From: Arjan van de Ven Date: Mon, 18 Feb 2008 17:58:45 +0000 (-0800) Subject: x86: fix page_is_ram() thinko X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=156fbc3fbe4ab640297b1ae2092821363840aeb6;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git x86: fix page_is_ram() thinko page_is_ram() has a special case for the 640k-1M bios area, however due to a thinko the special case checks the e820 table entry and not the memory the user has asked for. This patch fixes the bug. [ mingo@elte.hu: this too is better solved in the e820 space, but those fixes are too intrusive for v2.6.25. ] Signed-off-by: Arjan van de Ven Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 7fb6eff644b3..f4c95aec5acb 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -50,6 +50,13 @@ int page_is_ram(unsigned long pagenr) if (pagenr == 0) return 0; + /* + * Second special case: Some BIOSen report the PC BIOS + * area (640->1Mb) as ram even though it is not. + */ + if (pagenr >= (BIOS_BEGIN >> PAGE_SHIFT) && + pagenr < (BIOS_END >> PAGE_SHIFT)) + return 0; for (i = 0; i < e820.nr_map; i++) { /* @@ -60,14 +67,6 @@ int page_is_ram(unsigned long pagenr) addr = (e820.map[i].addr + PAGE_SIZE-1) >> PAGE_SHIFT; end = (e820.map[i].addr + e820.map[i].size) >> PAGE_SHIFT; - /* - * Sanity check: Some BIOSen report areas as RAM that - * are not. Notably the 640->1Mb area, which is the - * PCI BIOS area. - */ - if (addr >= (BIOS_BEGIN >> PAGE_SHIFT) && - end < (BIOS_END >> PAGE_SHIFT)) - continue; if ((pagenr >= addr) && (pagenr < end)) return 1;