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

2 files changed, 48 insertions, 6 deletions

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 67a60076dd7..6ba0f1ecb21 100644
--- a/kernel/cpu.c
+++ b/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();
diff --git a/kernel/smp.c b/kernel/smp.c
index 94188b8ecc3..8e218500ab1 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -177,6 +177,11 @@ void generic_smp_call_function_interrupt(void)
         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.
          * If we don't have this, then we may miss an entry on the list
@@ -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);