The patch titled x86: ioremap ram check fix has been removed from the -mm tree. Its filename was x86-ioremap-ram-check-fix.patch This patch was dropped because it was merged into mainline or a subsystem tree The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: x86: ioremap ram check fix From: Andres Salomon <dilinger@xxxxxxxxxx> bdd3cee2e4b7279457139058615ced6c2b41e7de (x86: ioremap(), extend check to all RAM pages) breaks OLPC's ioremap call. The ioremap that OLPC uses is: romsig = ioremap(0xffffffc0, 16); The commit that breaks it is basically: - for (pfn = phys_addr >> PAGE_SHIFT; pfn < max_pfn_mapped && - (pfn << PAGE_SHIFT) < last_addr; pfn++) { + for (pfn = phys_addr >> PAGE_SHIFT; + (pfn << PAGE_SHIFT) < last_addr; pfn++) { + Previously, the 'pfn < max_pfn_mapped' check would've caused us to not enter the loop. Removing that check means we loop infinitely. The reason for that is because pfn is 0xfffff, and last_addr is 0xffffffcf. The remaining check that is used to exit the loop is not sufficient; when pfn<<PAGE_SHIFT is 0xfffff000, that is less than 0xffffffcf; when we increment pfn and it overflows (pfn == 0x100000), pfn<<PAGE_SHIFT ends up being 0. That, of course, is less than last_addr. In effect, pfn<<PAGE_SHIFT is never lower than last_addr. The simple fix for this is to limit the last_addr check to the PAGE_MASK; a patch is below. Signed-off-by: Andres Salomon <dilinger@xxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/x86/mm/ioremap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff -puN arch/x86/mm/ioremap.c~x86-ioremap-ram-check-fix arch/x86/mm/ioremap.c --- a/arch/x86/mm/ioremap.c~x86-ioremap-ram-check-fix +++ a/arch/x86/mm/ioremap.c @@ -149,7 +149,8 @@ static void __iomem *__ioremap_caller(re * Don't allow anybody to remap normal RAM that we're using.. */ for (pfn = phys_addr >> PAGE_SHIFT; - (pfn << PAGE_SHIFT) < last_addr; pfn++) { + (pfn << PAGE_SHIFT) < (last_addr & PAGE_MASK); + pfn++) { int is_ram = page_is_ram(pfn); _ Patches currently in -mm which might be from dilinger@xxxxxxxxxx are origin.patch x86-geode-cache-results-from-geode_has_vsa2-and-uninline.patch x86-geode-cache-results-from-geode_has_vsa2-and-uninline-cleanup.patch power_supply-add-eeprom-dump-file-to-olpc_batterys-sysfs.patch power_supply-cleanup-of-the-olpc-battery-driver.patch power_supply-bump-ec-version-check-that-we-refuse-to-run-with-in-olpc_battery.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html