irqchip: hip04: Enable Hisilicon HiP04 interrupt controller

HiP04 GIC is the variate of ARM GICv2.

ARM GICv2 supports 8 cores. HiP04 GIC extends to support 16 cores. It
results that bit fields in GIC_DIST_TARGET & GIC_DIST_SOFTINT are
different from ARM GICv2. And the maximium IRQ is downgrade from 1020 to 510.

Since different register offset & bitfields definitation breaks
compartible with ARM GICv2, create a new hip04 irq driver.

And this driver is derived from irq-gic.c to support the Hisilicon HiP04
interrupt controller, which is similar to the GIC, but deviates at some
points. Support for power management, non-banked registers, cascaded
GICs (and multiple controllers in general) and bigLittle support has
been removed from the GIC driver.

Affinity related functions have been adjusted to match the Hisilicon
hardware implementation.

Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Link: https://lkml.kernel.org/r/1407408695-19626-9-git-send-email-haojian.zhuang@linaro.org
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

2 files changed, 425 insertions, 0 deletions

diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 73052ba9ca6..1dca5bc2cc4 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -2,6 +2,7 @@ obj-$(CONFIG_IRQCHIP)			+= irqchip.o
 
 obj-$(CONFIG_ARCH_BCM2835)		+= irq-bcm2835.o
 obj-$(CONFIG_ARCH_EXYNOS)		+= exynos-combiner.o
+obj-$(CONFIG_ARCH_HIP04)		+= irq-hip04.o
 obj-$(CONFIG_ARCH_MMP)			+= irq-mmp.o
 obj-$(CONFIG_ARCH_MVEBU)		+= irq-armada-370-xp.o
 obj-$(CONFIG_ARCH_MXS)			+= irq-mxs.o
diff --git a/drivers/irqchip/irq-hip04.c b/drivers/irqchip/irq-hip04.c
new file mode 100644
index 00000000000..9c8f833522e
--- /dev/null
+++ b/drivers/irqchip/irq-hip04.c
@@ -0,0 +1,424 @@
+/*
+ * Hisilicon HiP04 INTC
+ *
+ * Copyright (C) 2002-2014 ARM Limited.
+ * Copyright (c) 2013-2014 Hisilicon Ltd.
+ * Copyright (c) 2013-2014 Linaro Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Interrupt architecture for the HIP04 INTC:
+ *
+ * o There is one Interrupt Distributor, which receives interrupts
+ *   from system devices and sends them to the Interrupt Controllers.
+ *
+ * o There is one CPU Interface per CPU, which sends interrupts sent
+ *   by the Distributor, and interrupts generated locally, to the
+ *   associated CPU. The base address of the CPU interface is usually
+ *   aliased so that the same address points to different chips depending
+ *   on the CPU it is accessed from.
+ *
+ * Note that IRQs 0-31 are special - they are local to each CPU.
+ * As such, the enable set/clear, pending set/clear and active bit
+ * registers are banked per-cpu for these sources.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/smp.h>
+#include <linux/cpu.h>
+#include <linux/cpu_pm.h>
+#include <linux/cpumask.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/irqchip/arm-gic.h>
+
+#include <asm/irq.h>
+#include <asm/exception.h>
+#include <asm/smp_plat.h>
+
+#include "irq-gic-common.h"
+#include "irqchip.h"
+
+#define HIP04_MAX_IRQS		510
+
+struct hip04_irq_data {
+	void __iomem *dist_base;
+	void __iomem *cpu_base;
+	struct irq_domain *domain;
+	unsigned int nr_irqs;
+};
+
+static DEFINE_RAW_SPINLOCK(irq_controller_lock);
+
+/*
+ * The GIC mapping of CPU interfaces does not necessarily match
+ * the logical CPU numbering.  Let's use a mapping as returned
+ * by the GIC itself.
+ */
+#define NR_HIP04_CPU_IF 16
+static u16 hip04_cpu_map[NR_HIP04_CPU_IF] __read_mostly;
+
+static struct hip04_irq_data hip04_data __read_mostly;
+
+static inline void __iomem *hip04_dist_base(struct irq_data *d)
+{
+	struct hip04_irq_data *hip04_data = irq_data_get_irq_chip_data(d);
+	return hip04_data->dist_base;
+}
+
+static inline void __iomem *hip04_cpu_base(struct irq_data *d)
+{
+	struct hip04_irq_data *hip04_data = irq_data_get_irq_chip_data(d);
+	return hip04_data->cpu_base;
+}
+
+static inline unsigned int hip04_irq(struct irq_data *d)
+{
+	return d->hwirq;
+}
+
+/*
+ * Routines to acknowledge, disable and enable interrupts
+ */
+static void hip04_mask_irq(struct irq_data *d)
+{
+	u32 mask = 1 << (hip04_irq(d) % 32);
+
+	raw_spin_lock(&irq_controller_lock);
+	writel_relaxed(mask, hip04_dist_base(d) + GIC_DIST_ENABLE_CLEAR +
+		       (hip04_irq(d) / 32) * 4);
+	raw_spin_unlock(&irq_controller_lock);
+}
+
+static void hip04_unmask_irq(struct irq_data *d)
+{
+	u32 mask = 1 << (hip04_irq(d) % 32);
+
+	raw_spin_lock(&irq_controller_lock);
+	writel_relaxed(mask, hip04_dist_base(d) + GIC_DIST_ENABLE_SET +
+		       (hip04_irq(d) / 32) * 4);
+	raw_spin_unlock(&irq_controller_lock);
+}
+
+static void hip04_eoi_irq(struct irq_data *d)
+{
+	writel_relaxed(hip04_irq(d), hip04_cpu_base(d) + GIC_CPU_EOI);
+}
+
+static int hip04_irq_set_type(struct irq_data *d, unsigned int type)
+{
+	void __iomem *base = hip04_dist_base(d);
+	unsigned int irq = hip04_irq(d);
+
+	/* Interrupt configuration for SGIs can't be changed */
+	if (irq < 16)
+		return -EINVAL;
+
+	if (type != IRQ_TYPE_LEVEL_HIGH && type != IRQ_TYPE_EDGE_RISING)
+		return -EINVAL;
+
+	raw_spin_lock(&irq_controller_lock);
+
+	gic_configure_irq(irq, type, base, NULL);
+
+	raw_spin_unlock(&irq_controller_lock);
+
+	return 0;
+}
+
+#ifdef CONFIG_SMP
+static int hip04_irq_set_affinity(struct irq_data *d,
+				  const struct cpumask *mask_val,
+				  bool force)
+{
+	void __iomem *reg;
+	unsigned int cpu, shift = (hip04_irq(d) % 2) * 16;
+	u32 val, mask, bit;
+
+	if (!force)
+		cpu = cpumask_any_and(mask_val, cpu_online_mask);
+	else
+		cpu = cpumask_first(mask_val);
+
+	if (cpu >= NR_HIP04_CPU_IF || cpu >= nr_cpu_ids)
+		return -EINVAL;
+
+	raw_spin_lock(&irq_controller_lock);
+	reg = hip04_dist_base(d) + GIC_DIST_TARGET + ((hip04_irq(d) * 2) & ~3);
+	mask = 0xffff << shift;
+	bit = hip04_cpu_map[cpu] << shift;
+	val = readl_relaxed(reg) & ~mask;
+	writel_relaxed(val | bit, reg);
+	raw_spin_unlock(&irq_controller_lock);
+
+	return IRQ_SET_MASK_OK;
+}
+#endif
+
+static void __exception_irq_entry hip04_handle_irq(struct pt_regs *regs)
+{
+	u32 irqstat, irqnr;
+	void __iomem *cpu_base = hip04_data.cpu_base;
+
+	do {
+		irqstat = readl_relaxed(cpu_base + GIC_CPU_INTACK);
+		irqnr = irqstat & GICC_IAR_INT_ID_MASK;
+
+		if (likely(irqnr > 15 && irqnr <= HIP04_MAX_IRQS)) {
+			irqnr = irq_find_mapping(hip04_data.domain, irqnr);
+			handle_IRQ(irqnr, regs);
+			continue;
+		}
+		if (irqnr < 16) {
+			writel_relaxed(irqstat, cpu_base + GIC_CPU_EOI);
+#ifdef CONFIG_SMP
+			handle_IPI(irqnr, regs);
+#endif
+			continue;
+		}
+		break;
+	} while (1);
+}
+
+static struct irq_chip hip04_irq_chip = {
+	.name			= "HIP04 INTC",
+	.irq_mask		= hip04_mask_irq,
+	.irq_unmask		= hip04_unmask_irq,
+	.irq_eoi		= hip04_eoi_irq,
+	.irq_set_type		= hip04_irq_set_type,
+#ifdef CONFIG_SMP
+	.irq_set_affinity	= hip04_irq_set_affinity,
+#endif
+};
+
+static u16 hip04_get_cpumask(struct hip04_irq_data *intc)
+{
+	void __iomem *base = intc->dist_base;
+	u32 mask, i;
+
+	for (i = mask = 0; i < 32; i += 2) {
+		mask = readl_relaxed(base + GIC_DIST_TARGET + i * 2);
+		mask |= mask >> 16;
+		if (mask)
+			break;
+	}
+
+	if (!mask)
+		pr_crit("GIC CPU mask not found - kernel will fail to boot.\n");
+
+	return mask;
+}
+
+static void __init hip04_irq_dist_init(struct hip04_irq_data *intc)
+{
+	unsigned int i;
+	u32 cpumask;
+	unsigned int nr_irqs = intc->nr_irqs;
+	void __iomem *base = intc->dist_base;
+
+	writel_relaxed(0, base + GIC_DIST_CTRL);
+
+	/*
+	 * Set all global interrupts to this CPU only.
+	 */
+	cpumask = hip04_get_cpumask(intc);
+	cpumask |= cpumask << 16;
+	for (i = 32; i < nr_irqs; i += 2)
+		writel_relaxed(cpumask, base + GIC_DIST_TARGET + ((i * 2) & ~3));
+
+	gic_dist_config(base, nr_irqs, NULL);
+
+	writel_relaxed(1, base + GIC_DIST_CTRL);
+}
+
+static void hip04_irq_cpu_init(struct hip04_irq_data *intc)
+{
+	void __iomem *dist_base = intc->dist_base;
+	void __iomem *base = intc->cpu_base;
+	unsigned int cpu_mask, cpu = smp_processor_id();
+	int i;
+
+	/*
+	 * Get what the GIC says our CPU mask is.
+	 */
+	BUG_ON(cpu >= NR_HIP04_CPU_IF);
+	cpu_mask = hip04_get_cpumask(intc);
+	hip04_cpu_map[cpu] = cpu_mask;
+
+	/*
+	 * Clear our mask from the other map entries in case they're
+	 * still undefined.
+	 */
+	for (i = 0; i < NR_HIP04_CPU_IF; i++)
+		if (i != cpu)
+			hip04_cpu_map[i] &= ~cpu_mask;
+
+	gic_cpu_config(dist_base, NULL);
+
+	writel_relaxed(0xf0, base + GIC_CPU_PRIMASK);
+	writel_relaxed(1, base + GIC_CPU_CTRL);
+}
+
+#ifdef CONFIG_SMP
+static void hip04_raise_softirq(const struct cpumask *mask, unsigned int irq)
+{
+	int cpu;
+	unsigned long flags, map = 0;
+
+	raw_spin_lock_irqsave(&irq_controller_lock, flags);
+
+	/* Convert our logical CPU mask into a physical one. */
+	for_each_cpu(cpu, mask)
+		map |= hip04_cpu_map[cpu];
+
+	/*
+	 * Ensure that stores to Normal memory are visible to the
+	 * other CPUs before they observe us issuing the IPI.
+	 */
+	dmb(ishst);
+
+	/* this always happens on GIC0 */
+	writel_relaxed(map << 8 | irq, hip04_data.dist_base + GIC_DIST_SOFTINT);
+
+	raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
+}
+#endif
+
+static int hip04_irq_domain_map(struct irq_domain *d, unsigned int irq,
+				irq_hw_number_t hw)
+{
+	if (hw < 32) {
+		irq_set_percpu_devid(irq);
+		irq_set_chip_and_handler(irq, &hip04_irq_chip,
+					 handle_percpu_devid_irq);
+		set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN);
+	} else {
+		irq_set_chip_and_handler(irq, &hip04_irq_chip,
+					 handle_fasteoi_irq);
+		set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
+	}
+	irq_set_chip_data(irq, d->host_data);
+	return 0;
+}
+
+static int hip04_irq_domain_xlate(struct irq_domain *d,
+				  struct device_node *controller,
+				  const u32 *intspec, unsigned int intsize,
+				  unsigned long *out_hwirq,
+				  unsigned int *out_type)
+{
+	unsigned long ret = 0;
+
+	if (d->of_node != controller)
+		return -EINVAL;
+	if (intsize < 3)
+		return -EINVAL;
+
+	/* Get the interrupt number and add 16 to skip over SGIs */
+	*out_hwirq = intspec[1] + 16;
+
+	/* For SPIs, we need to add 16 more to get the irq ID number */
+	if (!intspec[0])
+		*out_hwirq += 16;
+
+	*out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
+
+	return ret;
+}
+
+#ifdef CONFIG_SMP
+static int hip04_irq_secondary_init(struct notifier_block *nfb,
+				    unsigned long action,
+				    void *hcpu)
+{
+	if (action == CPU_STARTING || action == CPU_STARTING_FROZEN)
+		hip04_irq_cpu_init(&hip04_data);
+	return NOTIFY_OK;
+}
+
+/*
+ * Notifier for enabling the INTC CPU interface. Set an arbitrarily high
+ * priority because the GIC needs to be up before the ARM generic timers.
+ */
+static struct notifier_block hip04_irq_cpu_notifier = {
+	.notifier_call	= hip04_irq_secondary_init,
+	.priority	= 100,
+};
+#endif
+
+static const struct irq_domain_ops hip04_irq_domain_ops = {
+	.map	= hip04_irq_domain_map,
+	.xlate	= hip04_irq_domain_xlate,
+};
+
+static int __init
+hip04_of_init(struct device_node *node, struct device_node *parent)
+{
+	irq_hw_number_t hwirq_base = 16;
+	int nr_irqs, irq_base, i;
+
+	if (WARN_ON(!node))
+		return -ENODEV;
+
+	hip04_data.dist_base = of_iomap(node, 0);
+	WARN(!hip04_data.dist_base, "fail to map hip04 intc dist registers\n");
+
+	hip04_data.cpu_base = of_iomap(node, 1);
+	WARN(!hip04_data.cpu_base, "unable to map hip04 intc cpu registers\n");
+
+	/*
+	 * Initialize the CPU interface map to all CPUs.
+	 * It will be refined as each CPU probes its ID.
+	 */
+	for (i = 0; i < NR_HIP04_CPU_IF; i++)
+		hip04_cpu_map[i] = 0xff;
+
+	/*
+	 * Find out how many interrupts are supported.
+	 * The HIP04 INTC only supports up to 510 interrupt sources.
+	 */
+	nr_irqs = readl_relaxed(hip04_data.dist_base + GIC_DIST_CTR) & 0x1f;
+	nr_irqs = (nr_irqs + 1) * 32;
+	if (nr_irqs > HIP04_MAX_IRQS)
+		nr_irqs = HIP04_MAX_IRQS;
+	hip04_data.nr_irqs = nr_irqs;
+
+	nr_irqs -= hwirq_base; /* calculate # of irqs to allocate */
+
+	irq_base = irq_alloc_descs(-1, hwirq_base, nr_irqs, numa_node_id());
+	if (IS_ERR_VALUE(irq_base)) {
+		pr_err("failed to allocate IRQ numbers\n");
+		return -EINVAL;
+	}
+
+	hip04_data.domain = irq_domain_add_legacy(node, nr_irqs, irq_base,
+						  hwirq_base,
+						  &hip04_irq_domain_ops,
+						  &hip04_data);
+
+	if (WARN_ON(!hip04_data.domain))
+		return -EINVAL;
+
+#ifdef CONFIG_SMP
+	set_smp_cross_call(hip04_raise_softirq);
+	register_cpu_notifier(&hip04_irq_cpu_notifier);
+#endif
+	set_handle_irq(hip04_handle_irq);
+
+	hip04_irq_dist_init(&hip04_data);
+	hip04_irq_cpu_init(&hip04_data);
+
+	return 0;
+}
+IRQCHIP_DECLARE(hip04_intc, "hisilicon,hip04-intc", hip04_of_init);