diff options
Diffstat (limited to 'include/linux/mm.h')
| -rw-r--r-- | include/linux/mm.h | 92 |
1 files changed, 75 insertions, 17 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 57b2ead51db..6eb7f48317f 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -397,40 +397,80 @@ static inline void put_page(struct page *page) * sets it, so none of the operations on it need to be atomic. */ -/* Page flags: | NODE | ZONE | ... | FLAGS | */ -#define NODES_PGOFF ((sizeof(page_flags_t)*8) - NODES_SHIFT) -#define ZONES_PGOFF (NODES_PGOFF - ZONES_SHIFT) + +/* + * page->flags layout: + * + * There are three possibilities for how page->flags get + * laid out. The first is for the normal case, without + * sparsemem. The second is for sparsemem when there is + * plenty of space for node and section. The last is when + * we have run out of space and have to fall back to an + * alternate (slower) way of determining the node. + * + * No sparsemem: | NODE | ZONE | ... | FLAGS | + * with space for node: | SECTION | NODE | ZONE | ... | FLAGS | + * no space for node: | SECTION | ZONE | ... | FLAGS | + */ +#ifdef CONFIG_SPARSEMEM +#define SECTIONS_WIDTH SECTIONS_SHIFT +#else +#define SECTIONS_WIDTH 0 +#endif + +#define ZONES_WIDTH ZONES_SHIFT + +#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT <= FLAGS_RESERVED +#define NODES_WIDTH NODES_SHIFT +#else +#define NODES_WIDTH 0 +#endif + +/* Page flags: | [SECTION] | [NODE] | ZONE | ... | FLAGS | */ +#define SECTIONS_PGOFF ((sizeof(page_flags_t)*8) - SECTIONS_WIDTH) +#define NODES_PGOFF (SECTIONS_PGOFF - NODES_WIDTH) +#define ZONES_PGOFF (NODES_PGOFF - ZONES_WIDTH) + +/* + * We are going to use the flags for the page to node mapping if its in + * there. This includes the case where there is no node, so it is implicit. + */ +#define FLAGS_HAS_NODE (NODES_WIDTH > 0 || NODES_SHIFT == 0) + +#ifndef PFN_SECTION_SHIFT +#define PFN_SECTION_SHIFT 0 +#endif /* * Define the bit shifts to access each section. For non-existant * sections we define the shift as 0; that plus a 0 mask ensures * the compiler will optimise away reference to them. */ -#define NODES_PGSHIFT (NODES_PGOFF * (NODES_SHIFT != 0)) -#define ZONES_PGSHIFT (ZONES_PGOFF * (ZONES_SHIFT != 0)) +#define SECTIONS_PGSHIFT (SECTIONS_PGOFF * (SECTIONS_WIDTH != 0)) +#define NODES_PGSHIFT (NODES_PGOFF * (NODES_WIDTH != 0)) +#define ZONES_PGSHIFT (ZONES_PGOFF * (ZONES_WIDTH != 0)) -/* NODE:ZONE is used to lookup the zone from a page. */ +/* NODE:ZONE or SECTION:ZONE is used to lookup the zone from a page. */ +#if FLAGS_HAS_NODE #define ZONETABLE_SHIFT (NODES_SHIFT + ZONES_SHIFT) +#else +#define ZONETABLE_SHIFT (SECTIONS_SHIFT + ZONES_SHIFT) +#endif #define ZONETABLE_PGSHIFT ZONES_PGSHIFT -#if NODES_SHIFT+ZONES_SHIFT > FLAGS_RESERVED -#error NODES_SHIFT+ZONES_SHIFT > FLAGS_RESERVED +#if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > FLAGS_RESERVED +#error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > FLAGS_RESERVED #endif -#define NODEZONE(node, zone) ((node << ZONES_SHIFT) | zone) - -#define ZONES_MASK ((1UL << ZONES_SHIFT) - 1) -#define NODES_MASK ((1UL << NODES_SHIFT) - 1) +#define ZONES_MASK ((1UL << ZONES_WIDTH) - 1) +#define NODES_MASK ((1UL << NODES_WIDTH) - 1) +#define SECTIONS_MASK ((1UL << SECTIONS_WIDTH) - 1) #define ZONETABLE_MASK ((1UL << ZONETABLE_SHIFT) - 1) static inline unsigned long page_zonenum(struct page *page) { return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK; } -static inline unsigned long page_to_nid(struct page *page) -{ - return (page->flags >> NODES_PGSHIFT) & NODES_MASK; -} struct zone; extern struct zone *zone_table[]; @@ -441,6 +481,18 @@ static inline struct zone *page_zone(struct page *page) ZONETABLE_MASK]; } +static inline unsigned long page_to_nid(struct page *page) +{ + if (FLAGS_HAS_NODE) + return (page->flags >> NODES_PGSHIFT) & NODES_MASK; + else + return page_zone(page)->zone_pgdat->node_id; +} +static inline unsigned long page_to_section(struct page *page) +{ + return (page->flags >> SECTIONS_PGSHIFT) & SECTIONS_MASK; +} + static inline void set_page_zone(struct page *page, unsigned long zone) { page->flags &= ~(ZONES_MASK << ZONES_PGSHIFT); @@ -451,12 +503,18 @@ static inline void set_page_node(struct page *page, unsigned long node) page->flags &= ~(NODES_MASK << NODES_PGSHIFT); page->flags |= (node & NODES_MASK) << NODES_PGSHIFT; } +static inline void set_page_section(struct page *page, unsigned long section) +{ + page->flags &= ~(SECTIONS_MASK << SECTIONS_PGSHIFT); + page->flags |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT; +} static inline void set_page_links(struct page *page, unsigned long zone, - unsigned long node) + unsigned long node, unsigned long pfn) { set_page_zone(page, zone); set_page_node(page, node); + set_page_section(page, pfn_to_section_nr(pfn)); } #ifndef CONFIG_DISCONTIGMEM |