From 1c10070a55a38ad8489df8afd52c9a3ffd46bbb5 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sat, 21 Jul 2007 17:11:09 +0200 Subject: [PATCH] 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 Acked-by: Pavel Machek Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- arch/i386/kernel/e820.c | 32 ++++++++++++++++++++++++++++++++ arch/i386/kernel/setup.c | 1 + include/asm-i386/e820.h | 8 ++++++++ 3 files changed, 41 insertions(+) diff --git a/arch/i386/kernel/e820.c b/arch/i386/kernel/e820.c index fc822a4689..e60cddbc4c 100644 --- a/arch/i386/kernel/e820.c +++ b/arch/i386/kernel/e820.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include @@ -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) { diff --git a/arch/i386/kernel/setup.c b/arch/i386/kernel/setup.c index ec4dfcc50c..2986b48a82 100644 --- a/arch/i386/kernel/setup.c +++ b/arch/i386/kernel/setup.c @@ -640,6 +640,7 @@ void __init setup_arch(char **cmdline_p) #endif e820_register_memory(); + e820_mark_nosave_regions(); #ifdef CONFIG_VT #if defined(CONFIG_VGA_CONSOLE) diff --git a/include/asm-i386/e820.h b/include/asm-i386/e820.h index c03290ccec..43114c8246 100644 --- a/include/asm-i386/e820.h +++ b/include/asm-i386/e820.h @@ -47,6 +47,14 @@ extern void e820_register_memory(void); extern void limit_regions(unsigned long long size); extern void print_memory_map(char *who); +#if defined(CONFIG_PM) && defined(CONFIG_SOFTWARE_SUSPEND) +extern void e820_mark_nosave_regions(void); +#else +static inline void e820_mark_nosave_regions(void) +{ +} +#endif + #endif/*!__ASSEMBLY__*/ #endif/*__E820_HEADER*/ -- 2.39.5