From a361ee5cb8011763ece7b4add393e206439db8b3 Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Thu, 10 Jul 2008 10:09:59 +0200 Subject: [PATCH] x86: fix /dev/mem compatibility under PAT Add ioremap_default(), which gives a sane mapping without worrying about type conflicts. Use it in /dev/mem read in place of ioremap(), as with ioremap(), any mapping of the region (other than UC_MINUS) will cause a conflict and failure of /dev/mem read. Should address the vbetest failure reported at: http://bugzilla.kernel.org/show_bug.cgi?id=11057 Signed-off-by: Venkatesh Pallipadi Signed-off-by: Ingo Molnar --- arch/x86/mm/ioremap.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 2b2bb3f9b683..d1b867101e5f 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -300,6 +300,29 @@ void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size) } EXPORT_SYMBOL(ioremap_cache); +static void __iomem *ioremap_default(resource_size_t phys_addr, + unsigned long size) +{ + unsigned long flags; + void *ret; + int err; + + /* + * - WB for WB-able memory and no other conflicting mappings + * - UC_MINUS for non-WB-able memory with no other conflicting mappings + * - Inherit from confliting mappings otherwise + */ + err = reserve_memtype(phys_addr, phys_addr + size, -1, &flags); + if (err < 0) + return NULL; + + ret = (void *) __ioremap_caller(phys_addr, size, flags, + __builtin_return_address(0)); + + free_memtype(phys_addr, phys_addr + size); + return (void __iomem *)ret; +} + /** * iounmap - Free a IO remapping * @addr: virtual address from ioremap_* @@ -365,7 +388,7 @@ void *xlate_dev_mem_ptr(unsigned long phys) if (page_is_ram(start >> PAGE_SHIFT)) return __va(phys); - addr = (void *)ioremap(start, PAGE_SIZE); + addr = (void *)ioremap_default(start, PAGE_SIZE); if (addr) addr = (void *)((unsigned long)addr | (phys & ~PAGE_MASK)); -- 2.20.1