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author | Michael Ellerman <mpe@ellerman.id.au> | 2016-04-29 23:25:27 +1000 |
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committer | Michael Ellerman <mpe@ellerman.id.au> | 2016-05-01 18:32:16 +1000 |
commit | 3910a7f485e1222de2176ef5bf3a1d8de3152920 (patch) | |
tree | 66de016468eb80717dbe0fc4a3d9b0081031b98c /arch/powerpc/include/asm/pgtable-types.h | |
parent | 4bece39b503c2340de154c82bf6d928e72d74d4e (diff) | |
download | op-kernel-dev-3910a7f485e1222de2176ef5bf3a1d8de3152920.zip op-kernel-dev-3910a7f485e1222de2176ef5bf3a1d8de3152920.tar.gz |
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 <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/include/asm/pgtable-types.h')
-rw-r--r-- | arch/powerpc/include/asm/pgtable-types.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/pgtable-types.h b/arch/powerpc/include/asm/pgtable-types.h index 1464e74..e7f4f3e 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 <asm/cmpxchg.h> + +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 */ |