#ifndef _LINUX_HIGHMEM_H #define _LINUX_HIGHMEM_H #include <linux/fs.h> #include <linux/kernel.h> #include <linux/bug.h> #include <linux/mm.h> #include <linux/uaccess.h> #include <linux/hardirq.h> #include <asm/cacheflush.h> #ifndef ARCH_HAS_FLUSH_ANON_PAGE static inline void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr) { } #endif #ifndef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE static inline void flush_kernel_dcache_page(struct page *page) { } static inline void flush_kernel_vmap_range(void *vaddr, int size) { } static inline void invalidate_kernel_vmap_range(void *vaddr, int size) { } #endif #include <asm/kmap_types.h> #ifdef CONFIG_HIGHMEM #include <asm/highmem.h> /* declarations for linux/mm/highmem.c */ unsigned int nr_free_highpages(void); extern unsigned long totalhigh_pages; void kmap_flush_unused(void); struct page *kmap_to_page(void *addr); #else /* CONFIG_HIGHMEM */ static inline unsigned int nr_free_highpages(void) { return 0; } static inline struct page *kmap_to_page(void *addr) { return virt_to_page(addr); } #define totalhigh_pages 0UL #ifndef ARCH_HAS_KMAP static inline void *kmap(struct page *page) { might_sleep(); return page_address(page); } static inline void kunmap(struct page *page) { } static inline void *kmap_atomic(struct page *page) { preempt_disable(); pagefault_disable(); return page_address(page); } #define kmap_atomic_prot(page, prot) kmap_atomic(page) static inline void __kunmap_atomic(void *addr) { pagefault_enable(); preempt_enable(); } #define kmap_atomic_pfn(pfn) kmap_atomic(pfn_to_page(pfn)) #define kmap_flush_unused() do {} while(0) #endif #endif /* CONFIG_HIGHMEM */ #if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32) DECLARE_PER_CPU(int, __kmap_atomic_idx); static inline int kmap_atomic_idx_push(void) { int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1; #ifdef CONFIG_DEBUG_HIGHMEM WARN_ON_ONCE(in_irq() && !irqs_disabled()); BUG_ON(idx >= KM_TYPE_NR); #endif return idx; } static inline int kmap_atomic_idx(void) { return __this_cpu_read(__kmap_atomic_idx) - 1; } static inline void kmap_atomic_idx_pop(void) { #ifdef CONFIG_DEBUG_HIGHMEM int idx = __this_cpu_dec_return(__kmap_atomic_idx); BUG_ON(idx < 0); #else __this_cpu_dec(__kmap_atomic_idx); #endif } #endif /* * 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(addr); \ } while (0) /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */ #ifndef clear_user_highpage static inline void clear_user_highpage(struct page *page, unsigned long vaddr) { void *addr = kmap_atomic(page); clear_user_page(addr, vaddr, page); kunmap_atomic(addr); } #endif #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE /** * __alloc_zeroed_user_highpage - Allocate a zeroed HIGHMEM page for a VMA with caller-specified movable GFP flags * @movableflags: The GFP flags related to the pages future ability to move like __GFP_MOVABLE * @vma: The VMA the page is to be allocated for * @vaddr: The virtual address the page will be inserted into * * This function will allocate a page for a VMA but the caller is expected * to specify via movableflags whether the page will be movable in the * future or not * * An architecture may override this function by defining * __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE and providing their own * implementation. */ static inline struct page * __alloc_zeroed_user_highpage(gfp_t movableflags, struct vm_area_struct *vma, unsigned long vaddr) { struct page *page = alloc_page_vma(GFP_HIGHUSER | movableflags, vma, vaddr); if (page) clear_user_highpage(page, vaddr); return page; } #endif /** * alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for a VMA that the caller knows can move * @vma: The VMA the page is to be allocated for * @vaddr: The virtual address the page will be inserted into * * This function will allocate a page for a VMA that the caller knows will * be able to migrate in the future using move_pages() or reclaimed */ static inline struct page * alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma, unsigned long vaddr) { return __alloc_zeroed_user_highpage(__GFP_MOVABLE, vma, vaddr); } static inline void clear_highpage(struct page *page) { void *kaddr = kmap_atomic(page); clear_page(kaddr); kunmap_atomic(kaddr); } static inline void zero_user_segments(struct page *page, unsigned start1, unsigned end1, unsigned start2, unsigned end2) { void *kaddr = kmap_atomic(page); BUG_ON(end1 > PAGE_SIZE || end2 > PAGE_SIZE); if (end1 > start1) memset(kaddr + start1, 0, end1 - start1); if (end2 > start2) memset(kaddr + start2, 0, end2 - start2); kunmap_atomic(kaddr); flush_dcache_page(page); } static inline void zero_user_segment(struct page *page, unsigned start, unsigned end) { zero_user_segments(page, start, end, 0, 0); } static inline void zero_user(struct page *page, unsigned start, unsigned size) { zero_user_segments(page, start, start + size, 0, 0); } #ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE static inline void copy_user_highpage(struct page *to, struct page *from, unsigned long vaddr, struct vm_area_struct *vma) { char *vfrom, *vto; vfrom = kmap_atomic(from); vto = kmap_atomic(to); copy_user_page(vto, vfrom, vaddr, to); kunmap_atomic(vto); kunmap_atomic(vfrom); } #endif static inline void copy_highpage(struct page *to, struct page *from) { char *vfrom, *vto; vfrom = kmap_atomic(from); vto = kmap_atomic(to); copy_page(vto, vfrom); kunmap_atomic(vto); kunmap_atomic(vfrom); } #endif /* _LINUX_HIGHMEM_H */