Merge branch 'x86-pat-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-pat-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, pat: Fix cacheflush address in change_page_attr_set_clr()
  mm: remove !NUMA condition from PAGEFLAGS_EXTENDED condition set
  x86: Fix earlyprintk=dbgp for machines without NX
  x86, pat: Sanity check remap_pfn_range for RAM region
  x86, pat: Lookup the protection from memtype list on vm_insert_pfn()
  x86, pat: Add lookup_memtype to get the current memtype of a paddr
  x86, pat: Use page flags to track memtypes of RAM pages
  x86, pat: Generalize the use of page flag PG_uncached
  x86, pat: Add rbtree to do quick lookup in memtype tracking
  x86, pat: Add PAT reserve free to io_mapping* APIs
  x86, pat: New i/f for driver to request memtype for IO regions
  x86, pat: ioremap to follow same PAT restrictions as other PAT users
  x86, pat: Keep identity maps consistent with mmaps even when pat_disabled
  x86, mtrr: make mtrr_aps_delayed_init static bool
  x86, pat/mtrr: Rendezvous all the cpus for MTRR/PAT init
  generic-ipi: Allow cpus not yet online to call smp_call_function with irqs disabled
  x86: Fix an incorrect argument of reserve_bootmem()
  x86: Fix system crash when loading with "reservetop" parameter

kernel/cpu.c

@@ -414,6 +414,14 @@ int disable_nonboot_cpus(void)
 	return error;
 }
 
+void __weak arch_enable_nonboot_cpus_begin(void)
+{
+}
+
+void __weak arch_enable_nonboot_cpus_end(void)
+{
+}
+
 void __ref enable_nonboot_cpus(void)
 {
 	int cpu, error;
@@ -425,6 +433,9 @@ void __ref enable_nonboot_cpus(void)
 		goto out;
 
 	printk("Enabling non-boot CPUs ...\n");
+
+	arch_enable_nonboot_cpus_begin();
+
 	for_each_cpu(cpu, frozen_cpus) {
 		error = _cpu_up(cpu, 1);
 		if (!error) {
@@ -433,6 +444,9 @@ void __ref enable_nonboot_cpus(void)
 		}
 		printk(KERN_WARNING "Error taking CPU%d up: %d\n", cpu, error);
 	}
+
+	arch_enable_nonboot_cpus_end();
+
 	cpumask_clear(frozen_cpus);
 out:
 	cpu_maps_update_done();

kernel/smp.c

@@ -176,6 +176,11 @@ void generic_smp_call_function_interrupt(void)
 	struct call_function_data *data;
 	int cpu = get_cpu();
 
+	/*
+	 * Shouldn't receive this interrupt on a cpu that is not yet online.
+	 */
+	WARN_ON_ONCE(!cpu_online(cpu));
+
 	/*
 	 * Ensure entry is visible on call_function_queue after we have
 	 * entered the IPI. See comment in smp_call_function_many.
@@ -230,6 +235,11 @@ void generic_smp_call_function_single_interrupt(void)
 	unsigned int data_flags;
 	LIST_HEAD(list);
 
+	/*
+	 * Shouldn't receive this interrupt on a cpu that is not yet online.
+	 */
+	WARN_ON_ONCE(!cpu_online(smp_processor_id()));
+
 	spin_lock(&q->lock);
 	list_replace_init(&q->list, &list);
 	spin_unlock(&q->lock);
@@ -285,8 +295,14 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
 	 */
 	this_cpu = get_cpu();
 
-	/* Can deadlock when called with interrupts disabled */
-	WARN_ON_ONCE(irqs_disabled() && !oops_in_progress);
+	/*
+	 * Can deadlock when called with interrupts disabled.
+	 * We allow cpu's that are not yet online though, as no one else can
+	 * send smp call function interrupt to this cpu and as such deadlocks
+	 * can't happen.
+	 */
+	WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled()
+		     && !oops_in_progress);
 
 	if (cpu == this_cpu) {
 		local_irq_save(flags);
@@ -329,8 +345,14 @@ void __smp_call_function_single(int cpu, struct call_single_data *data,
 {
 	csd_lock(data);
 
-	/* Can deadlock when called with interrupts disabled */
-	WARN_ON_ONCE(wait && irqs_disabled() && !oops_in_progress);
+	/*
+	 * Can deadlock when called with interrupts disabled.
+	 * We allow cpu's that are not yet online though, as no one else can
+	 * send smp call function interrupt to this cpu and as such deadlocks
+	 * can't happen.
+	 */
+	WARN_ON_ONCE(cpu_online(smp_processor_id()) && wait && irqs_disabled()
+		     && !oops_in_progress);
 
 	generic_exec_single(cpu, data, wait);
 }
@@ -365,8 +387,14 @@ void smp_call_function_many(const struct cpumask *mask,
 	unsigned long flags;
 	int cpu, next_cpu, this_cpu = smp_processor_id();
 
-	/* Can deadlock when called with interrupts disabled */
-	WARN_ON_ONCE(irqs_disabled() && !oops_in_progress);
+	/*
+	 * Can deadlock when called with interrupts disabled.
+	 * We allow cpu's that are not yet online though, as no one else can
+	 * send smp call function interrupt to this cpu and as such deadlocks
+	 * can't happen.
+	 */
+	WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled()
+		     && !oops_in_progress);
 
 	/* So, what's a CPU they want? Ignoring this one. */
 	cpu = cpumask_first_and(mask, cpu_online_mask);