[PATCH v5 1/7] genirq: Add flags for software interrupt moderation.

[Luigi Rizzo <lrizzo@google.com>]

Add two flags to support software interrupt moderation:

- IRQ_MODERATABLE is an irqdesc flag indicating that an interrupt supports
  moderation. This is a capability that can be set for eligible sources.

- IRQD_MODERATED is an internal irqdata flag indicating that the
  interrupt is currently being moderated. This is a state flag.

Signed-off-by: Luigi Rizzo <lrizzo@google.com>
---
 include/linux/irq.h   | 11 ++++++++++-
 kernel/irq/debugfs.c  |  3 +++
 kernel/irq/settings.h | 17 +++++++++++++++++
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/include/linux/irq.h b/include/linux/irq.h
index f485369b1b4f7..232df18af1b66 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -76,6 +76,7 @@ enum irqchip_irq_state;
  * IRQ_DISABLE_UNLAZY		- Disable lazy irq disable
  * IRQ_HIDDEN			- Don't show up in /proc/interrupts
  * IRQ_NO_DEBUG			- Exclude from note_interrupt() debugging
+ * IRQ_MODERATABLE		- Can do software interrupt moderation
  */
 enum {
 	IRQ_TYPE_NONE		= 0x00000000,
@@ -104,13 +105,14 @@ enum {
 	IRQ_HIDDEN		= (1 << 20),
 	IRQ_NO_DEBUG		= (1 << 21),
 	IRQ_RESERVED		= (1 << 22),
+	IRQ_MODERATABLE		= (1 << 23),
 };
 
 #define IRQF_MODIFY_MASK	\
 	(IRQ_TYPE_SENSE_MASK | IRQ_NOPROBE | IRQ_NOREQUEST | \
 	 IRQ_NOAUTOEN | IRQ_LEVEL | IRQ_NO_BALANCING | \
 	 IRQ_PER_CPU | IRQ_NESTED_THREAD | IRQ_NOTHREAD | IRQ_PER_CPU_DEVID | \
-	 IRQ_IS_POLLED | IRQ_DISABLE_UNLAZY | IRQ_HIDDEN)
+	 IRQ_IS_POLLED | IRQ_DISABLE_UNLAZY | IRQ_HIDDEN | IRQ_MODERATABLE)
 
 #define IRQ_NO_BALANCING_MASK	(IRQ_PER_CPU | IRQ_NO_BALANCING)
 
@@ -224,6 +226,7 @@ struct irq_data {
  *				  irqchip have flag IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND set.
  * IRQD_RESEND_WHEN_IN_PROGRESS	- Interrupt may fire when already in progress in which
  *				  case it must be resent at the next available opportunity.
+ * IRQD_MODERATED		- Interrupt is currently moderated.
  */
 enum {
 	IRQD_TRIGGER_MASK		= 0xf,
@@ -249,6 +252,7 @@ enum {
 	IRQD_AFFINITY_ON_ACTIVATE	= BIT(28),
 	IRQD_IRQ_ENABLED_ON_SUSPEND	= BIT(29),
 	IRQD_RESEND_WHEN_IN_PROGRESS    = BIT(30),
+	IRQD_MODERATED			= BIT(31),
 };
 
 #define __irqd_to_state(d) ACCESS_PRIVATE((d)->common, state_use_accessors)
@@ -438,6 +442,11 @@ static inline bool irqd_needs_resend_when_in_progress(struct irq_data *d)
 	return __irqd_to_state(d) & IRQD_RESEND_WHEN_IN_PROGRESS;
 }
 
+static inline bool irqd_is_moderated(struct irq_data *d)
+{
+	return __irqd_to_state(d) & IRQD_MODERATED;
+}
+
 #undef __irqd_to_state
 
 static inline irq_hw_number_t irqd_to_hwirq(struct irq_data *d)
diff --git a/kernel/irq/debugfs.c b/kernel/irq/debugfs.c
index 5c5ebaee35f2c..634f00c0f0f59 100644
--- a/kernel/irq/debugfs.c
+++ b/kernel/irq/debugfs.c
@@ -128,6 +128,8 @@ static const struct irq_bit_descr irqdata_states[] = {
 	BIT_MASK_DESCR(IRQD_IRQ_ENABLED_ON_SUSPEND),
 
 	BIT_MASK_DESCR(IRQD_RESEND_WHEN_IN_PROGRESS),
+
+	BIT_MASK_DESCR(IRQD_MODERATED),
 };
 
 static const struct irq_bit_descr irqdesc_states[] = {
@@ -140,6 +142,7 @@ static const struct irq_bit_descr irqdesc_states[] = {
 	BIT_MASK_DESCR(_IRQ_IS_POLLED),
 	BIT_MASK_DESCR(_IRQ_DISABLE_UNLAZY),
 	BIT_MASK_DESCR(_IRQ_HIDDEN),
+	BIT_MASK_DESCR(_IRQ_MODERATABLE),
 };
 
 static const struct irq_bit_descr irqdesc_istates[] = {
diff --git a/kernel/irq/settings.h b/kernel/irq/settings.h
index 0a0c027a5d342..1663bb46d3a99 100644
--- a/kernel/irq/settings.h
+++ b/kernel/irq/settings.h
@@ -19,6 +19,7 @@ enum {
 	_IRQ_HIDDEN		= IRQ_HIDDEN,
 	_IRQ_NO_DEBUG		= IRQ_NO_DEBUG,
 	_IRQ_PROC_VALID		= IRQ_RESERVED,
+	_IRQ_MODERATABLE	= IRQ_MODERATABLE,
 	_IRQF_MODIFY_MASK	= IRQF_MODIFY_MASK,
 };
 
@@ -36,6 +37,7 @@ enum {
 #define IRQ_HIDDEN		GOT_YOU_MORON
 #define IRQ_NO_DEBUG		GOT_YOU_MORON
 #define IRQ_RESERVED		GOT_YOU_MORON
+#define IRQ_MODERATABLE		GOT_YOU_MORON
 #undef IRQF_MODIFY_MASK
 #define IRQF_MODIFY_MASK	GOT_YOU_MORON
 
@@ -193,3 +195,18 @@ static inline void irq_settings_update_proc_valid(struct irq_desc *desc, u32 set
 	desc->status_use_accessors &= ~_IRQ_PROC_VALID;
 	desc->status_use_accessors |= (set & _IRQ_PROC_VALID);
 }
+
+static inline bool irq_settings_moderatable(struct irq_desc *desc)
+{
+	return desc->status_use_accessors & _IRQ_MODERATABLE;
+}
+
+static inline void irq_settings_set_moderatable(struct irq_desc *desc)
+{
+	desc->status_use_accessors |= _IRQ_MODERATABLE;
+}
+
+static inline void irq_settings_clr_moderatable(struct irq_desc *desc)
+{
+	desc->status_use_accessors &= ~_IRQ_MODERATABLE;
+}
-- 
2.55.0.737.g08866a6d13-goog