From 16a05bff128de196fc17edd2beaa40d0f07ae04a Mon Sep 17 00:00:00 2001 From: Li Zhong Date: Wed, 11 Jun 2014 16:23:39 +0800 Subject: [PATCH] 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 Cc: Nathan Fontenot Acked-by: Nathan Fontenot Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/mm/init_64.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) 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; -- 2.11.0