/*
 *  linux/arch/arm/common/gic.c
 *
 *  Copyright (C) 2002 ARM Limited, All Rights Reserved.
 *
 * 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 GIC:
 *
 * 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/percpu.h>
#include <linux/slab.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/irqchip/arm-gic.h>

#include <asm/irq.h>
#include <asm/exception.h>
#include <asm/smp_plat.h>

#include "irqchip.h"

union gic_base {
        void __iomem *common_base;
        void __percpu __iomem **percpu_base;
};

struct gic_chip_data {
        union gic_base dist_base;
        union gic_base cpu_base;
#ifdef CONFIG_CPU_PM
        u32 saved_spi_enable[DIV_ROUND_UP(1020, 32)];
        u32 saved_spi_conf[DIV_ROUND_UP(1020, 16)];
        u32 saved_spi_target[DIV_ROUND_UP(1020, 4)];
        u32 __percpu *saved_ppi_enable;
        u32 __percpu *saved_ppi_conf;
#endif
        struct irq_domain *domain;
        unsigned int gic_irqs;
#ifdef CONFIG_GIC_NON_BANKED
        void __iomem *(*get_base)(union gic_base *);
#endif
};

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_GIC_CPU_IF 8
static u8 gic_cpu_map[NR_GIC_CPU_IF] __read_mostly;

/*
 * Supported arch specific GIC irq extension.
 * Default make them NULL.
 */
struct irq_chip gic_arch_extn = {
        .irq_eoi        = NULL,
        .irq_mask       = NULL,
        .irq_unmask     = NULL,
        .irq_retrigger  = NULL,
        .irq_set_type   = NULL,
        .irq_set_wake   = NULL,
};

#ifndef MAX_GIC_NR
#define MAX_GIC_NR      1
#endif

static struct gic_chip_data gic_data[MAX_GIC_NR] __read_mostly;

#ifdef CONFIG_GIC_NON_BANKED
static void __iomem *gic_get_percpu_base(union gic_base *base)
{
        return *__this_cpu_ptr(base->percpu_base);
}

static void __iomem *gic_get_common_base(union gic_base *base)
{
        return base->common_base;
}

static inline void __iomem *gic_data_dist_base(struct gic_chip_data *data)
{
        return data->get_base(&data->dist_base);
}

static inline void __iomem *gic_data_cpu_base(struct gic_chip_data *data)
{
        return data->get_base(&data->cpu_base);
}

static inline void gic_set_base_accessor(struct gic_chip_data *data,
                                         void __iomem *(*f)(union gic_base *))
{
        data->get_base = f;
}
#else
#define gic_data_dist_base(d)   ((d)->dist_base.common_base)
#define gic_data_cpu_base(d)    ((d)->cpu_base.common_base)
#define gic_set_base_accessor(d, f)
#endif

static inline void __iomem *gic_dist_base(struct irq_data *d)
{
        struct gic_chip_data *gic_data = irq_data_get_irq_chip_data(d);
        return gic_data_dist_base(gic_data);
}

static inline void __iomem *gic_cpu_base(struct irq_data *d)
{
        struct gic_chip_data *gic_data = irq_data_get_irq_chip_data(d);
        return gic_data_cpu_base(gic_data);
}

static inline unsigned int gic_irq(struct irq_data *d)
{
        return d->hwirq;
}

/*
 * Routines to acknowledge, disable and enable interrupts
 */
static void gic_mask_irq(struct irq_data *d)
{
        u32 mask = 1 << (gic_irq(d) % 32);

        raw_spin_lock(&irq_controller_lock);
        writel_relaxed(mask, gic_dist_base(d) + GIC_DIST_ENABLE_CLEAR + (gic_irq(d) / 32) * 4);
        if (gic_arch_extn.irq_mask)
                gic_arch_extn.irq_mask(d);
        raw_spin_unlock(&irq_controller_lock);
}

static void gic_unmask_irq(struct irq_data *d)
{
        u32 mask = 1 << (gic_irq(d) % 32);

        raw_spin_lock(&irq_controller_lock);
        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);
        raw_spin_unlock(&irq_controller_lock);
}

static void gic_eoi_irq(struct irq_data *d)
{
        if (gic_arch_extn.irq_eoi) {
                raw_spin_lock(&irq_controller_lock);
                gic_arch_extn.irq_eoi(d);
                raw_spin_unlock(&irq_controller_lock);
        }

        writel_relaxed(gic_irq(d), gic_cpu_base(d) + GIC_CPU_EOI);
}

static int gic_set_type(struct irq_data *d, unsigned int type)
{
        void __iomem *base = gic_dist_base(d);
        unsigned int gicirq = gic_irq(d);
        u32 enablemask = 1 << (gicirq % 32);
        u32 enableoff = (gicirq / 32) * 4;
        u32 confmask = 0x2 << ((gicirq % 16) * 2);
        u32 confoff = (gicirq / 16) * 4;
        bool enabled = false;
        u32 val;

        /* Interrupt configuration for SGIs can't be changed */
        if (gicirq < 16)
                return -EINVAL;

        if (type != IRQ_TYPE_LEVEL_HIGH && type != IRQ_TYPE_EDGE_RISING)
                return -EINVAL;

        raw_spin_lock(&irq_controller_lock);

        if (gic_arch_extn.irq_set_type)
                gic_arch_extn.irq_set_type(d, type);

        val = readl_relaxed(base + GIC_DIST_CONFIG + confoff);
        if (type == IRQ_TYPE_LEVEL_HIGH)
                val &= ~confmask;
        else if (type == IRQ_TYPE_EDGE_RISING)
                val |= confmask;

        /*
         * As recommended by the spec, disable the interrupt before changing
         * the configuration
         */
        if (readl_relaxed(base + GIC_DIST_ENABLE_SET + enableoff) & enablemask) {
                writel_relaxed(enablemask, base + GIC_DIST_ENABLE_CLEAR + enableoff);
                enabled = true;
        }

        writel_relaxed(val, base + GIC_DIST_CONFIG + confoff);

        if (enabled)
                writel_relaxed(enablemask, base + GIC_DIST_ENABLE_SET + enableoff);

        raw_spin_unlock(&irq_controller_lock);

        return 0;
}

static int gic_retrigger(struct irq_data *d)
{
        if (gic_arch_extn.irq_retrigger)
                return gic_arch_extn.irq_retrigger(d);

        /* the genirq layer expects 0 if we can't retrigger in hardware */
        return 0;
}

#ifdef CONFIG_SMP
static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
                            bool force)
{
        void __iomem *reg = gic_dist_base(d) + GIC_DIST_TARGET + (gic_irq(d) & ~3);
        unsigned int shift = (gic_irq(d) % 4) * 8;
        unsigned int cpu = cpumask_any_and(mask_val, cpu_online_mask);
        u32 val, mask, bit;

        if (cpu >= NR_GIC_CPU_IF || cpu >= nr_cpu_ids)
                return -EINVAL;

        raw_spin_lock(&irq_controller_lock);
        mask = 0xff << shift;
        bit = gic_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

#ifdef CONFIG_PM
static int gic_set_wake(struct irq_data *d, unsigned int on)
{
        int ret = -ENXIO;

        if (gic_arch_extn.irq_set_wake)
                ret = gic_arch_extn.irq_set_wake(d, on);

        return ret;
}

#else
#define gic_set_wake    NULL
#endif

static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs)
{
        u32 irqstat, irqnr;
        struct gic_chip_data *gic = &gic_data[0];
        void __iomem *cpu_base = gic_data_cpu_base(gic);

        do {
                irqstat = readl_relaxed(cpu_base + GIC_CPU_INTACK);
                irqnr = irqstat & ~0x1c00;

                if (likely(irqnr > 15 && irqnr < 1021)) {
                        irqnr = irq_find_mapping(gic->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 void gic_handle_cascade_irq(unsigned int irq, struct irq_desc *desc)
{
        struct gic_chip_data *chip_data = irq_get_handler_data(irq);
        struct irq_chip *chip = irq_get_chip(irq);
        unsigned int cascade_irq, gic_irq;
        unsigned long status;

        chained_irq_enter(chip, desc);

        raw_spin_lock(&irq_controller_lock);
        status = readl_relaxed(gic_data_cpu_base(chip_data) + GIC_CPU_INTACK);
        raw_spin_unlock(&irq_controller_lock);

        gic_irq = (status & 0x3ff);
        if (gic_irq == 1023)
                goto out;

        cascade_irq = irq_find_mapping(chip_data->domain, gic_irq);
        if (unlikely(gic_irq < 32 || gic_irq > 1020))
                handle_bad_irq(cascade_irq, desc);
        else
                generic_handle_irq(cascade_irq);

 out:
        chained_irq_exit(chip, desc);
}

static struct irq_chip gic_chip = {
        .name                   = "GIC",
        .irq_mask               = gic_mask_irq,
        .irq_unmask             = gic_unmask_irq,
        .irq_eoi                = gic_eoi_irq,
        .irq_set_type           = gic_set_type,
        .irq_retrigger          = gic_retrigger,
#ifdef CONFIG_SMP
        .irq_set_affinity       = gic_set_affinity,
#endif
        .irq_set_wake           = gic_set_wake,
};

void __init gic_cascade_irq(unsigned int gic_nr, unsigned int irq)
{
        if (gic_nr >= MAX_GIC_NR)
                BUG();
        if (irq_set_handler_data(irq, &gic_data[gic_nr]) != 0)
                BUG();
        irq_set_chained_handler(irq, gic_handle_cascade_irq);
}

static u8 gic_get_cpumask(struct gic_chip_data *gic)
{
        void __iomem *base = gic_data_dist_base(gic);
        u32 mask, i;

        for (i = mask = 0; i < 32; i += 4) {
                mask = readl_relaxed(base + GIC_DIST_TARGET + i);
                mask |= mask >> 16;
                mask |= mask >> 8;
                if (mask)
                        break;
        }

        if (!mask)
                pr_crit("GIC CPU mask not found - kernel will fail to boot.\n");

        return mask;
}

static void __init gic_dist_init(struct gic_chip_data *gic)
{
        unsigned int i;
        u32 cpumask;
        unsigned int gic_irqs = gic->gic_irqs;
        void __iomem *base = gic_data_dist_base(gic);

        writel_relaxed(0, base + GIC_DIST_CTRL);

        /*
         * Set all global interrupts to be level triggered, active low.
         */
        for (i = 32; i < gic_irqs; i += 16)
                writel_relaxed(0, base + GIC_DIST_CONFIG + i * 4 / 16);

        /*
         * Set all global interrupts to this CPU only.
         */
        cpumask = gic_get_cpumask(gic);
        cpumask |= cpumask << 8;
        cpumask |= cpumask << 16;
        for (i = 32; i < gic_irqs; i += 4)
                writel_relaxed(cpumask, base + GIC_DIST_TARGET + i * 4 / 4);

        /*
         * Set priority on all global interrupts.
         */
        for (i = 32; i < gic_irqs; i += 4)
                writel_relaxed(0xa0a0a0a0, base + GIC_DIST_PRI + i * 4 / 4);

        /*
         * Disable all interrupts.  Leave the PPI and SGIs alone
         * as these enables are banked registers.
         */
        for (i = 32; i < gic_irqs; i += 32)
                writel_relaxed(0xffffffff, base + GIC_DIST_ENABLE_CLEAR + i * 4 / 32);

        writel_relaxed(1, base + GIC_DIST_CTRL);
}

static void gic_cpu_init(struct gic_chip_data *gic)
{
        void __iomem *dist_base = gic_data_dist_base(gic);
        void __iomem *base = gic_data_cpu_base(gic);
        unsigned int cpu_mask, cpu = smp_processor_id();
        int i;

        /*
         * Get what the GIC says our CPU mask is.
         */
        BUG_ON(cpu >= NR_GIC_CPU_IF);
        cpu_mask = gic_get_cpumask(gic);
        gic_cpu_map[cpu] = cpu_mask;

        /*
         * Clear our mask from the other map entries in case they're
         * still undefined.
         */
        for (i = 0; i < NR_GIC_CPU_IF; i++)
                if (i != cpu)
                        gic_cpu_map[i] &= ~cpu_mask;

        /*
         * Deal with the banked PPI and SGI interrupts - disable all
         * PPI interrupts, ensure all SGI interrupts are enabled.
         */
        writel_relaxed(0xffff0000, dist_base + GIC_DIST_ENABLE_CLEAR);
        writel_relaxed(0x0000ffff, dist_base + GIC_DIST_ENABLE_SET);

        /*
         * Set priority on PPI and SGI interrupts
         */
        for (i = 0; i < 32; i += 4)
                writel_relaxed(0xa0a0a0a0, dist_base + GIC_DIST_PRI + i * 4 / 4);

        writel_relaxed(0xf0, base + GIC_CPU_PRIMASK);
        writel_relaxed(1, base + GIC_CPU_CTRL);
}

void gic_cpu_if_down(void)
{
        void __iomem *cpu_base = gic_data_cpu_base(&gic_data[0]);
        writel_relaxed(0, cpu_base + GIC_CPU_CTRL);
}

#ifdef CONFIG_CPU_PM
/*
 * Saves the GIC distributor registers during suspend or idle.  Must be called
 * with interrupts disabled but before powering down the GIC.  After calling
 * this function, no interrupts will be delivered by the GIC, and another
 * platform-specific wakeup source must be enabled.
 */
static void gic_dist_save(unsigned int gic_nr)
{
        unsigned int gic_irqs;
        void __iomem *dist_base;
        int i;

        if (gic_nr >= MAX_GIC_NR)
                BUG();

        gic_irqs = gic_data[gic_nr].gic_irqs;
        dist_base = gic_data_dist_base(&gic_data[gic_nr]);

        if (!dist_base)
                return;

        for (i = 0; i < DIV_ROUND_UP(gic_irqs, 16); i++)
                gic_data[gic_nr].saved_spi_conf[i] =
                        readl_relaxed(dist_base + GIC_DIST_CONFIG + i * 4);

        for (i = 0; i < DIV_ROUND_UP(gic_irqs, 4); i++)
                gic_data[gic_nr].saved_spi_target[i] =
                        readl_relaxed(dist_base + GIC_DIST_TARGET + i * 4);

        for (i = 0; i < DIV_ROUND_UP(gic_irqs, 32); i++)
                gic_data[gic_nr].saved_spi_enable[i] =
                        readl_relaxed(dist_base + GIC_DIST_ENABLE_SET + i * 4);
}

/*
 * Restores the GIC distributor registers during resume or when coming out of
 * idle.  Must be called before enabling interrupts.  If a level interrupt
 * that occured while the GIC was suspended is still present, it will be
 * handled normally, but any edge interrupts that occured will not be seen by
 * the GIC and need to be handled by the platform-specific wakeup source.
 */
static void gic_dist_restore(unsigned int gic_nr)
{
        unsigned int gic_irqs;
        unsigned int i;
        void __iomem *dist_base;

        if (gic_nr >= MAX_GIC_NR)
                BUG();

        gic_irqs = gic_data[gic_nr].gic_irqs;
        dist_base = gic_data_dist_base(&gic_data[gic_nr]);

        if (!dist_base)
                return;

        writel_relaxed(0, dist_base + GIC_DIST_CTRL);

        for (i = 0; i < DIV_ROUND_UP(gic_irqs, 16); i++)
                writel_relaxed(gic_data[gic_nr].saved_spi_conf[i],
                        dist_base + GIC_DIST_CONFIG + i * 4);

        for (i = 0; i < DIV_ROUND_UP(gic_irqs, 4); i++)
                writel_relaxed(0xa0a0a0a0,
                        dist_base + GIC_DIST_PRI + i * 4);

        for (i = 0; i < DIV_ROUND_UP(gic_irqs, 4); i++)
                writel_relaxed(gic_data[gic_nr].saved_spi_target[i],
                        dist_base + GIC_DIST_TARGET + i * 4);

        for (i = 0; i < DIV_ROUND_UP(gic_irqs, 32); i++)
                writel_relaxed(gic_data[gic_nr].saved_spi_enable[i],
                        dist_base + GIC_DIST_ENABLE_SET + i * 4);

        writel_relaxed(1, dist_base + GIC_DIST_CTRL);
}

static void gic_cpu_save(unsigned int gic_nr)
{
        int i;
        u32 *ptr;
        void __iomem *dist_base;
        void __iomem *cpu_base;

        if (gic_nr >= MAX_GIC_NR)
                BUG();

        dist_base = gic_data_dist_base(&gic_data[gic_nr]);
        cpu_base = gic_data_cpu_base(&gic_data[gic_nr]);

        if (!dist_base || !cpu_base)
                return;

        ptr = __this_cpu_ptr(gic_data[gic_nr].saved_ppi_enable);
        for (i = 0; i < DIV_ROUND_UP(32, 32); i++)
                ptr[i] = readl_relaxed(dist_base + GIC_DIST_ENABLE_SET + i * 4);

        ptr = __this_cpu_ptr(gic_data[gic_nr].saved_ppi_conf);
        for (i = 0; i < DIV_ROUND_UP(32, 16); i++)
                ptr[i] = readl_relaxed(dist_base + GIC_DIST_CONFIG + i * 4);

}

static void gic_cpu_restore(unsigned int gic_nr)
{
        int i;
        u32 *ptr;
        void __iomem *dist_base;
        void __iomem *cpu_base;

        if (gic_nr >= MAX_GIC_NR)
                BUG();

        dist_base = gic_data_dist_base(&gic_data[gic_nr]);
        cpu_base = gic_data_cpu_base(&gic_data[gic_nr]);

        if (!dist_base || !cpu_base)
                return;

        ptr = __this_cpu_ptr(gic_data[gic_nr].saved_ppi_enable);
        for (i = 0; i < DIV_ROUND_UP(32, 32); i++)
                writel_relaxed(ptr[i], dist_base + GIC_DIST_ENABLE_SET + i * 4);

        ptr = __this_cpu_ptr(gic_data[gic_nr].saved_ppi_conf);
        for (i = 0; i < DIV_ROUND_UP(32, 16); i++)
                writel_relaxed(ptr[i], dist_base + GIC_DIST_CONFIG + i * 4);

        for (i = 0; i < DIV_ROUND_UP(32, 4); i++)
                writel_relaxed(0xa0a0a0a0, dist_base + GIC_DIST_PRI + i * 4);

        writel_relaxed(0xf0, cpu_base + GIC_CPU_PRIMASK);
        writel_relaxed(1, cpu_base + GIC_CPU_CTRL);
}

static int gic_notifier(struct notifier_block *self, unsigned long cmd, void *v)
{
        int i;

        for (i = 0; i < MAX_GIC_NR; i++) {
#ifdef CONFIG_GIC_NON_BANKED
                /* Skip over unused GICs */
                if (!gic_data[i].get_base)
                        continue;
#endif
                switch (cmd) {
                case CPU_PM_ENTER:
                        gic_cpu_save(i);
                        break;
                case CPU_PM_ENTER_FAILED:
                case CPU_PM_EXIT:
                        gic_cpu_restore(i);
                        break;
                case CPU_CLUSTER_PM_ENTER:
                        gic_dist_save(i);
                        break;
                case CPU_CLUSTER_PM_ENTER_FAILED:
                case CPU_CLUSTER_PM_EXIT:
                        gic_dist_restore(i);
                        break;
                }
        }

        return NOTIFY_OK;
}

static struct notifier_block gic_notifier_block = {
        .notifier_call = gic_notifier,
};

static void __init gic_pm_init(struct gic_chip_data *gic)
{
        gic->saved_ppi_enable = __alloc_percpu(DIV_ROUND_UP(32, 32) * 4,
                sizeof(u32));
        BUG_ON(!gic->saved_ppi_enable);

        gic->saved_ppi_conf = __alloc_percpu(DIV_ROUND_UP(32, 16) * 4,
                sizeof(u32));
        BUG_ON(!gic->saved_ppi_conf);

        if (gic == &gic_data[0])
                cpu_pm_register_notifier(&gic_notifier_block);
}
#else
static void __init gic_pm_init(struct gic_chip_data *gic)
{
}
#endif

#ifdef CONFIG_SMP
void gic_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 |= gic_cpu_map[cpu];

        /*
         * Ensure that stores to Normal memory are visible to the
         * other CPUs before issuing the IPI.
         */
        dsb();

        /* this always happens on GIC0 */
        writel_relaxed(map << 16 | irq, gic_data_dist_base(&gic_data[0]) + GIC_DIST_SOFTINT);

        raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
}
#endif

#ifdef CONFIG_BL_SWITCHER
/*
 * gic_send_sgi - send a SGI directly to given CPU interface number
 *
 * cpu_id: the ID for the destination CPU interface
 * irq: the IPI number to send a SGI for
 */
void gic_send_sgi(unsigned int cpu_id, unsigned int irq)
{
        BUG_ON(cpu_id >= NR_GIC_CPU_IF);
        cpu_id = 1 << cpu_id;
        /* this always happens on GIC0 */
        writel_relaxed((cpu_id << 16) | irq, gic_data_dist_base(&gic_data[0]) + GIC_DIST_SOFTINT);
}

/*
 * gic_get_cpu_id - get the CPU interface ID for the specified CPU
 *
 * @cpu: the logical CPU number to get the GIC ID for.
 *
 * Return the CPU interface ID for the given logical CPU number,
 * or -1 if the CPU number is too large or the interface ID is
 * unknown (more than one bit set).
 */
int gic_get_cpu_id(unsigned int cpu)
{
        unsigned int cpu_bit;

        if (cpu >= NR_GIC_CPU_IF)
                return -1;
        cpu_bit = gic_cpu_map[cpu];
        if (cpu_bit & (cpu_bit - 1))
                return -1;
        return __ffs(cpu_bit);
}

/*
 * gic_migrate_target - migrate IRQs to another CPU interface
 *
 * @new_cpu_id: the CPU target ID to migrate IRQs to
 *
 * Migrate all peripheral interrupts with a target matching the current CPU
 * to the interface corresponding to @new_cpu_id.  The CPU interface mapping
 * is also updated.  Targets to other CPU interfaces are unchanged.
 * This must be called with IRQs locally disabled.
 */
void gic_migrate_target(unsigned int new_cpu_id)
{
        unsigned int cur_cpu_id, gic_irqs, gic_nr = 0;
        void __iomem *dist_base;
        int i, ror_val, cpu = smp_processor_id();
        u32 val, cur_target_mask, active_mask;

        if (gic_nr >= MAX_GIC_NR)
                BUG();

        dist_base = gic_data_dist_base(&gic_data[gic_nr]);
        if (!dist_base)
                return;
        gic_irqs = gic_data[gic_nr].gic_irqs;

        cur_cpu_id = __ffs(gic_cpu_map[cpu]);
        cur_target_mask = 0x01010101 << cur_cpu_id;
        ror_val = (cur_cpu_id - new_cpu_id) & 31;

        raw_spin_lock(&irq_controller_lock);

        /* Update the target interface for this logical CPU */
        gic_cpu_map[cpu] = 1 << new_cpu_id;

        /*
         * Find all the peripheral interrupts targetting the current
         * CPU interface and migrate them to the new CPU interface.
         * We skip DIST_TARGET 0 to 7 as they are read-only.
         */
        for (i = 8; i < DIV_ROUND_UP(gic_irqs, 4); i++) {
                val = readl_relaxed(dist_base + GIC_DIST_TARGET + i * 4);
                active_mask = val & cur_target_mask;
                if (active_mask) {
                        val &= ~active_mask;
                        val |= ror32(active_mask, ror_val);
                        writel_relaxed(val, dist_base + GIC_DIST_TARGET + i*4);
                }
        }

        raw_spin_unlock(&irq_controller_lock);

        /*
         * Now let's migrate and clear any potential SGIs that might be
         * pending for us (cur_cpu_id).  Since GIC_DIST_SGI_PENDING_SET
         * is a banked register, we can only forward the SGI using
         * GIC_DIST_SOFTINT.  The original SGI source is lost but Linux
         * doesn't use that information anyway.
         *
         * For the same reason we do not adjust SGI source information
         * for previously sent SGIs by us to other CPUs either.
         */
        for (i = 0; i < 16; i += 4) {
                int j;
                val = readl_relaxed(dist_base + GIC_DIST_SGI_PENDING_SET + i);
                if (!val)
                        continue;
                writel_relaxed(val, dist_base + GIC_DIST_SGI_PENDING_CLEAR + i);
                for (j = i; j < i + 4; j++) {
                        if (val & 0xff)
                                writel_relaxed((1 << (new_cpu_id + 16)) | j,
                                                dist_base + GIC_DIST_SOFTINT);
                        val >>= 8;
                }
        }
}

/*
 * gic_get_sgir_physaddr - get the physical address for the SGI register
 *
 * REturn the physical address of the SGI register to be used
 * by some early assembly code when the kernel is not yet available.
 */
static unsigned long gic_dist_physaddr;

unsigned long gic_get_sgir_physaddr(void)
{
        if (!gic_dist_physaddr)
                return 0;
        return gic_dist_physaddr + GIC_DIST_SOFTINT;
}

void __init gic_init_physaddr(struct device_node *node)
{
        struct resource res;
        if (of_address_to_resource(node, 0, &res) == 0) {
                gic_dist_physaddr = res.start;
                pr_info("GIC physical location is %#lx\n", gic_dist_physaddr);
        }
}

#else
#define gic_init_physaddr(node)  do { } while (0)
#endif

static int gic_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, &gic_chip,
                                         handle_percpu_devid_irq);
                set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN);
        } else {
                irq_set_chip_and_handler(irq, &gic_chip,
                                         handle_fasteoi_irq);
                set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
        }
        irq_set_chip_data(irq, d->host_data);
        return 0;
}

static int gic_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)
{
        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 GIC irq ID number */
        if (!intspec[0])
                *out_hwirq += 16;

        *out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
        return 0;
}

#ifdef CONFIG_SMP
static int gic_secondary_init(struct notifier_block *nfb, unsigned long action,
                              void *hcpu)
{
        if (action == CPU_STARTING || action == CPU_STARTING_FROZEN)
                gic_cpu_init(&gic_data[0]);
        return NOTIFY_OK;
}

/*
 * Notifier for enabling the GIC CPU interface. Set an arbitrarily high
 * priority because the GIC needs to be up before the ARM generic timers.
 */
static struct notifier_block gic_cpu_notifier = {
        .notifier_call = gic_secondary_init,
        .priority = 100,
};
#endif

const struct irq_domain_ops gic_irq_domain_ops = {
        .map = gic_irq_domain_map,
        .xlate = gic_irq_domain_xlate,
};

void __init gic_init_bases(unsigned int gic_nr, int irq_start,
                           void __iomem *dist_base, void __iomem *cpu_base,
                           u32 percpu_offset, struct device_node *node)
{
        irq_hw_number_t hwirq_base;
        struct gic_chip_data *gic;
        int gic_irqs, irq_base, i;

        BUG_ON(gic_nr >= MAX_GIC_NR);

        gic = &gic_data[gic_nr];
#ifdef CONFIG_GIC_NON_BANKED
        if (percpu_offset) { /* Frankein-GIC without banked registers... */
                unsigned int cpu;

                gic->dist_base.percpu_base = alloc_percpu(void __iomem *);
                gic->cpu_base.percpu_base = alloc_percpu(void __iomem *);
                if (WARN_ON(!gic->dist_base.percpu_base ||
                            !gic->cpu_base.percpu_base)) {
                        free_percpu(gic->dist_base.percpu_base);
                        free_percpu(gic->cpu_base.percpu_base);
                        return;
                }

                for_each_possible_cpu(cpu) {
                        unsigned long offset = percpu_offset * cpu_logical_map(cpu);
                        *per_cpu_ptr(gic->dist_base.percpu_base, cpu) = dist_base + offset;
                        *per_cpu_ptr(gic->cpu_base.percpu_base, cpu) = cpu_base + offset;
                }

                gic_set_base_accessor(gic, gic_get_percpu_base);
        } else
#endif
        {                       /* Normal, sane GIC... */
                WARN(percpu_offset,
                     "GIC_NON_BANKED not enabled, ignoring %08x offset!",
                     percpu_offset);
                gic->dist_base.common_base = dist_base;
                gic->cpu_base.common_base = cpu_base;
                gic_set_base_accessor(gic, gic_get_common_base);
        }

        /*
         * Initialize the CPU interface map to all CPUs.
         * It will be refined as each CPU probes its ID.
         */
        for (i = 0; i < NR_GIC_CPU_IF; i++)
                gic_cpu_map[i] = 0xff;

        /*
         * For primary GICs, skip over SGIs.
         * For secondary GICs, skip over PPIs, too.
         */
        if (gic_nr == 0 && (irq_start & 31) > 0) {
                hwirq_base = 16;
                if (irq_start != -1)
                        irq_start = (irq_start & ~31) + 16;
        } else {
                hwirq_base = 32;
        }

        /*
         * Find out how many interrupts are supported.
         * The GIC only supports up to 1020 interrupt sources.
         */
        gic_irqs = readl_relaxed(gic_data_dist_base(gic) + GIC_DIST_CTR) & 0x1f;
        gic_irqs = (gic_irqs + 1) * 32;
        if (gic_irqs > 1020)
                gic_irqs = 1020;
        gic->gic_irqs = gic_irqs;

        gic_irqs -= hwirq_base; /* calculate # of irqs to allocate */
        irq_base = irq_alloc_descs(irq_start, 16, gic_irqs, numa_node_id());
        if (IS_ERR_VALUE(irq_base)) {
                WARN(1, "Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n",
                     irq_start);
                irq_base = irq_start;
        }
        gic->domain = irq_domain_add_legacy(node, gic_irqs, irq_base,
                                    hwirq_base, &gic_irq_domain_ops, gic);
        if (WARN_ON(!gic->domain))
                return;

        if (gic_nr == 0) {
#ifdef CONFIG_SMP
                set_smp_cross_call(gic_raise_softirq);
                register_cpu_notifier(&gic_cpu_notifier);
#endif
                set_handle_irq(gic_handle_irq);
        }

        gic_chip.flags |= gic_arch_extn.flags;
        gic_dist_init(gic);
        gic_cpu_init(gic);
        gic_pm_init(gic);
}

#ifdef CONFIG_OF
static int gic_cnt __initdata;

int __init gic_of_init(struct device_node *node, struct device_node *parent)
{
        void __iomem *cpu_base;
        void __iomem *dist_base;
        u32 percpu_offset;
        int irq;

        if (WARN_ON(!node))
                return -ENODEV;

        dist_base = of_iomap(node, 0);
        WARN(!dist_base, "unable to map gic dist registers\n");

        cpu_base = of_iomap(node, 1);
        WARN(!cpu_base, "unable to map gic cpu registers\n");

        if (of_property_read_u32(node, "cpu-offset", &percpu_offset))
                percpu_offset = 0;

        gic_init_bases(gic_cnt, -1, dist_base, cpu_base, percpu_offset, node);
        if (!gic_cnt)
                gic_init_physaddr(node);

        if (parent) {

                irq = irq_of_parse_and_map(node, 0);
                gic_cascade_irq(gic_cnt, irq);
        }
        gic_cnt++;
        return 0;
}
IRQCHIP_DECLARE(cortex_a15_gic, "arm,cortex-a15-gic", gic_of_init);
IRQCHIP_DECLARE(cortex_a9_gic, "arm,cortex-a9-gic", gic_of_init);
IRQCHIP_DECLARE(msm_8660_qgic, "qcom,msm-8660-qgic", gic_of_init);
IRQCHIP_DECLARE(msm_qgic2, "qcom,msm-qgic2", gic_of_init);

#endif