5 files changed, 302 insertions, 22 deletions

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index dc5114b4c16c..f7c543a801d9 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -26,7 +26,7 @@
 int irq_set_chip(unsigned int irq, struct irq_chip *chip)
 {
         unsigned long flags;
-        struct irq_desc *desc = irq_get_desc_lock(irq, &flags);
+        struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
 
         if (!desc)
                 return -EINVAL;
@@ -54,7 +54,7 @@ EXPORT_SYMBOL(irq_set_chip);
 int irq_set_irq_type(unsigned int irq, unsigned int type)
 {
         unsigned long flags;
-        struct irq_desc *desc = irq_get_desc_buslock(irq, &flags);
+        struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
         int ret = 0;
 
         if (!desc)
@@ -78,7 +78,7 @@ EXPORT_SYMBOL(irq_set_irq_type);
 int irq_set_handler_data(unsigned int irq, void *data)
 {
         unsigned long flags;
-        struct irq_desc *desc = irq_get_desc_lock(irq, &flags);
+        struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
 
         if (!desc)
                 return -EINVAL;
@@ -98,7 +98,7 @@ EXPORT_SYMBOL(irq_set_handler_data);
 int irq_set_msi_desc(unsigned int irq, struct msi_desc *entry)
 {
         unsigned long flags;
-        struct irq_desc *desc = irq_get_desc_lock(irq, &flags);
+        struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
 
         if (!desc)
                 return -EINVAL;
@@ -119,7 +119,7 @@ int irq_set_msi_desc(unsigned int irq, struct msi_desc *entry)
 int irq_set_chip_data(unsigned int irq, void *data)
 {
         unsigned long flags;
-        struct irq_desc *desc = irq_get_desc_lock(irq, &flags);
+        struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
 
         if (!desc)
                 return -EINVAL;
@@ -204,6 +204,24 @@ void irq_disable(struct irq_desc *desc)
         }
 }
 
+void irq_percpu_enable(struct irq_desc *desc, unsigned int cpu)
+{
+        if (desc->irq_data.chip->irq_enable)
+                desc->irq_data.chip->irq_enable(&desc->irq_data);
+        else
+                desc->irq_data.chip->irq_unmask(&desc->irq_data);
+        cpumask_set_cpu(cpu, desc->percpu_enabled);
+}
+
+void irq_percpu_disable(struct irq_desc *desc, unsigned int cpu)
+{
+        if (desc->irq_data.chip->irq_disable)
+                desc->irq_data.chip->irq_disable(&desc->irq_data);
+        else
+                desc->irq_data.chip->irq_mask(&desc->irq_data);
+        cpumask_clear_cpu(cpu, desc->percpu_enabled);
+}
+
 static inline void mask_ack_irq(struct irq_desc *desc)
 {
         if (desc->irq_data.chip->irq_mask_ack)
@@ -544,12 +562,44 @@ handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
                 chip->irq_eoi(&desc->irq_data);
 }
 
+/**
+ * handle_percpu_devid_irq - Per CPU local irq handler with per cpu dev ids
+ * @irq:        the interrupt number
+ * @desc:       the interrupt description structure for this irq
+ *
+ * Per CPU interrupts on SMP machines without locking requirements. Same as
+ * handle_percpu_irq() above but with the following extras:
+ *
+ * action->percpu_dev_id is a pointer to percpu variables which
+ * contain the real device id for the cpu on which this handler is
+ * called
+ */
+void handle_percpu_devid_irq(unsigned int irq, struct irq_desc *desc)
+{
+        struct irq_chip *chip = irq_desc_get_chip(desc);
+        struct irqaction *action = desc->action;
+        void *dev_id = __this_cpu_ptr(action->percpu_dev_id);
+        irqreturn_t res;
+
+        kstat_incr_irqs_this_cpu(irq, desc);
+
+        if (chip->irq_ack)
+                chip->irq_ack(&desc->irq_data);
+
+        trace_irq_handler_entry(irq, action);
+        res = action->handler(irq, dev_id);
+        trace_irq_handler_exit(irq, action, res);
+
+        if (chip->irq_eoi)
+                chip->irq_eoi(&desc->irq_data);
+}
+
 void
 __irq_set_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
                   const char *name)
 {
         unsigned long flags;
-        struct irq_desc *desc = irq_get_desc_buslock(irq, &flags);
+        struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, 0);
 
         if (!desc)
                 return;
@@ -593,7 +643,7 @@ irq_set_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
 void irq_modify_status(unsigned int irq, unsigned long clr, unsigned long set)
 {
         unsigned long flags;
-        struct irq_desc *desc = irq_get_desc_lock(irq, &flags);
+        struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
 
         if (!desc)
                 return;
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index 6546431447d7..a73dd6c7372d 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -71,6 +71,8 @@ extern int irq_startup(struct irq_desc *desc);
 extern void irq_shutdown(struct irq_desc *desc);
 extern void irq_enable(struct irq_desc *desc);
 extern void irq_disable(struct irq_desc *desc);
+extern void irq_percpu_enable(struct irq_desc *desc, unsigned int cpu);
+extern void irq_percpu_disable(struct irq_desc *desc, unsigned int cpu);
 extern void mask_irq(struct irq_desc *desc);
 extern void unmask_irq(struct irq_desc *desc);
 
@@ -114,14 +116,21 @@ static inline void chip_bus_sync_unlock(struct irq_desc *desc)
                 desc->irq_data.chip->irq_bus_sync_unlock(&desc->irq_data);
 }
 
+#define _IRQ_DESC_CHECK         (1 << 0)
+#define _IRQ_DESC_PERCPU        (1 << 1)
+
+#define IRQ_GET_DESC_CHECK_GLOBAL       (_IRQ_DESC_CHECK)
+#define IRQ_GET_DESC_CHECK_PERCPU       (_IRQ_DESC_CHECK | _IRQ_DESC_PERCPU)
+
 struct irq_desc *
-__irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus);
+__irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
+                    unsigned int check);
 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus);
 
 static inline struct irq_desc *
-irq_get_desc_buslock(unsigned int irq, unsigned long *flags)
+irq_get_desc_buslock(unsigned int irq, unsigned long *flags, unsigned int check)
 {
-        return __irq_get_desc_lock(irq, flags, true);
+        return __irq_get_desc_lock(irq, flags, true, check);
 }
 
 static inline void
@@ -131,9 +140,9 @@ irq_put_desc_busunlock(struct irq_desc *desc, unsigned long flags)
 }
 
 static inline struct irq_desc *
-irq_get_desc_lock(unsigned int irq, unsigned long *flags)
+irq_get_desc_lock(unsigned int irq, unsigned long *flags, unsigned int check)
 {
-        return __irq_get_desc_lock(irq, flags, false);
+        return __irq_get_desc_lock(irq, flags, false, check);
 }
 
 static inline void
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 039b889ea053..1550e8447a16 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -424,11 +424,22 @@ unsigned int irq_get_next_irq(unsigned int offset)
 }
 
 struct irq_desc *
-__irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus)
+__irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
+                    unsigned int check)
 {
         struct irq_desc *desc = irq_to_desc(irq);
 
         if (desc) {
+                if (check & _IRQ_DESC_CHECK) {
+                        if ((check & _IRQ_DESC_PERCPU) &&
+                            !irq_settings_is_per_cpu_devid(desc))
+                                return NULL;
+
+                        if (!(check & _IRQ_DESC_PERCPU) &&
+                            irq_settings_is_per_cpu_devid(desc))
+                                return NULL;
+                }
+
                 if (bus)
                         chip_bus_lock(desc);
                 raw_spin_lock_irqsave(&desc->lock, *flags);
@@ -443,6 +454,25 @@ void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
                 chip_bus_sync_unlock(desc);
 }
 
+int irq_set_percpu_devid(unsigned int irq)
+{
+        struct irq_desc *desc = irq_to_desc(irq);
+
+        if (!desc)
+                return -EINVAL;
+
+        if (desc->percpu_enabled)
+                return -EINVAL;
+
+        desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
+
+        if (!desc->percpu_enabled)
+                return -ENOMEM;
+
+        irq_set_percpu_devid_flags(irq);
+        return 0;
+}
+
 /**
  * dynamic_irq_cleanup - cleanup a dynamically allocated irq
  * @irq:        irq number to initialize
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 7e1a3ed1e61a..7b4b156d065c 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -195,7 +195,7 @@ int irq_set_affinity(unsigned int irq, const struct cpumask *mask)
 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
 {
         unsigned long flags;
-        struct irq_desc *desc = irq_get_desc_lock(irq, &flags);
+        struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
 
         if (!desc)
                 return -EINVAL;
@@ -356,7 +356,7 @@ void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend)
 static int __disable_irq_nosync(unsigned int irq)
 {
         unsigned long flags;
-        struct irq_desc *desc = irq_get_desc_buslock(irq, &flags);
+        struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
 
         if (!desc)
                 return -EINVAL;
@@ -448,7 +448,7 @@ void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume)
 void enable_irq(unsigned int irq)
 {
         unsigned long flags;
-        struct irq_desc *desc = irq_get_desc_buslock(irq, &flags);
+        struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
 
         if (!desc)
                 return;
@@ -491,7 +491,7 @@ static int set_irq_wake_real(unsigned int irq, unsigned int on)
 int irq_set_irq_wake(unsigned int irq, unsigned int on)
 {
         unsigned long flags;
-        struct irq_desc *desc = irq_get_desc_buslock(irq, &flags);
+        struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
         int ret = 0;
 
         if (!desc)
@@ -532,7 +532,7 @@ EXPORT_SYMBOL(irq_set_irq_wake);
 int can_request_irq(unsigned int irq, unsigned long irqflags)
 {
         unsigned long flags;
-        struct irq_desc *desc = irq_get_desc_lock(irq, &flags);
+        struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
         int canrequest = 0;
 
         if (!desc)
@@ -1121,6 +1121,8 @@ int setup_irq(unsigned int irq, struct irqaction *act)
         int retval;
         struct irq_desc *desc = irq_to_desc(irq);
 
+        if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
+                return -EINVAL;
         chip_bus_lock(desc);
         retval = __setup_irq(irq, desc, act);
         chip_bus_sync_unlock(desc);
@@ -1129,7 +1131,7 @@ int setup_irq(unsigned int irq, struct irqaction *act)
 }
 EXPORT_SYMBOL_GPL(setup_irq);
 
- /*
+/*
  * Internal function to unregister an irqaction - used to free
  * regular and special interrupts that are part of the architecture.
  */
@@ -1227,7 +1229,10 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
  */
 void remove_irq(unsigned int irq, struct irqaction *act)
 {
-        __free_irq(irq, act->dev_id);
+        struct irq_desc *desc = irq_to_desc(irq);
+
+        if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
+            __free_irq(irq, act->dev_id);
 }
 EXPORT_SYMBOL_GPL(remove_irq);
 
@@ -1249,7 +1254,7 @@ void free_irq(unsigned int irq, void *dev_id)
 {
         struct irq_desc *desc = irq_to_desc(irq);
 
-        if (!desc)
+        if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
                 return;
 
 #ifdef CONFIG_SMP
@@ -1327,7 +1332,8 @@ int request_threaded_irq(unsigned int irq, irq_handler_t handler,
         if (!desc)
                 return -EINVAL;
 
-        if (!irq_settings_can_request(desc))
+        if (!irq_settings_can_request(desc) ||
+            WARN_ON(irq_settings_is_per_cpu_devid(desc)))
                 return -EINVAL;
 
         if (!handler) {
@@ -1412,3 +1418,181 @@ int request_any_context_irq(unsigned int irq, irq_handler_t handler,
         return !ret ? IRQC_IS_HARDIRQ : ret;
 }
 EXPORT_SYMBOL_GPL(request_any_context_irq);
+
+void enable_percpu_irq(unsigned int irq)
+{
+        unsigned int cpu = smp_processor_id();
+        unsigned long flags;
+        struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
+
+        if (!desc)
+                return;
+
+        irq_percpu_enable(desc, cpu);
+        irq_put_desc_unlock(desc, flags);
+}
+
+void disable_percpu_irq(unsigned int irq)
+{
+        unsigned int cpu = smp_processor_id();
+        unsigned long flags;
+        struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
+
+        if (!desc)
+                return;
+
+        irq_percpu_disable(desc, cpu);
+        irq_put_desc_unlock(desc, flags);
+}
+
+/*
+ * Internal function to unregister a percpu irqaction.
+ */
+static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
+{
+        struct irq_desc *desc = irq_to_desc(irq);
+        struct irqaction *action;
+        unsigned long flags;
+
+        WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
+
+        if (!desc)
+                return NULL;
+
+        raw_spin_lock_irqsave(&desc->lock, flags);
+
+        action = desc->action;
+        if (!action || action->percpu_dev_id != dev_id) {
+                WARN(1, "Trying to free already-free IRQ %d\n", irq);
+                goto bad;
+        }
+
+        if (!cpumask_empty(desc->percpu_enabled)) {
+                WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
+                     irq, cpumask_first(desc->percpu_enabled));
+                goto bad;
+        }
+
+        /* Found it - now remove it from the list of entries: */
+        desc->action = NULL;
+
+        raw_spin_unlock_irqrestore(&desc->lock, flags);
+
+        unregister_handler_proc(irq, action);
+
+        module_put(desc->owner);
+        return action;
+
+bad:
+        raw_spin_unlock_irqrestore(&desc->lock, flags);
+        return NULL;
+}
+
+/**
+ *      remove_percpu_irq - free a per-cpu interrupt
+ *      @irq: Interrupt line to free
+ *      @act: irqaction for the interrupt
+ *
+ * Used to remove interrupts statically setup by the early boot process.
+ */
+void remove_percpu_irq(unsigned int irq, struct irqaction *act)
+{
+        struct irq_desc *desc = irq_to_desc(irq);
+
+        if (desc && irq_settings_is_per_cpu_devid(desc))
+            __free_percpu_irq(irq, act->percpu_dev_id);
+}
+
+/**
+ *      free_percpu_irq - free an interrupt allocated with request_percpu_irq
+ *      @irq: Interrupt line to free
+ *      @dev_id: Device identity to free
+ *
+ *      Remove a percpu interrupt handler. The handler is removed, but
+ *      the interrupt line is not disabled. This must be done on each
+ *      CPU before calling this function. The function does not return
+ *      until any executing interrupts for this IRQ have completed.
+ *
+ *      This function must not be called from interrupt context.
+ */
+void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
+{
+        struct irq_desc *desc = irq_to_desc(irq);
+
+        if (!desc || !irq_settings_is_per_cpu_devid(desc))
+                return;
+
+        chip_bus_lock(desc);
+        kfree(__free_percpu_irq(irq, dev_id));
+        chip_bus_sync_unlock(desc);
+}
+
+/**
+ *      setup_percpu_irq - setup a per-cpu interrupt
+ *      @irq: Interrupt line to setup
+ *      @act: irqaction for the interrupt
+ *
+ * Used to statically setup per-cpu interrupts in the early boot process.
+ */
+int setup_percpu_irq(unsigned int irq, struct irqaction *act)
+{
+        struct irq_desc *desc = irq_to_desc(irq);
+        int retval;
+
+        if (!desc || !irq_settings_is_per_cpu_devid(desc))
+                return -EINVAL;
+        chip_bus_lock(desc);
+        retval = __setup_irq(irq, desc, act);
+        chip_bus_sync_unlock(desc);
+
+        return retval;
+}
+
+/**
+ *      request_percpu_irq - allocate a percpu interrupt line
+ *      @irq: Interrupt line to allocate
+ *      @handler: Function to be called when the IRQ occurs.
+ *      @devname: An ascii name for the claiming device
+ *      @dev_id: A percpu cookie passed back to the handler function
+ *
+ *      This call allocates interrupt resources, but doesn't
+ *      automatically enable the interrupt. It has to be done on each
+ *      CPU using enable_percpu_irq().
+ *
+ *      Dev_id must be globally unique. It is a per-cpu variable, and
+ *      the handler gets called with the interrupted CPU's instance of
+ *      that variable.
+ */
+int request_percpu_irq(unsigned int irq, irq_handler_t handler,
+                       const char *devname, void __percpu *dev_id)
+{
+        struct irqaction *action;
+        struct irq_desc *desc;
+        int retval;
+
+        if (!dev_id)
+                return -EINVAL;
+
+        desc = irq_to_desc(irq);
+        if (!desc || !irq_settings_can_request(desc) ||
+            !irq_settings_is_per_cpu_devid(desc))
+                return -EINVAL;
+
+        action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
+        if (!action)
+                return -ENOMEM;
+
+        action->handler = handler;
+        action->flags = IRQF_PERCPU;
+        action->name = devname;
+        action->percpu_dev_id = dev_id;
+
+        chip_bus_lock(desc);
+        retval = __setup_irq(irq, desc, action);
+        chip_bus_sync_unlock(desc);
+
+        if (retval)
+                kfree(action);
+
+        return retval;
+}
diff --git a/kernel/irq/settings.h b/kernel/irq/settings.h
index f1667833d444..1162f1030f18 100644
--- a/kernel/irq/settings.h
+++ b/kernel/irq/settings.h
@@ -13,6 +13,7 @@ enum {
         _IRQ_MOVE_PCNTXT        = IRQ_MOVE_PCNTXT,
         _IRQ_NO_BALANCING       = IRQ_NO_BALANCING,
         _IRQ_NESTED_THREAD      = IRQ_NESTED_THREAD,
+        _IRQ_PER_CPU_DEVID      = IRQ_PER_CPU_DEVID,
         _IRQF_MODIFY_MASK       = IRQF_MODIFY_MASK,
 };
 
@@ -24,6 +25,7 @@ enum {
 #define IRQ_NOTHREAD            GOT_YOU_MORON
 #define IRQ_NOAUTOEN            GOT_YOU_MORON
 #define IRQ_NESTED_THREAD       GOT_YOU_MORON
+#define IRQ_PER_CPU_DEVID       GOT_YOU_MORON
 #undef IRQF_MODIFY_MASK
 #define IRQF_MODIFY_MASK        GOT_YOU_MORON
 
@@ -39,6 +41,11 @@ static inline bool irq_settings_is_per_cpu(struct irq_desc *desc)
         return desc->status_use_accessors & _IRQ_PER_CPU;
 }
 
+static inline bool irq_settings_is_per_cpu_devid(struct irq_desc *desc)
+{
+        return desc->status_use_accessors & _IRQ_PER_CPU_DEVID;
+}
+
 static inline void irq_settings_set_per_cpu(struct irq_desc *desc)
 {
         desc->status_use_accessors |= _IRQ_PER_CPU;