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#ifndef _LINUX_HIGHMEM_H
#define _LINUX_HIGHMEM_H
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/uaccess.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)
{
}
#endif
#ifdef CONFIG_HIGHMEM
#include <asm/highmem.h>
/* declarations for linux/mm/highmem.c */
unsigned int nr_free_highpages(void);
extern unsigned long totalhigh_pages;
#else /* CONFIG_HIGHMEM */
static inline unsigned int nr_free_highpages(void) { return 0; }
#define totalhigh_pages 0
#ifndef ARCH_HAS_KMAP
static inline void *kmap(struct page *page)
{
might_sleep();
return page_address(page);
}
#define kunmap(page) do { (void) (page); } while (0)
#define kmap_atomic(page, idx) \
({ pagefault_disable(); page_address(page); })
#define kunmap_atomic(addr, idx) do { pagefault_enable(); } while (0)
#define kmap_atomic_pfn(pfn, idx) kmap_atomic(pfn_to_page(pfn), (idx))
#define kmap_atomic_to_page(ptr) virt_to_page(ptr)
#endif
#endif /* CONFIG_HIGHMEM */
/* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
{
void *addr = kmap_atomic(page, KM_USER0);
clear_user_page(addr, vaddr, page);
kunmap_atomic(addr, KM_USER0);
/* Make sure this page is cleared on other CPU's too before using it */
smp_wmb();
}
#ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
static inline struct page *
alloc_zeroed_user_highpage(struct vm_area_struct *vma, unsigned long vaddr)
{
struct page *page = alloc_page_vma(GFP_HIGHUSER, vma, vaddr);
if (page)
clear_user_highpage(page, vaddr);
return page;
}
#endif
static inline void clear_highpage(struct page *page)
{
void *kaddr = kmap_atomic(page, KM_USER0);
clear_page(kaddr);
kunmap_atomic(kaddr, KM_USER0);
}
/*
* Same but also flushes aliased cache contents to RAM.
*/
static inline void memclear_highpage_flush(struct page *page, unsigned int offset, unsigned int size)
{
void *kaddr;
BUG_ON(offset + size > PAGE_SIZE);
kaddr = kmap_atomic(page, KM_USER0);
memset((char *)kaddr + offset, 0, size);
flush_dcache_page(page);
kunmap_atomic(kaddr, KM_USER0);
}
#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, KM_USER0);
vto = kmap_atomic(to, KM_USER1);
copy_user_page(vto, vfrom, vaddr, to);
kunmap_atomic(vfrom, KM_USER0);
kunmap_atomic(vto, KM_USER1);
/* Make sure this page is cleared on other CPU's too before using it */
smp_wmb();
}
#endif
static inline void copy_highpage(struct page *to, struct page *from)
{
char *vfrom, *vto;
vfrom = kmap_atomic(from, KM_USER0);
vto = kmap_atomic(to, KM_USER1);
copy_page(vto, vfrom);
kunmap_atomic(vfrom, KM_USER0);
kunmap_atomic(vto, KM_USER1);
}
#endif /* _LINUX_HIGHMEM_H */
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