From 540557b9439ec19668553830c90222f9fb0c2e95 Mon Sep 17 00:00:00 2001 From: Andy Whitcroft Date: Tue, 16 Oct 2007 01:24:11 -0700 Subject: sparsemem: record when a section has a valid mem_map We have flags to indicate whether a section actually has a valid mem_map associated with it. This is never set and we rely solely on the present bit to indicate a section is valid. By definition a section is not valid if it has no mem_map and there is a window during init where the present bit is set but there is no mem_map, during which pfn_valid() will return true incorrectly. Use the existing SECTION_HAS_MEM_MAP flag to indicate the presence of a valid mem_map. Switch valid_section{,_nr} and pfn_valid() to this bit. Add a new present_section{,_nr} and pfn_present() interfaces for those users who care to know that a section is going to be valid. [akpm@linux-foundation.org: coding-syle fixes] Signed-off-by: Andy Whitcroft Acked-by: Mel Gorman Cc: Christoph Lameter Cc: "Luck, Tony" Cc: Andi Kleen Cc: "David S. Miller" Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mmzone.h | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) (limited to 'include/linux/mmzone.h') diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 4e5627379b0..f21e5951038 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -771,12 +771,17 @@ static inline struct page *__section_mem_map_addr(struct mem_section *section) return (struct page *)map; } -static inline int valid_section(struct mem_section *section) +static inline int present_section(struct mem_section *section) { return (section && (section->section_mem_map & SECTION_MARKED_PRESENT)); } -static inline int section_has_mem_map(struct mem_section *section) +static inline int present_section_nr(unsigned long nr) +{ + return present_section(__nr_to_section(nr)); +} + +static inline int valid_section(struct mem_section *section) { return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP)); } @@ -798,6 +803,13 @@ static inline int pfn_valid(unsigned long pfn) return valid_section(__nr_to_section(pfn_to_section_nr(pfn))); } +static inline int pfn_present(unsigned long pfn) +{ + if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) + return 0; + return present_section(__nr_to_section(pfn_to_section_nr(pfn))); +} + /* * These are _only_ used during initialisation, therefore they * can use __initdata ... They could have names to indicate -- cgit v1.2.3