diff options
Diffstat (limited to 'include/linux/mmzone.h')
| -rw-r--r-- | include/linux/mmzone.h | 27 |
1 files changed, 25 insertions, 2 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 265a32e1ff74..fcb535560028 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -114,7 +114,7 @@ static inline bool free_area_empty(struct free_area *area, int migratetype) struct pglist_data; /* - * Add a wild amount of padding here to ensure datas fall into separate + * Add a wild amount of padding here to ensure data fall into separate * cachelines. There are very few zone structures in the machine, so space * consumption is not a concern here. */ @@ -1064,7 +1064,10 @@ extern char numa_zonelist_order[]; #ifndef CONFIG_NUMA extern struct pglist_data contig_page_data; -#define NODE_DATA(nid) (&contig_page_data) +static inline struct pglist_data *NODE_DATA(int nid) +{ + return &contig_page_data; +} #define NODE_MEM_MAP(nid) mem_map #else /* CONFIG_NUMA */ @@ -1445,10 +1448,30 @@ static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn) #endif #ifndef CONFIG_HAVE_ARCH_PFN_VALID +/** + * pfn_valid - check if there is a valid memory map entry for a PFN + * @pfn: the page frame number to check + * + * Check if there is a valid memory map entry aka struct page for the @pfn. + * Note, that availability of the memory map entry does not imply that + * there is actual usable memory at that @pfn. The struct page may + * represent a hole or an unusable page frame. + * + * Return: 1 for PFNs that have memory map entries and 0 otherwise + */ static inline int pfn_valid(unsigned long pfn) { struct mem_section *ms; + /* + * Ensure the upper PAGE_SHIFT bits are clear in the + * pfn. Else it might lead to false positives when + * some of the upper bits are set, but the lower bits + * match a valid pfn. + */ + if (PHYS_PFN(PFN_PHYS(pfn)) != pfn) + return 0; + if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) return 0; ms = __nr_to_section(pfn_to_section_nr(pfn)); |