From: Jianyu Zhan Date: Tue, 21 Jan 2014 23:49:12 +0000 (-0800) Subject: mm/vmalloc: interchage the implementation of vmalloc_to_{pfn,page} X-Git-Tag: v3.14-rc1~134^2~71 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=ece86e222db4;p=karo-tx-linux.git mm/vmalloc: interchage the implementation of vmalloc_to_{pfn,page} Currently we are implementing vmalloc_to_pfn() as a wrapper around vmalloc_to_page(), which is implemented as follow: 1. walks the page talbes to generates the corresponding pfn, 2. then converts the pfn to struct page, 3. returns it. And vmalloc_to_pfn() re-wraps vmalloc_to_page() to get the pfn. This seems too circuitous, so this patch reverses the way: implement vmalloc_to_page() as a wrapper around vmalloc_to_pfn(). This makes vmalloc_to_pfn() and vmalloc_to_page() slightly more efficient. No functional change. Signed-off-by: Jianyu Zhan Cc: Vladimir Murzin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 0fdf96803c5b..e4f0db2a3eae 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -220,12 +220,12 @@ int is_vmalloc_or_module_addr(const void *x) } /* - * Walk a vmap address to the struct page it maps. + * Walk a vmap address to the physical pfn it maps to. */ -struct page *vmalloc_to_page(const void *vmalloc_addr) +unsigned long vmalloc_to_pfn(const void *vmalloc_addr) { unsigned long addr = (unsigned long) vmalloc_addr; - struct page *page = NULL; + unsigned long pfn = 0; pgd_t *pgd = pgd_offset_k(addr); /* @@ -244,23 +244,23 @@ struct page *vmalloc_to_page(const void *vmalloc_addr) ptep = pte_offset_map(pmd, addr); pte = *ptep; if (pte_present(pte)) - page = pte_page(pte); + pfn = pte_pfn(pte); pte_unmap(ptep); } } } - return page; + return pfn; } -EXPORT_SYMBOL(vmalloc_to_page); +EXPORT_SYMBOL(vmalloc_to_pfn); /* - * Map a vmalloc()-space virtual address to the physical page frame number. + * Map a vmalloc()-space virtual address to the struct page. */ -unsigned long vmalloc_to_pfn(const void *vmalloc_addr) +struct page *vmalloc_to_page(const void *vmalloc_addr) { - return page_to_pfn(vmalloc_to_page(vmalloc_addr)); + return pfn_to_page(vmalloc_to_pfn(vmalloc_addr)); } -EXPORT_SYMBOL(vmalloc_to_pfn); +EXPORT_SYMBOL(vmalloc_to_page); /*** Global kva allocator ***/