diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c
index 2a34aaf3c8f139ff8bd35f702b7431ff75895c9c..33120100ff5e50486e306f35688620ee8c05754f 100644
--- a/arch/x86/kernel/acpi/sleep.c
+++ b/arch/x86/kernel/acpi/sleep.c
@@ -48,9 +48,20 @@ int x86_acpi_suspend_lowlevel(void)
 #ifndef CONFIG_64BIT
 	native_store_gdt((struct desc_ptr *)&header->pmode_gdt);
 
+	/*
+	 * We have to check that we can write back the value, and not
+	 * just read it.  At least on 90 nm Pentium M (Family 6, Model
+	 * 13), reading an invalid MSR is not guaranteed to trap, see
+	 * Erratum X4 in "Intel Pentium M Processor on 90 nm Process
+	 * with 2-MB L2 Cache and Intel® Processor A100 and A110 on 90
+	 * nm process with 512-KB L2 Cache Specification Update".
+	 */
 	if (!rdmsr_safe(MSR_EFER,
 			&header->pmode_efer_low,
-			&header->pmode_efer_high))
+			&header->pmode_efer_high) &&
+	    !wrmsr_safe(MSR_EFER,
+			header->pmode_efer_low,
+			header->pmode_efer_high))
 		header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_EFER);
 #endif /* !CONFIG_64BIT */
 
@@ -61,7 +72,10 @@ int x86_acpi_suspend_lowlevel(void)
 	}
 	if (!rdmsr_safe(MSR_IA32_MISC_ENABLE,
 			&header->pmode_misc_en_low,
-			&header->pmode_misc_en_high))
+			&header->pmode_misc_en_high) &&
+	    !wrmsr_safe(MSR_IA32_MISC_ENABLE,
+			header->pmode_misc_en_low,
+			header->pmode_misc_en_high))
 		header->pmode_behavior |=
 			(1 << WAKEUP_BEHAVIOR_RESTORE_MISC_ENABLE);
 	header->realmode_flags = acpi_realmode_flags;
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 5e4d8a8a5c407b7cae67f3d7f86392962c506d0d..e1aabdb314c83740dd686eb4c70a6f40c312e258 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -512,21 +512,6 @@ ENTRY(phys_base)
 
 #include "../../x86/xen/xen-head.S"
 	
-	.section .bss, "aw", @nobits
-	.align L1_CACHE_BYTES
-ENTRY(idt_table)
-	.skip IDT_ENTRIES * 16
-
-	.align L1_CACHE_BYTES
-ENTRY(debug_idt_table)
-	.skip IDT_ENTRIES * 16
-
-#ifdef CONFIG_TRACING
-	.align L1_CACHE_BYTES
-ENTRY(trace_idt_table)
-	.skip IDT_ENTRIES * 16
-#endif
-
 	__PAGE_ALIGNED_BSS
 NEXT_PAGE(empty_zero_page)
 	.skip PAGE_SIZE
diff --git a/arch/x86/kernel/tracepoint.c b/arch/x86/kernel/tracepoint.c
index 4e584a8d6eddf1fa2dbd8c540ce0f6542850bb79..1c113db9ed573c3d8723fccc177431861df2bd19 100644
--- a/arch/x86/kernel/tracepoint.c
+++ b/arch/x86/kernel/tracepoint.c
@@ -12,10 +12,8 @@ atomic_t trace_idt_ctr = ATOMIC_INIT(0);
 struct desc_ptr trace_idt_descr = { NR_VECTORS * 16 - 1,
 				(unsigned long) trace_idt_table };
 
-#ifndef CONFIG_X86_64
-gate_desc trace_idt_table[NR_VECTORS] __page_aligned_data
-					= { { { { 0, 0 } } }, };
-#endif
+/* No need to be aligned, but done to keep all IDTs defined the same way. */
+gate_desc trace_idt_table[NR_VECTORS] __page_aligned_bss;
 
 static int trace_irq_vector_refcount;
 static DEFINE_MUTEX(irq_vector_mutex);
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index b0865e88d3ccf4e272e5dbf654ff5de25492e672..1b23a1c9274696f108dcf2ad2482445523930de0 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -63,19 +63,19 @@
 #include <asm/x86_init.h>
 #include <asm/pgalloc.h>
 #include <asm/proto.h>
+
+/* No need to be aligned, but done to keep all IDTs defined the same way. */
+gate_desc debug_idt_table[NR_VECTORS] __page_aligned_bss;
 #else
 #include <asm/processor-flags.h>
 #include <asm/setup.h>
 
 asmlinkage int system_call(void);
-
-/*
- * The IDT has to be page-aligned to simplify the Pentium
- * F0 0F bug workaround.
- */
-gate_desc idt_table[NR_VECTORS] __page_aligned_data = { { { { 0, 0 } } }, };
 #endif
 
+/* Must be page-aligned because the real IDT is used in a fixmap. */
+gate_desc idt_table[NR_VECTORS] __page_aligned_bss;
+
 DECLARE_BITMAP(used_vectors, NR_VECTORS);
 EXPORT_SYMBOL_GPL(used_vectors);
 
diff --git a/arch/x86/platform/ce4100/ce4100.c b/arch/x86/platform/ce4100/ce4100.c
index baec704231b31385d7751c07bc5e8a1a5dfb53be..643b8b5eee86b3eee7edb2cf99dfa31ad7f9318d 100644
--- a/arch/x86/platform/ce4100/ce4100.c
+++ b/arch/x86/platform/ce4100/ce4100.c
@@ -14,6 +14,7 @@
 #include <linux/module.h>
 #include <linux/serial_reg.h>
 #include <linux/serial_8250.h>
+#include <linux/reboot.h>
 
 #include <asm/ce4100.h>
 #include <asm/prom.h>
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index c8d5577044bb678412d7c1d528e926a29f29f6c1..90f6ed127096566ab06c0a9e6f25a355ccdfc048 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -931,13 +931,6 @@ void __init efi_enter_virtual_mode(void)
 			va = efi_ioremap(md->phys_addr, size,
 					 md->type, md->attribute);
 
-		if (!(md->attribute & EFI_MEMORY_RUNTIME)) {
-			if (!va)
-				pr_err("ioremap of 0x%llX failed!\n",
-				       (unsigned long long)md->phys_addr);
-			continue;
-		}
-
 		md->virt_addr = (u64) (unsigned long) va;
 
 		if (!va) {
diff --git a/drivers/firmware/efi/efivars.c b/drivers/firmware/efi/efivars.c
index 8bd1bb6dbe4739cf0914a129a12363c1bf157820..8a7432a4b4136807ad9a00015a00f5a249d6b112 100644
--- a/drivers/firmware/efi/efivars.c
+++ b/drivers/firmware/efi/efivars.c
@@ -583,6 +583,9 @@ int efivars_sysfs_init(void)
 	struct kobject *parent_kobj = efivars_kobject();
 	int error = 0;
 
+	if (!efi_enabled(EFI_RUNTIME_SERVICES))
+		return -ENODEV;
+
 	/* No efivars has been registered yet */
 	if (!parent_kobj)
 		return 0;