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memory_model.h
Chen Gang
authored and
Linus Torvalds
committed
__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:
memory_model.h 2.12 KiB
#ifndef __ASM_MEMORY_MODEL_H
#define __ASM_MEMORY_MODEL_H
#include <linux/pfn.h>
#ifndef __ASSEMBLY__
#if defined(CONFIG_FLATMEM)
#ifndef ARCH_PFN_OFFSET
#define ARCH_PFN_OFFSET (0UL)
#endif
#elif defined(CONFIG_DISCONTIGMEM)
#ifndef arch_pfn_to_nid
#define arch_pfn_to_nid(pfn) pfn_to_nid(pfn)
#endif
#ifndef arch_local_page_offset
#define arch_local_page_offset(pfn, nid) \
((pfn) - NODE_DATA(nid)->node_start_pfn)
#endif
#endif /* CONFIG_DISCONTIGMEM */
/*
* supports 3 memory models.
*/
#if defined(CONFIG_FLATMEM)
#define __pfn_to_page(pfn) (mem_map + ((pfn) - ARCH_PFN_OFFSET))
#define __page_to_pfn(page) ((unsigned long)((page) - mem_map) + \
ARCH_PFN_OFFSET)
#elif defined(CONFIG_DISCONTIGMEM)
#define __pfn_to_page(pfn) \
({ unsigned long __pfn = (pfn); \
unsigned long __nid = arch_pfn_to_nid(__pfn); \
NODE_DATA(__nid)->node_mem_map + arch_local_page_offset(__pfn, __nid);\
})
#define __page_to_pfn(pg) \
({ const struct page *__pg = (pg); \
struct pglist_data *__pgdat = NODE_DATA(page_to_nid(__pg)); \
(unsigned long)(__pg - __pgdat->node_mem_map) + \
__pgdat->node_start_pfn; \
})
#elif defined(CONFIG_SPARSEMEM_VMEMMAP)
/* memmap is virtually contiguous. */
#define __pfn_to_page(pfn) (vmemmap + (pfn))
#define __page_to_pfn(page) (unsigned long)((page) - vmemmap)
#elif defined(CONFIG_SPARSEMEM)
/*
* Note: section's mem_map is encoded to reflect its start_pfn.
* section[i].section_mem_map == mem_map's address - start_pfn;
*/
#define __page_to_pfn(pg) \
({ const struct page *__pg = (pg); \
int __sec = page_to_section(__pg); \
(unsigned long)(__pg - __section_mem_map_addr(__nr_to_section(__sec))); \
})
#define __pfn_to_page(pfn) \
({ unsigned long __pfn = (pfn); \
struct mem_section *__sec = __pfn_to_section(__pfn); \
__section_mem_map_addr(__sec) + __pfn; \})
#endif /* CONFIG_FLATMEM/DISCONTIGMEM/SPARSEMEM */
/*
* Convert a physical address to a Page Frame Number and back
*/
#define __phys_to_pfn(paddr) PHYS_PFN(paddr)
#define __pfn_to_phys(pfn) PFN_PHYS(pfn)
#define page_to_pfn __page_to_pfn
#define pfn_to_page __pfn_to_page
#endif /* __ASSEMBLY__ */
#endif