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

Pull core irq updates from Thomas Gleixner:
 "The irq department delivers:

   - Another tree wide update to get rid of the horrible create_irq
     interface along with its even more horrible variants.  That also
     gets rid of the last leftovers of the initial sparse irq hackery.
     arch/driver specific changes have been either acked or ignored.

   - A fix for the spurious interrupt detection logic with threaded
     interrupts.

   - A new ARM SoC interrupt controller

   - The usual pile of fixes and improvements all over the place"

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
  Documentation: brcmstb-l2: Add Broadcom STB Level-2 interrupt controller binding
  irqchip: brcmstb-l2: Add Broadcom Set Top Box Level-2 interrupt controller
  genirq: Improve documentation to match current implementation
  ARM: iop13xx: fix msi support with sparse IRQ
  genirq: Provide !SMP stub for irq_set_affinity_notifier()
  irqchip: armada-370-xp: Move the devicetree binding documentation
  irqchip: gic: Use mask field in GICC_IAR
  genirq: Remove dynamic_irq mess
  ia64: Use irq_init_desc
  genirq: Replace dynamic_irq_init/cleanup
  genirq: Remove irq_reserve_irq[s]
  genirq: Replace reserve_irqs in core code
  s390: Avoid call to irq_reserve_irqs()
  s390: Remove pointless arch_show_interrupts()
  s390: pci: Check return value of alloc_irq_desc() proper
  sh: intc: Remove pointless irq_reserve_irqs() invocation
  x86, irq: Remove pointless irq_reserve_irqs() call
  genirq: Make create/destroy_irq() ia64 private
  tile: Use SPARSE_IRQ
  tile: pci: Use irq_alloc/free_hwirq()
  ...

7 files changed, 188 insertions, 45 deletions

diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig
index 07cbdfea9ae2..d269cecdfbf0 100644
--- a/kernel/irq/Kconfig
+++ b/kernel/irq/Kconfig
@@ -5,6 +5,10 @@ menu "IRQ subsystem"
 config MAY_HAVE_SPARSE_IRQ
        bool
 
+# Legacy support, required for itanic
+config GENERIC_IRQ_LEGACY
+       bool
+
 # Enable the generic irq autoprobe mechanism
 config GENERIC_IRQ_PROBE
 	bool
@@ -17,6 +21,11 @@ config GENERIC_IRQ_SHOW
 config GENERIC_IRQ_SHOW_LEVEL
        bool
 
+# Facility to allocate a hardware interrupt. This is legacy support
+# and should not be used in new code. Use irq domains instead.
+config GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
+       bool
+
 # Support for delayed migration from interrupt context
 config GENERIC_PENDING_IRQ
 	bool
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 6397df2d6945..a2b28a2fd7b1 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -40,10 +40,9 @@ int irq_set_chip(unsigned int irq, struct irq_chip *chip)
 	irq_put_desc_unlock(desc, flags);
 	/*
 	 * For !CONFIG_SPARSE_IRQ make the irq show up in
-	 * allocated_irqs. For the CONFIG_SPARSE_IRQ case, it is
-	 * already marked, and this call is harmless.
+	 * allocated_irqs.
 	 */
-	irq_reserve_irq(irq);
+	irq_mark_irq(irq);
 	return 0;
 }
 EXPORT_SYMBOL(irq_set_chip);
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index ddf1ffeb79f1..099ea2e0eb88 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -33,7 +33,7 @@ enum {
 };
 
 /*
- * Bit masks for desc->state
+ * Bit masks for desc->core_internal_state__do_not_mess_with_it
  *
  * IRQS_AUTODETECT		- autodetection in progress
  * IRQS_SPURIOUS_DISABLED	- was disabled due to spurious interrupt
@@ -76,6 +76,12 @@ 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);
 
+#ifdef CONFIG_SPARSE_IRQ
+static inline void irq_mark_irq(unsigned int irq) { }
+#else
+extern void irq_mark_irq(unsigned int irq);
+#endif
+
 extern void init_kstat_irqs(struct irq_desc *desc, int node, int nr);
 
 irqreturn_t handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action);
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index bb07f2928f4b..7339e42a85ab 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -278,7 +278,12 @@ EXPORT_SYMBOL(irq_to_desc);
 
 static void free_desc(unsigned int irq)
 {
-	dynamic_irq_cleanup(irq);
+	struct irq_desc *desc = irq_to_desc(irq);
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&desc->lock, flags);
+	desc_set_defaults(irq, desc, desc_node(desc), NULL);
+	raw_spin_unlock_irqrestore(&desc->lock, flags);
 }
 
 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
@@ -299,6 +304,20 @@ static int irq_expand_nr_irqs(unsigned int nr)
 	return -ENOMEM;
 }
 
+void irq_mark_irq(unsigned int irq)
+{
+	mutex_lock(&sparse_irq_lock);
+	bitmap_set(allocated_irqs, irq, 1);
+	mutex_unlock(&sparse_irq_lock);
+}
+
+#ifdef CONFIG_GENERIC_IRQ_LEGACY
+void irq_init_desc(unsigned int irq)
+{
+	free_desc(irq);
+}
+#endif
+
 #endif /* !CONFIG_SPARSE_IRQ */
 
 /**
@@ -396,30 +415,56 @@ err:
 }
 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
 
+#ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
 /**
- * irq_reserve_irqs - mark irqs allocated
- * @from:	mark from irq number
- * @cnt:	number of irqs to mark
+ * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
+ * @cnt:	number of interrupts to allocate
+ * @node:	node on which to allocate
  *
- * Returns 0 on success or an appropriate error code
+ * Returns an interrupt number > 0 or 0, if the allocation fails.
  */
-int irq_reserve_irqs(unsigned int from, unsigned int cnt)
+unsigned int irq_alloc_hwirqs(int cnt, int node)
 {
-	unsigned int start;
-	int ret = 0;
+	int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL);
 
-	if (!cnt || (from + cnt) > nr_irqs)
-		return -EINVAL;
+	if (irq < 0)
+		return 0;
 
-	mutex_lock(&sparse_irq_lock);
-	start = bitmap_find_next_zero_area(allocated_irqs, nr_irqs, from, cnt, 0);
-	if (start == from)
-		bitmap_set(allocated_irqs, start, cnt);
-	else
-		ret = -EEXIST;
-	mutex_unlock(&sparse_irq_lock);
-	return ret;
+	for (i = irq; cnt > 0; i++, cnt--) {
+		if (arch_setup_hwirq(i, node))
+			goto err;
+		irq_clear_status_flags(i, _IRQ_NOREQUEST);
+	}
+	return irq;
+
+err:
+	for (i--; i >= irq; i--) {
+		irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
+		arch_teardown_hwirq(i);
+	}
+	irq_free_descs(irq, cnt);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
+
+/**
+ * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
+ * @from:	Free from irq number
+ * @cnt:	number of interrupts to free
+ *
+ */
+void irq_free_hwirqs(unsigned int from, int cnt)
+{
+	int i;
+
+	for (i = from; cnt > 0; i++, cnt--) {
+		irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
+		arch_teardown_hwirq(i);
+	}
+	irq_free_descs(from, cnt);
 }
+EXPORT_SYMBOL_GPL(irq_free_hwirqs);
+#endif
 
 /**
  * irq_get_next_irq - get next allocated irq number
@@ -482,20 +527,6 @@ int irq_set_percpu_devid(unsigned int irq)
 	return 0;
 }
 
-/**
- * dynamic_irq_cleanup - cleanup a dynamically allocated irq
- * @irq:	irq number to initialize
- */
-void dynamic_irq_cleanup(unsigned int irq)
-{
-	struct irq_desc *desc = irq_to_desc(irq);
-	unsigned long flags;
-
-	raw_spin_lock_irqsave(&desc->lock, flags);
-	desc_set_defaults(irq, desc, desc_node(desc), NULL);
-	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));
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index f14033700c25..eb5e10e32e05 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -27,14 +27,14 @@ static struct irq_domain *irq_default_domain;
  * __irq_domain_add() - Allocate a new irq_domain data structure
  * @of_node: optional device-tree node of the interrupt controller
  * @size: Size of linear map; 0 for radix mapping only
+ * @hwirq_max: Maximum number of interrupts supported by controller
  * @direct_max: Maximum value of direct maps; Use ~0 for no limit; 0 for no
  *              direct mapping
  * @ops: map/unmap domain callbacks
  * @host_data: Controller private data pointer
  *
- * Allocates and initialize and irq_domain structure.  Caller is expected to
- * register allocated irq_domain with irq_domain_register().  Returns pointer
- * to IRQ domain, or NULL on failure.
+ * Allocates and initialize and irq_domain structure.
+ * Returns pointer to IRQ domain, or NULL on failure.
  */
 struct irq_domain *__irq_domain_add(struct device_node *of_node, int size,
 				    irq_hw_number_t hwirq_max, int direct_max,
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index d34131ca372b..3dc6a61bf06a 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -886,8 +886,8 @@ static int irq_thread(void *data)
 		irq_thread_check_affinity(desc, action);
 
 		action_ret = handler_fn(desc, action);
-		if (!noirqdebug)
-			note_interrupt(action->irq, desc, action_ret);
+		if (action_ret == IRQ_HANDLED)
+			atomic_inc(&desc->threads_handled);
 
 		wake_threads_waitq(desc);
 	}
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index a1d8cc63b56e..e2514b0e439e 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -270,6 +270,8 @@ try_misrouted_irq(unsigned int irq, struct irq_desc *desc,
 	return action && (action->flags & IRQF_IRQPOLL);
 }
 
+#define SPURIOUS_DEFERRED	0x80000000
+
 void note_interrupt(unsigned int irq, struct irq_desc *desc,
 		    irqreturn_t action_ret)
 {
@@ -277,15 +279,111 @@ void note_interrupt(unsigned int irq, struct irq_desc *desc,
 	    irq_settings_is_polled(desc))
 		return;
 
-	/* we get here again via the threaded handler */
-	if (action_ret == IRQ_WAKE_THREAD)
-		return;
-
 	if (bad_action_ret(action_ret)) {
 		report_bad_irq(irq, desc, action_ret);
 		return;
 	}
 
+	/*
+	 * We cannot call note_interrupt from the threaded handler
+	 * because we need to look at the compound of all handlers
+	 * (primary and threaded). Aside of that in the threaded
+	 * shared case we have no serialization against an incoming
+	 * hardware interrupt while we are dealing with a threaded
+	 * result.
+	 *
+	 * So in case a thread is woken, we just note the fact and
+	 * defer the analysis to the next hardware interrupt.
+	 *
+	 * The threaded handlers store whether they sucessfully
+	 * handled an interrupt and we check whether that number
+	 * changed versus the last invocation.
+	 *
+	 * We could handle all interrupts with the delayed by one
+	 * mechanism, but for the non forced threaded case we'd just
+	 * add pointless overhead to the straight hardirq interrupts
+	 * for the sake of a few lines less code.
+	 */
+	if (action_ret & IRQ_WAKE_THREAD) {
+		/*
+		 * There is a thread woken. Check whether one of the
+		 * shared primary handlers returned IRQ_HANDLED. If
+		 * not we defer the spurious detection to the next
+		 * interrupt.
+		 */
+		if (action_ret == IRQ_WAKE_THREAD) {
+			int handled;
+			/*
+			 * We use bit 31 of thread_handled_last to
+			 * denote the deferred spurious detection
+			 * active. No locking necessary as
+			 * thread_handled_last is only accessed here
+			 * and we have the guarantee that hard
+			 * interrupts are not reentrant.
+			 */
+			if (!(desc->threads_handled_last & SPURIOUS_DEFERRED)) {
+				desc->threads_handled_last |= SPURIOUS_DEFERRED;
+				return;
+			}
+			/*
+			 * Check whether one of the threaded handlers
+			 * returned IRQ_HANDLED since the last
+			 * interrupt happened.
+			 *
+			 * For simplicity we just set bit 31, as it is
+			 * set in threads_handled_last as well. So we
+			 * avoid extra masking. And we really do not
+			 * care about the high bits of the handled
+			 * count. We just care about the count being
+			 * different than the one we saw before.
+			 */
+			handled = atomic_read(&desc->threads_handled);
+			handled |= SPURIOUS_DEFERRED;
+			if (handled != desc->threads_handled_last) {
+				action_ret = IRQ_HANDLED;
+				/*
+				 * Note: We keep the SPURIOUS_DEFERRED
+				 * bit set. We are handling the
+				 * previous invocation right now.
+				 * Keep it for the current one, so the
+				 * next hardware interrupt will
+				 * account for it.
+				 */
+				desc->threads_handled_last = handled;
+			} else {
+				/*
+				 * None of the threaded handlers felt
+				 * responsible for the last interrupt
+				 *
+				 * We keep the SPURIOUS_DEFERRED bit
+				 * set in threads_handled_last as we
+				 * need to account for the current
+				 * interrupt as well.
+				 */
+				action_ret = IRQ_NONE;
+			}
+		} else {
+			/*
+			 * One of the primary handlers returned
+			 * IRQ_HANDLED. So we don't care about the
+			 * threaded handlers on the same line. Clear
+			 * the deferred detection bit.
+			 *
+			 * In theory we could/should check whether the
+			 * deferred bit is set and take the result of
+			 * the previous run into account here as
+			 * well. But it's really not worth the
+			 * trouble. If every other interrupt is
+			 * handled we never trigger the spurious
+			 * detector. And if this is just the one out
+			 * of 100k unhandled ones which is handled
+			 * then we merily delay the spurious detection
+			 * by one hard interrupt. Not a real problem.
+			 */
+			desc->threads_handled_last &= ~SPURIOUS_DEFERRED;
+		}
+	}
+
 	if (unlikely(action_ret == IRQ_NONE)) {
 		/*
 		 * If we are seeing only the odd spurious IRQ caused by