提交 ad76fb6b 编写于 作者: P Peter Zijlstra 提交者: Linus Torvalds

[PATCH] mm: k{,um}map_atomic() vs in_atomic()

Make kmap_atomic/kunmap_atomic denote a pagefault disabled scope.  All non
trivial implementations already do this anyway.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
上级 a866374a
......@@ -21,6 +21,7 @@
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/uaccess.h>
#include <asm/kmap_types.h>
/* undef for production */
......@@ -70,11 +71,16 @@ static inline void *kmap(struct page *page)
static inline void *kmap_atomic(struct page *page, enum km_type type)
{
pagefault_disable();
return page_address(page);
}
static inline void kunmap_atomic(void *kvaddr, enum km_type type) { }
#define kmap_atomic_pfn(pfn, idx) page_address(pfn_to_page(pfn))
static inline void kunmap_atomic(void *kvaddr, enum km_type type)
{
pagefault_enable();
}
#define kmap_atomic_pfn(pfn, idx) kmap_atomic(pfn_to_page(pfn), (idx))
#define kmap_atomic_to_page(ptr) virt_to_page(ptr)
......
......@@ -3,6 +3,7 @@
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/uaccess.h>
#include <asm/cacheflush.h>
......@@ -41,9 +42,10 @@ static inline void *kmap(struct page *page)
#define kunmap(page) do { (void) (page); } while (0)
#define kmap_atomic(page, idx) page_address(page)
#define kunmap_atomic(addr, idx) do { } while (0)
#define kmap_atomic_pfn(pfn, idx) page_address(pfn_to_page(pfn))
#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
......
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