From 8b150478aeb1a8edb9015c2f7ac4da637ff65c45 Mon Sep 17 00:00:00 2001 From: Roland Dreier Date: Fri, 28 Oct 2005 17:46:18 -0700 Subject: [PATCH] ppc: make phys_mem_access_prot() work with pfns instead of addresses Change the phys_mem_access_prot() function to take a pfn instead of an address. This allows mmap64() to work on /dev/mem for addresses above 4G on 32-bit architectures. We start with a pfn in mmap_mem(), so there's no need to convert to an address; in fact, it's actively bad, since the conversion can overflow when the address is above 4G. Similarly fix the ppc32 page_is_ram() function to avoid a conversion to an address by directly comparing to max_pfn. Working with max_pfn instead of high_memory fixes page_is_ram() to give the right answer for highmem pages. Signed-off-by: Roland Dreier Cc: Anton Blanchard Cc: Benjamin Herrenschmidt Signed-off-by: Andrew Morton Signed-off-by: Paul Mackerras --- drivers/char/mem.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'drivers/char/mem.c') diff --git a/drivers/char/mem.c b/drivers/char/mem.c index f182752fe918..9df928d4f68d 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -231,9 +231,7 @@ static ssize_t write_mem(struct file * file, const char __user * buf, static int mmap_mem(struct file * file, struct vm_area_struct * vma) { #if defined(__HAVE_PHYS_MEM_ACCESS_PROT) - unsigned long offset = vma->vm_pgoff << PAGE_SHIFT; - - vma->vm_page_prot = phys_mem_access_prot(file, offset, + vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff, vma->vm_end - vma->vm_start, vma->vm_page_prot); #elif defined(pgprot_noncached) -- cgit v1.2.2