diff options
Diffstat (limited to 'include/linux/mmzone.h')
| -rw-r--r-- | include/linux/mmzone.h | 30 |
1 files changed, 28 insertions, 2 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 6c90461ed99..b97054bbc39 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -487,6 +487,28 @@ struct mem_section { unsigned long section_mem_map; }; +#ifdef CONFIG_ARCH_SPARSEMEM_EXTREME +/* + * Should we ever require GCC 4 or later then the flat array scheme + * can be eliminated and a uniform solution for EXTREME and !EXTREME can + * be arrived at. + */ +#define SECTION_ROOT_SHIFT (PAGE_SHIFT-3) +#define SECTION_ROOT_MASK ((1UL<<SECTION_ROOT_SHIFT) - 1) +#define SECTION_TO_ROOT(_sec) ((_sec) >> SECTION_ROOT_SHIFT) +#define NR_SECTION_ROOTS (NR_MEM_SECTIONS >> SECTION_ROOT_SHIFT) + +extern struct mem_section *mem_section[NR_SECTION_ROOTS]; + +static inline struct mem_section *__nr_to_section(unsigned long nr) +{ + if (!mem_section[SECTION_TO_ROOT(nr)]) + return NULL; + return &mem_section[SECTION_TO_ROOT(nr)][nr & SECTION_ROOT_MASK]; +} + +#else + extern struct mem_section mem_section[NR_MEM_SECTIONS]; static inline struct mem_section *__nr_to_section(unsigned long nr) @@ -494,6 +516,10 @@ static inline struct mem_section *__nr_to_section(unsigned long nr) return &mem_section[nr]; } +#define sparse_index_init(_sec, _nid) do {} while (0) + +#endif + /* * We use the lower bits of the mem_map pointer to store * a little bit of information. There should be at least @@ -513,12 +539,12 @@ static inline struct page *__section_mem_map_addr(struct mem_section *section) static inline int valid_section(struct mem_section *section) { - return (section->section_mem_map & SECTION_MARKED_PRESENT); + return (section && (section->section_mem_map & SECTION_MARKED_PRESENT)); } static inline int section_has_mem_map(struct mem_section *section) { - return (section->section_mem_map & SECTION_HAS_MEM_MAP); + return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP)); } static inline int valid_section_nr(unsigned long nr) |