6 files changed, 80 insertions, 40 deletions

diff --git a/arch/x86/kernel/io_apic.c b/arch/x86/kernel/io_apic.c
index 1fec0f9b150..9043251210f 100644
--- a/arch/x86/kernel/io_apic.c
+++ b/arch/x86/kernel/io_apic.c
@@ -3755,7 +3755,9 @@ int acpi_get_override_irq(int bus_irq, int *trigger, int *polarity)
 void __init setup_ioapic_dest(void)
 {
         int pin, ioapic, irq, irq_entry;
+        struct irq_desc *desc;
         struct irq_cfg *cfg;
+        cpumask_t mask;
 
         if (skip_ioapic_setup == 1)
                 return;
@@ -3772,16 +3774,30 @@ void __init setup_ioapic_dest(void)
                          * cpu is online.
                          */
                         cfg = irq_cfg(irq);
-                        if (!cfg->vector)
+                        if (!cfg->vector) {
                                 setup_IO_APIC_irq(ioapic, pin, irq,
                                                   irq_trigger(irq_entry),
                                                   irq_polarity(irq_entry));
+                                continue;
+
+                        }
+
+                        /*
+                         * Honour affinities which have been set in early boot
+                         */
+                        desc = irq_to_desc(irq);
+                        if (desc->status &
+                            (IRQ_NO_BALANCING | IRQ_AFFINITY_SET))
+                                mask = desc->affinity;
+                        else
+                                mask = TARGET_CPUS;
+
 #ifdef CONFIG_INTR_REMAP
-                        else if (intr_remapping_enabled)
-                                set_ir_ioapic_affinity_irq(irq, TARGET_CPUS);
-#endif
+                        if (intr_remapping_enabled)
+                                set_ir_ioapic_affinity_irq(irq, mask);
                         else
-                                set_ioapic_affinity_irq(irq, TARGET_CPUS);
+#endif
+                                set_ioapic_affinity_irq(irq, mask);
                 }
 
         }
diff --git a/include/linux/irq.h b/include/linux/irq.h
index d058c57be02..3dddfa703eb 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -63,7 +63,8 @@ typedef	void (*irq_flow_handler_t)(unsigned int irq,
 #define IRQ_MOVE_PENDING        0x00200000      /* need to re-target IRQ destination */
 #define IRQ_NO_BALANCING        0x00400000      /* IRQ is excluded from balancing */
 #define IRQ_SPURIOUS_DISABLED   0x00800000      /* IRQ was disabled by the spurious trap */
-#define IRQ_MOVE_PCNTXT 0x01000000      /* IRQ migration from process context */
+#define IRQ_MOVE_PCNTXT         0x01000000      /* IRQ migration from process context */
+#define IRQ_AFFINITY_SET        0x02000000      /* IRQ affinity was set from userspace*/
 
 #ifdef CONFIG_IRQ_PER_CPU
 # define CHECK_IRQ_PER_CPU(var) ((var) & IRQ_PER_CPU)
@@ -130,7 +131,7 @@ struct irq_chip {
 
 /**
  * struct irq_desc - interrupt descriptor
- *
+ * @irq:                interrupt number for this descriptor
  * @handle_irq:         highlevel irq-events handler [if NULL, __do_IRQ()]
  * @chip:               low level interrupt hardware access
  * @msi_desc:           MSI descriptor
@@ -149,7 +150,6 @@ struct irq_chip {
  * @cpu:                cpu index useful for balancing
  * @pending_mask:       pending rebalanced interrupts
  * @dir:                /proc/irq/ procfs entry
- * @affinity_entry:     /proc/irq/smp_affinity procfs entry on SMP
  * @name:               flow handler name for /proc/interrupts output
  */
 struct irq_desc {
@@ -210,7 +210,6 @@ extern int setup_irq(unsigned int irq, struct irqaction *new);
 
 #ifdef CONFIG_GENERIC_PENDING_IRQ
 
-void set_pending_irq(unsigned int irq, cpumask_t mask);
 void move_native_irq(int irq);
 void move_masked_irq(int irq);
 
@@ -228,10 +227,6 @@ static inline void move_masked_irq(int irq)
 {
 }
 
-static inline void set_pending_irq(unsigned int irq, cpumask_t mask)
-{
-}
-
 #endif /* CONFIG_GENERIC_PENDING_IRQ */
 
 #else /* CONFIG_SMP */
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index c9767e64198..64c1c7253da 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -25,6 +25,8 @@ static inline void unregister_handler_proc(unsigned int irq,
                                            struct irqaction *action) { }
 #endif
 
+extern int irq_select_affinity_usr(unsigned int irq);
+
 /*
  * Debugging printout:
  */
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index c498a1b8c62..801addda3c4 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -82,24 +82,27 @@ int irq_can_set_affinity(unsigned int irq)
 int irq_set_affinity(unsigned int irq, cpumask_t cpumask)
 {
         struct irq_desc *desc = irq_to_desc(irq);
+        unsigned long flags;
 
         if (!desc->chip->set_affinity)
                 return -EINVAL;
 
+        spin_lock_irqsave(&desc->lock, flags);
+
 #ifdef CONFIG_GENERIC_PENDING_IRQ
         if (desc->status & IRQ_MOVE_PCNTXT || desc->status & IRQ_DISABLED) {
-                unsigned long flags;
-
-                spin_lock_irqsave(&desc->lock, flags);
                 desc->affinity = cpumask;
                 desc->chip->set_affinity(irq, cpumask);
-                spin_unlock_irqrestore(&desc->lock, flags);
-        } else
-                set_pending_irq(irq, cpumask);
+        } else {
+                desc->status |= IRQ_MOVE_PENDING;
+                desc->pending_mask = cpumask;
+        }
 #else
         desc->affinity = cpumask;
         desc->chip->set_affinity(irq, cpumask);
 #endif
+        desc->status |= IRQ_AFFINITY_SET;
+        spin_unlock_irqrestore(&desc->lock, flags);
         return 0;
 }
 
@@ -107,24 +110,59 @@ int irq_set_affinity(unsigned int irq, cpumask_t cpumask)
 /*
  * Generic version of the affinity autoselector.
  */
-int irq_select_affinity(unsigned int irq)
+int do_irq_select_affinity(unsigned int irq, struct irq_desc *desc)
 {
         cpumask_t mask;
-        struct irq_desc *desc;
 
         if (!irq_can_set_affinity(irq))
                 return 0;
 
         cpus_and(mask, cpu_online_map, irq_default_affinity);
 
-        desc = irq_to_desc(irq);
+        /*
+         * Preserve an userspace affinity setup, but make sure that
+         * one of the targets is online.
+         */
+        if (desc->status & (IRQ_AFFINITY_SET | IRQ_NO_BALANCING)) {
+                if (cpus_intersects(desc->affinity, cpu_online_map))
+                        mask = desc->affinity;
+                else
+                        desc->status &= ~IRQ_AFFINITY_SET;
+        }
+
         desc->affinity = mask;
         desc->chip->set_affinity(irq, mask);
 
         return 0;
 }
+#else
+static inline int do_irq_select_affinity(unsigned int irq, struct irq_desc *d)
+{
+        return irq_select_affinity(irq);
+}
 #endif
 
+/*
+ * Called when affinity is set via /proc/irq
+ */
+int irq_select_affinity_usr(unsigned int irq)
+{
+        struct irq_desc *desc = irq_to_desc(irq);
+        unsigned long flags;
+        int ret;
+
+        spin_lock_irqsave(&desc->lock, flags);
+        ret = do_irq_select_affinity(irq, desc);
+        spin_unlock_irqrestore(&desc->lock, flags);
+
+        return ret;
+}
+
+#else
+static inline int do_irq_select_affinity(int irq, struct irq_desc *desc)
+{
+        return 0;
+}
 #endif
 
 /**
@@ -327,7 +365,7 @@ int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
                  * IRQF_TRIGGER_* but the PIC does not support multiple
                  * flow-types?
                  */
-                pr_warning("No set_type function for IRQ %d (%s)\n", irq,
+                pr_debug("No set_type function for IRQ %d (%s)\n", irq,
                                 chip ? (chip->name ? : "unknown") : "unknown");
                 return 0;
         }
@@ -445,8 +483,12 @@ __setup_irq(unsigned int irq, struct irq_desc * desc, struct irqaction *new)
                         /* Undo nested disables: */
                         desc->depth = 1;
 
+                /* Exclude IRQ from balancing if requested */
+                if (new->flags & IRQF_NOBALANCING)
+                        desc->status |= IRQ_NO_BALANCING;
+
                 /* Set default affinity mask once everything is setup */
-                irq_select_affinity(irq);
+                do_irq_select_affinity(irq, desc);
 
         } else if ((new->flags & IRQF_TRIGGER_MASK)
                         && (new->flags & IRQF_TRIGGER_MASK)
@@ -459,10 +501,6 @@ __setup_irq(unsigned int irq, struct irq_desc * desc, struct irqaction *new)
 
         *p = new;
 
-        /* Exclude IRQ from balancing */
-        if (new->flags & IRQF_NOBALANCING)
-                desc->status |= IRQ_NO_BALANCING;
-
         /* Reset broken irq detection when installing new handler */
         desc->irq_count = 0;
         desc->irqs_unhandled = 0;
diff --git a/kernel/irq/migration.c b/kernel/irq/migration.c
index 90b920d3f52..9db681d9581 100644
--- a/kernel/irq/migration.c
+++ b/kernel/irq/migration.c
@@ -1,17 +1,6 @@
 
 #include <linux/irq.h>
 
-void set_pending_irq(unsigned int irq, cpumask_t mask)
-{
-        struct irq_desc *desc = irq_to_desc(irq);
-        unsigned long flags;
-
-        spin_lock_irqsave(&desc->lock, flags);
-        desc->status |= IRQ_MOVE_PENDING;
-        desc->pending_mask = mask;
-        spin_unlock_irqrestore(&desc->lock, flags);
-}
-
 void move_masked_irq(int irq)
 {
         struct irq_desc *desc = irq_to_desc(irq);
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index 4d161c70ba5..d257e7d6a8a 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -62,7 +62,7 @@ static ssize_t irq_affinity_proc_write(struct file *file,
         if (!cpus_intersects(new_value, cpu_online_map))
                 /* Special case for empty set - allow the architecture
                    code to set default SMP affinity. */
-                return irq_select_affinity(irq) ? -EINVAL : count;
+                return irq_select_affinity_usr(irq) ? -EINVAL : count;
 
         irq_set_affinity(irq, new_value);