irqchip: GIC: Add support for irq_[get, set]_irqchip_state()

Add the required hooks for the internal state of an interrupt
to be exposed to other subsystems.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Phong Vo <pvo@apm.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Tin Huynh <tnhuynh@apm.com>
Cc: Y Vo <yvo@apm.com>
Cc: Toan Le <toanle@apm.com>
Cc: Bjorn Andersson <bjorn@kryo.se>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Link: http://lkml.kernel.org/r/1426676484-21812-3-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

drivers/irqchip/irq-gic.c

@@ -151,27 +151,37 @@ static inline unsigned int gic_irq(struct irq_data *d)
 /*
  * Routines to acknowledge, disable and enable interrupts
  */
-static void gic_mask_irq(struct irq_data *d)
+static void gic_poke_irq(struct irq_data *d, u32 offset)
+{
+	u32 mask = 1 << (gic_irq(d) % 32);
+	writel_relaxed(mask, gic_dist_base(d) + offset + (gic_irq(d) / 32) * 4);
+}
+
+static int gic_peek_irq(struct irq_data *d, u32 offset)
 {
 	u32 mask = 1 << (gic_irq(d) % 32);
+	return !!(readl_relaxed(gic_dist_base(d) + offset + (gic_irq(d) / 32) * 4) & mask);
+}
+
+static void gic_mask_irq(struct irq_data *d)
+{
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&irq_controller_lock, flags);
-	writel_relaxed(mask, gic_dist_base(d) + GIC_DIST_ENABLE_CLEAR + (gic_irq(d) / 32) * 4);
+	gic_poke_irq(d, GIC_DIST_ENABLE_CLEAR);
 	if (gic_arch_extn.irq_mask)
 		gic_arch_extn.irq_mask(d);
 	raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
 }
 
 static void gic_unmask_irq(struct irq_data *d)
 {
-	u32 mask = 1 << (gic_irq(d) % 32);
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&irq_controller_lock, flags);
 	if (gic_arch_extn.irq_unmask)
 		gic_arch_extn.irq_unmask(d);
-	writel_relaxed(mask, gic_dist_base(d) + GIC_DIST_ENABLE_SET + (gic_irq(d) / 32) * 4);
+	gic_poke_irq(d, GIC_DIST_ENABLE_SET);
 	raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
 }
 
@@ -186,6 +196,55 @@ static void gic_eoi_irq(struct irq_data *d)
 	writel_relaxed(gic_irq(d), gic_cpu_base(d) + GIC_CPU_EOI);
 }
 
+static int gic_irq_set_irqchip_state(struct irq_data *d,
+				     enum irqchip_irq_state which, bool val)
+{
+	u32 reg;
+
+	switch (which) {
+	case IRQCHIP_STATE_PENDING:
+		reg = val ? GIC_DIST_PENDING_SET : GIC_DIST_PENDING_CLEAR;
+		break;
+
+	case IRQCHIP_STATE_ACTIVE:
+		reg = val ? GIC_DIST_ACTIVE_SET : GIC_DIST_ACTIVE_CLEAR;
+		break;
+
+	case IRQCHIP_STATE_MASKED:
+		reg = val ? GIC_DIST_ENABLE_CLEAR : GIC_DIST_ENABLE_SET;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	gic_poke_irq(d, reg);
+	return 0;
+}
+
+static int gic_irq_get_irqchip_state(struct irq_data *d,
+				      enum irqchip_irq_state which, bool *val)
+{
+	switch (which) {
+	case IRQCHIP_STATE_PENDING:
+		*val = gic_peek_irq(d, GIC_DIST_PENDING_SET);
+		break;
+
+	case IRQCHIP_STATE_ACTIVE:
+		*val = gic_peek_irq(d, GIC_DIST_ACTIVE_SET);
+		break;
+
+	case IRQCHIP_STATE_MASKED:
+		*val = !gic_peek_irq(d, GIC_DIST_ENABLE_SET);
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int gic_set_type(struct irq_data *d, unsigned int type)
 {
 	void __iomem *base = gic_dist_base(d);
@@ -329,6 +388,8 @@ static struct irq_chip gic_chip = {
 	.irq_set_affinity	= gic_set_affinity,
 #endif
 	.irq_set_wake		= gic_set_wake,
+	.irq_get_irqchip_state	= gic_irq_get_irqchip_state,
+	.irq_set_irqchip_state	= gic_irq_set_irqchip_state,
 };
 
 void __init gic_cascade_irq(unsigned int gic_nr, unsigned int irq)