From 83e6decef8f7970d46f0945a1bb6a39590cfc683 Mon Sep 17 00:00:00 2001
From: "H. Peter Anvin" <hpa@zytor.com>
Date: Sat, 28 Mar 2009 13:53:26 -0700
Subject: [PATCH] --- yaml --- r: 139573 b: refs/heads/master c:
 c549e71d073a6e9a4847497344db28a784061455 h: refs/heads/master i:   139571:
 8f5af982ac6d1db2922acb27d0e50c437e8bb9e8 v: v3

---
 [refs]                       |  2 +-
 trunk/arch/x86/boot/memory.c | 21 +++++++++++++++++----
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/[refs] b/[refs]
index 56f48cf62ebe..b6b696d047b8 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 32ec7fd08b597586774b92ac1cd2678021ccac1b
+refs/heads/master: c549e71d073a6e9a4847497344db28a784061455
diff --git a/trunk/arch/x86/boot/memory.c b/trunk/arch/x86/boot/memory.c
index fcdb10add9c8..d5d2360763dc 100644
--- a/trunk/arch/x86/boot/memory.c
+++ b/trunk/arch/x86/boot/memory.c
@@ -2,6 +2,7 @@
  *
  *   Copyright (C) 1991, 1992 Linus Torvalds
  *   Copyright 2007 rPath, Inc. - All Rights Reserved
+ *   Copyright 2009 Intel Corporation; author H. Peter Anvin
  *
  *   This file is part of the Linux kernel, and is made available under
  *   the terms of the GNU General Public License version 2.
@@ -16,6 +17,11 @@
 
 #define SMAP	0x534d4150	/* ASCII "SMAP" */
 
+struct e820_ext_entry {
+	struct e820entry std;
+	u32 ext_flags;
+} __attribute__((packed));
+
 static int detect_memory_e820(void)
 {
 	int count = 0;
@@ -23,9 +29,10 @@ static int detect_memory_e820(void)
 	u32 size, id, edi;
 	u8 err;
 	struct e820entry *desc = boot_params.e820_map;
+	static struct e820_ext_entry buf; /* static so it is zeroed */
 
 	do {
-		size = sizeof(struct e820entry);
+		size = sizeof buf;
 
 		/* Important: %edx and %esi are clobbered by some BIOSes,
 		   so they must be either used for the error output
@@ -33,8 +40,8 @@ static int detect_memory_e820(void)
 		   is something out there clobbering %ebp and %edi, too. */
 		asm("pushl %%ebp; int $0x15; popl %%ebp; setc %0"
 		    : "=d" (err), "+b" (next), "=a" (id), "+c" (size),
-		      "=D" (edi), "=m" (*desc)
-		    : "D" (desc), "d" (SMAP), "a" (0xe820)
+		      "=D" (edi), "+m" (buf)
+		    : "D" (&buf), "d" (SMAP), "a" (0xe820)
 		    : "esi");
 
 		/* BIOSes which terminate the chain with CF = 1 as opposed
@@ -53,8 +60,14 @@ static int detect_memory_e820(void)
 			break;
 		}
 
+		/* ACPI 3.0 added the extended flags support.  If bit 0
+		   in the extended flags is zero, we're supposed to simply
+		   ignore the entry -- a backwards incompatible change! */
+		if (size > 20 && !(buf.ext_flags & 1))
+			continue;
+
+		*desc++ = buf.std;
 		count++;
-		desc++;
 	} while (next && count < ARRAY_SIZE(boot_params.e820_map));
 
 	return boot_params.e820_entries = count;