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authorRafael J. Wysocki <rjw@sisk.pl>2007-07-21 17:11:09 +0200
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-21 18:37:12 -0700
commit1c10070a55a38ad8489df8afd52c9a3ffd46bbb5 (patch)
treee4c1ab4e436fbc3345cb465c8c896153f6a33ff3 /arch/i386/kernel/e820.c
parent114ab8e99c52828b37c994f580e39ce341c17d3b (diff)
i386: do not restore reserved memory after hibernation
On some systems the ACPI NVS area is located in the first 1 MB of RAM and it is overwritten by the i386 code during the restore after hibernation. This confuses the ACPI platform firmware that doesn't update the AC adapter status appropriately as a result (http://bugzilla.kernel.org/show_bug.cgi?id=7995). The solution is to register the reserved memory in the first 1 MB as 'nosave', so that swsusp doesn't touch it during the restore. Also, this has been done on x86_64 for a long time now, so this patch makes the i386 restore code behave like the x86_64 one. [akpm@linux-foundation.org: build fix] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/i386/kernel/e820.c')
-rw-r--r--arch/i386/kernel/e820.c32
1 files changed, 32 insertions, 0 deletions
diff --git a/arch/i386/kernel/e820.c b/arch/i386/kernel/e820.c
index fc822a46897..e60cddbc4cf 100644
--- a/arch/i386/kernel/e820.c
+++ b/arch/i386/kernel/e820.c
@@ -10,6 +10,7 @@
#include <linux/efi.h>
#include <linux/pfn.h>
#include <linux/uaccess.h>
+#include <linux/suspend.h>
#include <asm/pgtable.h>
#include <asm/page.h>
@@ -320,6 +321,37 @@ static int __init request_standard_resources(void)
subsys_initcall(request_standard_resources);
+#if defined(CONFIG_PM) && defined(CONFIG_SOFTWARE_SUSPEND)
+/**
+ * e820_mark_nosave_regions - Find the ranges of physical addresses that do not
+ * correspond to e820 RAM areas and mark the corresponding pages as nosave for
+ * hibernation.
+ *
+ * This function requires the e820 map to be sorted and without any
+ * overlapping entries and assumes the first e820 area to be RAM.
+ */
+void __init e820_mark_nosave_regions(void)
+{
+ int i;
+ unsigned long pfn;
+
+ pfn = PFN_DOWN(e820.map[0].addr + e820.map[0].size);
+ for (i = 1; i < e820.nr_map; i++) {
+ struct e820entry *ei = &e820.map[i];
+
+ if (pfn < PFN_UP(ei->addr))
+ register_nosave_region(pfn, PFN_UP(ei->addr));
+
+ pfn = PFN_DOWN(ei->addr + ei->size);
+ if (ei->type != E820_RAM)
+ register_nosave_region(PFN_UP(ei->addr), pfn);
+
+ if (pfn >= max_low_pfn)
+ break;
+ }
+}
+#endif
+
void __init add_memory_region(unsigned long long start,
unsigned long long size, int type)
{