genirq: Introduce IRQD_SINGLE_TARGET flag

Many interrupt chips allow only a single CPU as interrupt target. The core code has no knowledge about that. That's unfortunate as it could avoid trying to readd a newly online CPU to the effective affinity mask. Add the status flag and the necessary accessors. Signed-off-by: Thomas Gleixner <[email protected]> Cc: Jens Axboe <[email protected]> Cc: Marc Zyngier <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Keith Busch <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Christoph Hellwig <[email protected]> Link: http://lkml.kernel.org/r/[email protected]
cail · Jun 22, 2017 · d52dd44 · d52dd44
1 parent c5cb83b
commit d52dd44
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diff --git a/include/linux/irq.h b/include/linux/irq.h
@@ -209,6 +209,7 @@ struct irq_data {
  * IRQD_IRQ_STARTED		- Startup state of the interrupt
  * IRQD_MANAGED_SHUTDOWN	- Interrupt was shutdown due to empty affinity
  *				  mask. Applies only to affinity managed irqs.
+ * IRQD_SINGLE_TARGET		- IRQ allows only a single affinity target
  */
 enum {
 	IRQD_TRIGGER_MASK		= 0xf,
@@ -228,6 +229,7 @@ enum {
 	IRQD_AFFINITY_MANAGED		= (1 << 21),
 	IRQD_IRQ_STARTED		= (1 << 22),
 	IRQD_MANAGED_SHUTDOWN		= (1 << 23),
+	IRQD_SINGLE_TARGET		= (1 << 24),
 };
 
 #define __irqd_to_state(d) ACCESS_PRIVATE((d)->common, state_use_accessors)
@@ -276,6 +278,20 @@ static inline bool irqd_is_level_type(struct irq_data *d)
 	return __irqd_to_state(d) & IRQD_LEVEL;
 }
 
+/*
+ * Must only be called of irqchip.irq_set_affinity() or low level
+ * hieararchy domain allocation functions.
+ */
+static inline void irqd_set_single_target(struct irq_data *d)
+{
+	__irqd_to_state(d) |= IRQD_SINGLE_TARGET;
+}
+
+static inline bool irqd_is_single_target(struct irq_data *d)
+{
+	return __irqd_to_state(d) & IRQD_SINGLE_TARGET;
+}
+
 static inline bool irqd_is_wakeup_set(struct irq_data *d)
 {
 	return __irqd_to_state(d) & IRQD_WAKEUP_STATE;

diff --git a/kernel/irq/debugfs.c b/kernel/irq/debugfs.c
@@ -105,6 +105,7 @@ static const struct irq_bit_descr irqdata_states[] = {
 	BIT_MASK_DESCR(IRQD_PER_CPU),
 	BIT_MASK_DESCR(IRQD_NO_BALANCING),
 
+	BIT_MASK_DESCR(IRQD_SINGLE_TARGET),
 	BIT_MASK_DESCR(IRQD_MOVE_PCNTXT),
 	BIT_MASK_DESCR(IRQD_AFFINITY_SET),
 	BIT_MASK_DESCR(IRQD_SETAFFINITY_PENDING),