2 files changed, 23 insertions, 1 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 7820d447bb8d..633f25dd9ee2 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1089,6 +1089,26 @@ config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
          Set whether the default state of memory_corruption_check is
          on or off.
 
+config X86_RESERVE_LOW_64K
+        bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
+        default y
+        help
+         Reserve the first 64K of physical RAM on BIOSes that are known
+         to potentially corrupt that memory range. A numbers of BIOSes are
+         known to utilize this area during suspend/resume, so it must not
+         be used by the kernel.
+
+         Set this to N if you are absolutely sure that you trust the BIOS
+         to get all its memory reservations and usages right.
+
+         If you have doubts about the BIOS (e.g. suspend/resume does not
+         work or there's kernel crashes after certain hardware hotplug
+         events) and it's not AMI or Phoenix, then you might want to enable
+         X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
+         corruption patterns.
+
+         Say Y if unsure.
+
 config MATH_EMULATION
         bool
         prompt "Math emulation" if X86_32
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 33719544a224..786c1886ae53 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -735,13 +735,14 @@ static int __init dmi_low_memory_corruption(const struct dmi_system_id *d)
                 "%s detected: BIOS may corrupt low RAM, working it around.\n",
                 d->ident);
 
-        reserve_early(0x0, 0x10000, "BIOS quirk");
+        reserve_early_overlap_ok(0x0, 0x10000, "BIOS quirk");
 
         return 0;
 }
 
 /* List of systems that have known low memory corruption BIOS problems */
 static struct dmi_system_id __initdata bad_bios_dmi_table[] = {
+#ifdef CONFIG_X86_RESERVE_LOW_64K
         {
                 .callback = dmi_low_memory_corruption,
                 .ident = "AMI BIOS",
@@ -757,6 +758,7 @@ static struct dmi_system_id __initdata bad_bios_dmi_table[] = {
                 },
         },
         {}
+#endif
 };
 
 /*