From 3910a7f485e1222de2176ef5bf3a1d8de3152920 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Fri, 29 Apr 2016 23:25:27 +1000 Subject: [PATCH] powerpc/mm: Add pte_xchg() helper We have five locations in 64-bit hash MMU code that do a cmpxchg() of a PTE. Currently doing it inline OK, but in a future patch we will be converting the PTEs to __be64 in some configs. In that case we will need casts at every cmpxchg() site in order to keep sparse happy. So move the logic into a helper, this is a reasonably nice cleanup on its own. Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/kvm_book3s_64.h | 5 +---- arch/powerpc/include/asm/pgtable-types.h | 12 ++++++++++++ arch/powerpc/mm/hash64_4k.c | 4 ++-- arch/powerpc/mm/hash64_64k.c | 7 +++---- arch/powerpc/mm/hugetlbpage-hash64.c | 4 ++-- 5 files changed, 20 insertions(+), 12 deletions(-) diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h index 7529aab068f5..42da513fec2d 100644 --- a/arch/powerpc/include/asm/kvm_book3s_64.h +++ b/arch/powerpc/include/asm/kvm_book3s_64.h @@ -319,11 +319,8 @@ static inline pte_t kvmppc_read_update_linux_pte(pte_t *ptep, int writing) if (writing && pte_write(old_pte)) new_pte = pte_mkdirty(new_pte); - if (pte_val(old_pte) == __cmpxchg_u64((unsigned long *)ptep, - pte_val(old_pte), - pte_val(new_pte))) { + if (pte_xchg(ptep, old_pte, new_pte)) break; - } } return new_pte; } diff --git a/arch/powerpc/include/asm/pgtable-types.h b/arch/powerpc/include/asm/pgtable-types.h index 1464e74178d8..e7f4f3e0fcde 100644 --- a/arch/powerpc/include/asm/pgtable-types.h +++ b/arch/powerpc/include/asm/pgtable-types.h @@ -54,4 +54,16 @@ typedef struct { pte_t pte; unsigned long hidx; } real_pte_t; #else typedef struct { pte_t pte; } real_pte_t; #endif + +#ifdef CONFIG_PPC_STD_MMU_64 +#include + +static inline bool pte_xchg(pte_t *ptep, pte_t old, pte_t new) +{ + unsigned long *p = (unsigned long *)ptep; + + return pte_val(old) == __cmpxchg_u64(p, pte_val(old), pte_val(new)); +} +#endif + #endif /* _ASM_POWERPC_PGTABLE_TYPES_H */ diff --git a/arch/powerpc/mm/hash64_4k.c b/arch/powerpc/mm/hash64_4k.c index 47d1b26effc6..dbd3133a8562 100644 --- a/arch/powerpc/mm/hash64_4k.c +++ b/arch/powerpc/mm/hash64_4k.c @@ -47,8 +47,8 @@ int __hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid, new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED; if (access & _PAGE_RW) new_pte |= _PAGE_DIRTY; - } while (old_pte != __cmpxchg_u64((unsigned long *)ptep, - old_pte, new_pte)); + } while (!pte_xchg(ptep, __pte(old_pte), __pte(new_pte))); + /* * PP bits. _PAGE_USER is already PP bit 0x2, so we only * need to add in 0x1 if it's a read-only user page diff --git a/arch/powerpc/mm/hash64_64k.c b/arch/powerpc/mm/hash64_64k.c index b2d659cf51c6..6fbf983b3ae5 100644 --- a/arch/powerpc/mm/hash64_64k.c +++ b/arch/powerpc/mm/hash64_64k.c @@ -79,8 +79,8 @@ int __hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid, new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED | _PAGE_COMBO; if (access & _PAGE_RW) new_pte |= _PAGE_DIRTY; - } while (old_pte != __cmpxchg_u64((unsigned long *)ptep, - old_pte, new_pte)); + } while (!pte_xchg(ptep, __pte(old_pte), __pte(new_pte))); + /* * Handle the subpage protection bits */ @@ -254,8 +254,7 @@ int __hash_page_64K(unsigned long ea, unsigned long access, new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED; if (access & _PAGE_RW) new_pte |= _PAGE_DIRTY; - } while (old_pte != __cmpxchg_u64((unsigned long *)ptep, - old_pte, new_pte)); + } while (!pte_xchg(ptep, __pte(old_pte), __pte(new_pte))); rflags = htab_convert_pte_flags(new_pte); diff --git a/arch/powerpc/mm/hugetlbpage-hash64.c b/arch/powerpc/mm/hugetlbpage-hash64.c index 8555fce902fe..9c0518761279 100644 --- a/arch/powerpc/mm/hugetlbpage-hash64.c +++ b/arch/powerpc/mm/hugetlbpage-hash64.c @@ -57,8 +57,8 @@ int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid, new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED; if (access & _PAGE_RW) new_pte |= _PAGE_DIRTY; - } while(old_pte != __cmpxchg_u64((unsigned long *)ptep, - old_pte, new_pte)); + } while(!pte_xchg(ptep, __pte(old_pte), __pte(new_pte))); + rflags = htab_convert_pte_flags(new_pte); sz = ((1UL) << shift); -- GitLab