diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/memory_hotplug.h | 22 | ||||
| -rw-r--r-- | include/linux/mmzone.h | 35 |
2 files changed, 51 insertions, 6 deletions
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 3c8cf86201c3..a61aede1b391 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -14,6 +14,20 @@ struct memory_block; struct resource; #ifdef CONFIG_MEMORY_HOTPLUG +/* + * Return page for the valid pfn only if the page is online. All pfn + * walkers which rely on the fully initialized page->flags and others + * should use this rather than pfn_valid && pfn_to_page + */ +#define pfn_to_online_page(pfn) \ +({ \ + struct page *___page = NULL; \ + unsigned long ___nr = pfn_to_section_nr(pfn); \ + \ + if (___nr < NR_MEM_SECTIONS && online_section_nr(___nr))\ + ___page = pfn_to_page(pfn); \ + ___page; \ +}) /* * Types for free bootmem stored in page->lru.next. These have to be in @@ -203,6 +217,14 @@ extern void set_zone_contiguous(struct zone *zone); extern void clear_zone_contiguous(struct zone *zone); #else /* ! CONFIG_MEMORY_HOTPLUG */ +#define pfn_to_online_page(pfn) \ +({ \ + struct page *___page = NULL; \ + if (pfn_valid(pfn)) \ + ___page = pfn_to_page(pfn); \ + ___page; \ + }) + /* * Stub functions for when hotplug is off */ diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 976a1202bec1..2aaf7e08c5a8 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1144,9 +1144,10 @@ extern unsigned long usemap_size(void); */ #define SECTION_MARKED_PRESENT (1UL<<0) #define SECTION_HAS_MEM_MAP (1UL<<1) -#define SECTION_MAP_LAST_BIT (1UL<<2) +#define SECTION_IS_ONLINE (1UL<<2) +#define SECTION_MAP_LAST_BIT (1UL<<3) #define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1)) -#define SECTION_NID_SHIFT 2 +#define SECTION_NID_SHIFT 3 static inline struct page *__section_mem_map_addr(struct mem_section *section) { @@ -1175,6 +1176,23 @@ static inline int valid_section_nr(unsigned long nr) return valid_section(__nr_to_section(nr)); } +static inline int online_section(struct mem_section *section) +{ + return (section && (section->section_mem_map & SECTION_IS_ONLINE)); +} + +static inline int online_section_nr(unsigned long nr) +{ + return online_section(__nr_to_section(nr)); +} + +#ifdef CONFIG_MEMORY_HOTPLUG +void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn); +#ifdef CONFIG_MEMORY_HOTREMOVE +void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn); +#endif +#endif + static inline struct mem_section *__pfn_to_section(unsigned long pfn) { return __nr_to_section(pfn_to_section_nr(pfn)); @@ -1253,10 +1271,15 @@ unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long); #ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL /* * pfn_valid() is meant to be able to tell if a given PFN has valid memmap - * associated with it or not. In FLATMEM, it is expected that holes always - * have valid memmap as long as there is valid PFNs either side of the hole. - * In SPARSEMEM, it is assumed that a valid section has a memmap for the - * entire section. + * associated with it or not. This means that a struct page exists for this + * pfn. The caller cannot assume the page is fully initialized in general. + * Hotplugable pages might not have been onlined yet. pfn_to_online_page() + * will ensure the struct page is fully online and initialized. Special pages + * (e.g. ZONE_DEVICE) are never onlined and should be treated accordingly. + * + * In FLATMEM, it is expected that holes always have valid memmap as long as + * there is valid PFNs either side of the hole. In SPARSEMEM, it is assumed + * that a valid section has a memmap for the entire section. * * However, an ARM, and maybe other embedded architectures in the future * free memmap backing holes to save memory on the assumption the memmap is |