From d7677d4034f040f4ce565713e0b83a31cc26f23e Mon Sep 17 00:00:00 2001 From: "venkatesh.pallipadi@intel.com" Date: Tue, 18 Mar 2008 17:00:17 -0700 Subject: [PATCH] x86: PAT use reserve free memtype in ioremap and iounmap Use reserve_memtype and free_memtype interfaces in ioremap/iounmap to avoid aliasing. If there is an existing alias for the region, inherit the memory type from the alias. If there are conflicting aliases for the entire region, then fail ioremap. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Suresh Siddha Signed-off-by: Ingo Molnar --- arch/x86/mm/ioremap.c | 35 ++++++++++++++++++++++++++++------- 1 file changed, 28 insertions(+), 7 deletions(-) diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 2ac09a5822cb..20c01f2b2e11 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -19,6 +19,7 @@ #include #include #include +#include #ifdef CONFIG_X86_64 @@ -118,6 +119,7 @@ static void __iomem *__ioremap(resource_size_t phys_addr, unsigned long size, { unsigned long pfn, offset, last_addr, vaddr; struct vm_struct *area; + unsigned long new_prot_val; pgprot_t prot; /* Don't allow wraparound or zero size */ @@ -151,6 +153,28 @@ static void __iomem *__ioremap(resource_size_t phys_addr, unsigned long size, WARN_ON_ONCE(is_ram); } + /* + * Mappings have to be page-aligned + */ + offset = phys_addr & ~PAGE_MASK; + phys_addr &= PAGE_MASK; + size = PAGE_ALIGN(last_addr+1) - phys_addr; + + if (reserve_memtype(phys_addr, phys_addr + size, + prot_val, &new_prot_val)) { + /* + * Do not fallback to certain memory types with certain + * requested type: + * - request is uncached, return cannot be write-back + */ + if ((prot_val == _PAGE_CACHE_UC && + new_prot_val == _PAGE_CACHE_WB)) { + free_memtype(phys_addr, phys_addr + size); + return NULL; + } + prot_val = new_prot_val; + } + switch (prot_val) { case _PAGE_CACHE_UC: default: @@ -161,13 +185,6 @@ static void __iomem *__ioremap(resource_size_t phys_addr, unsigned long size, break; } - /* - * Mappings have to be page-aligned - */ - offset = phys_addr & ~PAGE_MASK; - phys_addr &= PAGE_MASK; - size = PAGE_ALIGN(last_addr+1) - phys_addr; - /* * Ok, go for it.. */ @@ -177,11 +194,13 @@ static void __iomem *__ioremap(resource_size_t phys_addr, unsigned long size, area->phys_addr = phys_addr; vaddr = (unsigned long) area->addr; if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot)) { + free_memtype(phys_addr, phys_addr + size); free_vm_area(area); return NULL; } if (ioremap_change_attr(vaddr, size, prot_val) < 0) { + free_memtype(phys_addr, phys_addr + size); vunmap(area->addr); return NULL; } @@ -265,6 +284,8 @@ void iounmap(volatile void __iomem *addr) return; } + free_memtype(p->phys_addr, p->phys_addr + get_vm_area_size(p)); + /* Finally remove it */ o = remove_vm_area((void *)addr); BUG_ON(p != o || o == NULL); -- 2.20.1