This patch uses the optimized ioresource lookup, "region_is_ram", for the ioremap function. If the region is not found, it falls back to the "page_is_ram" function. If it is found and it is RAM, then the usual warning message is issued, and the ioremap operation is aborted. Otherwise, the ioremap operation continues. Signed-off-by: Mike Travis Acked-by: Alex Thorlton Reviewed-by: Cliff Wickman Cc: --- v2: slight rearrangement of code v3: added Cc: stable --- arch/x86/mm/ioremap.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) --- linux.orig/arch/x86/mm/ioremap.c +++ linux/arch/x86/mm/ioremap.c @@ -86,6 +86,7 @@ static void __iomem *__ioremap_caller(re pgprot_t prot; int retval; void __iomem *ret_addr; + int ram_region; /* Don't allow wraparound or zero size */ last_addr = phys_addr + size - 1; @@ -108,12 +109,23 @@ static void __iomem *__ioremap_caller(re /* * Don't allow anybody to remap normal RAM that we're using.. */ - pfn = phys_addr >> PAGE_SHIFT; - last_pfn = last_addr >> PAGE_SHIFT; - if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL, - __ioremap_check_ram) == 1) + /* First check if whole region can be identified as RAM or not */ + ram_region = region_is_ram(phys_addr, size); + if (ram_region > 0) { + WARN_ONCE(1, "ioremap on RAM at 0x%lx - 0x%lx\n", + (unsigned long int)phys_addr, + (unsigned long int)last_addr); return NULL; + } + /* If could not be identified(-1), check page by page */ + if (ram_region < 0) { + pfn = phys_addr >> PAGE_SHIFT; + last_pfn = last_addr >> PAGE_SHIFT; + if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL, + __ioremap_check_ram) == 1) + return NULL; + } /* * Mappings have to be page-aligned */ -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/