From: KAMEZAWA Hiroyuki 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 Cc: Hugh Dickins Cc: Andi Kleen Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Russell King Cc: Ian Molton Cc: Mikael Starvik Cc: David Howells Cc: Yoshinori Sato Cc: Hirokazu Takata Cc: Ralf Baechle Cc: Kyle McMartin Cc: Heiko Carstens Cc: Martin Schwidefsky Cc: Paul Mundt Cc: Kazumoto Kojima Cc: Richard Curnow Cc: William Lee Irwin III Cc: "David S. Miller" Cc: Jeff Dike Cc: Paolo 'Blaisorblade' Giarrusso Cc: Miles Bader Cc: Chris Zankel Cc: "Luck, Tony" Signed-off-by: Andrew Morton --- include/asm-generic/memory_model.h | 77 +++++++++++++++++++++++++++ include/linux/mmzone.h | 11 --- mm/page_alloc.c | 42 ++++++++++++++ 3 files changed, 119 insertions(+), 11 deletions(-) diff -puN /dev/null include/asm-generic/memory_model.h --- /dev/null 2003-09-15 06:40:47.000000000 -0700 +++ devel-akpm/include/asm-generic/memory_model.h 2006-03-11 02:50:39.000000000 -0800 @@ -0,0 +1,77 @@ +#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 diff -puN include/linux/mmzone.h~unify-pfn_to_page-generic-functions include/linux/mmzone.h --- devel/include/linux/mmzone.h~unify-pfn_to_page-generic-functions 2006-03-11 02:50:39.000000000 -0800 +++ devel-akpm/include/linux/mmzone.h 2006-03-11 02:50:39.000000000 -0800 @@ -602,17 +602,6 @@ static inline struct mem_section *__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) diff -puN mm/page_alloc.c~unify-pfn_to_page-generic-functions mm/page_alloc.c --- devel/mm/page_alloc.c~unify-pfn_to_page-generic-functions 2006-03-11 02:50:39.000000000 -0800 +++ devel-akpm/mm/page_alloc.c 2006-03-11 02:50:39.000000000 -0800 @@ -2747,3 +2747,45 @@ void *__init alloc_large_system_hash(con 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 */ _