![Russell King](/assets/img/avatar_default.png)
Since get_user_pages() may be used with processes other than the current process and calls flush_anon_page(), flush_anon_page() has to cope in some way with non-current processes. It may not be appropriate, or even desirable to flush a region of virtual memory cache in the current process when that is different to the process that we want the flush to occur for. Therefore, pass the vma into flush_anon_page() so that the architecture can work out whether the 'vmaddr' is for the current process or not. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
129 lines
3 KiB
C
129 lines
3 KiB
C
#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 */
|