genirq: Introduce IRQD_CAN_RESERVE flag

Add a new flag to mark interrupts which can use reservation mode. This is
going to be used in subsequent patches to disable reservation mode for a
certain class of MSI devices.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexandru Chirvasitu <achirvasub@gmail.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Dou Liyang <douly.fnst@cn.fujitsu.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Mikael Pettersson <mikpelinux@gmail.com>
Cc: Josh Poulson <jopoulso@microsoft.com>
Cc: Mihai Costache <v-micos@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: linux-pci@vger.kernel.org
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Simon Xiao <sixiao@microsoft.com>
Cc: Saeed Mahameed <saeedm@mellanox.com>
Cc: Jork Loeser <Jork.Loeser@microsoft.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: devel@linuxdriverproject.org
Cc: KY Srinivasan <kys@microsoft.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Sakari Ailus <sakari.ailus@intel.com>,
Cc: linux-media@vger.kernel.org

include/linux/irq.h

@@ -212,6 +212,7 @@ struct irq_data {
  *				  mask. Applies only to affinity managed irqs.
  * IRQD_SINGLE_TARGET		- IRQ allows only a single affinity target
  * IRQD_DEFAULT_TRIGGER_SET	- Expected trigger already been set
+ * IRQD_CAN_RESERVE		- Can use reservation mode
  */
 enum {
 	IRQD_TRIGGER_MASK		= 0xf,
@@ -233,6 +234,7 @@ enum {
 	IRQD_MANAGED_SHUTDOWN		= (1 << 23),
 	IRQD_SINGLE_TARGET		= (1 << 24),
 	IRQD_DEFAULT_TRIGGER_SET	= (1 << 25),
+	IRQD_CAN_RESERVE		= (1 << 26),
 };
 
 #define __irqd_to_state(d) ACCESS_PRIVATE((d)->common, state_use_accessors)
@@ -377,6 +379,21 @@ static inline bool irqd_is_managed_and_shutdown(struct irq_data *d)
 	return __irqd_to_state(d) & IRQD_MANAGED_SHUTDOWN;
 }
 
+static inline void irqd_set_can_reserve(struct irq_data *d)
+{
+	__irqd_to_state(d) |= IRQD_CAN_RESERVE;
+}
+
+static inline void irqd_clr_can_reserve(struct irq_data *d)
+{
+	__irqd_to_state(d) &= ~IRQD_CAN_RESERVE;
+}
+
+static inline bool irqd_can_reserve(struct irq_data *d)
+{
+	return __irqd_to_state(d) & IRQD_CAN_RESERVE;
+}
+
 #undef __irqd_to_state
 
 static inline irq_hw_number_t irqd_to_hwirq(struct irq_data *d)

kernel/irq/debugfs.c

@@ -113,6 +113,7 @@ static const struct irq_bit_descr irqdata_states[] = {
 	BIT_MASK_DESCR(IRQD_SETAFFINITY_PENDING),
 	BIT_MASK_DESCR(IRQD_AFFINITY_MANAGED),
 	BIT_MASK_DESCR(IRQD_MANAGED_SHUTDOWN),
+	BIT_MASK_DESCR(IRQD_CAN_RESERVE),
 
 	BIT_MASK_DESCR(IRQD_FORWARDED_TO_VCPU),