diff options
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index e69f19e..332f46d 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2931,6 +2931,41 @@ static void __meminit calculate_node_totalpages(struct pglist_data *pgdat, realtotalpages); } +#ifndef CONFIG_SPARSEMEM +/* + * Calculate the size of the zone->blockflags rounded to an unsigned long + * Start by making sure zonesize is a multiple of MAX_ORDER-1 by rounding up + * Then figure 1 NR_PAGEBLOCK_BITS worth of bits per MAX_ORDER-1, finally + * round what is now in bits to nearest long in bits, then return it in + * bytes. + */ +static unsigned long __init usemap_size(unsigned long zonesize) +{ + unsigned long usemapsize; + + usemapsize = roundup(zonesize, MAX_ORDER_NR_PAGES); + usemapsize = usemapsize >> (MAX_ORDER-1); + usemapsize *= NR_PAGEBLOCK_BITS; + usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long)); + + return usemapsize / 8; +} + +static void __init setup_usemap(struct pglist_data *pgdat, + struct zone *zone, unsigned long zonesize) +{ + unsigned long usemapsize = usemap_size(zonesize); + zone->pageblock_flags = NULL; + if (usemapsize) { + zone->pageblock_flags = alloc_bootmem_node(pgdat, usemapsize); + memset(zone->pageblock_flags, 0, usemapsize); + } +} +#else +static void inline setup_usemap(struct pglist_data *pgdat, + struct zone *zone, unsigned long zonesize) {} +#endif /* CONFIG_SPARSEMEM */ + /* * Set up the zone data structures: * - mark all pages reserved @@ -3011,6 +3046,7 @@ static void __meminit free_area_init_core(struct pglist_data *pgdat, if (!size) continue; + setup_usemap(pgdat, zone, size); ret = init_currently_empty_zone(zone, zone_start_pfn, size, MEMMAP_EARLY); BUG_ON(ret); @@ -3991,4 +4027,79 @@ EXPORT_SYMBOL(pfn_to_page); EXPORT_SYMBOL(page_to_pfn); #endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */ +/* Return a pointer to the bitmap storing bits affecting a block of pages */ +static inline unsigned long *get_pageblock_bitmap(struct zone *zone, + unsigned long pfn) +{ +#ifdef CONFIG_SPARSEMEM + return __pfn_to_section(pfn)->pageblock_flags; +#else + return zone->pageblock_flags; +#endif /* CONFIG_SPARSEMEM */ +} + +static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn) +{ +#ifdef CONFIG_SPARSEMEM + pfn &= (PAGES_PER_SECTION-1); + return (pfn >> (MAX_ORDER-1)) * NR_PAGEBLOCK_BITS; +#else + pfn = pfn - zone->zone_start_pfn; + return (pfn >> (MAX_ORDER-1)) * NR_PAGEBLOCK_BITS; +#endif /* CONFIG_SPARSEMEM */ +} + +/** + * get_pageblock_flags_group - Return the requested group of flags for the MAX_ORDER_NR_PAGES block of pages + * @page: The page within the block of interest + * @start_bitidx: The first bit of interest to retrieve + * @end_bitidx: The last bit of interest + * returns pageblock_bits flags + */ +unsigned long get_pageblock_flags_group(struct page *page, + int start_bitidx, int end_bitidx) +{ + struct zone *zone; + unsigned long *bitmap; + unsigned long pfn, bitidx; + unsigned long flags = 0; + unsigned long value = 1; + + zone = page_zone(page); + pfn = page_to_pfn(page); + bitmap = get_pageblock_bitmap(zone, pfn); + bitidx = pfn_to_bitidx(zone, pfn); + + for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) + if (test_bit(bitidx + start_bitidx, bitmap)) + flags |= value; + return flags; +} + +/** + * set_pageblock_flags_group - Set the requested group of flags for a MAX_ORDER_NR_PAGES block of pages + * @page: The page within the block of interest + * @start_bitidx: The first bit of interest + * @end_bitidx: The last bit of interest + * @flags: The flags to set + */ +void set_pageblock_flags_group(struct page *page, unsigned long flags, + int start_bitidx, int end_bitidx) +{ + struct zone *zone; + unsigned long *bitmap; + unsigned long pfn, bitidx; + unsigned long value = 1; + + zone = page_zone(page); + pfn = page_to_pfn(page); + bitmap = get_pageblock_bitmap(zone, pfn); + bitidx = pfn_to_bitidx(zone, pfn); + + for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) + if (flags & value) + __set_bit(bitidx + start_bitidx, bitmap); + else + __clear_bit(bitidx + start_bitidx, bitmap); +} |
