diff --git a/arch/x86/entry/vdso/vclock_gettime.c b/arch/x86/entry/vdso/vclock_gettime.c
index 1a50e09c945b..03c3eb77bfce 100644
--- a/arch/x86/entry/vdso/vclock_gettime.c
+++ b/arch/x86/entry/vdso/vclock_gettime.c
@@ -178,7 +178,7 @@ notrace static cycle_t vread_tsc(void)
 
 	/*
 	 * GCC likes to generate cmov here, but this branch is extremely
-	 * predictable (it's just a funciton of time and the likely is
+	 * predictable (it's just a function of time and the likely is
 	 * very likely) and there's a data dependence, so force GCC
 	 * to generate a branch instead.  I don't barrier() because
 	 * we don't actually need a barrier, and if this function
diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c
index 69dd11887dd1..6c3b7c1780c9 100644
--- a/arch/x86/events/intel/lbr.c
+++ b/arch/x86/events/intel/lbr.c
@@ -649,7 +649,7 @@ int intel_pmu_setup_lbr_filter(struct perf_event *event)
 
 /*
  * return the type of control flow change at address "from"
- * intruction is not necessarily a branch (in case of interrupt).
+ * instruction is not necessarily a branch (in case of interrupt).
  *
  * The branch type returned also includes the priv level of the
  * target of the control flow change (X86_BR_USER, X86_BR_KERNEL).
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index 68155cafa8a1..ba6ef18528c9 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -272,7 +272,7 @@ struct cpu_hw_events {
  * events to select for counter rescheduling.
  *
  * Care must be taken as the rescheduling algorithm is O(n!) which
- * will increase scheduling cycles for an over-commited system
+ * will increase scheduling cycles for an over-committed system
  * dramatically.  The number of such EVENT_CONSTRAINT_OVERLAP() macros
  * and its counter masks must be kept at a minimum.
  */
diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 0899cfc8dfe8..98f25bbafac4 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -643,8 +643,8 @@ static inline void entering_irq(void)
 
 static inline void entering_ack_irq(void)
 {
-	ack_APIC_irq();
 	entering_irq();
+	ack_APIC_irq();
 }
 
 static inline void ipi_entering_ack_irq(void)
diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
index 21b66dbf3601..a4820d4df617 100644
--- a/arch/x86/include/asm/ftrace.h
+++ b/arch/x86/include/asm/ftrace.h
@@ -52,7 +52,7 @@ int ftrace_int3_handler(struct pt_regs *regs);
  * this screws up the trace output when tracing a ia32 task.
  * Instead of reporting bogus syscalls, just do not trace them.
  *
- * If the user realy wants these, then they should use the
+ * If the user really wants these, then they should use the
  * raw syscall tracepoints with filtering.
  */
 #define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS 1
diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
index 1815b736269d..b90e1053049b 100644
--- a/arch/x86/include/asm/hw_irq.h
+++ b/arch/x86/include/asm/hw_irq.h
@@ -141,6 +141,7 @@ struct irq_alloc_info {
 struct irq_cfg {
 	unsigned int		dest_apicid;
 	u8			vector;
+	u8			old_vector;
 };
 
 extern struct irq_cfg *irq_cfg(unsigned int irq);
@@ -168,20 +169,6 @@ extern atomic_t irq_mis_count;
 
 extern void elcr_set_level_irq(unsigned int irq);
 
-/* SMP */
-extern __visible void smp_apic_timer_interrupt(struct pt_regs *);
-extern __visible void smp_spurious_interrupt(struct pt_regs *);
-extern __visible void smp_x86_platform_ipi(struct pt_regs *);
-extern __visible void smp_error_interrupt(struct pt_regs *);
-#ifdef CONFIG_X86_IO_APIC
-extern asmlinkage void smp_irq_move_cleanup_interrupt(void);
-#endif
-#ifdef CONFIG_SMP
-extern __visible void smp_reschedule_interrupt(struct pt_regs *);
-extern __visible void smp_call_function_interrupt(struct pt_regs *);
-extern __visible void smp_call_function_single_interrupt(struct pt_regs *);
-#endif
-
 extern char irq_entries_start[];
 #ifdef CONFIG_TRACING
 #define trace_irq_entries_start irq_entries_start
diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
index 93fb7c1cffda..7a79ee2778b3 100644
--- a/arch/x86/include/asm/msr.h
+++ b/arch/x86/include/asm/msr.h
@@ -42,14 +42,6 @@ struct saved_msrs {
 	struct saved_msr *array;
 };
 
-static inline unsigned long long native_read_tscp(unsigned int *aux)
-{
-	unsigned long low, high;
-	asm volatile(".byte 0x0f,0x01,0xf9"
-		     : "=a" (low), "=d" (high), "=c" (*aux));
-	return low | ((u64)high << 32);
-}
-
 /*
  * both i386 and x86_64 returns 64-bit value in edx:eax, but gcc's "A"
  * constraint has different meanings. For i386, "A" means exactly
diff --git a/arch/x86/include/asm/rwsem.h b/arch/x86/include/asm/rwsem.h
index cad82c9c2fde..ceec86eb68e9 100644
--- a/arch/x86/include/asm/rwsem.h
+++ b/arch/x86/include/asm/rwsem.h
@@ -25,7 +25,7 @@
  * This should be totally fair - if anything is waiting, a process that wants a
  * lock will go to the back of the queue. When the currently active lock is
  * released, if there's a writer at the front of the queue, then that and only
- * that will be woken up; if there's a bunch of consequtive readers at the
+ * that will be woken up; if there's a bunch of consecutive readers at the
  * front, then they'll all be woken up, but no other readers will be.
  */
 
diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h
index ca6ba3607705..90dbbd9666d4 100644
--- a/arch/x86/include/asm/string_64.h
+++ b/arch/x86/include/asm/string_64.h
@@ -87,9 +87,9 @@ int strcmp(const char *cs, const char *ct);
  *
  * Low level memory copy function that catches machine checks
  *
- * Return true for success, false for fail
+ * Return 0 for success, -EFAULT for fail
  */
-bool memcpy_mcsafe(void *dst, const void *src, size_t cnt);
+int memcpy_mcsafe(void *dst, const void *src, size_t cnt);
 
 #endif /* __KERNEL__ */
 
diff --git a/arch/x86/include/asm/xen/hypervisor.h b/arch/x86/include/asm/xen/hypervisor.h
index 8b2d4bea9962..39171b3646bb 100644
--- a/arch/x86/include/asm/xen/hypervisor.h
+++ b/arch/x86/include/asm/xen/hypervisor.h
@@ -62,4 +62,6 @@ void xen_arch_register_cpu(int num);
 void xen_arch_unregister_cpu(int num);
 #endif
 
+extern void xen_set_iopl_mask(unsigned mask);
+
 #endif /* _ASM_X86_XEN_HYPERVISOR_H */
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index e75907601a41..8c2f1ef6ca23 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -956,7 +956,7 @@ static int __init early_acpi_parse_madt_lapic_addr_ovr(void)
 
 	/*
 	 * Note that the LAPIC address is obtained from the MADT (32-bit value)
-	 * and (optionally) overriden by a LAPIC_ADDR_OVR entry (64-bit value).
+	 * and (optionally) overridden by a LAPIC_ADDR_OVR entry (64-bit value).
 	 */
 
 	count = acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_APIC_OVERRIDE,
@@ -984,7 +984,7 @@ static int __init acpi_parse_madt_lapic_entries(void)
 
 	/*
 	 * Note that the LAPIC address is obtained from the MADT (32-bit value)
-	 * and (optionally) overriden by a LAPIC_ADDR_OVR entry (64-bit value).
+	 * and (optionally) overridden by a LAPIC_ADDR_OVR entry (64-bit value).
 	 */
 
 	count = acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_APIC_OVERRIDE,
diff --git a/arch/x86/kernel/apb_timer.c b/arch/x86/kernel/apb_timer.c
index 222a57076039..cefacbad1531 100644
--- a/arch/x86/kernel/apb_timer.c
+++ b/arch/x86/kernel/apb_timer.c
@@ -221,7 +221,7 @@ static int apbt_cpuhp_notify(struct notifier_block *n,
 	unsigned long cpu = (unsigned long)hcpu;
 	struct apbt_dev *adev = &per_cpu(cpu_apbt_dev, cpu);
 
-	switch (action & 0xf) {
+	switch (action & ~CPU_TASKS_FROZEN) {
 	case CPU_DEAD:
 		dw_apb_clockevent_pause(adev->timer);
 		if (system_state == SYSTEM_RUNNING) {
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 531b9611c51d..d356987a04e9 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1611,7 +1611,7 @@ void __init enable_IR_x2apic(void)
 	legacy_pic->mask_all();
 	mask_ioapic_entries();
 
-	/* If irq_remapping_prepare() succeded, try to enable it */
+	/* If irq_remapping_prepare() succeeded, try to enable it */
 	if (ir_stat >= 0)
 		ir_stat = try_to_enable_IR();
 	/* ir_stat contains the remap mode or an error code */
diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
index 3b670df4ba7b..ad59d70bcb1a 100644
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -213,6 +213,7 @@ update:
 	 */
 	cpumask_and(d->old_domain, d->old_domain, cpu_online_mask);
 	d->move_in_progress = !cpumask_empty(d->old_domain);
+	d->cfg.old_vector = d->move_in_progress ? d->cfg.vector : 0;
 	d->cfg.vector = vector;
 	cpumask_copy(d->domain, vector_cpumask);
 success:
@@ -655,46 +656,97 @@ void irq_complete_move(struct irq_cfg *cfg)
 }
 
 /*
- * Called with @desc->lock held and interrupts disabled.
+ * Called from fixup_irqs() with @desc->lock held and interrupts disabled.
  */
 void irq_force_complete_move(struct irq_desc *desc)
 {
 	struct irq_data *irqdata = irq_desc_get_irq_data(desc);
 	struct apic_chip_data *data = apic_chip_data(irqdata);
 	struct irq_cfg *cfg = data ? &data->cfg : NULL;
+	unsigned int cpu;
 
 	if (!cfg)
 		return;
 
-	__irq_complete_move(cfg, cfg->vector);
-
 	/*
 	 * This is tricky. If the cleanup of @data->old_domain has not been
 	 * done yet, then the following setaffinity call will fail with
 	 * -EBUSY. This can leave the interrupt in a stale state.
 	 *
-	 * The cleanup cannot make progress because we hold @desc->lock. So in
-	 * case @data->old_domain is not yet cleaned up, we need to drop the
-	 * lock and acquire it again. @desc cannot go away, because the
-	 * hotplug code holds the sparse irq lock.
+	 * All CPUs are stuck in stop machine with interrupts disabled so
+	 * calling __irq_complete_move() would be completely pointless.
 	 */
 	raw_spin_lock(&vector_lock);
-	/* Clean out all offline cpus (including ourself) first. */
+	/*
+	 * Clean out all offline cpus (including the outgoing one) from the
+	 * old_domain mask.
+	 */
 	cpumask_and(data->old_domain, data->old_domain, cpu_online_mask);
-	while (!cpumask_empty(data->old_domain)) {
+
+	/*
+	 * If move_in_progress is cleared and the old_domain mask is empty,
+	 * then there is nothing to cleanup. fixup_irqs() will take care of
+	 * the stale vectors on the outgoing cpu.
+	 */
+	if (!data->move_in_progress && cpumask_empty(data->old_domain)) {
 		raw_spin_unlock(&vector_lock);
-		raw_spin_unlock(&desc->lock);
-		cpu_relax();
-		raw_spin_lock(&desc->lock);
-		/*
-		 * Reevaluate apic_chip_data. It might have been cleared after
-		 * we dropped @desc->lock.
-		 */
-		data = apic_chip_data(irqdata);
-		if (!data)
-			return;
-		raw_spin_lock(&vector_lock);
+		return;
 	}
+
+	/*
+	 * 1) The interrupt is in move_in_progress state. That means that we
+	 *    have not seen an interrupt since the io_apic was reprogrammed to
+	 *    the new vector.
+	 *
+	 * 2) The interrupt has fired on the new vector, but the cleanup IPIs
+	 *    have not been processed yet.
+	 */
+	if (data->move_in_progress) {
+		/*
+		 * In theory there is a race:
+		 *
+		 * set_ioapic(new_vector) <-- Interrupt is raised before update
+		 *			      is effective, i.e. it's raised on
+		 *			      the old vector.
+		 *
+		 * So if the target cpu cannot handle that interrupt before
+		 * the old vector is cleaned up, we get a spurious interrupt
+		 * and in the worst case the ioapic irq line becomes stale.
+		 *
+		 * But in case of cpu hotplug this should be a non issue
+		 * because if the affinity update happens right before all
+		 * cpus rendevouz in stop machine, there is no way that the
+		 * interrupt can be blocked on the target cpu because all cpus
+		 * loops first with interrupts enabled in stop machine, so the
+		 * old vector is not yet cleaned up when the interrupt fires.
+		 *
+		 * So the only way to run into this issue is if the delivery
+		 * of the interrupt on the apic/system bus would be delayed
+		 * beyond the point where the target cpu disables interrupts
+		 * in stop machine. I doubt that it can happen, but at least
+		 * there is a theroretical chance. Virtualization might be
+		 * able to expose this, but AFAICT the IOAPIC emulation is not
+		 * as stupid as the real hardware.
+		 *
+		 * Anyway, there is nothing we can do about that at this point
+		 * w/o refactoring the whole fixup_irq() business completely.
+		 * We print at least the irq number and the old vector number,
+		 * so we have the necessary information when a problem in that
+		 * area arises.
+		 */
+		pr_warn("IRQ fixup: irq %d move in progress, old vector %d\n",
+			irqdata->irq, cfg->old_vector);
+	}
+	/*
+	 * If old_domain is not empty, then other cpus still have the irq
+	 * descriptor set in their vector array. Clean it up.
+	 */
+	for_each_cpu(cpu, data->old_domain)
+		per_cpu(vector_irq, cpu)[cfg->old_vector] = VECTOR_UNUSED;
+
+	/* Cleanup the left overs of the (half finished) move */
+	cpumask_clear(data->old_domain);
+	data->move_in_progress = 0;
 	raw_spin_unlock(&vector_lock);
 }
 #endif
diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index 624db00583f4..8f4942e2bcbb 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -792,7 +792,8 @@ static int uv_scir_cpu_notify(struct notifier_block *self, unsigned long action,
 {
 	long cpu = (long)hcpu;
 
-	switch (action) {
+	switch (action & ~CPU_TASKS_FROZEN) {
+	case CPU_DOWN_FAILED:
 	case CPU_ONLINE:
 		uv_heartbeat_enable(cpu);
 		break;
@@ -860,7 +861,7 @@ int uv_set_vga_state(struct pci_dev *pdev, bool decode,
  */
 void uv_cpu_init(void)
 {
-	/* CPU 0 initilization will be done via uv_system_init. */
+	/* CPU 0 initialization will be done via uv_system_init. */
 	if (!uv_blade_info)
 		return;
 
diff --git a/arch/x86/kernel/apm_32.c b/arch/x86/kernel/apm_32.c
index 052c9c3026cc..9307f182fe30 100644
--- a/arch/x86/kernel/apm_32.c
+++ b/arch/x86/kernel/apm_32.c
@@ -1088,7 +1088,7 @@ static int apm_get_battery_status(u_short which, u_short *status,
  *	@device: identity of device
  *	@enable: on/off
  *
- *	Activate or deactive power management on either a specific device
+ *	Activate or deactivate power management on either a specific device
  *	or the entire system (%APM_DEVICE_ALL).
  */
 
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 5026a13356c4..e51021c9207a 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -85,7 +85,7 @@ static void init_amd_k5(struct cpuinfo_x86 *c)
 #ifdef CONFIG_X86_32
 /*
  * General Systems BIOSen alias the cpu frequency registers
- * of the Elan at 0x000df000. Unfortuantly, one of the Linux
+ * of the Elan at 0x000df000. Unfortunately, one of the Linux
  * drivers subsequently pokes it, and changes the CPU speed.
  * Workaround : Remove the unneeded alias.
  */
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 06ad72383b4e..9988caf42161 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -968,7 +968,7 @@ static void identify_cpu(struct cpuinfo_x86 *c)
 	if (this_cpu->c_identify)
 		this_cpu->c_identify(c);
 
-	/* Clear/Set all flags overriden by options, after probe */
+	/* Clear/Set all flags overridden by options, after probe */
 	for (i = 0; i < NCAPINTS; i++) {
 		c->x86_capability[i] &= ~cpu_caps_cleared[i];
 		c->x86_capability[i] |= cpu_caps_set[i];
@@ -1028,7 +1028,7 @@ static void identify_cpu(struct cpuinfo_x86 *c)
 	setup_pku(c);
 
 	/*
-	 * Clear/Set all flags overriden by options, need do it
+	 * Clear/Set all flags overridden by options, need do it
 	 * before following smp all cpus cap AND.
 	 */
 	for (i = 0; i < NCAPINTS; i++) {
diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c
index fcbcb2f678ca..19f57360dfd2 100644
--- a/arch/x86/kernel/cpu/mtrr/generic.c
+++ b/arch/x86/kernel/cpu/mtrr/generic.c
@@ -42,7 +42,7 @@ EXPORT_SYMBOL_GPL(mtrr_state);
  * "BIOS and Kernel Developer's Guide for the AMD Athlon 64 and AMD
  * Opteron Processors" (26094 Rev. 3.30 February 2006), section
  * "13.2.1.2 SYSCFG Register": "The MtrrFixDramModEn bit should be set
- * to 1 during BIOS initalization of the fixed MTRRs, then cleared to
+ * to 1 during BIOS initialization of the fixed MTRRs, then cleared to
  * 0 for operation."
  */
 static inline void k8_check_syscfg_dram_mod_en(void)
diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c
index 21bf92490a7b..8a121991e5ba 100644
--- a/arch/x86/kernel/early_printk.c
+++ b/arch/x86/kernel/early_printk.c
@@ -287,7 +287,7 @@ static __init void early_pci_serial_init(char *s)
 	}
 
 	/*
-	 * Lastly, initalize the hardware
+	 * Lastly, initialize the hardware
 	 */
 	if (*s) {
 		if (strcmp(s, "nocfg") == 0)
diff --git a/arch/x86/kernel/fpu/regset.c b/arch/x86/kernel/fpu/regset.c
index 0bc3490420c5..8bd1c003942a 100644
--- a/arch/x86/kernel/fpu/regset.c
+++ b/arch/x86/kernel/fpu/regset.c
@@ -8,7 +8,7 @@
 /*
  * The xstateregs_active() routine is the same as the regset_fpregs_active() routine,
  * as the "regset->n" for the xstate regset will be updated based on the feature
- * capabilites supported by the xsave.
+ * capabilities supported by the xsave.
  */
 int regset_fpregs_active(struct task_struct *target, const struct user_regset *regset)
 {
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index be0ebbb6d1d1..a1f0e4a5c47e 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -717,7 +717,7 @@ static int hpet_cpuhp_notify(struct notifier_block *n,
 	struct hpet_work_struct work;
 	struct hpet_dev *hdev = per_cpu(cpu_hpet_dev, cpu);
 
-	switch (action & 0xf) {
+	switch (action & ~CPU_TASKS_FROZEN) {
 	case CPU_ONLINE:
 		INIT_DELAYED_WORK_ONSTACK(&work.work, hpet_work);
 		init_completion(&work.complete);
diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c
index 37dae792dbbe..589b3193f102 100644
--- a/arch/x86/kernel/ioport.c
+++ b/arch/x86/kernel/ioport.c
@@ -96,9 +96,14 @@ asmlinkage long sys_ioperm(unsigned long from, unsigned long num, int turn_on)
 SYSCALL_DEFINE1(iopl, unsigned int, level)
 {
 	struct pt_regs *regs = current_pt_regs();
-	unsigned int old = (regs->flags >> 12) & 3;
 	struct thread_struct *t = &current->thread;
 
+	/*
+	 * Careful: the IOPL bits in regs->flags are undefined under Xen PV
+	 * and changing them has no effect.
+	 */
+	unsigned int old = t->iopl >> X86_EFLAGS_IOPL_BIT;
+
 	if (level > 3)
 		return -EINVAL;
 	/* Trying to gain more privileges? */
@@ -106,8 +111,9 @@ SYSCALL_DEFINE1(iopl, unsigned int, level)
 		if (!capable(CAP_SYS_RAWIO))
 			return -EPERM;
 	}
-	regs->flags = (regs->flags & ~X86_EFLAGS_IOPL) | (level << 12);
-	t->iopl = level << 12;
+	regs->flags = (regs->flags & ~X86_EFLAGS_IOPL) |
+		(level << X86_EFLAGS_IOPL_BIT);
+	t->iopl = level << X86_EFLAGS_IOPL_BIT;
 	set_iopl_mask(t->iopl);
 
 	return 0;
diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
index 0f8a6bbaaa44..2af478e3fd4e 100644
--- a/arch/x86/kernel/kexec-bzimage64.c
+++ b/arch/x86/kernel/kexec-bzimage64.c
@@ -271,7 +271,7 @@ static int bzImage64_probe(const char *buf, unsigned long len)
 	int ret = -ENOEXEC;
 	struct setup_header *header;
 
-	/* kernel should be atleast two sectors long */
+	/* kernel should be at least two sectors long */
 	if (len < 2 * 512) {
 		pr_err("File is too short to be a bzImage\n");
 		return ret;
diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
index ed15cd486d06..2da6ee9ae69b 100644
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -609,9 +609,9 @@ static struct notifier_block kgdb_notifier = {
 };
 
 /**
- *	kgdb_arch_init - Perform any architecture specific initalization.
+ *	kgdb_arch_init - Perform any architecture specific initialization.
  *
- *	This function will handle the initalization of any architecture
+ *	This function will handle the initialization of any architecture
  *	specific callbacks.
  */
 int kgdb_arch_init(void)
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index 72cef58693c7..1d39bfbd26bb 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -226,7 +226,7 @@ static void kvm_setup_secondary_clock(void)
  * registered memory location. If the guest happens to shutdown, this memory
  * won't be valid. In cases like kexec, in which you install a new kernel, this
  * means a random memory location will be kept being written. So before any
- * kind of shutdown from our side, we unregister the clock by writting anything
+ * kind of shutdown from our side, we unregister the clock by writing anything
  * that does not have the 'enable' bit set in the msr
  */
 #ifdef CONFIG_KEXEC_CORE
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index dfa2781610e8..6cbab31ac23a 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -48,6 +48,7 @@
 #include <asm/syscalls.h>
 #include <asm/debugreg.h>
 #include <asm/switch_to.h>
+#include <asm/xen/hypervisor.h>
 
 asmlinkage extern void ret_from_fork(void);
 
@@ -413,6 +414,17 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
 		     task_thread_info(prev_p)->flags & _TIF_WORK_CTXSW_PREV))
 		__switch_to_xtra(prev_p, next_p, tss);
 
+#ifdef CONFIG_XEN
+	/*
+	 * On Xen PV, IOPL bits in pt_regs->flags have no effect, and
+	 * current_pt_regs()->flags may not match the current task's
+	 * intended IOPL.  We need to switch it manually.
+	 */
+	if (unlikely(static_cpu_has(X86_FEATURE_XENPV) &&
+		     prev->iopl != next->iopl))
+		xen_set_iopl_mask(next->iopl);
+#endif
+
 	if (static_cpu_has_bug(X86_BUG_SYSRET_SS_ATTRS)) {
 		/*
 		 * AMD CPUs have a misfeature: SYSRET sets the SS selector but
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 643dbdccf4bc..b2c99f811c3f 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -274,11 +274,6 @@ int topology_update_package_map(unsigned int apicid, unsigned int cpu)
 	if (test_and_set_bit(pkg, physical_package_map))
 		goto found;
 
-	if (pkg < __max_logical_packages) {
-		set_bit(pkg, logical_package_map);
-		physical_to_logical_pkg[pkg] = pkg;
-		goto found;
-	}
 	new = find_first_zero_bit(logical_package_map, __max_logical_packages);
 	if (new >= __max_logical_packages) {
 		physical_to_logical_pkg[pkg] = -1;
@@ -317,9 +312,27 @@ static void __init smp_init_package_map(void)
 	/*
 	 * Today neither Intel nor AMD support heterogenous systems. That
 	 * might change in the future....
+	 *
+	 * While ideally we'd want '* smp_num_siblings' in the below @ncpus
+	 * computation, this won't actually work since some Intel BIOSes
+	 * report inconsistent HT data when they disable HT.
+	 *
+	 * In particular, they reduce the APIC-IDs to only include the cores,
+	 * but leave the CPUID topology to say there are (2) siblings.
+	 * This means we don't know how many threads there will be until
+	 * after the APIC enumeration.
+	 *
+	 * By not including this we'll sometimes over-estimate the number of
+	 * logical packages by the amount of !present siblings, but this is
+	 * still better than MAX_LOCAL_APIC.
+	 *
+	 * We use total_cpus not nr_cpu_ids because nr_cpu_ids can be limited
+	 * on the command line leading to a similar issue as the HT disable
+	 * problem because the hyperthreads are usually enumerated after the
+	 * primary cores.
 	 */
-	ncpus = boot_cpu_data.x86_max_cores * smp_num_siblings;
-	__max_logical_packages = DIV_ROUND_UP(nr_cpu_ids, ncpus);
+	ncpus = boot_cpu_data.x86_max_cores;
+	__max_logical_packages = DIV_ROUND_UP(total_cpus, ncpus);
 
 	/*
 	 * Possibly larger than what we need as the number of apic ids per
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 56380440d862..c9c4c7ce3eb2 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -881,7 +881,7 @@ void tsc_restore_sched_clock_state(void)
 	local_irq_save(flags);
 
 	/*
-	 * We're comming out of suspend, there's no concurrency yet; don't
+	 * We're coming out of suspend, there's no concurrency yet; don't
 	 * bother being nice about the RCU stuff, just write to both
 	 * data fields.
 	 */
@@ -1306,11 +1306,15 @@ void __init tsc_init(void)
 unsigned long calibrate_delay_is_known(void)
 {
 	int sibling, cpu = smp_processor_id();
+	struct cpumask *mask = topology_core_cpumask(cpu);
 
 	if (!tsc_disabled && !cpu_has(&cpu_data(cpu), X86_FEATURE_CONSTANT_TSC))
 		return 0;
 
-	sibling = cpumask_any_but(topology_core_cpumask(cpu), cpu);
+	if (!mask)
+		return 0;
+
+	sibling = cpumask_any_but(mask, cpu);
 	if (sibling < nr_cpu_ids)
 		return cpu_data(sibling).loops_per_jiffy;
 	return 0;
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 6bdfbc23ecaa..70e95d097ef1 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -479,7 +479,7 @@ static bool spte_is_locklessly_modifiable(u64 spte)
 static bool spte_has_volatile_bits(u64 spte)
 {
 	/*
-	 * Always atomicly update spte if it can be updated
+	 * Always atomically update spte if it can be updated
 	 * out of mmu-lock, it can ensure dirty bit is not lost,
 	 * also, it can help us to get a stable is_writable_pte()
 	 * to ensure tlb flush is not missed.
@@ -550,7 +550,7 @@ static bool mmu_spte_update(u64 *sptep, u64 new_spte)
 
 	/*
 	 * For the spte updated out of mmu-lock is safe, since
-	 * we always atomicly update it, see the comments in
+	 * we always atomically update it, see the comments in
 	 * spte_has_volatile_bits().
 	 */
 	if (spte_is_locklessly_modifiable(old_spte) &&
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index efc243e4dabf..ee1c8a93871c 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5528,7 +5528,7 @@ static int handle_set_cr4(struct kvm_vcpu *vcpu, unsigned long val)
 		return kvm_set_cr4(vcpu, val);
 }
 
-/* called to set cr0 as approriate for clts instruction exit. */
+/* called to set cr0 as appropriate for clts instruction exit. */
 static void handle_clts(struct kvm_vcpu *vcpu)
 {
 	if (is_guest_mode(vcpu)) {
@@ -7267,7 +7267,7 @@ static int handle_vmwrite(struct kvm_vcpu *vcpu)
 	/* The value to write might be 32 or 64 bits, depending on L1's long
 	 * mode, and eventually we need to write that into a field of several
 	 * possible lengths. The code below first zero-extends the value to 64
-	 * bit (field_value), and then copies only the approriate number of
+	 * bit (field_value), and then copies only the appropriate number of
 	 * bits into the vmcs12 field.
 	 */
 	u64 field_value = 0;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index e260ccbc8f55..742d0f7d3556 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1562,7 +1562,7 @@ static cycle_t read_tsc(void)
 
 	/*
 	 * GCC likes to generate cmov here, but this branch is extremely
-	 * predictable (it's just a funciton of time and the likely is
+	 * predictable (it's just a function of time and the likely is
 	 * very likely) and there's a data dependence, so force GCC
 	 * to generate a branch instead.  I don't barrier() because
 	 * we don't actually need a barrier, and if this function
diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S
index cbb8ee5830ff..2ec0b0abbfaa 100644
--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -1,6 +1,7 @@
 /* Copyright 2002 Andi Kleen */
 
 #include <linux/linkage.h>
+#include <asm/errno.h>
 #include <asm/cpufeatures.h>
 #include <asm/alternative-asm.h>
 
@@ -268,16 +269,16 @@ ENTRY(memcpy_mcsafe)
 	decl %ecx
 	jnz .L_copy_trailing_bytes
 
-	/* Copy successful. Return true */
+	/* Copy successful. Return zero */
 .L_done_memcpy_trap:
 	xorq %rax, %rax
 	ret
 ENDPROC(memcpy_mcsafe)
 
 	.section .fixup, "ax"
-	/* Return false for any failure */
+	/* Return -EFAULT for any failure */
 .L_memcpy_mcsafe_fail:
-	mov	$1, %rax
+	mov	$-EFAULT, %rax
 	ret
 
 	.previous
diff --git a/arch/x86/lib/memset_64.S b/arch/x86/lib/memset_64.S
index c9c81227ea37..e1229ecd2a82 100644
--- a/arch/x86/lib/memset_64.S
+++ b/arch/x86/lib/memset_64.S
@@ -9,7 +9,7 @@
 /*
  * ISO C memset - set a memory block to a byte value. This function uses fast
  * string to get better performance than the original function. The code is
- * simpler and shorter than the orignal function as well.
+ * simpler and shorter than the original function as well.
  *
  * rdi   destination
  * rsi   value (char)
diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c
index a0a0b9861902..80476878eb4c 100644
--- a/arch/x86/mm/mpx.c
+++ b/arch/x86/mm/mpx.c
@@ -728,14 +728,14 @@ static inline unsigned long bd_entry_virt_space(struct mm_struct *mm)
 
 	/*
 	 * This covers 32-bit emulation as well as 32-bit kernels
-	 * running on 64-bit harware.
+	 * running on 64-bit hardware.
 	 */
 	if (!is_64bit_mm(mm))
 		return (4ULL * GB) / MPX_BD_NR_ENTRIES_32;
 
 	/*
 	 * 'x86_virt_bits' returns what the hardware is capable
-	 * of, and returns the full >32-bit adddress space when
+	 * of, and returns the full >32-bit address space when
 	 * running 32-bit kernels on 64-bit hardware.
 	 */
 	virt_space = (1ULL << boot_cpu_data.x86_virt_bits);
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 04e2e7144bee..faec01e7a17d 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -149,7 +149,7 @@ enum {
 	PAT_WT = 4,		/* Write Through */
 	PAT_WP = 5,		/* Write Protected */
 	PAT_WB = 6,		/* Write Back (default) */
-	PAT_UC_MINUS = 7,	/* UC, but can be overriden by MTRR */
+	PAT_UC_MINUS = 7,	/* UC, but can be overridden by MTRR */
 };
 
 #define CM(c) (_PAGE_CACHE_MODE_ ## c)
diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index 1d2e6392f5fa..0e07e0968c3a 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -437,7 +437,8 @@ static int oprofile_cpu_notifier(struct notifier_block *b, unsigned long action,
 				 void *data)
 {
 	int cpu = (unsigned long)data;
-	switch (action) {
+
+	switch (action & ~CPU_TASKS_FROZEN) {
 	case CPU_DOWN_FAILED:
 	case CPU_ONLINE:
 		smp_call_function_single(cpu, nmi_cpu_up, NULL, 0);
diff --git a/arch/x86/platform/intel-mid/device_libs/platform_bma023.c b/arch/x86/platform/intel-mid/device_libs/platform_bma023.c
index 0ae7f2ae2296..c26cf393d35a 100644
--- a/arch/x86/platform/intel-mid/device_libs/platform_bma023.c
+++ b/arch/x86/platform/intel-mid/device_libs/platform_bma023.c
@@ -1,5 +1,5 @@
 /*
- * platform_bma023.c: bma023 platform data initilization file
+ * platform_bma023.c: bma023 platform data initialization file
  *
  * (C) Copyright 2013 Intel Corporation
  *
diff --git a/arch/x86/platform/intel-mid/device_libs/platform_emc1403.c b/arch/x86/platform/intel-mid/device_libs/platform_emc1403.c
index 69a783689d21..c259fb6c8f4f 100644
--- a/arch/x86/platform/intel-mid/device_libs/platform_emc1403.c
+++ b/arch/x86/platform/intel-mid/device_libs/platform_emc1403.c
@@ -1,5 +1,5 @@
 /*
- * platform_emc1403.c: emc1403 platform data initilization file
+ * platform_emc1403.c: emc1403 platform data initialization file
  *
  * (C) Copyright 2013 Intel Corporation
  * Author: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@intel.com>
diff --git a/arch/x86/platform/intel-mid/device_libs/platform_gpio_keys.c b/arch/x86/platform/intel-mid/device_libs/platform_gpio_keys.c
index dccae6b0413f..52534ec29765 100644
--- a/arch/x86/platform/intel-mid/device_libs/platform_gpio_keys.c
+++ b/arch/x86/platform/intel-mid/device_libs/platform_gpio_keys.c
@@ -1,5 +1,5 @@
 /*
- * platform_gpio_keys.c: gpio_keys platform data initilization file
+ * platform_gpio_keys.c: gpio_keys platform data initialization file
  *
  * (C) Copyright 2013 Intel Corporation
  * Author: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@intel.com>
diff --git a/arch/x86/platform/intel-mid/device_libs/platform_lis331.c b/arch/x86/platform/intel-mid/device_libs/platform_lis331.c
index 54226de7541a..a35cf912de43 100644
--- a/arch/x86/platform/intel-mid/device_libs/platform_lis331.c
+++ b/arch/x86/platform/intel-mid/device_libs/platform_lis331.c
@@ -1,5 +1,5 @@
 /*
- * platform_lis331.c:  lis331 platform data initilization file
+ * platform_lis331.c:  lis331 platform data initialization file
  *
  * (C) Copyright 2013 Intel Corporation
  * Author: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@intel.com>
diff --git a/arch/x86/platform/intel-mid/device_libs/platform_max7315.c b/arch/x86/platform/intel-mid/device_libs/platform_max7315.c
index 2c8acbc1e9ad..6e075afa7877 100644
--- a/arch/x86/platform/intel-mid/device_libs/platform_max7315.c
+++ b/arch/x86/platform/intel-mid/device_libs/platform_max7315.c
@@ -1,5 +1,5 @@
 /*
- * platform_max7315.c: max7315 platform data initilization file
+ * platform_max7315.c: max7315 platform data initialization file
  *
  * (C) Copyright 2013 Intel Corporation
  * Author: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@intel.com>
diff --git a/arch/x86/platform/intel-mid/device_libs/platform_mpu3050.c b/arch/x86/platform/intel-mid/device_libs/platform_mpu3050.c
index cfe9a47a1e87..ee22864bbc2f 100644
--- a/arch/x86/platform/intel-mid/device_libs/platform_mpu3050.c
+++ b/arch/x86/platform/intel-mid/device_libs/platform_mpu3050.c
@@ -1,5 +1,5 @@
 /*
- * platform_mpu3050.c: mpu3050 platform data initilization file
+ * platform_mpu3050.c: mpu3050 platform data initialization file
  *
  * (C) Copyright 2013 Intel Corporation
  * Author: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@intel.com>
diff --git a/arch/x86/platform/intel-mid/device_libs/platform_msic.c b/arch/x86/platform/intel-mid/device_libs/platform_msic.c
index 9f4a775a69d6..e421106c11cf 100644
--- a/arch/x86/platform/intel-mid/device_libs/platform_msic.c
+++ b/arch/x86/platform/intel-mid/device_libs/platform_msic.c
@@ -1,5 +1,5 @@
 /*
- * platform_msic.c: MSIC platform data initilization file
+ * platform_msic.c: MSIC platform data initialization file
  *
  * (C) Copyright 2013 Intel Corporation
  * Author: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@intel.com>
diff --git a/arch/x86/platform/intel-mid/device_libs/platform_msic_audio.c b/arch/x86/platform/intel-mid/device_libs/platform_msic_audio.c
index 29629397d2b3..cb3490ecb341 100644
--- a/arch/x86/platform/intel-mid/device_libs/platform_msic_audio.c
+++ b/arch/x86/platform/intel-mid/device_libs/platform_msic_audio.c
@@ -1,5 +1,5 @@
 /*
- * platform_msic_audio.c: MSIC audio platform data initilization file
+ * platform_msic_audio.c: MSIC audio platform data initialization file
  *
  * (C) Copyright 2013 Intel Corporation
  * Author: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@intel.com>
diff --git a/arch/x86/platform/intel-mid/device_libs/platform_msic_battery.c b/arch/x86/platform/intel-mid/device_libs/platform_msic_battery.c
index f446c33df1a8..4f72193939a6 100644
--- a/arch/x86/platform/intel-mid/device_libs/platform_msic_battery.c
+++ b/arch/x86/platform/intel-mid/device_libs/platform_msic_battery.c
@@ -1,5 +1,5 @@
 /*
- * platform_msic_battery.c: MSIC battery platform data initilization file
+ * platform_msic_battery.c: MSIC battery platform data initialization file
  *
  * (C) Copyright 2013 Intel Corporation
  * Author: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@intel.com>
diff --git a/arch/x86/platform/intel-mid/device_libs/platform_msic_gpio.c b/arch/x86/platform/intel-mid/device_libs/platform_msic_gpio.c
index 2a4f7b1dd917..70de5b531ba0 100644
--- a/arch/x86/platform/intel-mid/device_libs/platform_msic_gpio.c
+++ b/arch/x86/platform/intel-mid/device_libs/platform_msic_gpio.c
@@ -1,5 +1,5 @@
 /*
- * platform_msic_gpio.c: MSIC GPIO platform data initilization file
+ * platform_msic_gpio.c: MSIC GPIO platform data initialization file
  *
  * (C) Copyright 2013 Intel Corporation
  * Author: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@intel.com>
diff --git a/arch/x86/platform/intel-mid/device_libs/platform_msic_ocd.c b/arch/x86/platform/intel-mid/device_libs/platform_msic_ocd.c
index 6497111ddb54..3d7c2011b6cf 100644
--- a/arch/x86/platform/intel-mid/device_libs/platform_msic_ocd.c
+++ b/arch/x86/platform/intel-mid/device_libs/platform_msic_ocd.c
@@ -1,5 +1,5 @@
 /*
- * platform_msic_ocd.c: MSIC OCD platform data initilization file
+ * platform_msic_ocd.c: MSIC OCD platform data initialization file
  *
  * (C) Copyright 2013 Intel Corporation
  * Author: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@intel.com>
diff --git a/arch/x86/platform/intel-mid/device_libs/platform_msic_power_btn.c b/arch/x86/platform/intel-mid/device_libs/platform_msic_power_btn.c
index 83a3459bc337..038f618fbc52 100644
--- a/arch/x86/platform/intel-mid/device_libs/platform_msic_power_btn.c
+++ b/arch/x86/platform/intel-mid/device_libs/platform_msic_power_btn.c
@@ -1,5 +1,5 @@
 /*
- * platform_msic_power_btn.c: MSIC power btn platform data initilization file
+ * platform_msic_power_btn.c: MSIC power btn platform data initialization file
  *
  * (C) Copyright 2013 Intel Corporation
  * Author: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@intel.com>
diff --git a/arch/x86/platform/intel-mid/device_libs/platform_msic_thermal.c b/arch/x86/platform/intel-mid/device_libs/platform_msic_thermal.c
index a351878b96bc..114a5755b1e4 100644
--- a/arch/x86/platform/intel-mid/device_libs/platform_msic_thermal.c
+++ b/arch/x86/platform/intel-mid/device_libs/platform_msic_thermal.c
@@ -1,5 +1,5 @@
 /*
- * platform_msic_thermal.c: msic_thermal platform data initilization file
+ * platform_msic_thermal.c: msic_thermal platform data initialization file
  *
  * (C) Copyright 2013 Intel Corporation
  * Author: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@intel.com>
diff --git a/arch/x86/platform/intel-mid/device_libs/platform_pmic_gpio.c b/arch/x86/platform/intel-mid/device_libs/platform_pmic_gpio.c
index 65c2a9a19db4..e30cb62e3300 100644
--- a/arch/x86/platform/intel-mid/device_libs/platform_pmic_gpio.c
+++ b/arch/x86/platform/intel-mid/device_libs/platform_pmic_gpio.c
@@ -1,5 +1,5 @@
 /*
- * platform_pmic_gpio.c: PMIC GPIO platform data initilization file
+ * platform_pmic_gpio.c: PMIC GPIO platform data initialization file
  *
  * (C) Copyright 2013 Intel Corporation
  * Author: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@intel.com>
diff --git a/arch/x86/platform/intel-mid/device_libs/platform_tc35876x.c b/arch/x86/platform/intel-mid/device_libs/platform_tc35876x.c
index 740fc757050c..b1526b95fd43 100644
--- a/arch/x86/platform/intel-mid/device_libs/platform_tc35876x.c
+++ b/arch/x86/platform/intel-mid/device_libs/platform_tc35876x.c
@@ -1,5 +1,5 @@
 /*
- * platform_tc35876x.c: tc35876x platform data initilization file
+ * platform_tc35876x.c: tc35876x platform data initialization file
  *
  * (C) Copyright 2013 Intel Corporation
  * Author: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@intel.com>
diff --git a/arch/x86/platform/intel-mid/device_libs/platform_tca6416.c b/arch/x86/platform/intel-mid/device_libs/platform_tca6416.c
index 33be0b3be6e1..4f41372ce400 100644
--- a/arch/x86/platform/intel-mid/device_libs/platform_tca6416.c
+++ b/arch/x86/platform/intel-mid/device_libs/platform_tca6416.c
@@ -1,5 +1,5 @@
 /*
- * platform_tca6416.c: tca6416 platform data initilization file
+ * platform_tca6416.c: tca6416 platform data initialization file
  *
  * (C) Copyright 2013 Intel Corporation
  * Author: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@intel.com>
diff --git a/arch/x86/purgatory/stack.S b/arch/x86/purgatory/stack.S
index 3cefba1fefc8..50a4147f91fb 100644
--- a/arch/x86/purgatory/stack.S
+++ b/arch/x86/purgatory/stack.S
@@ -8,7 +8,7 @@
  */
 
 	/* A stack for the loaded kernel.
-	 * Seperate and in the data section so it can be prepopulated.
+	 * Separate and in the data section so it can be prepopulated.
 	 */
 	.data
 	.balign 4096
diff --git a/arch/x86/video/fbdev.c b/arch/x86/video/fbdev.c
index d5644bbe8cba..9fd24846d094 100644
--- a/arch/x86/video/fbdev.c
+++ b/arch/x86/video/fbdev.c
@@ -14,26 +14,24 @@
 int fb_is_primary_device(struct fb_info *info)
 {
 	struct device *device = info->device;
-	struct pci_dev *pci_dev = NULL;
 	struct pci_dev *default_device = vga_default_device();
-	struct resource *res = NULL;
+	struct pci_dev *pci_dev;
+	struct resource *res;
 
-	if (device)
-		pci_dev = to_pci_dev(device);
-
-	if (!pci_dev)
+	if (!device || !dev_is_pci(device))
 		return 0;
 
+	pci_dev = to_pci_dev(device);
+
 	if (default_device) {
 		if (pci_dev == default_device)
 			return 1;
-		else
-			return 0;
+		return 0;
 	}
 
-	res = &pci_dev->resource[PCI_ROM_RESOURCE];
+	res = pci_dev->resource + PCI_ROM_RESOURCE;
 
-	if (res && res->flags & IORESOURCE_ROM_SHADOW)
+	if (res->flags & IORESOURCE_ROM_SHADOW)
 		return 1;
 
 	return 0;
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 2379a5a88504..880862c7d9dd 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -962,7 +962,7 @@ static void xen_load_sp0(struct tss_struct *tss,
 	tss->x86_tss.sp0 = thread->sp0;
 }
 
-static void xen_set_iopl_mask(unsigned mask)
+void xen_set_iopl_mask(unsigned mask)
 {
 	struct physdev_set_iopl set_iopl;
 
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index c913ca4f6958..478a2de543a5 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1256,7 +1256,7 @@ static void __init xen_pagetable_cleanhighmap(void)
 	xen_cleanhighmap(addr, addr + size);
 	xen_start_info->pt_base = (unsigned long)__va(__pa(xen_start_info->pt_base));
 #ifdef DEBUG
-	/* This is superflous and is not neccessary, but you know what
+	/* This is superfluous and is not necessary, but you know what
 	 * lets do it. The MODULES_VADDR -> MODULES_END should be clear of
 	 * anything at this stage. */
 	xen_cleanhighmap(MODULES_VADDR, roundup(MODULES_VADDR, PUD_SIZE) - 1);
@@ -1474,7 +1474,7 @@ static void xen_write_cr3(unsigned long cr3)
 /*
  * At the start of the day - when Xen launches a guest, it has already
  * built pagetables for the guest. We diligently look over them
- * in xen_setup_kernel_pagetable and graft as appropiate them in the
+ * in xen_setup_kernel_pagetable and graft as appropriate them in the
  * init_level4_pgt and its friends. Then when we are happy we load
  * the new init_level4_pgt - and continue on.
  *
@@ -2792,7 +2792,7 @@ static int remap_area_mfn_pte_fn(pte_t *ptep, pgtable_t token,
 	struct remap_data *rmd = data;
 	pte_t pte = pte_mkspecial(mfn_pte(*rmd->mfn, rmd->prot));
 
-	/* If we have a contigious range, just update the mfn itself,
+	/* If we have a contiguous range, just update the mfn itself,
 	   else update pointer to be "next mfn". */
 	if (rmd->contiguous)
 		(*rmd->mfn)++;
@@ -2833,7 +2833,7 @@ static int do_remap_gfn(struct vm_area_struct *vma,
 
 	rmd.mfn = gfn;
 	rmd.prot = prot;
-	/* We use the err_ptr to indicate if there we are doing a contigious
+	/* We use the err_ptr to indicate if there we are doing a contiguous
 	 * mapping or a discontigious mapping. */
 	rmd.contiguous = !err_ptr;
 
diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S
index de93b20fa0d2..7f8d8abf4c1a 100644
--- a/arch/x86/xen/xen-head.S
+++ b/arch/x86/xen/xen-head.S
@@ -26,7 +26,7 @@
 		      (1 << XENFEAT_auto_translated_physmap) | \
 		      (1 << XENFEAT_supervisor_mode_kernel) | \
 		      (1 << XENFEAT_hvm_callback_vector))
-/* The XENFEAT_writable_page_tables is not stricly neccessary as we set that
+/* The XENFEAT_writable_page_tables is not stricly necessary as we set that
  * up regardless whether this CONFIG option is enabled or not, but it
  * clarifies what the right flags need to be.
  */
diff --git a/include/linux/nmi.h b/include/linux/nmi.h
index 7ec5b86735f3..4630eeae18e0 100644
--- a/include/linux/nmi.h
+++ b/include/linux/nmi.h
@@ -65,7 +65,6 @@ static inline bool trigger_allbutself_cpu_backtrace(void)
 #endif
 
 #ifdef CONFIG_LOCKUP_DETECTOR
-int hw_nmi_is_cpu_stuck(struct pt_regs *);
 u64 hw_nmi_get_sample_period(int watchdog_thresh);
 extern int nmi_watchdog_enabled;
 extern int soft_watchdog_enabled;
diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile
index d5ce7d7aae3e..b47ebd170690 100644
--- a/tools/testing/selftests/x86/Makefile
+++ b/tools/testing/selftests/x86/Makefile
@@ -5,7 +5,7 @@ include ../lib.mk
 .PHONY: all all_32 all_64 warn_32bit_failure clean
 
 TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs syscall_nt ptrace_syscall \
-			check_initial_reg_state sigreturn ldt_gdt
+			check_initial_reg_state sigreturn ldt_gdt iopl
 TARGETS_C_32BIT_ONLY := entry_from_vm86 syscall_arg_fault test_syscall_vdso unwind_vdso \
 			test_FCMOV test_FCOMI test_FISTTP \
 			vdso_restorer
diff --git a/tools/testing/selftests/x86/iopl.c b/tools/testing/selftests/x86/iopl.c
new file mode 100644
index 000000000000..c496ca97bc18
--- /dev/null
+++ b/tools/testing/selftests/x86/iopl.c
@@ -0,0 +1,135 @@
+/*
+ * iopl.c - Test case for a Linux on Xen 64-bit bug
+ * Copyright (c) 2015 Andrew Lutomirski
+ */
+
+#define _GNU_SOURCE
+#include <err.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <signal.h>
+#include <setjmp.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <stdbool.h>
+#include <sched.h>
+#include <sys/io.h>
+
+static int nerrs = 0;
+
+static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *),
+		       int flags)
+{
+	struct sigaction sa;
+	memset(&sa, 0, sizeof(sa));
+	sa.sa_sigaction = handler;
+	sa.sa_flags = SA_SIGINFO | flags;
+	sigemptyset(&sa.sa_mask);
+	if (sigaction(sig, &sa, 0))
+		err(1, "sigaction");
+
+}
+
+static jmp_buf jmpbuf;
+
+static void sigsegv(int sig, siginfo_t *si, void *ctx_void)
+{
+	siglongjmp(jmpbuf, 1);
+}
+
+int main(void)
+{
+	cpu_set_t cpuset;
+	CPU_ZERO(&cpuset);
+	CPU_SET(0, &cpuset);
+	if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0)
+		err(1, "sched_setaffinity to CPU 0");
+
+	/* Probe for iopl support.  Note that iopl(0) works even as nonroot. */
+	if (iopl(3) != 0) {
+		printf("[OK]\tiopl(3) failed (%d) -- try running as root\n",
+		       errno);
+		return 0;
+	}
+
+	/* Restore our original state prior to starting the test. */
+	if (iopl(0) != 0)
+		err(1, "iopl(0)");
+
+	pid_t child = fork();
+	if (child == -1)
+		err(1, "fork");
+
+	if (child == 0) {
+		printf("\tchild: set IOPL to 3\n");
+		if (iopl(3) != 0)
+			err(1, "iopl");
+
+		printf("[RUN]\tchild: write to 0x80\n");
+		asm volatile ("outb %%al, $0x80" : : "a" (0));
+
+		return 0;
+	} else {
+		int status;
+		if (waitpid(child, &status, 0) != child ||
+		    !WIFEXITED(status)) {
+			printf("[FAIL]\tChild died\n");
+			nerrs++;
+		} else if (WEXITSTATUS(status) != 0) {
+			printf("[FAIL]\tChild failed\n");
+			nerrs++;
+		} else {
+			printf("[OK]\tChild succeeded\n");
+		}
+	}
+
+	printf("[RUN]\tparent: write to 0x80 (should fail)\n");
+
+	sethandler(SIGSEGV, sigsegv, 0);
+	if (sigsetjmp(jmpbuf, 1) != 0) {
+		printf("[OK]\twrite was denied\n");
+	} else {
+		asm volatile ("outb %%al, $0x80" : : "a" (0));
+		printf("[FAIL]\twrite was allowed\n");
+		nerrs++;
+	}
+
+	/* Test the capability checks. */
+	printf("\tiopl(3)\n");
+	if (iopl(3) != 0)
+		err(1, "iopl(3)");
+
+	printf("\tDrop privileges\n");
+	if (setresuid(1, 1, 1) != 0) {
+		printf("[WARN]\tDropping privileges failed\n");
+		goto done;
+	}
+
+	printf("[RUN]\tiopl(3) unprivileged but with IOPL==3\n");
+	if (iopl(3) != 0) {
+		printf("[FAIL]\tiopl(3) should work if iopl is already 3 even if unprivileged\n");
+		nerrs++;
+	}
+
+	printf("[RUN]\tiopl(0) unprivileged\n");
+	if (iopl(0) != 0) {
+		printf("[FAIL]\tiopl(0) should work if iopl is already 3 even if unprivileged\n");
+		nerrs++;
+	}
+
+	printf("[RUN]\tiopl(3) unprivileged\n");
+	if (iopl(3) == 0) {
+		printf("[FAIL]\tiopl(3) should fail if when unprivileged if iopl==0\n");
+		nerrs++;
+	} else {
+		printf("[OK]\tFailed as expected\n");
+	}
+
+done:
+	return nerrs ? 1 : 0;
+}
+