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authorLi Zhong <zhong@linux.vnet.ibm.com>2014-06-11 12:23:39 +0400
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2014-08-05 10:34:23 +0400
commit16a05bff128de196fc17edd2beaa40d0f07ae04a (patch)
treea5762ba28bc5623f05d478f75d368e99e5afecef /arch
parent71b0bfe4f1608dbabb54a1e964046267a2c7f7b3 (diff)
downloadlinux-16a05bff128de196fc17edd2beaa40d0f07ae04a.tar.xz
powerpc: start loop at section start of start in vmemmap_populated()
vmemmap_populated() checks whether the [start, start + page_size) has valid pfn numbers, to know whether a vmemmap mapping has been created that includes this range. Some range before end might not be checked by this loop: sec11start......start11..sec11end/sec12start..end....start12..sec12end as the above, for start11(section 11), it checks [sec11start, sec11end), and loop ends as the next start(start12) is bigger than end. However, [sec11end/sec12start, end) is not checked here. So before the loop, adjust the start to be the start of the section, so we don't miss ranges like the above. After we adjust start to be the start of the section, it also means it's aligned with vmemmap as of the sizeof struct page, so we could use page_to_pfn directly in the loop. Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Acked-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/mm/init_64.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c
index 496379013873..253b4b971c8a 100644
--- a/arch/powerpc/mm/init_64.c
+++ b/arch/powerpc/mm/init_64.c
@@ -175,9 +175,10 @@ static unsigned long __meminit vmemmap_section_start(unsigned long page)
static int __meminit vmemmap_populated(unsigned long start, int page_size)
{
unsigned long end = start + page_size;
+ start = (unsigned long)(pfn_to_page(vmemmap_section_start(start)));
for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct page)))
- if (pfn_valid(vmemmap_section_start(start)))
+ if (pfn_valid(page_to_pfn((struct page *)start)))
return 1;
return 0;