable-4k.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable-4k.h

@@ -11,7 +11,7 @@ static inline int pmd_huge(pmd_t pmd)
 	 * leaf pte for huge page
 	 */
 	if (radix_enabled())
-		return !!(pmd_val(pmd) & _PAGE_PTE);
+		return !!(pmd_raw(pmd) & cpu_to_be64(_PAGE_PTE));
 	return 0;
 }
 

@@ -21,7 +21,7 @@ static inline int pud_huge(pud_t pud)
 	 * leaf pte for huge page
 	 */
 	if (radix_enabled())
-		return !!(pud_val(pud) & _PAGE_PTE);
+		return !!(pud_raw(pud) & cpu_to_be64(_PAGE_PTE));
 	return 0;
 }
 

@@ -31,7 +31,7 @@ static inline int pgd_huge(pgd_t pgd)
 	 * leaf pte for huge page
 	 */
 	if (radix_enabled())
-		return !!(pgd_val(pgd) & _PAGE_PTE);
+		return !!(pgd_raw(pgd) & cpu_to_be64(_PAGE_PTE));