Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq code updates from Thomas Gleixner:
 "The irq department proudly presents:

   - Another tree wide sweep of irq infrastructure abuse.  Clear winner
     of the trainwreck engineering contest was:
         #include "../../../kernel/irq/settings.h"

   - Tree wide update of irq_set_affinity() callbacks which miss a cpu
     online check when picking a single cpu out of the affinity mask.

   - Tree wide consolidation of interrupt statistics.

   - Updates to the threaded interrupt infrastructure to allow explicit
     wakeup of the interrupt thread and a variant of synchronize_irq()
     which synchronizes only the hard interrupt handler.  Both are
     needed to replace the homebrewn thread handling in the mmc/sdhci
     code.

   - New irq chip callbacks to allow proper support for GPIO based irqs.
     The GPIO based interrupts need to request/release GPIO resources
     from request/free_irq.

   - A few new ARM interrupt chips.  No revolutionary new hardware, just
     differently wreckaged variations of the scheme.

   - Small improvments, cleanups and updates all over the place"

I was hoping that that trainwreck engineering contest was a April Fools'
joke.  But no.

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (68 commits)
  irqchip: sun7i/sun6i: Disable NMI before registering the handler
  ARM: sun7i/sun6i: dts: Fix IRQ number for sun6i NMI controller
  ARM: sun7i/sun6i: irqchip: Update the documentation
  ARM: sun7i/sun6i: dts: Add NMI irqchip support
  ARM: sun7i/sun6i: irqchip: Add irqchip driver for NMI controller
  genirq: Export symbol no_action()
  arm: omap: Fix typo in ams-delta-fiq.c
  m68k: atari: Fix the last kernel_stat.h fallout
  irqchip: sun4i: Simplify sun4i_irq_ack
  irqchip: sun4i: Use handle_fasteoi_irq for all interrupts
  genirq: procfs: Make smp_affinity values go+r
  softirq: Add linux/irq.h to make it compile again
  m68k: amiga: Add linux/irq.h to make it compile again
  irqchip: sun4i: Don't ack IRQs > 0, fix acking of IRQ 0
  irqchip: sun4i: Fix a comment about mask register initialization
  irqchip: sun4i: Fix irq 0 not working
  genirq: Add a new IRQCHIP_EOI_THREADED flag
  genirq: Document IRQCHIP_ONESHOT_SAFE flag
  ARM: sunxi: dt: Convert to the new irq controller compatibles
  irqchip: sunxi: Change compatibles
  ...

7 files changed, 168 insertions, 37 deletions

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index dc04c16..6397df2 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -281,6 +281,19 @@ void unmask_irq(struct irq_desc *desc)
 	}
 }
 
+void unmask_threaded_irq(struct irq_desc *desc)
+{
+	struct irq_chip *chip = desc->irq_data.chip;
+
+	if (chip->flags & IRQCHIP_EOI_THREADED)
+		chip->irq_eoi(&desc->irq_data);
+
+	if (chip->irq_unmask) {
+		chip->irq_unmask(&desc->irq_data);
+		irq_state_clr_masked(desc);
+	}
+}
+
 /*
  *	handle_nested_irq - Handle a nested irq from a irq thread
  *	@irq:	the interrupt number
@@ -435,6 +448,27 @@ static inline void preflow_handler(struct irq_desc *desc)
 static inline void preflow_handler(struct irq_desc *desc) { }
 #endif
 
+static void cond_unmask_eoi_irq(struct irq_desc *desc, struct irq_chip *chip)
+{
+	if (!(desc->istate & IRQS_ONESHOT)) {
+		chip->irq_eoi(&desc->irq_data);
+		return;
+	}
+	/*
+	 * We need to unmask in the following cases:
+	 * - Oneshot irq which did not wake the thread (caused by a
+	 *   spurious interrupt or a primary handler handling it
+	 *   completely).
+	 */
+	if (!irqd_irq_disabled(&desc->irq_data) &&
+	    irqd_irq_masked(&desc->irq_data) && !desc->threads_oneshot) {
+		chip->irq_eoi(&desc->irq_data);
+		unmask_irq(desc);
+	} else if (!(chip->flags & IRQCHIP_EOI_THREADED)) {
+		chip->irq_eoi(&desc->irq_data);
+	}
+}
+
 /**
  *	handle_fasteoi_irq - irq handler for transparent controllers
  *	@irq:	the interrupt number
@@ -448,6 +482,8 @@ static inline void preflow_handler(struct irq_desc *desc) { }
 void
 handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
 {
+	struct irq_chip *chip = desc->irq_data.chip;
+
 	raw_spin_lock(&desc->lock);
 
 	if (unlikely(irqd_irq_inprogress(&desc->irq_data)))
@@ -473,18 +509,14 @@ handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
 	preflow_handler(desc);
 	handle_irq_event(desc);
 
-	if (desc->istate & IRQS_ONESHOT)
-		cond_unmask_irq(desc);
+	cond_unmask_eoi_irq(desc, chip);
 
-out_eoi:
-	desc->irq_data.chip->irq_eoi(&desc->irq_data);
-out_unlock:
 	raw_spin_unlock(&desc->lock);
 	return;
 out:
-	if (!(desc->irq_data.chip->flags & IRQCHIP_EOI_IF_HANDLED))
-		goto out_eoi;
-	goto out_unlock;
+	if (!(chip->flags & IRQCHIP_EOI_IF_HANDLED))
+		chip->irq_eoi(&desc->irq_data);
+	raw_spin_unlock(&desc->lock);
 }
 
 /**
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 131ca17..6354802 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -41,6 +41,7 @@ irqreturn_t no_action(int cpl, void *dev_id)
 {
 	return IRQ_NONE;
 }
+EXPORT_SYMBOL_GPL(no_action);
 
 static void warn_no_thread(unsigned int irq, struct irqaction *action)
 {
@@ -51,7 +52,7 @@ static void warn_no_thread(unsigned int irq, struct irqaction *action)
 	       "but no thread function available.", irq, action->name);
 }
 
-static void irq_wake_thread(struct irq_desc *desc, struct irqaction *action)
+void __irq_wake_thread(struct irq_desc *desc, struct irqaction *action)
 {
 	/*
 	 * In case the thread crashed and was killed we just pretend that
@@ -157,7 +158,7 @@ handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action)
 				break;
 			}
 
-			irq_wake_thread(desc, action);
+			__irq_wake_thread(desc, action);
 
 			/* Fall through to add to randomness */
 		case IRQ_HANDLED:
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index 001fa5b..ddf1ffe 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -6,6 +6,7 @@
  * of this file for your non core code.
  */
 #include <linux/irqdesc.h>
+#include <linux/kernel_stat.h>
 
 #ifdef CONFIG_SPARSE_IRQ
 # define IRQ_BITMAP_BITS	(NR_IRQS + 8196)
@@ -73,6 +74,7 @@ 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);
+extern void unmask_threaded_irq(struct irq_desc *desc);
 
 extern void init_kstat_irqs(struct irq_desc *desc, int node, int nr);
 
@@ -82,6 +84,7 @@ irqreturn_t handle_irq_event(struct irq_desc *desc);
 /* Resending of interrupts :*/
 void check_irq_resend(struct irq_desc *desc, unsigned int irq);
 bool irq_wait_for_poll(struct irq_desc *desc);
+void __irq_wake_thread(struct irq_desc *desc, struct irqaction *action);
 
 #ifdef CONFIG_PROC_FS
 extern void register_irq_proc(unsigned int irq, struct irq_desc *desc);
@@ -179,3 +182,9 @@ static inline bool irqd_has_set(struct irq_data *d, unsigned int mask)
 {
 	return d->state_use_accessors & mask;
 }
+
+static inline void kstat_incr_irqs_this_cpu(unsigned int irq, struct irq_desc *desc)
+{
+	__this_cpu_inc(*desc->kstat_irqs);
+	__this_cpu_inc(kstat.irqs_sum);
+}
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 8ab8e93..a7174617 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -489,6 +489,11 @@ void dynamic_irq_cleanup(unsigned int irq)
 	raw_spin_unlock_irqrestore(&desc->lock, flags);
 }
 
+void kstat_incr_irq_this_cpu(unsigned int irq)
+{
+	kstat_incr_irqs_this_cpu(irq, irq_to_desc(irq));
+}
+
 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index d3bf660..2486a4c 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -32,24 +32,10 @@ static int __init setup_forced_irqthreads(char *arg)
 early_param("threadirqs", setup_forced_irqthreads);
 #endif
 
-/**
- *	synchronize_irq - wait for pending IRQ handlers (on other CPUs)
- *	@irq: interrupt number to wait for
- *
- *	This function waits for any pending IRQ handlers for this interrupt
- *	to complete before returning. If you use this function while
- *	holding a resource the IRQ handler may need you will deadlock.
- *
- *	This function may be called - with care - from IRQ context.
- */
-void synchronize_irq(unsigned int irq)
+static void __synchronize_hardirq(struct irq_desc *desc)
 {
-	struct irq_desc *desc = irq_to_desc(irq);
 	bool inprogress;
 
-	if (!desc)
-		return;
-
 	do {
 		unsigned long flags;
 
@@ -67,12 +53,56 @@ void synchronize_irq(unsigned int irq)
 
 		/* Oops, that failed? */
 	} while (inprogress);
+}
 
-	/*
-	 * We made sure that no hardirq handler is running. Now verify
-	 * that no threaded handlers are active.
-	 */
-	wait_event(desc->wait_for_threads, !atomic_read(&desc->threads_active));
+/**
+ *	synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
+ *	@irq: interrupt number to wait for
+ *
+ *	This function waits for any pending hard IRQ handlers for this
+ *	interrupt to complete before returning. If you use this
+ *	function while holding a resource the IRQ handler may need you
+ *	will deadlock. It does not take associated threaded handlers
+ *	into account.
+ *
+ *	Do not use this for shutdown scenarios where you must be sure
+ *	that all parts (hardirq and threaded handler) have completed.
+ *
+ *	This function may be called - with care - from IRQ context.
+ */
+void synchronize_hardirq(unsigned int irq)
+{
+	struct irq_desc *desc = irq_to_desc(irq);
+
+	if (desc)
+		__synchronize_hardirq(desc);
+}
+EXPORT_SYMBOL(synchronize_hardirq);
+
+/**
+ *	synchronize_irq - wait for pending IRQ handlers (on other CPUs)
+ *	@irq: interrupt number to wait for
+ *
+ *	This function waits for any pending IRQ handlers for this interrupt
+ *	to complete before returning. If you use this function while
+ *	holding a resource the IRQ handler may need you will deadlock.
+ *
+ *	This function may be called - with care - from IRQ context.
+ */
+void synchronize_irq(unsigned int irq)
+{
+	struct irq_desc *desc = irq_to_desc(irq);
+
+	if (desc) {
+		__synchronize_hardirq(desc);
+		/*
+		 * We made sure that no hardirq handler is
+		 * running. Now verify that no threaded handlers are
+		 * active.
+		 */
+		wait_event(desc->wait_for_threads,
+			   !atomic_read(&desc->threads_active));
+	}
 }
 EXPORT_SYMBOL(synchronize_irq);
 
@@ -718,7 +748,7 @@ again:
 
 	if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
 	    irqd_irq_masked(&desc->irq_data))
-		unmask_irq(desc);
+		unmask_threaded_irq(desc);
 
 out_unlock:
 	raw_spin_unlock_irq(&desc->lock);
@@ -727,7 +757,7 @@ out_unlock:
 
 #ifdef CONFIG_SMP
 /*
- * Check whether we need to chasnge the affinity of the interrupt thread.
+ * Check whether we need to change the affinity of the interrupt thread.
  */
 static void
 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
@@ -880,6 +910,33 @@ static int irq_thread(void *data)
 	return 0;
 }
 
+/**
+ *	irq_wake_thread - wake the irq thread for the action identified by dev_id
+ *	@irq:		Interrupt line
+ *	@dev_id:	Device identity for which the thread should be woken
+ *
+ */
+void irq_wake_thread(unsigned int irq, void *dev_id)
+{
+	struct irq_desc *desc = irq_to_desc(irq);
+	struct irqaction *action;
+	unsigned long flags;
+
+	if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
+		return;
+
+	raw_spin_lock_irqsave(&desc->lock, flags);
+	for (action = desc->action; action; action = action->next) {
+		if (action->dev_id == dev_id) {
+			if (action->thread)
+				__irq_wake_thread(desc, action);
+			break;
+		}
+	}
+	raw_spin_unlock_irqrestore(&desc->lock, flags);
+}
+EXPORT_SYMBOL_GPL(irq_wake_thread);
+
 static void irq_setup_forced_threading(struct irqaction *new)
 {
 	if (!force_irqthreads)
@@ -896,6 +953,23 @@ static void irq_setup_forced_threading(struct irqaction *new)
 	}
 }
 
+static int irq_request_resources(struct irq_desc *desc)
+{
+	struct irq_data *d = &desc->irq_data;
+	struct irq_chip *c = d->chip;
+
+	return c->irq_request_resources ? c->irq_request_resources(d) : 0;
+}
+
+static void irq_release_resources(struct irq_desc *desc)
+{
+	struct irq_data *d = &desc->irq_data;
+	struct irq_chip *c = d->chip;
+
+	if (c->irq_release_resources)
+		c->irq_release_resources(d);
+}
+
 /*
  * Internal function to register an irqaction - typically used to
  * allocate special interrupts that are part of the architecture.
@@ -1091,6 +1165,13 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 	}
 
 	if (!shared) {
+		ret = irq_request_resources(desc);
+		if (ret) {
+			pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
+			       new->name, irq, desc->irq_data.chip->name);
+			goto out_mask;
+		}
+
 		init_waitqueue_head(&desc->wait_for_threads);
 
 		/* Setup the type (level, edge polarity) if configured: */
@@ -1261,8 +1342,10 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
 	*action_ptr = action->next;
 
 	/* If this was the last handler, shut down the IRQ line: */
-	if (!desc->action)
+	if (!desc->action) {
 		irq_shutdown(desc);
+		irq_release_resources(desc);
+	}
 
 #ifdef CONFIG_SMP
 	/* make sure affinity_hint is cleaned up */
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index 36f6ee1..ac1ba2f 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -324,15 +324,15 @@ void register_irq_proc(unsigned int irq, struct irq_desc *desc)
 
 #ifdef CONFIG_SMP
 	/* create /proc/irq/<irq>/smp_affinity */
-	proc_create_data("smp_affinity", 0600, desc->dir,
+	proc_create_data("smp_affinity", 0644, desc->dir,
 			 &irq_affinity_proc_fops, (void *)(long)irq);
 
 	/* create /proc/irq/<irq>/affinity_hint */
-	proc_create_data("affinity_hint", 0400, desc->dir,
+	proc_create_data("affinity_hint", 0444, desc->dir,
 			 &irq_affinity_hint_proc_fops, (void *)(long)irq);
 
 	/* create /proc/irq/<irq>/smp_affinity_list */
-	proc_create_data("smp_affinity_list", 0600, desc->dir,
+	proc_create_data("smp_affinity_list", 0644, desc->dir,
 			 &irq_affinity_list_proc_fops, (void *)(long)irq);
 
 	proc_create_data("node", 0444, desc->dir,
@@ -372,7 +372,7 @@ void unregister_handler_proc(unsigned int irq, struct irqaction *action)
 static void register_default_affinity_proc(void)
 {
 #ifdef CONFIG_SMP
-	proc_create("irq/default_smp_affinity", 0600, NULL,
+	proc_create("irq/default_smp_affinity", 0644, NULL,
 		    &default_affinity_proc_fops);
 #endif
 }
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 490fcbb..b50990a 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -25,6 +25,7 @@
 #include <linux/smp.h>
 #include <linux/smpboot.h>
 #include <linux/tick.h>
+#include <linux/irq.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/irq.h>