3 files changed, 38 insertions, 6 deletions

diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index cf9750004a08..68894fdc034b 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -112,8 +112,10 @@ static void nmi_cpu_start(void *dummy)
 static int nmi_start(void)
 {
         get_online_cpus();
-        on_each_cpu(nmi_cpu_start, NULL, 1);
         ctr_running = 1;
+        /* make ctr_running visible to the nmi handler: */
+        smp_mb();
+        on_each_cpu(nmi_cpu_start, NULL, 1);
         put_online_cpus();
         return 0;
 }
@@ -504,15 +506,18 @@ static int nmi_setup(void)
 
         nmi_enabled = 0;
         ctr_running = 0;
-        barrier();
+        /* make variables visible to the nmi handler: */
+        smp_mb();
         err = register_die_notifier(&profile_exceptions_nb);
         if (err)
                 goto fail;
 
         get_online_cpus();
         register_cpu_notifier(&oprofile_cpu_nb);
-        on_each_cpu(nmi_cpu_setup, NULL, 1);
         nmi_enabled = 1;
+        /* make nmi_enabled visible to the nmi handler: */
+        smp_mb();
+        on_each_cpu(nmi_cpu_setup, NULL, 1);
         put_online_cpus();
 
         return 0;
@@ -531,7 +536,8 @@ static void nmi_shutdown(void)
         nmi_enabled = 0;
         ctr_running = 0;
         put_online_cpus();
-        barrier();
+        /* make variables visible to the nmi handler: */
+        smp_mb();
         unregister_die_notifier(&profile_exceptions_nb);
         msrs = &get_cpu_var(cpu_msrs);
         model->shutdown(msrs);
diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index 8214724ce54d..fe008309ffec 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -333,6 +333,7 @@ static int xen_register_pirq(u32 gsi, int triggering)
         struct physdev_map_pirq map_irq;
         int shareable = 0;
         char *name;
+        bool gsi_override = false;
 
         if (!xen_pv_domain())
                 return -1;
@@ -349,11 +350,32 @@ static int xen_register_pirq(u32 gsi, int triggering)
         if (pirq < 0)
                 goto out;
 
-        irq = xen_bind_pirq_gsi_to_irq(gsi, pirq, shareable, name);
+        /* Before we bind the GSI to a Linux IRQ, check whether
+         * we need to override it with bus_irq (IRQ) value. Usually for
+         * IRQs below IRQ_LEGACY_IRQ this holds IRQ == GSI, as so:
+         *  ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 low level)
+         * but there are oddballs where the IRQ != GSI:
+         *  ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 20 low level)
+         * which ends up being: gsi_to_irq[9] == 20
+         * (which is what acpi_gsi_to_irq ends up calling when starting the
+         * the ACPI interpreter and keels over since IRQ 9 has not been
+         * setup as we had setup IRQ 20 for it).
+         */
+        if (gsi == acpi_sci_override_gsi) {
+                /* Check whether the GSI != IRQ */
+                acpi_gsi_to_irq(gsi, &irq);
+                if (irq != gsi)
+                        /* Bugger, we MUST have that IRQ. */
+                        gsi_override = true;
+        }
+        if (gsi_override)
+                irq = xen_bind_pirq_gsi_to_irq(irq, pirq, shareable, name);
+        else
+                irq = xen_bind_pirq_gsi_to_irq(gsi, pirq, shareable, name);
         if (irq < 0)
                 goto out;
 
-        printk(KERN_DEBUG "xen: --> pirq=%d -> irq=%d\n", pirq, irq);
+        printk(KERN_DEBUG "xen: --> pirq=%d -> irq=%d (gsi=%d)\n", pirq, irq, gsi);
 
         map_irq.domid = DOMID_SELF;
         map_irq.type = MAP_PIRQ_TYPE_GSI;
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 673e968df3cf..0ccccb67a993 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1232,7 +1232,11 @@ static void xen_flush_tlb_others(const struct cpumask *cpus,
 {
         struct {
                 struct mmuext_op op;
+#ifdef CONFIG_SMP
                 DECLARE_BITMAP(mask, num_processors);
+#else
+                DECLARE_BITMAP(mask, NR_CPUS);
+#endif
         } *args;
         struct multicall_space mcs;