From 3ebad5905609476a4ff1151a66b21d9794009961 Mon Sep 17 00:00:00 2001 From: Bernhard Kaindl Date: Wed, 2 May 2007 19:27:17 +0200 Subject: [PATCH] x86: Save and restore the fixed-range MTRRs of the BSP when suspending Note: This patch didn'nt need an update since it's initial post. Some BIOSes may modify fixed-range MTRRs in SMM, e.g. when they transition the system into ACPI mode, which is entered thru an SMI, triggered by Linux in acpi_enable(). SMIs which cause that Linux is interrupted and BIOS code is executed (which may change e.g. fixed-range MTRRs) in SMM may be raised by an embedded system controller which is often found in notebooks also at other occasions. If we would not update our copy of the fixed-range MTRRs before suspending to RAM or to disk, restore_processor_state() would set the fixed-range MTRRs of the BSP using old backup values which may be outdated and this could cause the system to fail later during resume. This patch ensures that our copy of the fixed-range MTRRs is updated when saving the boot processor state on suspend to disk and suspend to RAM. In combination with other patches this allows to fix s2ram and s2disk on the Acer Ferrari 1000 notebook and at least s2disk on the Acer Ferrari 5000 notebook. Signed-off-by: Bernhard Kaindl Signed-off-by: Andi Kleen Cc: Andrew Morton Cc: Andi Kleen Cc: Dave Jones --- arch/i386/power/cpu.c | 1 + arch/x86_64/kernel/suspend.c | 2 ++ 2 files changed, 3 insertions(+) diff --git a/arch/i386/power/cpu.c b/arch/i386/power/cpu.c index 2c15500f871..998fd3ec0d6 100644 --- a/arch/i386/power/cpu.c +++ b/arch/i386/power/cpu.c @@ -21,6 +21,7 @@ unsigned long saved_context_eflags; void __save_processor_state(struct saved_context *ctxt) { + mtrr_save_fixed_ranges(NULL); kernel_fpu_begin(); /* diff --git a/arch/x86_64/kernel/suspend.c b/arch/x86_64/kernel/suspend.c index 4ca523d58a5..6a5a98f2a75 100644 --- a/arch/x86_64/kernel/suspend.c +++ b/arch/x86_64/kernel/suspend.c @@ -12,6 +12,7 @@ #include #include #include +#include /* References to section boundaries */ extern const void __nosave_begin, __nosave_end; @@ -48,6 +49,7 @@ void __save_processor_state(struct saved_context *ctxt) rdmsrl(MSR_FS_BASE, ctxt->fs_base); rdmsrl(MSR_GS_BASE, ctxt->gs_base); rdmsrl(MSR_KERNEL_GS_BASE, ctxt->gs_kernel_base); + mtrr_save_fixed_ranges(NULL); /* * control registers -- cgit v1.2.3