Merge tag 'irqchip-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core

Pull irqchip updates for v4.13 from Marc Zyngier

- support for the new Marvell wire-to-MSI bridge
- support for the Aspeed I2C irqchip
- Armada XP370 per-cpu interrupt fixes
- GICv3 ITS ACPI NUMA support
- sunxi-nmi cleanup and updates for new platform support
- various GICv3 ITS cleanups and fixes
- some constifying in various places

1 files changed, 129 insertions, 17 deletions

diff --git a/drivers/irqchip/irq-armada-370-xp.c b/drivers/irqchip/irq-armada-370-xp.c
index 5e16d042f281..b207b2c3aa55 100644
--- a/drivers/irqchip/irq-armada-370-xp.c
+++ b/drivers/irqchip/irq-armada-370-xp.c
@@ -34,25 +34,104 @@
 #include <asm/smp_plat.h>
 #include <asm/mach/irq.h>
 
-/* Interrupt Controller Registers Map */
-#define ARMADA_370_XP_INT_SET_MASK_OFFS		(0x48)
-#define ARMADA_370_XP_INT_CLEAR_MASK_OFFS	(0x4C)
-#define ARMADA_370_XP_INT_FABRIC_MASK_OFFS	(0x54)
-#define ARMADA_370_XP_INT_CAUSE_PERF(cpu)	(1 << cpu)
+/*
+ * Overall diagram of the Armada XP interrupt controller:
+ *
+ *    To CPU 0                 To CPU 1
+ *
+ *       /\                       /\
+ *       ||                       ||
+ * +---------------+     +---------------+
+ * |               |	 |               |
+ * |    per-CPU    |	 |    per-CPU    |
+ * |  mask/unmask  |	 |  mask/unmask  |
+ * |     CPU0      |	 |     CPU1      |
+ * |               |	 |               |
+ * +---------------+	 +---------------+
+ *        /\                       /\
+ *        ||                       ||
+ *        \\_______________________//
+ *                     ||
+ *            +-------------------+
+ *            |                   |
+ *            | Global interrupt  |
+ *            |    mask/unmask    |
+ *            |                   |
+ *            +-------------------+
+ *                     /\
+ *                     ||
+ *               interrupt from
+ *                   device
+ *
+ * The "global interrupt mask/unmask" is modified using the
+ * ARMADA_370_XP_INT_SET_ENABLE_OFFS and
+ * ARMADA_370_XP_INT_CLEAR_ENABLE_OFFS registers, which are relative
+ * to "main_int_base".
+ *
+ * The "per-CPU mask/unmask" is modified using the
+ * ARMADA_370_XP_INT_SET_MASK_OFFS and
+ * ARMADA_370_XP_INT_CLEAR_MASK_OFFS registers, which are relative to
+ * "per_cpu_int_base". This base address points to a special address,
+ * which automatically accesses the registers of the current CPU.
+ *
+ * The per-CPU mask/unmask can also be adjusted using the global
+ * per-interrupt ARMADA_370_XP_INT_SOURCE_CTL register, which we use
+ * to configure interrupt affinity.
+ *
+ * Due to this model, all interrupts need to be mask/unmasked at two
+ * different levels: at the global level and at the per-CPU level.
+ *
+ * This driver takes the following approach to deal with this:
+ *
+ *  - For global interrupts:
+ *
+ *    At ->map() time, a global interrupt is unmasked at the per-CPU
+ *    mask/unmask level. It is therefore unmasked at this level for
+ *    the current CPU, running the ->map() code. This allows to have
+ *    the interrupt unmasked at this level in non-SMP
+ *    configurations. In SMP configurations, the ->set_affinity()
+ *    callback is called, which using the
+ *    ARMADA_370_XP_INT_SOURCE_CTL() readjusts the per-CPU mask/unmask
+ *    for the interrupt.
+ *
+ *    The ->mask() and ->unmask() operations only mask/unmask the
+ *    interrupt at the "global" level.
+ *
+ *    So, a global interrupt is enabled at the per-CPU level as soon
+ *    as it is mapped. At run time, the masking/unmasking takes place
+ *    at the global level.
+ *
+ *  - For per-CPU interrupts
+ *
+ *    At ->map() time, a per-CPU interrupt is unmasked at the global
+ *    mask/unmask level.
+ *
+ *    The ->mask() and ->unmask() operations mask/unmask the interrupt
+ *    at the per-CPU level.
+ *
+ *    So, a per-CPU interrupt is enabled at the global level as soon
+ *    as it is mapped. At run time, the masking/unmasking takes place
+ *    at the per-CPU level.
+ */
 
+/* Registers relative to main_int_base */
 #define ARMADA_370_XP_INT_CONTROL		(0x00)
+#define ARMADA_370_XP_SW_TRIG_INT_OFFS		(0x04)
 #define ARMADA_370_XP_INT_SET_ENABLE_OFFS	(0x30)
 #define ARMADA_370_XP_INT_CLEAR_ENABLE_OFFS	(0x34)
 #define ARMADA_370_XP_INT_SOURCE_CTL(irq)	(0x100 + irq*4)
 #define ARMADA_370_XP_INT_SOURCE_CPU_MASK	0xF
 #define ARMADA_370_XP_INT_IRQ_FIQ_MASK(cpuid)	((BIT(0) | BIT(8)) << cpuid)
 
-#define ARMADA_370_XP_CPU_INTACK_OFFS		(0x44)
+/* Registers relative to per_cpu_int_base */
+#define ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS	(0x08)
+#define ARMADA_370_XP_IN_DRBEL_MSK_OFFS		(0x0c)
 #define ARMADA_375_PPI_CAUSE			(0x10)
-
-#define ARMADA_370_XP_SW_TRIG_INT_OFFS           (0x4)
-#define ARMADA_370_XP_IN_DRBEL_MSK_OFFS          (0xc)
-#define ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS        (0x8)
+#define ARMADA_370_XP_CPU_INTACK_OFFS		(0x44)
+#define ARMADA_370_XP_INT_SET_MASK_OFFS		(0x48)
+#define ARMADA_370_XP_INT_CLEAR_MASK_OFFS	(0x4C)
+#define ARMADA_370_XP_INT_FABRIC_MASK_OFFS	(0x54)
+#define ARMADA_370_XP_INT_CAUSE_PERF(cpu)	(1 << cpu)
 
 #define ARMADA_370_XP_MAX_PER_CPU_IRQS		(28)
 
@@ -281,13 +360,11 @@ static int armada_370_xp_mpic_irq_map(struct irq_domain *h,
 		irq_set_percpu_devid(virq);
 		irq_set_chip_and_handler(virq, &armada_370_xp_irq_chip,
 					handle_percpu_devid_irq);
-
 	} else {
 		irq_set_chip_and_handler(virq, &armada_370_xp_irq_chip,
 					handle_level_irq);
 	}
 	irq_set_probe(virq);
-	irq_clear_status_flags(virq, IRQ_NOAUTOEN);
 
 	return 0;
 }
@@ -345,16 +422,40 @@ static void armada_mpic_send_doorbell(const struct cpumask *mask,
 		ARMADA_370_XP_SW_TRIG_INT_OFFS);
 }
 
+static void armada_xp_mpic_reenable_percpu(void)
+{
+	unsigned int irq;
+
+	/* Re-enable per-CPU interrupts that were enabled before suspend */
+	for (irq = 0; irq < ARMADA_370_XP_MAX_PER_CPU_IRQS; irq++) {
+		struct irq_data *data;
+		int virq;
+
+		virq = irq_linear_revmap(armada_370_xp_mpic_domain, irq);
+		if (virq == 0)
+			continue;
+
+		data = irq_get_irq_data(virq);
+
+		if (!irq_percpu_is_enabled(virq))
+			continue;
+
+		armada_370_xp_irq_unmask(data);
+	}
+}
+
 static int armada_xp_mpic_starting_cpu(unsigned int cpu)
 {
 	armada_xp_mpic_perf_init();
 	armada_xp_mpic_smp_cpu_init();
+	armada_xp_mpic_reenable_percpu();
 	return 0;
 }
 
 static int mpic_cascaded_starting_cpu(unsigned int cpu)
 {
 	armada_xp_mpic_perf_init();
+	armada_xp_mpic_reenable_percpu();
 	enable_percpu_irq(parent_irq, IRQ_TYPE_NONE);
 	return 0;
 }
@@ -502,16 +603,27 @@ static void armada_370_xp_mpic_resume(void)
 		if (virq == 0)
 			continue;
 
-		if (!is_percpu_irq(irq))
+		data = irq_get_irq_data(virq);
+
+		if (!is_percpu_irq(irq)) {
+			/* Non per-CPU interrupts */
 			writel(irq, per_cpu_int_base +
 			       ARMADA_370_XP_INT_CLEAR_MASK_OFFS);
-		else
+			if (!irqd_irq_disabled(data))
+				armada_370_xp_irq_unmask(data);
+		} else {
+			/* Per-CPU interrupts */
 			writel(irq, main_int_base +
 			       ARMADA_370_XP_INT_SET_ENABLE_OFFS);
 
-		data = irq_get_irq_data(virq);
-		if (!irqd_irq_disabled(data))
-			armada_370_xp_irq_unmask(data);
+			/*
+			 * Re-enable on the current CPU,
+			 * armada_xp_mpic_reenable_percpu() will take
+			 * care of secondary CPUs when they come up.
+			 */
+			if (irq_percpu_is_enabled(virq))
+				armada_370_xp_irq_unmask(data);
+		}
 	}
 
 	/* Reconfigure doorbells for IPIs and MSIs */