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 --- arch/ppc64/kernel/pci.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'arch/ppc64/kernel') diff --git a/arch/ppc64/kernel/pci.c b/arch/ppc64/kernel/pci.c index b2fb6746f00b..3d2106b022a1 100644 --- a/arch/ppc64/kernel/pci.c +++ b/arch/ppc64/kernel/pci.c @@ -726,16 +726,17 @@ static pgprot_t __pci_mmap_set_pgprot(struct pci_dev *dev, struct resource *rp, * above routine */ pgprot_t pci_phys_mem_access_prot(struct file *file, - unsigned long offset, + unsigned long pfn, unsigned long size, pgprot_t protection) { struct pci_dev *pdev = NULL; struct resource *found = NULL; unsigned long prot = pgprot_val(protection); + unsigned long offset = pfn << PAGE_SHIFT; int i; - if (page_is_ram(offset >> PAGE_SHIFT)) + if (page_is_ram(pfn)) return __pgprot(prot); prot |= _PAGE_NO_CACHE | _PAGE_GUARDED; -- cgit v1.2.3