510b819279
(cherry pick from commit 8f235d1a3eb7198affe7cadf676a10afb8a46a1a) __phys_to_pfn and __pfn_to_phys are symmetric, PHYS_PFN and PFN_PHYS are semmetric: - y = (phys_addr_t)x << PAGE_SHIFT - y >> PAGE_SHIFT = (phys_add_t)x - (unsigned long)(y >> PAGE_SHIFT) = x [akpm@linux-foundation.org: use macro arg name `x'] [arnd@arndb.de: include linux/pfn.h for PHYS_PFN definition] Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Bug: 20045882 Bug: 19198045 Change-Id: If968d2246b381b9e5d6446e9d6d9fa45bb718e91
14 lines
385 B
C
14 lines
385 B
C
#ifndef _LINUX_PFN_H_
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#define _LINUX_PFN_H_
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#ifndef __ASSEMBLY__
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#include <linux/types.h>
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#endif
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#define PFN_ALIGN(x) (((unsigned long)(x) + (PAGE_SIZE - 1)) & PAGE_MASK)
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#define PFN_UP(x) (((x) + PAGE_SIZE-1) >> PAGE_SHIFT)
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#define PFN_DOWN(x) ((x) >> PAGE_SHIFT)
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#define PFN_PHYS(x) ((phys_addr_t)(x) << PAGE_SHIFT)
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#define PHYS_PFN(x) ((unsigned long)((x) >> PAGE_SHIFT))
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#endif
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