linux/include/asm-generic/memory_model.h
KAMEZAWA Hiroyuki a117e66ed4 [PATCH] unify pfn_to_page: generic functions
There are 3 memory models, FLATMEM, DISCONTIGMEM, SPARSEMEM.
Each arch has its own page_to_pfn(), pfn_to_page() for each models.
But most of them can use the same arithmetic.

This patch adds asm-generic/memory_model.h, which includes generic
page_to_pfn(), pfn_to_page() definitions for each memory model.

When CONFIG_OUT_OF_LINE_PFN_TO_PAGE=y, out-of-line functions are
used instead of macro. This is enabled by some archs and  reduces
text size.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Hirokazu Takata <takata.hirokazu@renesas.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Richard Curnow <rc@rc0.org.uk>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
Cc: Chris Zankel <chris@zankel.net>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 08:44:44 -08:00

78 lines
1.9 KiB
C

#ifndef __ASM_MEMORY_MODEL_H
#define __ASM_MEMORY_MODEL_H
#ifdef __KERNEL__
#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 */
#ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
struct page;
/* this is useful when inlined pfn_to_page is too big */
extern struct page *pfn_to_page(unsigned long pfn);
extern unsigned long page_to_pfn(struct page *page);
#else
/*
* 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) \
({ struct page *__pg = (pg); \
struct zone *__zone = page_zone(__pg); \
(unsigned long)(__pg - __zone->zone_mem_map) + \
__zone->zone_start_pfn; \
})
#elif defined(CONFIG_SPARSEMEM)
/*
* Note: section's mem_map is encorded to reflect its start_pfn.
* section[i].section_mem_map == mem_map's address - start_pfn;
*/
#define page_to_pfn(pg) \
({ struct page *__pg = (pg); \
int __sec = page_to_section(__pg); \
__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 */
#endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */
#endif /* __ASSEMBLY__ */
#endif /* __KERNEL__ */
#endif