Commit a117e66e authored by KAMEZAWA Hiroyuki's avatar KAMEZAWA Hiroyuki Committed by Linus Torvalds
Browse files

[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: default avatarKAMEZAWA 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: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent b06be912

include/asm-generic/memory_model.h

0 → 100644
+77 −0
Original line number Diff line number Diff line 
#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

include/asm-sparc64/page.h

+2 −0
Original line number Diff line number Diff line
@@ -111,6 +111,8 @@ typedef unsigned long pgprot_t; 
				 (_AC(0x0000000070000000,UL)) : \

				 (_AC(0xfffff80000000000,UL) + (1UL << 32UL)))



#include <asm-generic/memory_model.h>



#endif /* !(__ASSEMBLY__) */



/* to align the pointer to the (next) page boundary */

include/linux/mmzone.h

+0 −11
Original line number Diff line number Diff line
@@ -602,17 +602,6 @@ static inline struct mem_section *__pfn_to_section(unsigned long pfn) 
	return __nr_to_section(pfn_to_section_nr(pfn));

}



#define pfn_to_page(pfn) 						\

({ 									\

	unsigned long __pfn = (pfn);					\

	__section_mem_map_addr(__pfn_to_section(__pfn)) + __pfn;	\

})

#define page_to_pfn(page)						\

({									\

	page - __section_mem_map_addr(__nr_to_section(			\

		page_to_section(page)));				\

})



static inline int pfn_valid(unsigned long pfn)

{

	if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)

mm/page_alloc.c

+42 −0
Original line number Diff line number Diff line
@@ -2745,3 +2745,45 @@ void *__init alloc_large_system_hash(const char *tablename, 


	return table;

}



#ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE

/*

 * pfn <-> page translation. out-of-line version.

 * (see asm-generic/memory_model.h)

 */

#if defined(CONFIG_FLATMEM)

struct page *pfn_to_page(unsigned long pfn)

{

	return mem_map + (pfn - ARCH_PFN_OFFSET);

}

unsigned long page_to_pfn(struct page *page)

{

	return (page - mem_map) + ARCH_PFN_OFFSET;

}

#elif defined(CONFIG_DISCONTIGMEM)

struct page *pfn_to_page(unsigned long pfn)

{

	int nid = arch_pfn_to_nid(pfn);

	return NODE_DATA(nid)->node_mem_map + arch_local_page_offset(pfn,nid);

}

unsigned long page_to_pfn(struct page *page)

{

	struct zone *zone = page_zone(page);

	return (page - zone->zone_mem_map) + zone->zone_start_pfn;



}

#elif defined(CONFIG_SPARSEMEM)

struct page *pfn_to_page(unsigned long pfn)

{

	return __section_mem_map_addr(__pfn_to_section(pfn)) + pfn;

}



unsigned long page_to_pfn(struct page *page)

{

	long section_id = page_to_section(page);

	return page - __section_mem_map_addr(__nr_to_section(section_id));

}

#endif /* CONFIG_FLATMEM/DISCONTIGMME/SPARSEMEM */

EXPORT_SYMBOL(pfn_to_page);

EXPORT_SYMBOL(page_to_pfn);

#endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */

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