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author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2008-07-15 15:44:51 +1000 |
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committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2008-07-15 15:44:51 +1000 |
commit | 43d2548bb2ef7e6d753f91468a746784041e522d (patch) | |
tree | 77d13fcd48fd998393abb825ec36e2b732684a73 /include/asm-generic/pgtable.h | |
parent | 585583d95c5660973bc0cf64add517b040acd8a4 (diff) | |
parent | 85082fd7cbe3173198aac0eb5e85ab1edcc6352c (diff) | |
download | op-kernel-dev-43d2548bb2ef7e6d753f91468a746784041e522d.zip op-kernel-dev-43d2548bb2ef7e6d753f91468a746784041e522d.tar.gz |
Merge commit '85082fd7cbe3173198aac0eb5e85ab1edcc6352c' into test-build
Manual fixup of:
arch/powerpc/Kconfig
Diffstat (limited to 'include/asm-generic/pgtable.h')
-rw-r--r-- | include/asm-generic/pgtable.h | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 44ef329..4fce3db 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -197,6 +197,63 @@ static inline int pmd_none_or_clear_bad(pmd_t *pmd) } #endif /* CONFIG_MMU */ +static inline pte_t __ptep_modify_prot_start(struct mm_struct *mm, + unsigned long addr, + pte_t *ptep) +{ + /* + * Get the current pte state, but zero it out to make it + * non-present, preventing the hardware from asynchronously + * updating it. + */ + return ptep_get_and_clear(mm, addr, ptep); +} + +static inline void __ptep_modify_prot_commit(struct mm_struct *mm, + unsigned long addr, + pte_t *ptep, pte_t pte) +{ + /* + * The pte is non-present, so there's no hardware state to + * preserve. + */ + set_pte_at(mm, addr, ptep, pte); +} + +#ifndef __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION +/* + * Start a pte protection read-modify-write transaction, which + * protects against asynchronous hardware modifications to the pte. + * The intention is not to prevent the hardware from making pte + * updates, but to prevent any updates it may make from being lost. + * + * This does not protect against other software modifications of the + * pte; the appropriate pte lock must be held over the transation. + * + * Note that this interface is intended to be batchable, meaning that + * ptep_modify_prot_commit may not actually update the pte, but merely + * queue the update to be done at some later time. The update must be + * actually committed before the pte lock is released, however. + */ +static inline pte_t ptep_modify_prot_start(struct mm_struct *mm, + unsigned long addr, + pte_t *ptep) +{ + return __ptep_modify_prot_start(mm, addr, ptep); +} + +/* + * Commit an update to a pte, leaving any hardware-controlled bits in + * the PTE unmodified. + */ +static inline void ptep_modify_prot_commit(struct mm_struct *mm, + unsigned long addr, + pte_t *ptep, pte_t pte) +{ + __ptep_modify_prot_commit(mm, addr, ptep, pte); +} +#endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */ + /* * A facility to provide lazy MMU batching. This allows PTE updates and * page invalidations to be delayed until a call to leave lazy MMU mode |