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author | Ingo Molnar <mingo@elte.hu> | 2008-07-18 21:13:20 +0200 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-07-18 21:13:20 +0200 |
commit | f6dc8ccaab6d8f63cbae1e6c73fe972b26f5376c (patch) | |
tree | c5643fcdc884a8d0bfc3f1bc28039cab7394e5bc /include/asm-generic/pgtable.h | |
parent | 323ec001c6bb98eeabb5abbdbb8c8055d9496554 (diff) | |
parent | 5b664cb235e97afbf34db9c4d77f08ebd725335e (diff) | |
download | op-kernel-dev-f6dc8ccaab6d8f63cbae1e6c73fe972b26f5376c.zip op-kernel-dev-f6dc8ccaab6d8f63cbae1e6c73fe972b26f5376c.tar.gz |
Merge branch 'linus' into core/generic-dma-coherent
Conflicts:
kernel/Makefile
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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..ef87f88 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -195,6 +195,63 @@ static inline int pmd_none_or_clear_bad(pmd_t *pmd) } return 0; } + +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 */ #endif /* CONFIG_MMU */ /* |