The kmap_atomic* interfaces in all architectures are pretty much the same except for post map operations (flush) and pre- and post unmap operations.
Provide a generic variant for that.
Signed-off-by: Thomas Gleixner tglx@linutronix.de --- include/linux/highmem.h | 87 ++++++++++++++++++++++++++++------- mm/Kconfig | 3 + mm/highmem.c | 119 +++++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 192 insertions(+), 17 deletions(-)
--- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -31,9 +31,22 @@ static inline void invalidate_kernel_vma
#include <asm/kmap_types.h>
+/* + * Outside of CONFIG_HIGHMEM to support X86 32bit iomap_atomic() cruft. + */ +#ifdef CONFIG_KMAP_ATOMIC_GENERIC +void *kmap_atomic_pfn_prot(unsigned long pfn, pgprot_t prot); +void *kmap_atomic_page_prot(struct page *page, pgprot_t prot); +void kunmap_atomic_indexed(void *vaddr); +# ifndef ARCH_NEEDS_KMAP_HIGH_GET +static inline void *arch_kmap_temporary_high_get(struct page *page) +{ + return NULL; +} +# endif +#endif + #ifdef CONFIG_HIGHMEM -extern void *kmap_atomic_high_prot(struct page *page, pgprot_t prot); -extern void kunmap_atomic_high(void *kvaddr); #include <asm/highmem.h>
#ifndef ARCH_HAS_KMAP_FLUSH_TLB @@ -81,6 +94,11 @@ static inline void kunmap(struct page *p * be used in IRQ contexts, so in some (very limited) cases we need * it. */ + +#ifndef CONFIG_KMAP_ATOMIC_GENERIC +void *kmap_atomic_high_prot(struct page *page, pgprot_t prot); +void kunmap_atomic_high(void *kvaddr); + static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot) { preempt_disable(); @@ -89,7 +107,38 @@ static inline void *kmap_atomic_prot(str return page_address(page); return kmap_atomic_high_prot(page, prot); } -#define kmap_atomic(page) kmap_atomic_prot(page, kmap_prot) + +static inline void __kunmap_atomic(void *vaddr) +{ + kunmap_atomic_high(vaddr); + pagefault_enable(); +} +#else /* !CONFIG_KMAP_ATOMIC_GENERIC */ + +static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot) +{ + preempt_disable(); + return kmap_atomic_page_prot(page, prot); +} + +static inline void *kmap_atomic_pfn(unsigned long pfn) +{ + preempt_disable(); + return kmap_atomic_pfn_prot(pfn, kmap_prot); +} + +static inline void __kunmap_atomic(void *addr) +{ + kumap_atomic_indexed(addr); +} + + +#endif /* CONFIG_KMAP_ATOMIC_GENERIC */ + +static inline void *kmap_atomic(struct page *page) +{ + return kmap_atomic_prot(page, kmap_prot); +}
/* declarations for linux/mm/highmem.c */ unsigned int nr_free_highpages(void); @@ -157,21 +206,29 @@ static inline void *kmap_atomic(struct p pagefault_disable(); return page_address(page); } -#define kmap_atomic_prot(page, prot) kmap_atomic(page)
-static inline void kunmap_atomic_high(void *addr) +static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot) +{ + return kmap_atomic(page); +} + +static inline void *kmap_atomic_pfn(unsigned long pfn) +{ + return kmap_atomic(pfn_to_page(pfn)); +} + +static inline void __kunmap_atomic(void *addr) { /* * Mostly nothing to do in the CONFIG_HIGHMEM=n case as kunmap_atomic() - * handles re-enabling faults + preemption + * handles preemption */ #ifdef ARCH_HAS_FLUSH_ON_KUNMAP kunmap_flush_on_unmap(addr); #endif + pagefault_enable(); }
-#define kmap_atomic_pfn(pfn) kmap_atomic(pfn_to_page(pfn)) - #define kmap_flush_unused() do {} while(0)
#endif /* CONFIG_HIGHMEM */ @@ -213,14 +270,12 @@ static inline void kmap_atomic_idx_pop(v * Prevent people trying to call kunmap_atomic() as if it were kunmap() * kunmap_atomic() should get the return value of kmap_atomic, not the page. */ -#define kunmap_atomic(addr) \ -do { \ - BUILD_BUG_ON(__same_type((addr), struct page *)); \ - kunmap_atomic_high(addr); \ - pagefault_enable(); \ - preempt_enable(); \ -} while (0) - +#define kunmap_atomic(addr) \ + do { \ + BUILD_BUG_ON(__same_type((addr), struct page *)); \ + __kunmap_atomic(addr); \ + preempt_enable(); \ + } while (0)
/* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */ #ifndef clear_user_highpage --- a/mm/Kconfig +++ b/mm/Kconfig @@ -868,4 +868,7 @@ config ARCH_HAS_HUGEPD config MAPPING_DIRTY_HELPERS bool
+config KMAP_ATOMIC_GENERIC + bool + endmenu --- a/mm/highmem.c +++ b/mm/highmem.c @@ -314,6 +314,15 @@ void *kmap_high_get(struct page *page) unlock_kmap_any(flags); return (void*) vaddr; } + +/* Unmap a temporary mapping which was obtained by kmap_high_get() */ +static void kmap_high_unmap_temporary(unsigned long vaddr) +{ + if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) + kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)])); +} +#else +static inline void kmap_high_unmap_temporary(unsigned long vaddr) { } #endif
/** @@ -365,8 +374,116 @@ void kunmap_high(struct page *page) if (need_wakeup) wake_up(pkmap_map_wait); } - EXPORT_SYMBOL(kunmap_high); +#else +static inline void kmap_high_unmap_temporary(unsigned long vaddr) { } +#endif /* CONFIG_HIGHMEM */ + +#ifdef CONFIG_KMAP_ATOMIC_GENERIC +#ifndef arch_kmap_temp_post_map +# define arch_kmap_temp_post_map(vaddr, pteval) do { } while (0) +#endif + +#ifndef arch_kmap_temp_pre_unmap +# define arch_kmap_temp_pre_unmap(vaddr) do { } while (0) +#endif + +#ifndef arch_kmap_temp_post_unmap +# define arch_kmap_temp_post_unmap(vaddr) do { } while (0) +#endif + +#ifndef arch_kmap_temp_map_idx +#define arch_kmap_temp_map_idx(type, pfn) kmap_temp_idx(type) +#endif + +#ifndef arch_kmap_temp_unmap_idx +#define arch_kmap_temp_unmap_idx(type, vaddr) kmap_temp_idx(type) +#endif + +static inline int kmap_temp_idx(int type) +{ + return type + KM_TYPE_NR * smp_processor_id(); +} + +static pte_t *__kmap_pte; + +static pte_t *kmap_get_pte(void) +{ + if (!__kmap_pte) + __kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN)); + return __kmap_pte; +} + +static void *__kmap_atomic_pfn_prot(unsigned long pfn, pgprot_t prot) +{ + pte_t pteval, *kmap_pte = kmap_get_pte(); + unsigned long vaddr; + int idx; + + preempt_disable(); + idx = arch_kmap_temp_map_idx(kmap_atomic_idx_push(), pfn); + vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); + BUG_ON(!pte_none(*(kmap_pte - idx))); + pteval = pfn_pte(pfn, prot); + set_pte(kmap_pte - idx, pteval); + arch_kmap_temp_post_map(vaddr, pteval); + preempt_enable(); + + return (void *)vaddr; +} + +void *kmap_atomic_pfn_prot(unsigned long pfn, pgprot_t prot) +{ + pagefault_disable(); + return __kmap_atomic_pfn_prot(pfn, prot); +} +EXPORT_SYMBOL(kmap_atomic_pfn_prot); + +void *kmap_atomic_page_prot(struct page *page, pgprot_t prot) +{ + void *kmap; + + pagefault_disable(); + if (!PageHighMem(page)) + return page_address(page); + + /* Try kmap_high_get() if architecture has it enabled */ + kmap = arch_kmap_temporary_high_get(page); + if (kmap) + return kmap; + + return __kmap_atomic_pfn_prot(page_to_pfn(page), prot); +} +EXPORT_SYMBOL(kmap_atomic_page_prot); + +void kunmap_atomic_indexed(void *vaddr) +{ + unsigned long addr = (unsigned long) vaddr & PAGE_MASK; + pte_t *kmap_pte = kmap_get_pte(); + int idx; + + if (addr < __fix_to_virt(FIX_KMAP_END) || + addr > __fix_to_virt(FIX_KMAP_BEGIN)) { + WARN_ON_ONCE(addr < PAGE_OFFSET); + + /* Handle mappings which were obtained by kmap_high_get() */ + kmap_high_unmap_temporary(addr); + pagefault_enable(); + return; + } + + preempt_disable(); + idx = arch_kmap_temp_unmap_idx(kmap_atomic_idx(), addr); + WARN_ON_ONCE(addr != __fix_to_virt(FIX_KMAP_BEGIN + idx)); + + arch_kmap_temp_pre_unmap(addr); + pte_clear(&init_mm, addr, kmap_pte - idx); + arch_kmap_temp_post_unmap(addr); + kmap_atomic_idx_pop(); + preempt_enable(); + pagefault_enable(); +} +EXPORT_SYMBOL(kunmap_atomic_indexed); #endif
#if defined(HASHED_PAGE_VIRTUAL)