X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=include%2Fasm-generic%2Fpgtable.h;h=e2bd73e8f9c0b4db75755d1e4f0aadaaa0e20c2a;hb=53f824520b6d84ca5b4a8fd71addc91dbf64357e;hp=358e4d309ceb179776f2a7036dabce02cdfad1d2;hpb=8c65b4a60450590e79a28e9717ceffa9e4debb3f;p=safe%2Fjmp%2Flinux-2.6 diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 358e4d3..e2bd73e 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -1,45 +1,28 @@ #ifndef _ASM_GENERIC_PGTABLE_H #define _ASM_GENERIC_PGTABLE_H -#ifndef __HAVE_ARCH_PTEP_ESTABLISH -/* - * Establish a new mapping: - * - flush the old one - * - update the page tables - * - inform the TLB about the new one - * - * We hold the mm semaphore for reading, and the pte lock. - * - * Note: the old pte is known to not be writable, so we don't need to - * worry about dirty bits etc getting lost. - */ -#ifndef __HAVE_ARCH_SET_PTE_ATOMIC -#define ptep_establish(__vma, __address, __ptep, __entry) \ -do { \ - set_pte_at((__vma)->vm_mm, (__address), __ptep, __entry); \ - flush_tlb_page(__vma, __address); \ -} while (0) -#else /* __HAVE_ARCH_SET_PTE_ATOMIC */ -#define ptep_establish(__vma, __address, __ptep, __entry) \ -do { \ - set_pte_atomic(__ptep, __entry); \ - flush_tlb_page(__vma, __address); \ -} while (0) -#endif /* __HAVE_ARCH_SET_PTE_ATOMIC */ -#endif +#ifndef __ASSEMBLY__ +#ifdef CONFIG_MMU #ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS /* * Largely same as above, but only sets the access flags (dirty, * accessed, and writable). Furthermore, we know it always gets set * to a "more permissive" setting, which allows most architectures - * to optimize this. + * to optimize this. We return whether the PTE actually changed, which + * in turn instructs the caller to do things like update__mmu_cache. + * This used to be done in the caller, but sparc needs minor faults to + * force that call on sun4c so we changed this macro slightly */ #define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \ -do { \ - set_pte_at((__vma)->vm_mm, (__address), __ptep, __entry); \ - flush_tlb_page(__vma, __address); \ -} while (0) +({ \ + int __changed = !pte_same(*(__ptep), __entry); \ + if (__changed) { \ + set_pte_at((__vma)->vm_mm, (__address), __ptep, __entry); \ + flush_tlb_page(__vma, __address); \ + } \ + __changed; \ +}) #endif #ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG @@ -67,31 +50,6 @@ do { \ }) #endif -#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY -#define ptep_test_and_clear_dirty(__vma, __address, __ptep) \ -({ \ - pte_t __pte = *__ptep; \ - int r = 1; \ - if (!pte_dirty(__pte)) \ - r = 0; \ - else \ - set_pte_at((__vma)->vm_mm, (__address), (__ptep), \ - pte_mkclean(__pte)); \ - r; \ -}) -#endif - -#ifndef __HAVE_ARCH_PTEP_CLEAR_DIRTY_FLUSH -#define ptep_clear_flush_dirty(__vma, __address, __ptep) \ -({ \ - int __dirty; \ - __dirty = ptep_test_and_clear_dirty(__vma, __address, __ptep); \ - if (__dirty) \ - flush_tlb_page(__vma, __address); \ - __dirty; \ -}) -#endif - #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR #define ptep_get_and_clear(__mm, __address, __ptep) \ ({ \ @@ -110,8 +68,13 @@ do { \ }) #endif -#ifndef __HAVE_ARCH_PTE_CLEAR_FULL -#define pte_clear_full(__mm, __address, __ptep, __full) \ +/* + * Some architectures may be able to avoid expensive synchronization + * primitives when modifications are made to PTE's which are already + * not present, or in the process of an address space destruction. + */ +#ifndef __HAVE_ARCH_PTE_CLEAR_NOT_PRESENT_FULL +#define pte_clear_not_present_full(__mm, __address, __ptep, __full) \ do { \ pte_clear((__mm), (__address), (__ptep)); \ } while (0) @@ -140,8 +103,15 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres #define pte_same(A,B) (pte_val(A) == pte_val(B)) #endif -#ifndef __HAVE_ARCH_PAGE_TEST_AND_CLEAR_DIRTY -#define page_test_and_clear_dirty(page) (0) +#ifndef __HAVE_ARCH_PAGE_TEST_DIRTY +#define page_test_dirty(page) (0) +#endif + +#ifndef __HAVE_ARCH_PAGE_CLEAR_DIRTY +#define page_clear_dirty(page) do { } while (0) +#endif + +#ifndef __HAVE_ARCH_PAGE_TEST_DIRTY #define pte_maybe_dirty(pte) pte_dirty(pte) #else #define pte_maybe_dirty(pte) (1) @@ -155,21 +125,16 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres #define pgd_offset_gate(mm, addr) pgd_offset(mm, addr) #endif -#ifndef __HAVE_ARCH_LAZY_MMU_PROT_UPDATE -#define lazy_mmu_prot_update(pte) do { } while (0) +#ifndef __HAVE_ARCH_MOVE_PTE +#define move_pte(pte, prot, old_addr, new_addr) (pte) #endif -#ifndef __HAVE_ARCH_MULTIPLE_ZERO_PAGE -#define move_pte(pte, prot, old_addr, new_addr) (pte) -#else -#define move_pte(pte, prot, old_addr, new_addr) \ -({ \ - pte_t newpte = (pte); \ - if (pte_present(pte) && pfn_valid(pte_pfn(pte)) && \ - pte_page(pte) == ZERO_PAGE(old_addr)) \ - newpte = mk_pte(ZERO_PAGE(new_addr), (prot)); \ - newpte; \ -}) +#ifndef pgprot_noncached +#define pgprot_noncached(prot) (prot) +#endif + +#ifndef pgprot_writecombine +#define pgprot_writecombine pgprot_noncached #endif /* @@ -197,7 +162,6 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres }) #endif -#ifndef __ASSEMBLY__ /* * When walking page tables, we usually want to skip any p?d_none entries; * and any p?d_bad entries - reporting the error before resetting to none. @@ -239,6 +203,147 @@ 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 */ + +/* + * 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 + * is issued. Some architectures may benefit from doing this, and it is + * beneficial for both shadow and direct mode hypervisors, which may batch + * the PTE updates which happen during this window. Note that using this + * interface requires that read hazards be removed from the code. A read + * hazard could result in the direct mode hypervisor case, since the actual + * write to the page tables may not yet have taken place, so reads though + * a raw PTE pointer after it has been modified are not guaranteed to be + * up to date. This mode can only be entered and left under the protection of + * the page table locks for all page tables which may be modified. In the UP + * case, this is required so that preemption is disabled, and in the SMP case, + * it must synchronize the delayed page table writes properly on other CPUs. + */ +#ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE +#define arch_enter_lazy_mmu_mode() do {} while (0) +#define arch_leave_lazy_mmu_mode() do {} while (0) +#define arch_flush_lazy_mmu_mode() do {} while (0) +#endif + +/* + * A facility to provide batching of the reload of page tables and + * other process state with the actual context switch code for + * paravirtualized guests. By convention, only one of the batched + * update (lazy) modes (CPU, MMU) should be active at any given time, + * entry should never be nested, and entry and exits should always be + * paired. This is for sanity of maintaining and reasoning about the + * kernel code. In this case, the exit (end of the context switch) is + * in architecture-specific code, and so doesn't need a generic + * definition. + */ +#ifndef __HAVE_ARCH_START_CONTEXT_SWITCH +#define arch_start_context_switch(prev) do {} while (0) +#endif + +#ifndef __HAVE_PFNMAP_TRACKING +/* + * Interface that can be used by architecture code to keep track of + * memory type of pfn mappings (remap_pfn_range, vm_insert_pfn) + * + * track_pfn_vma_new is called when a _new_ pfn mapping is being established + * for physical range indicated by pfn and size. + */ +static inline int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot, + unsigned long pfn, unsigned long size) +{ + return 0; +} + +/* + * Interface that can be used by architecture code to keep track of + * memory type of pfn mappings (remap_pfn_range, vm_insert_pfn) + * + * track_pfn_vma_copy is called when vma that is covering the pfnmap gets + * copied through copy_page_range(). + */ +static inline int track_pfn_vma_copy(struct vm_area_struct *vma) +{ + return 0; +} + +/* + * Interface that can be used by architecture code to keep track of + * memory type of pfn mappings (remap_pfn_range, vm_insert_pfn) + * + * untrack_pfn_vma is called while unmapping a pfnmap for a region. + * untrack can be called for a specific region indicated by pfn and size or + * can be for the entire vma (in which case size can be zero). + */ +static inline void untrack_pfn_vma(struct vm_area_struct *vma, + unsigned long pfn, unsigned long size) +{ +} +#else +extern int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot, + unsigned long pfn, unsigned long size); +extern int track_pfn_vma_copy(struct vm_area_struct *vma); +extern void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn, + unsigned long size); +#endif + #endif /* !__ASSEMBLY__ */ #endif /* _ASM_GENERIC_PGTABLE_H */