From ec776ef6bbe1734c29cd6bd05219cd93b2731bd4 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 1 Apr 2015 09:12:18 +0200 Subject: x86/mm: Add support for the non-standard protected e820 type Various recent BIOSes support NVDIMMs or ADR using a non-standard e820 memory type, and Intel supplied reference Linux code using this type to various vendors. Wire this e820 table type up to export platform devices for the pmem driver so that we can use it in Linux. Based on earlier work from: Dave Jiang Dan Williams Includes fixes for NUMA regions from Boaz Harrosh. Tested-by: Ross Zwisler Signed-off-by: Christoph Hellwig Acked-by: Dan Williams Cc: Andrew Morton Cc: Andy Lutomirski Cc: Boaz Harrosh Cc: Borislav Petkov Cc: H. Peter Anvin Cc: Jens Axboe Cc: Jens Axboe Cc: Keith Busch Cc: Linus Torvalds Cc: Matthew Wilcox Cc: Thomas Gleixner Cc: linux-nvdimm@ml01.01.org Link: http://lkml.kernel.org/r/1427872339-6688-2-git-send-email-hch@lst.de [ Minor cleanups. ] Signed-off-by: Ingo Molnar --- arch/x86/include/uapi/asm/e820.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'arch/x86/include') diff --git a/arch/x86/include/uapi/asm/e820.h b/arch/x86/include/uapi/asm/e820.h index d993e33f5236..960a8a9dc4ab 100644 --- a/arch/x86/include/uapi/asm/e820.h +++ b/arch/x86/include/uapi/asm/e820.h @@ -33,6 +33,16 @@ #define E820_NVS 4 #define E820_UNUSABLE 5 +/* + * This is a non-standardized way to represent ADR or NVDIMM regions that + * persist over a reboot. The kernel will ignore their special capabilities + * unless the CONFIG_X86_PMEM_LEGACY=y option is set. + * + * ( Note that older platforms also used 6 for the same type of memory, + * but newer versions switched to 12 as 6 was assigned differently. Some + * time they will learn... ) + */ +#define E820_PRAM 12 /* * reserved RAM used by kernel itself -- cgit v1.2.3