// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2013-2017 ARM Limited, All Rights Reserved.
 * Author: Marc Zyngier <marc.zyngier@arm.com>
 */

#define pr_fmt(fmt)     "GICv3: " fmt

#include <linux/acpi.h>
#include <linux/cpu.h>
#include <linux/cpu_pm.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/irqdomain.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/percpu.h>
#include <linux/refcount.h>
#include <linux/slab.h>

#include <linux/irqchip.h>
#include <linux/irqchip/arm-gic-common.h>
#include <linux/irqchip/arm-gic-v3.h>
#include <linux/irqchip/irq-partition-percpu.h>

#include <asm/cputype.h>
#include <asm/exception.h>
#include <asm/smp_plat.h>
#include <asm/virt.h>

#include "irq-gic-common.h"

#define GICD_INT_NMI_PRI        (GICD_INT_DEF_PRI & ~0x80)

#define FLAGS_WORKAROUND_GICR_WAKER_MSM8996     (1ULL << 0)
#define FLAGS_WORKAROUND_CAVIUM_ERRATUM_38539   (1ULL << 1)

#define GIC_IRQ_TYPE_PARTITION  (GIC_IRQ_TYPE_LPI + 1)

struct redist_region {
        void __iomem            *redist_base;
        phys_addr_t             phys_base;
        bool                    single_redist;
};

struct gic_chip_data {
        struct fwnode_handle    *fwnode;
        void __iomem            *dist_base;
        struct redist_region    *redist_regions;
        struct rdists           rdists;
        struct irq_domain       *domain;
        u64                     redist_stride;
        u32                     nr_redist_regions;
        u64                     flags;
        bool                    has_rss;
        unsigned int            ppi_nr;
        struct partition_desc   **ppi_descs;
};

static struct gic_chip_data gic_data __read_mostly;
static DEFINE_STATIC_KEY_TRUE(supports_deactivate_key);

#define GIC_ID_NR       (1U << GICD_TYPER_ID_BITS(gic_data.rdists.gicd_typer))
#define GIC_LINE_NR     min(GICD_TYPER_SPIS(gic_data.rdists.gicd_typer), 1020U)
#define GIC_ESPI_NR     GICD_TYPER_ESPIS(gic_data.rdists.gicd_typer)

/*
 * The behaviours of RPR and PMR registers differ depending on the value of
 * SCR_EL3.FIQ, and the behaviour of non-secure priority registers of the
 * distributor and redistributors depends on whether security is enabled in the
 * GIC.
 *
 * When security is enabled, non-secure priority values from the (re)distributor
 * are presented to the GIC CPUIF as follow:
 *     (GIC_(R)DIST_PRI[irq] >> 1) | 0x80;
 *
 * If SCR_EL3.FIQ == 1, the values writen to/read from PMR and RPR at non-secure
 * EL1 are subject to a similar operation thus matching the priorities presented
 * from the (re)distributor when security is enabled. When SCR_EL3.FIQ == 0,
 * these values are unchanched by the GIC.
 *
 * see GICv3/GICv4 Architecture Specification (IHI0069D):
 * - section 4.8.1 Non-secure accesses to register fields for Secure interrupt
 *   priorities.
 * - Figure 4-7 Secure read of the priority field for a Non-secure Group 1
 *   interrupt.
 */
static DEFINE_STATIC_KEY_FALSE(supports_pseudo_nmis);

/*
 * Global static key controlling whether an update to PMR allowing more
 * interrupts requires to be propagated to the redistributor (DSB SY).
 * And this needs to be exported for modules to be able to enable
 * interrupts...
 */
DEFINE_STATIC_KEY_FALSE(gic_pmr_sync);
EXPORT_SYMBOL(gic_pmr_sync);

DEFINE_STATIC_KEY_FALSE(gic_nonsecure_priorities);
EXPORT_SYMBOL(gic_nonsecure_priorities);

/* ppi_nmi_refs[n] == number of cpus having ppi[n + 16] set as NMI */
static refcount_t *ppi_nmi_refs;

static struct gic_kvm_info gic_v3_kvm_info;
static DEFINE_PER_CPU(bool, has_rss);

#define MPIDR_RS(mpidr)                 (((mpidr) & 0xF0UL) >> 4)
#define gic_data_rdist()                (this_cpu_ptr(gic_data.rdists.rdist))
#define gic_data_rdist_rd_base()        (gic_data_rdist()->rd_base)
#define gic_data_rdist_sgi_base()       (gic_data_rdist_rd_base() + SZ_64K)

/* Our default, arbitrary priority value. Linux only uses one anyway. */
#define DEFAULT_PMR_VALUE       0xf0

enum gic_intid_range {
        SGI_RANGE,
        PPI_RANGE,
        SPI_RANGE,
        EPPI_RANGE,
        ESPI_RANGE,
        LPI_RANGE,
        __INVALID_RANGE__
};

static enum gic_intid_range __get_intid_range(irq_hw_number_t hwirq)
{
        switch (hwirq) {
        case 0 ... 15:
                return SGI_RANGE;
        case 16 ... 31:
                return PPI_RANGE;
        case 32 ... 1019:
                return SPI_RANGE;
        case EPPI_BASE_INTID ... (EPPI_BASE_INTID + 63):
                return EPPI_RANGE;
        case ESPI_BASE_INTID ... (ESPI_BASE_INTID + 1023):
                return ESPI_RANGE;
        case 8192 ... GENMASK(23, 0):
                return LPI_RANGE;
        default:
                return __INVALID_RANGE__;
        }
}

static enum gic_intid_range get_intid_range(struct irq_data *d)
{
        return __get_intid_range(d->hwirq);
}

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

static inline bool gic_irq_in_rdist(struct irq_data *d)
{
        switch (get_intid_range(d)) {
        case SGI_RANGE:
        case PPI_RANGE:
        case EPPI_RANGE:
                return true;
        default:
                return false;
        }
}

static inline void __iomem *gic_dist_base(struct irq_data *d)
{
        switch (get_intid_range(d)) {
        case SGI_RANGE:
        case PPI_RANGE:
        case EPPI_RANGE:
                /* SGI+PPI -> SGI_base for this CPU */
                return gic_data_rdist_sgi_base();

        case SPI_RANGE:
        case ESPI_RANGE:
                /* SPI -> dist_base */
                return gic_data.dist_base;

        default:
                return NULL;
        }
}

static void gic_do_wait_for_rwp(void __iomem *base)
{
        u32 count = 1000000;    /* 1s! */

        while (readl_relaxed(base + GICD_CTLR) & GICD_CTLR_RWP) {
                count--;
                if (!count) {
                        pr_err_ratelimited("RWP timeout, gone fishing\n");
                        return;
                }
                cpu_relax();
                udelay(1);
        }
}

/* Wait for completion of a distributor change */
static void gic_dist_wait_for_rwp(void)
{
        gic_do_wait_for_rwp(gic_data.dist_base);
}

/* Wait for completion of a redistributor change */
static void gic_redist_wait_for_rwp(void)
{
        gic_do_wait_for_rwp(gic_data_rdist_rd_base());
}

#ifdef CONFIG_ARM64

static u64 __maybe_unused gic_read_iar(void)
{
        if (cpus_have_const_cap(ARM64_WORKAROUND_CAVIUM_23154))
                return gic_read_iar_cavium_thunderx();
        else
                return gic_read_iar_common();
}
#endif

static void gic_enable_redist(bool enable)
{
        void __iomem *rbase;
        u32 count = 1000000;    /* 1s! */
        u32 val;

        if (gic_data.flags & FLAGS_WORKAROUND_GICR_WAKER_MSM8996)
                return;

        rbase = gic_data_rdist_rd_base();

        val = readl_relaxed(rbase + GICR_WAKER);
        if (enable)
                /* Wake up this CPU redistributor */
                val &= ~GICR_WAKER_ProcessorSleep;
        else
                val |= GICR_WAKER_ProcessorSleep;
        writel_relaxed(val, rbase + GICR_WAKER);

        if (!enable) {          /* Check that GICR_WAKER is writeable */
                val = readl_relaxed(rbase + GICR_WAKER);
                if (!(val & GICR_WAKER_ProcessorSleep))
                        return; /* No PM support in this redistributor */
        }

        while (--count) {
                val = readl_relaxed(rbase + GICR_WAKER);
                if (enable ^ (bool)(val & GICR_WAKER_ChildrenAsleep))
                        break;
                cpu_relax();
                udelay(1);
        }
        if (!count)
                pr_err_ratelimited("redistributor failed to %s...\n",
                                   enable ? "wakeup" : "sleep");
}

/*
 * Routines to disable, enable, EOI and route interrupts
 */
static u32 convert_offset_index(struct irq_data *d, u32 offset, u32 *index)
{
        switch (get_intid_range(d)) {
        case SGI_RANGE:
        case PPI_RANGE:
        case SPI_RANGE:
                *index = d->hwirq;
                return offset;
        case EPPI_RANGE:
                /*
                 * Contrary to the ESPI range, the EPPI range is contiguous
                 * to the PPI range in the registers, so let's adjust the
                 * displacement accordingly. Consistency is overrated.
                 */
                *index = d->hwirq - EPPI_BASE_INTID + 32;
                return offset;
        case ESPI_RANGE:
                *index = d->hwirq - ESPI_BASE_INTID;
                switch (offset) {
                case GICD_ISENABLER:
                        return GICD_ISENABLERnE;
                case GICD_ICENABLER:
                        return GICD_ICENABLERnE;
                case GICD_ISPENDR:
                        return GICD_ISPENDRnE;
                case GICD_ICPENDR:
                        return GICD_ICPENDRnE;
                case GICD_ISACTIVER:
                        return GICD_ISACTIVERnE;
                case GICD_ICACTIVER:
                        return GICD_ICACTIVERnE;
                case GICD_IPRIORITYR:
                        return GICD_IPRIORITYRnE;
                case GICD_ICFGR:
                        return GICD_ICFGRnE;
                case GICD_IROUTER:
                        return GICD_IROUTERnE;
                default:
                        break;
                }
                break;
        default:
                break;
        }

        WARN_ON(1);
        *index = d->hwirq;
        return offset;
}

static int gic_peek_irq(struct irq_data *d, u32 offset)
{
        void __iomem *base;
        u32 index, mask;

        offset = convert_offset_index(d, offset, &index);
        mask = 1 << (index % 32);

        if (gic_irq_in_rdist(d))
                base = gic_data_rdist_sgi_base();
        else
                base = gic_data.dist_base;

        return !!(readl_relaxed(base + offset + (index / 32) * 4) & mask);
}

static void gic_poke_irq(struct irq_data *d, u32 offset)
{
        void (*rwp_wait)(void);
        void __iomem *base;
        u32 index, mask;

        offset = convert_offset_index(d, offset, &index);
        mask = 1 << (index % 32);

        if (gic_irq_in_rdist(d)) {
                base = gic_data_rdist_sgi_base();
                rwp_wait = gic_redist_wait_for_rwp;
        } else {
                base = gic_data.dist_base;
                rwp_wait = gic_dist_wait_for_rwp;
        }

        writel_relaxed(mask, base + offset + (index / 32) * 4);
        rwp_wait();
}

static void gic_mask_irq(struct irq_data *d)
{
        gic_poke_irq(d, GICD_ICENABLER);
}

static void gic_eoimode1_mask_irq(struct irq_data *d)
{
        gic_mask_irq(d);
        /*
         * When masking a forwarded interrupt, make sure it is
         * deactivated as well.
         *
         * This ensures that an interrupt that is getting
         * disabled/masked will not get "stuck", because there is
         * noone to deactivate it (guest is being terminated).
         */
        if (irqd_is_forwarded_to_vcpu(d))
                gic_poke_irq(d, GICD_ICACTIVER);
}

static void gic_unmask_irq(struct irq_data *d)
{
        gic_poke_irq(d, GICD_ISENABLER);
}

static inline bool gic_supports_nmi(void)
{
        return IS_ENABLED(CONFIG_ARM64_PSEUDO_NMI) &&
               static_branch_likely(&supports_pseudo_nmis);
}

static int gic_irq_set_irqchip_state(struct irq_data *d,
                                     enum irqchip_irq_state which, bool val)
{
        u32 reg;

        if (d->hwirq >= 8192) /* SGI/PPI/SPI only */
                return -EINVAL;

        switch (which) {
        case IRQCHIP_STATE_PENDING:
                reg = val ? GICD_ISPENDR : GICD_ICPENDR;
                break;

        case IRQCHIP_STATE_ACTIVE:
                reg = val ? GICD_ISACTIVER : GICD_ICACTIVER;
                break;

        case IRQCHIP_STATE_MASKED:
                reg = val ? GICD_ICENABLER : GICD_ISENABLER;
                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)
{
        if (d->hwirq >= 8192) /* PPI/SPI only */
                return -EINVAL;

        switch (which) {
        case IRQCHIP_STATE_PENDING:
                *val = gic_peek_irq(d, GICD_ISPENDR);
                break;

        case IRQCHIP_STATE_ACTIVE:
                *val = gic_peek_irq(d, GICD_ISACTIVER);
                break;

        case IRQCHIP_STATE_MASKED:
                *val = !gic_peek_irq(d, GICD_ISENABLER);
                break;

        default:
                return -EINVAL;
        }

        return 0;
}

static void gic_irq_set_prio(struct irq_data *d, u8 prio)
{
        void __iomem *base = gic_dist_base(d);
        u32 offset, index;

        offset = convert_offset_index(d, GICD_IPRIORITYR, &index);

        writeb_relaxed(prio, base + offset + index);
}

static u32 gic_get_ppi_index(struct irq_data *d)
{
        switch (get_intid_range(d)) {
        case PPI_RANGE:
                return d->hwirq - 16;
        case EPPI_RANGE:
                return d->hwirq - EPPI_BASE_INTID + 16;
        default:
                unreachable();
        }
}

static int gic_irq_nmi_setup(struct irq_data *d)
{
        struct irq_desc *desc = irq_to_desc(d->irq);

        if (!gic_supports_nmi())
                return -EINVAL;

        if (gic_peek_irq(d, GICD_ISENABLER)) {
                pr_err("Cannot set NMI property of enabled IRQ %u\n", d->irq);
                return -EINVAL;
        }

        /*
         * A secondary irq_chip should be in charge of LPI request,
         * it should not be possible to get there
         */
        if (WARN_ON(gic_irq(d) >= 8192))
                return -EINVAL;

        /* desc lock should already be held */
        if (gic_irq_in_rdist(d)) {
                u32 idx = gic_get_ppi_index(d);

                /* Setting up PPI as NMI, only switch handler for first NMI */
                if (!refcount_inc_not_zero(&ppi_nmi_refs[idx])) {
                        refcount_set(&ppi_nmi_refs[idx], 1);
                        desc->handle_irq = handle_percpu_devid_fasteoi_nmi;
                }
        } else {
                desc->handle_irq = handle_fasteoi_nmi;
        }

        gic_irq_set_prio(d, GICD_INT_NMI_PRI);

        return 0;
}

static void gic_irq_nmi_teardown(struct irq_data *d)
{
        struct irq_desc *desc = irq_to_desc(d->irq);

        if (WARN_ON(!gic_supports_nmi()))
                return;

        if (gic_peek_irq(d, GICD_ISENABLER)) {
                pr_err("Cannot set NMI property of enabled IRQ %u\n", d->irq);
                return;
        }

        /*
         * A secondary irq_chip should be in charge of LPI request,
         * it should not be possible to get there
         */
        if (WARN_ON(gic_irq(d) >= 8192))
                return;

        /* desc lock should already be held */
        if (gic_irq_in_rdist(d)) {
                u32 idx = gic_get_ppi_index(d);

                /* Tearing down NMI, only switch handler for last NMI */
                if (refcount_dec_and_test(&ppi_nmi_refs[idx]))
                        desc->handle_irq = handle_percpu_devid_irq;
        } else {
                desc->handle_irq = handle_fasteoi_irq;
        }

        gic_irq_set_prio(d, GICD_INT_DEF_PRI);
}

static void gic_eoi_irq(struct irq_data *d)
{
        gic_write_eoir(gic_irq(d));
}

static void gic_eoimode1_eoi_irq(struct irq_data *d)
{
        /*
         * No need to deactivate an LPI, or an interrupt that
         * is is getting forwarded to a vcpu.
         */
        if (gic_irq(d) >= 8192 || irqd_is_forwarded_to_vcpu(d))
                return;
        gic_write_dir(gic_irq(d));
}

static int gic_set_type(struct irq_data *d, unsigned int type)
{
        enum gic_intid_range range;
        unsigned int irq = gic_irq(d);
        void (*rwp_wait)(void);
        void __iomem *base;
        u32 offset, index;
        int ret;

        range = get_intid_range(d);

        /* Interrupt configuration for SGIs can't be changed */
        if (range == SGI_RANGE)
                return type != IRQ_TYPE_EDGE_RISING ? -EINVAL : 0;

        /* SPIs have restrictions on the supported types */
        if ((range == SPI_RANGE || range == ESPI_RANGE) &&
            type != IRQ_TYPE_LEVEL_HIGH && type != IRQ_TYPE_EDGE_RISING)
                return -EINVAL;

        if (gic_irq_in_rdist(d)) {
                base = gic_data_rdist_sgi_base();
                rwp_wait = gic_redist_wait_for_rwp;
        } else {
                base = gic_data.dist_base;
                rwp_wait = gic_dist_wait_for_rwp;
        }

        offset = convert_offset_index(d, GICD_ICFGR, &index);

        ret = gic_configure_irq(index, type, base + offset, rwp_wait);
        if (ret && (range == PPI_RANGE || range == EPPI_RANGE)) {
                /* Misconfigured PPIs are usually not fatal */
                pr_warn("GIC: PPI INTID%d is secure or misconfigured\n", irq);
                ret = 0;
        }

        return ret;
}

static int gic_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu)
{
        if (get_intid_range(d) == SGI_RANGE)
                return -EINVAL;

        if (vcpu)
                irqd_set_forwarded_to_vcpu(d);
        else
                irqd_clr_forwarded_to_vcpu(d);
        return 0;
}

static u64 gic_mpidr_to_affinity(unsigned long mpidr)
{
        u64 aff;

        aff = ((u64)MPIDR_AFFINITY_LEVEL(mpidr, 3) << 32 |
               MPIDR_AFFINITY_LEVEL(mpidr, 2) << 16 |
               MPIDR_AFFINITY_LEVEL(mpidr, 1) << 8  |
               MPIDR_AFFINITY_LEVEL(mpidr, 0));

        return aff;
}

static void gic_deactivate_unhandled(u32 irqnr)
{
        if (static_branch_likely(&supports_deactivate_key)) {
                if (irqnr < 8192)
                        gic_write_dir(irqnr);
        } else {
                gic_write_eoir(irqnr);
        }
}

static inline void gic_handle_nmi(u32 irqnr, struct pt_regs *regs)
{
        bool irqs_enabled = interrupts_enabled(regs);
        int err;

        if (irqs_enabled)
                nmi_enter();

        if (static_branch_likely(&supports_deactivate_key))
                gic_write_eoir(irqnr);
        /*
         * Leave the PSR.I bit set to prevent other NMIs to be
         * received while handling this one.
         * PSR.I will be restored when we ERET to the
         * interrupted context.
         */
        err = handle_domain_nmi(gic_data.domain, irqnr, regs);
        if (err)
                gic_deactivate_unhandled(irqnr);

        if (irqs_enabled)
                nmi_exit();
}

static asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs)
{
        u32 irqnr;

        irqnr = gic_read_iar();

        if (gic_supports_nmi() &&
            unlikely(gic_read_rpr() == GICD_INT_NMI_PRI)) {
                gic_handle_nmi(irqnr, regs);
                return;
        }

        if (gic_prio_masking_enabled()) {
                gic_pmr_mask_irqs();
                gic_arch_enable_irqs();
        }

        /* Check for special IDs first */
        if ((irqnr >= 1020 && irqnr <= 1023))
                return;

        if (static_branch_likely(&supports_deactivate_key))
                gic_write_eoir(irqnr);
        else
                isb();

        if (handle_domain_irq(gic_data.domain, irqnr, regs)) {
                WARN_ONCE(true, "Unexpected interrupt received!\n");
                gic_deactivate_unhandled(irqnr);
        }
}

static u32 gic_get_pribits(void)
{
        u32 pribits;

        pribits = gic_read_ctlr();
        pribits &= ICC_CTLR_EL1_PRI_BITS_MASK;
        pribits >>= ICC_CTLR_EL1_PRI_BITS_SHIFT;
        pribits++;

        return pribits;
}

static bool gic_has_group0(void)
{
        u32 val;
        u32 old_pmr;

        old_pmr = gic_read_pmr();

        /*
         * Let's find out if Group0 is under control of EL3 or not by
         * setting the highest possible, non-zero priority in PMR.
         *
         * If SCR_EL3.FIQ is set, the priority gets shifted down in
         * order for the CPU interface to set bit 7, and keep the
         * actual priority in the non-secure range. In the process, it
         * looses the least significant bit and the actual priority
         * becomes 0x80. Reading it back returns 0, indicating that
         * we're don't have access to Group0.
         */
        gic_write_pmr(BIT(8 - gic_get_pribits()));
        val = gic_read_pmr();

        gic_write_pmr(old_pmr);

        return val != 0;
}

static void __init gic_dist_init(void)
{
        unsigned int i;
        u64 affinity;
        void __iomem *base = gic_data.dist_base;
        u32 val;

        /* Disable the distributor */
        writel_relaxed(0, base + GICD_CTLR);
        gic_dist_wait_for_rwp();

        /*
         * Configure SPIs as non-secure Group-1. This will only matter
         * if the GIC only has a single security state. This will not
         * do the right thing if the kernel is running in secure mode,
         * but that's not the intended use case anyway.
         */
        for (i = 32; i < GIC_LINE_NR; i += 32)
                writel_relaxed(~0, base + GICD_IGROUPR + i / 8);

        /* Extended SPI range, not handled by the GICv2/GICv3 common code */
        for (i = 0; i < GIC_ESPI_NR; i += 32) {
                writel_relaxed(~0U, base + GICD_ICENABLERnE + i / 8);
                writel_relaxed(~0U, base + GICD_ICACTIVERnE + i / 8);
        }

        for (i = 0; i < GIC_ESPI_NR; i += 32)
                writel_relaxed(~0U, base + GICD_IGROUPRnE + i / 8);

        for (i = 0; i < GIC_ESPI_NR; i += 16)
                writel_relaxed(0, base + GICD_ICFGRnE + i / 4);

        for (i = 0; i < GIC_ESPI_NR; i += 4)
                writel_relaxed(GICD_INT_DEF_PRI_X4, base + GICD_IPRIORITYRnE + i);

        /* Now do the common stuff, and wait for the distributor to drain */
        gic_dist_config(base, GIC_LINE_NR, gic_dist_wait_for_rwp);

        val = GICD_CTLR_ARE_NS | GICD_CTLR_ENABLE_G1A | GICD_CTLR_ENABLE_G1;
        if (gic_data.rdists.gicd_typer2 & GICD_TYPER2_nASSGIcap) {
                pr_info("Enabling SGIs without active state\n");
                val |= GICD_CTLR_nASSGIreq;
        }

        /* Enable distributor with ARE, Group1 */
        writel_relaxed(val, base + GICD_CTLR);

        /*
         * Set all global interrupts to the boot CPU only. ARE must be
         * enabled.
         */
        affinity = gic_mpidr_to_affinity(cpu_logical_map(smp_processor_id()));
        for (i = 32; i < GIC_LINE_NR; i++)
                gic_write_irouter(affinity, base + GICD_IROUTER + i * 8);

        for (i = 0; i < GIC_ESPI_NR; i++)
                gic_write_irouter(affinity, base + GICD_IROUTERnE + i * 8);
}

static int gic_iterate_rdists(int (*fn)(struct redist_region *, void __iomem *))
{
        int ret = -ENODEV;
        int i;

        for (i = 0; i < gic_data.nr_redist_regions; i++) {
                void __iomem *ptr = gic_data.redist_regions[i].redist_base;
                u64 typer;
                u32 reg;

                reg = readl_relaxed(ptr + GICR_PIDR2) & GIC_PIDR2_ARCH_MASK;
                if (reg != GIC_PIDR2_ARCH_GICv3 &&
                    reg != GIC_PIDR2_ARCH_GICv4) { /* We're in trouble... */
                        pr_warn("No redistributor present @%p\n", ptr);
                        break;
                }

                do {
                        typer = gic_read_typer(ptr + GICR_TYPER);
                        ret = fn(gic_data.redist_regions + i, ptr);
                        if (!ret)
                                return 0;

                        if (gic_data.redist_regions[i].single_redist)
                                break;

                        if (gic_data.redist_stride) {
                                ptr += gic_data.redist_stride;
                        } else {
                                ptr += SZ_64K * 2; /* Skip RD_base + SGI_base */
                                if (typer & GICR_TYPER_VLPIS)
                                        ptr += SZ_64K * 2; /* Skip VLPI_base + reserved page */
                        }
                } while (!(typer & GICR_TYPER_LAST));
        }

        return ret ? -ENODEV : 0;
}

static int __gic_populate_rdist(struct redist_region *region, void __iomem *ptr)
{
        unsigned long mpidr = cpu_logical_map(smp_processor_id());
        u64 typer;
        u32 aff;

        /*
         * Convert affinity to a 32bit value that can be matched to
         * GICR_TYPER bits [63:32].
         */
        aff = (MPIDR_AFFINITY_LEVEL(mpidr, 3) << 24 |
               MPIDR_AFFINITY_LEVEL(mpidr, 2) << 16 |
               MPIDR_AFFINITY_LEVEL(mpidr, 1) << 8 |
               MPIDR_AFFINITY_LEVEL(mpidr, 0));

        typer = gic_read_typer(ptr + GICR_TYPER);
        if ((typer >> 32) == aff) {
                u64 offset = ptr - region->redist_base;
                raw_spin_lock_init(&gic_data_rdist()->rd_lock);
                gic_data_rdist_rd_base() = ptr;
                gic_data_rdist()->phys_base = region->phys_base + offset;

                pr_info("CPU%d: found redistributor %lx region %d:%pa\n",
                        smp_processor_id(), mpidr,
                        (int)(region - gic_data.redist_regions),
                        &gic_data_rdist()->phys_base);
                return 0;
        }

        /* Try next one */
        return 1;
}

static int gic_populate_rdist(void)
{
        if (gic_iterate_rdists(__gic_populate_rdist) == 0)
                return 0;

        /* We couldn't even deal with ourselves... */
        WARN(true, "CPU%d: mpidr %lx has no re-distributor!\n",
             smp_processor_id(),
             (unsigned long)cpu_logical_map(smp_processor_id()));
        return -ENODEV;
}

static int __gic_update_rdist_properties(struct redist_region *region,
                                         void __iomem *ptr)
{
        u64 typer = gic_read_typer(ptr + GICR_TYPER);

        gic_data.rdists.has_vlpis &= !!(typer & GICR_TYPER_VLPIS);

        /* RVPEID implies some form of DirectLPI, no matter what the doc says... :-/ */
        gic_data.rdists.has_rvpeid &= !!(typer & GICR_TYPER_RVPEID);
        gic_data.rdists.has_direct_lpi &= (!!(typer & GICR_TYPER_DirectLPIS) |
                                           gic_data.rdists.has_rvpeid);
        gic_data.rdists.has_vpend_valid_dirty &= !!(typer & GICR_TYPER_DIRTY);

        /* Detect non-sensical configurations */
        if (WARN_ON_ONCE(gic_data.rdists.has_rvpeid && !gic_data.rdists.has_vlpis)) {
                gic_data.rdists.has_direct_lpi = false;
                gic_data.rdists.has_vlpis = false;
                gic_data.rdists.has_rvpeid = false;
        }

        gic_data.ppi_nr = min(GICR_TYPER_NR_PPIS(typer), gic_data.ppi_nr);

        return 1;
}

static void gic_update_rdist_properties(void)
{
        gic_data.ppi_nr = UINT_MAX;
        gic_iterate_rdists(__gic_update_rdist_properties);
        if (WARN_ON(gic_data.ppi_nr == UINT_MAX))
                gic_data.ppi_nr = 0;
        pr_info("%d PPIs implemented\n", gic_data.ppi_nr);
        if (gic_data.rdists.has_vlpis)
                pr_info("GICv4 features: %s%s%s\n",
                        gic_data.rdists.has_direct_lpi ? "DirectLPI " : "",
                        gic_data.rdists.has_rvpeid ? "RVPEID " : "",
                        gic_data.rdists.has_vpend_valid_dirty ? "Valid+Dirty " : "");
}

/* Check whether it's single security state view */
static inline bool gic_dist_security_disabled(void)
{
        return readl_relaxed(gic_data.dist_base + GICD_CTLR) & GICD_CTLR_DS;
}

static void gic_cpu_sys_reg_init(void)
{
        int i, cpu = smp_processor_id();
        u64 mpidr = cpu_logical_map(cpu);
        u64 need_rss = MPIDR_RS(mpidr);
        bool group0;
        u32 pribits;

        /*
         * Need to check that the SRE bit has actually been set. If
         * not, it means that SRE is disabled at EL2. We're going to
         * die painfully, and there is nothing we can do about it.
         *
         * Kindly inform the luser.
         */
        if (!gic_enable_sre())
                pr_err("GIC: unable to set SRE (disabled at EL2), panic ahead\n");

        pribits = gic_get_pribits();

        group0 = gic_has_group0();

        /* Set priority mask register */
        if (!gic_prio_masking_enabled()) {
                write_gicreg(DEFAULT_PMR_VALUE, ICC_PMR_EL1);
        } else if (gic_supports_nmi()) {
                /*
                 * Mismatch configuration with boot CPU, the system is likely
                 * to die as interrupt masking will not work properly on all
                 * CPUs
                 *
                 * The boot CPU calls this function before enabling NMI support,
                 * and as a result we'll never see this warning in the boot path
                 * for that CPU.
                 */
                if (static_branch_unlikely(&gic_nonsecure_priorities))
                        WARN_ON(!group0 || gic_dist_security_disabled());
                else
                        WARN_ON(group0 && !gic_dist_security_disabled());
        }

        /*
         * Some firmwares hand over to the kernel with the BPR changed from
         * its reset value (and with a value large enough to prevent
         * any pre-emptive interrupts from working at all). Writing a zero
         * to BPR restores is reset value.
         */
        gic_write_bpr1(0);

        if (static_branch_likely(&supports_deactivate_key)) {
                /* EOI drops priority only (mode 1) */
                gic_write_ctlr(ICC_CTLR_EL1_EOImode_drop);
        } else {
                /* EOI deactivates interrupt too (mode 0) */
                gic_write_ctlr(ICC_CTLR_EL1_EOImode_drop_dir);
        }

        /* Always whack Group0 before Group1 */
        if (group0) {
                switch(pribits) {
                case 8:
                case 7:
                        write_gicreg(0, ICC_AP0R3_EL1);
                        write_gicreg(0, ICC_AP0R2_EL1);
                        fallthrough;
                case 6:
                        write_gicreg(0, ICC_AP0R1_EL1);
                        fallthrough;
                case 5:
                case 4:
                        write_gicreg(0, ICC_AP0R0_EL1);
                }

                isb();
        }

        switch(pribits) {
        case 8:
        case 7:
                write_gicreg(0, ICC_AP1R3_EL1);
                write_gicreg(0, ICC_AP1R2_EL1);
                fallthrough;
        case 6:
                write_gicreg(0, ICC_AP1R1_EL1);
                fallthrough;
        case 5:
        case 4:
                write_gicreg(0, ICC_AP1R0_EL1);
        }

        isb();

        /* ... and let's hit the road... */
        gic_write_grpen1(1);

        /* Keep the RSS capability status in per_cpu variable */
        per_cpu(has_rss, cpu) = !!(gic_read_ctlr() & ICC_CTLR_EL1_RSS);

        /* Check all the CPUs have capable of sending SGIs to other CPUs */
        for_each_online_cpu(i) {
                bool have_rss = per_cpu(has_rss, i) && per_cpu(has_rss, cpu);

                need_rss |= MPIDR_RS(cpu_logical_map(i));
                if (need_rss && (!have_rss))
                        pr_crit("CPU%d (%lx) can't SGI CPU%d (%lx), no RSS\n",
                                cpu, (unsigned long)mpidr,
                                i, (unsigned long)cpu_logical_map(i));
        }

        /**
         * GIC spec says, when ICC_CTLR_EL1.RSS==1 and GICD_TYPER.RSS==0,
         * writing ICC_ASGI1R_EL1 register with RS != 0 is a CONSTRAINED
         * UNPREDICTABLE choice of :
         *   - The write is ignored.
         *   - The RS field is treated as 0.
         */
        if (need_rss && (!gic_data.has_rss))
                pr_crit_once("RSS is required but GICD doesn't support it\n");
}

static bool gicv3_nolpi;

static int __init gicv3_nolpi_cfg(char *buf)
{
        return strtobool(buf, &gicv3_nolpi);
}
early_param("irqchip.gicv3_nolpi", gicv3_nolpi_cfg);

static int gic_dist_supports_lpis(void)
{
        return (IS_ENABLED(CONFIG_ARM_GIC_V3_ITS) &&
                !!(readl_relaxed(gic_data.dist_base + GICD_TYPER) & GICD_TYPER_LPIS) &&
                !gicv3_nolpi);
}

static void gic_cpu_init(void)
{
        void __iomem *rbase;
        int i;

        /* Register ourselves with the rest of the world */
        if (gic_populate_rdist())
                return;

        gic_enable_redist(true);

        WARN((gic_data.ppi_nr > 16 || GIC_ESPI_NR != 0) &&
             !(gic_read_ctlr() & ICC_CTLR_EL1_ExtRange),
             "Distributor has extended ranges, but CPU%d doesn't\n",
             smp_processor_id());

        rbase = gic_data_rdist_sgi_base();

        /* Configure SGIs/PPIs as non-secure Group-1 */
        for (i = 0; i < gic_data.ppi_nr + 16; i += 32)
                writel_relaxed(~0, rbase + GICR_IGROUPR0 + i / 8);

        gic_cpu_config(rbase, gic_data.ppi_nr + 16, gic_redist_wait_for_rwp);

        /* initialise system registers */
        gic_cpu_sys_reg_init();
}

#ifdef CONFIG_SMP

#define MPIDR_TO_SGI_RS(mpidr)  (MPIDR_RS(mpidr) << ICC_SGI1R_RS_SHIFT)
#define MPIDR_TO_SGI_CLUSTER_ID(mpidr)  ((mpidr) & ~0xFUL)

static int gic_starting_cpu(unsigned int cpu)
{
        gic_cpu_init();

        if (gic_dist_supports_lpis())
                its_cpu_init();

        return 0;
}

static u16 gic_compute_target_list(int *base_cpu, const struct cpumask *mask,
                                   unsigned long cluster_id)
{
        int next_cpu, cpu = *base_cpu;
        unsigned long mpidr = cpu_logical_map(cpu);
        u16 tlist = 0;

        while (cpu < nr_cpu_ids) {
                tlist |= 1 << (mpidr & 0xf);

                next_cpu = cpumask_next(cpu, mask);
                if (next_cpu >= nr_cpu_ids)
                        goto out;
                cpu = next_cpu;

                mpidr = cpu_logical_map(cpu);

                if (cluster_id != MPIDR_TO_SGI_CLUSTER_ID(mpidr)) {
                        cpu--;
                        goto out;
                }
        }
out:
        *base_cpu = cpu;
        return tlist;
}

#define MPIDR_TO_SGI_AFFINITY(cluster_id, level) \
        (MPIDR_AFFINITY_LEVEL(cluster_id, level) \
                << ICC_SGI1R_AFFINITY_## level ##_SHIFT)

static void gic_send_sgi(u64 cluster_id, u16 tlist, unsigned int irq)
{
        u64 val;

        val = (MPIDR_TO_SGI_AFFINITY(cluster_id, 3)     |
               MPIDR_TO_SGI_AFFINITY(cluster_id, 2)     |
               irq << ICC_SGI1R_SGI_ID_SHIFT            |
               MPIDR_TO_SGI_AFFINITY(cluster_id, 1)     |
               MPIDR_TO_SGI_RS(cluster_id)              |
               tlist << ICC_SGI1R_TARGET_LIST_SHIFT);

        pr_devel("CPU%d: ICC_SGI1R_EL1 %llx\n", smp_processor_id(), val);
        gic_write_sgi1r(val);
}

static void gic_ipi_send_mask(struct irq_data *d, const struct cpumask *mask)
{
        int cpu;

        if (WARN_ON(d->hwirq >= 16))
                return;

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

        for_each_cpu(cpu, mask) {
                u64 cluster_id = MPIDR_TO_SGI_CLUSTER_ID(cpu_logical_map(cpu));
                u16 tlist;

                tlist = gic_compute_target_list(&cpu, mask, cluster_id);
                gic_send_sgi(cluster_id, tlist, d->hwirq);
        }

        /* Force the above writes to ICC_SGI1R_EL1 to be executed */
        isb();
}

static void __init gic_smp_init(void)
{
        struct irq_fwspec sgi_fwspec = {
                .fwnode         = gic_data.fwnode,
                .param_count    = 1,
        };
        int base_sgi;

        cpuhp_setup_state_nocalls(CPUHP_AP_IRQ_GIC_STARTING,
                                  "irqchip/arm/gicv3:starting",
                                  gic_starting_cpu, NULL);

        /* Register all 8 non-secure SGIs */
        base_sgi = __irq_domain_alloc_irqs(gic_data.domain, -1, 8,
                                           NUMA_NO_NODE, &sgi_fwspec,
                                           false, NULL);
        if (WARN_ON(base_sgi <= 0))
                return;

        set_smp_ipi_range(base_sgi, 8);
}

static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
                            bool force)
{
        unsigned int cpu;
        u32 offset, index;
        void __iomem *reg;
        int enabled;
        u64 val;

        if (force)
                cpu = cpumask_first(mask_val);
        else
                cpu = cpumask_any_and(mask_val, cpu_online_mask);

        if (cpu >= nr_cpu_ids)
                return -EINVAL;

        if (gic_irq_in_rdist(d))
                return -EINVAL;

        /* If interrupt was enabled, disable it first */
        enabled = gic_peek_irq(d, GICD_ISENABLER);
        if (enabled)
                gic_mask_irq(d);

        offset = convert_offset_index(d, GICD_IROUTER, &index);
        reg = gic_dist_base(d) + offset + (index * 8);
        val = gic_mpidr_to_affinity(cpu_logical_map(cpu));

        gic_write_irouter(val, reg);

        /*
         * If the interrupt was enabled, enabled it again. Otherwise,
         * just wait for the distributor to have digested our changes.
         */
        if (enabled)
                gic_unmask_irq(d);
        else
                gic_dist_wait_for_rwp();

        irq_data_update_effective_affinity(d, cpumask_of(cpu));

        return IRQ_SET_MASK_OK_DONE;
}
#else
#define gic_set_affinity        NULL
#define gic_ipi_send_mask       NULL
#define gic_smp_init()          do { } while(0)
#endif

static int gic_retrigger(struct irq_data *data)
{
        return !gic_irq_set_irqchip_state(data, IRQCHIP_STATE_PENDING, true);
}

#ifdef CONFIG_CPU_PM
static int gic_cpu_pm_notifier(struct notifier_block *self,
                               unsigned long cmd, void *v)
{
        if (cmd == CPU_PM_EXIT) {
                if (gic_dist_security_disabled())
                        gic_enable_redist(true);
                gic_cpu_sys_reg_init();
        } else if (cmd == CPU_PM_ENTER && gic_dist_security_disabled()) {
                gic_write_grpen1(0);
                gic_enable_redist(false);
        }
        return NOTIFY_OK;
}

static struct notifier_block gic_cpu_pm_notifier_block = {
        .notifier_call = gic_cpu_pm_notifier,
};

static void gic_cpu_pm_init(void)
{
        cpu_pm_register_notifier(&gic_cpu_pm_notifier_block);
}

#else
static inline void gic_cpu_pm_init(void) { }
#endif /* CONFIG_CPU_PM */

static struct irq_chip gic_chip = {
        .name                   = "GICv3",
        .irq_mask               = gic_mask_irq,
        .irq_unmask             = gic_unmask_irq,
        .irq_eoi                = gic_eoi_irq,
        .irq_set_type           = gic_set_type,
        .irq_set_affinity       = gic_set_affinity,
        .irq_retrigger          = gic_retrigger,
        .irq_get_irqchip_state  = gic_irq_get_irqchip_state,
        .irq_set_irqchip_state  = gic_irq_set_irqchip_state,
        .irq_nmi_setup          = gic_irq_nmi_setup,
        .irq_nmi_teardown       = gic_irq_nmi_teardown,
        .ipi_send_mask          = gic_ipi_send_mask,
        .flags                  = IRQCHIP_SET_TYPE_MASKED |
                                  IRQCHIP_SKIP_SET_WAKE |
                                  IRQCHIP_MASK_ON_SUSPEND,
};

static struct irq_chip gic_eoimode1_chip = {
        .name                   = "GICv3",
        .irq_mask               = gic_eoimode1_mask_irq,
        .irq_unmask             = gic_unmask_irq,
        .irq_eoi                = gic_eoimode1_eoi_irq,
        .irq_set_type           = gic_set_type,
        .irq_set_affinity       = gic_set_affinity,
        .irq_retrigger          = gic_retrigger,
        .irq_get_irqchip_state  = gic_irq_get_irqchip_state,
        .irq_set_irqchip_state  = gic_irq_set_irqchip_state,
        .irq_set_vcpu_affinity  = gic_irq_set_vcpu_affinity,
        .irq_nmi_setup          = gic_irq_nmi_setup,
        .irq_nmi_teardown       = gic_irq_nmi_teardown,
        .ipi_send_mask          = gic_ipi_send_mask,
        .flags                  = IRQCHIP_SET_TYPE_MASKED |
                                  IRQCHIP_SKIP_SET_WAKE |
                                  IRQCHIP_MASK_ON_SUSPEND,
};

static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
                              irq_hw_number_t hw)
{
        struct irq_chip *chip = &gic_chip;
        struct irq_data *irqd = irq_desc_get_irq_data(irq_to_desc(irq));

        if (static_branch_likely(&supports_deactivate_key))
                chip = &gic_eoimode1_chip;

        switch (__get_intid_range(hw)) {
        case SGI_RANGE:
        case PPI_RANGE:
        case EPPI_RANGE:
                irq_set_percpu_devid(irq);
                irq_domain_set_info(d, irq, hw, chip, d->host_data,
                                    handle_percpu_devid_irq, NULL, NULL);
                break;

        case SPI_RANGE:
        case ESPI_RANGE:
                irq_domain_set_info(d, irq, hw, chip, d->host_data,
                                    handle_fasteoi_irq, NULL, NULL);
                irq_set_probe(irq);
                irqd_set_single_target(irqd);
                break;

        case LPI_RANGE:
                if (!gic_dist_supports_lpis())
                        return -EPERM;
                irq_domain_set_info(d, irq, hw, chip, d->host_data,
                                    handle_fasteoi_irq, NULL, NULL);
                break;

        default:
                return -EPERM;
        }

        /* Prevents SW retriggers which mess up the ACK/EOI ordering */
        irqd_set_handle_enforce_irqctx(irqd);
        return 0;
}

static int gic_irq_domain_translate(struct irq_domain *d,
                                    struct irq_fwspec *fwspec,
                                    unsigned long *hwirq,
                                    unsigned int *type)
{
        if (fwspec->param_count == 1 && fwspec->param[0] < 16) {
                *hwirq = fwspec->param[0];
                *type = IRQ_TYPE_EDGE_RISING;
                return 0;
        }

        if (is_of_node(fwspec->fwnode)) {
                if (fwspec->param_count < 3)
                        return -EINVAL;

                switch (fwspec->param[0]) {
                case 0:                 /* SPI */
                        *hwirq = fwspec->param[1] + 32;
                        break;
                case 1:                 /* PPI */
                        *hwirq = fwspec->param[1] + 16;
                        break;
                case 2:                 /* ESPI */
                        *hwirq = fwspec->param[1] + ESPI_BASE_INTID;
                        break;
                case 3:                 /* EPPI */
                        *hwirq = fwspec->param[1] + EPPI_BASE_INTID;
                        break;
                case GIC_IRQ_TYPE_LPI:  /* LPI */
                        *hwirq = fwspec->param[1];
                        break;
                case GIC_IRQ_TYPE_PARTITION:
                        *hwirq = fwspec->param[1];
                        if (fwspec->param[1] >= 16)
                                *hwirq += EPPI_BASE_INTID - 16;
                        else
                                *hwirq += 16;
                        break;
                default:
                        return -EINVAL;
                }

                *type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;

                /*
                 * Make it clear that broken DTs are... broken.
                 * Partitionned PPIs are an unfortunate exception.
                 */
                WARN_ON(*type == IRQ_TYPE_NONE &&
                        fwspec->param[0] != GIC_IRQ_TYPE_PARTITION);
                return 0;
        }

        if (is_fwnode_irqchip(fwspec->fwnode)) {
                if(fwspec->param_count != 2)
                        return -EINVAL;

                *hwirq = fwspec->param[0];
                *type = fwspec->param[1];

                WARN_ON(*type == IRQ_TYPE_NONE);
                return 0;
        }

        return -EINVAL;
}

static int gic_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
                                unsigned int nr_irqs, void *arg)
{
        int i, ret;
        irq_hw_number_t hwirq;
        unsigned int type = IRQ_TYPE_NONE;
        struct irq_fwspec *fwspec = arg;

        ret = gic_irq_domain_translate(domain, fwspec, &hwirq, &type);
        if (ret)
                return ret;

        for (i = 0; i < nr_irqs; i++) {
                ret = gic_irq_domain_map(domain, virq + i, hwirq + i);
                if (ret)
                        return ret;
        }

        return 0;
}

static void gic_irq_domain_free(struct irq_domain *domain, unsigned int virq,
                                unsigned int nr_irqs)
{
        int i;

        for (i = 0; i < nr_irqs; i++) {
                struct irq_data *d = irq_domain_get_irq_data(domain, virq + i);
                irq_set_handler(virq + i, NULL);
                irq_domain_reset_irq_data(d);
        }
}

static int gic_irq_domain_select(struct irq_domain *d,
                                 struct irq_fwspec *fwspec,
                                 enum irq_domain_bus_token bus_token)
{
        /* Not for us */
        if (fwspec->fwnode != d->fwnode)
                return 0;

        /* If this is not DT, then we have a single domain */
        if (!is_of_node(fwspec->fwnode))
                return 1;

        /*
         * If this is a PPI and we have a 4th (non-null) parameter,
         * then we need to match the partition domain.
         */
        if (fwspec->param_count >= 4 &&
            fwspec->param[0] == 1 && fwspec->param[3] != 0 &&
            gic_data.ppi_descs)
                return d == partition_get_domain(gic_data.ppi_descs[fwspec->param[1]]);

        return d == gic_data.domain;
}

static const struct irq_domain_ops gic_irq_domain_ops = {
        .translate = gic_irq_domain_translate,
        .alloc = gic_irq_domain_alloc,
        .free = gic_irq_domain_free,
        .select = gic_irq_domain_select,
};

static int partition_domain_translate(struct irq_domain *d,
                                      struct irq_fwspec *fwspec,
                                      unsigned long *hwirq,
                                      unsigned int *type)
{
        struct device_node *np;
        int ret;

        if (!gic_data.ppi_descs)
                return -ENOMEM;

        np = of_find_node_by_phandle(fwspec->param[3]);
        if (WARN_ON(!np))
                return -EINVAL;

        ret = partition_translate_id(gic_data.ppi_descs[fwspec->param[1]],
                                     of_node_to_fwnode(np));
        if (ret < 0)
                return ret;

        *hwirq = ret;
        *type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;

        return 0;
}

static const struct irq_domain_ops partition_domain_ops = {
        .translate = partition_domain_translate,
        .select = gic_irq_domain_select,
};

static bool gic_enable_quirk_msm8996(void *data)
{
        struct gic_chip_data *d = data;

        d->flags |= FLAGS_WORKAROUND_GICR_WAKER_MSM8996;

        return true;
}

static bool gic_enable_quirk_cavium_38539(void *data)
{
        struct gic_chip_data *d = data;

        d->flags |= FLAGS_WORKAROUND_CAVIUM_ERRATUM_38539;

        return true;
}

static bool gic_enable_quirk_hip06_07(void *data)
{
        struct gic_chip_data *d = data;

        /*
         * HIP06 GICD_IIDR clashes with GIC-600 product number (despite
         * not being an actual ARM implementation). The saving grace is
         * that GIC-600 doesn't have ESPI, so nothing to do in that case.
         * HIP07 doesn't even have a proper IIDR, and still pretends to
         * have ESPI. In both cases, put them right.
         */
        if (d->rdists.gicd_typer & GICD_TYPER_ESPI) {
                /* Zero both ESPI and the RES0 field next to it... */
                d->rdists.gicd_typer &= ~GENMASK(9, 8);
                return true;
        }

        return false;
}

static const struct gic_quirk gic_quirks[] = {
        {
                .desc   = "GICv3: Qualcomm MSM8996 broken firmware",
                .compatible = "qcom,msm8996-gic-v3",
                .init   = gic_enable_quirk_msm8996,
        },
        {
                .desc   = "GICv3: HIP06 erratum 161010803",
                .iidr   = 0x0204043b,
                .mask   = 0xffffffff,
                .init   = gic_enable_quirk_hip06_07,
        },
        {
                .desc   = "GICv3: HIP07 erratum 161010803",
                .iidr   = 0x00000000,
                .mask   = 0xffffffff,
                .init   = gic_enable_quirk_hip06_07,
        },
        {
                /*
                 * Reserved register accesses generate a Synchronous
                 * External Abort. This erratum applies to:
                 * - ThunderX: CN88xx
                 * - OCTEON TX: CN83xx, CN81xx
                 * - OCTEON TX2: CN93xx, CN96xx, CN98xx, CNF95xx*
                 */
                .desc   = "GICv3: Cavium erratum 38539",
                .iidr   = 0xa000034c,
                .mask   = 0xe8f00fff,
                .init   = gic_enable_quirk_cavium_38539,
        },
        {
        }
};

static void gic_enable_nmi_support(void)
{
        int i;

        if (!gic_prio_masking_enabled())
                return;

        ppi_nmi_refs = kcalloc(gic_data.ppi_nr, sizeof(*ppi_nmi_refs), GFP_KERNEL);
        if (!ppi_nmi_refs)
                return;

        for (i = 0; i < gic_data.ppi_nr; i++)
                refcount_set(&ppi_nmi_refs[i], 0);

        /*
         * Linux itself doesn't use 1:N distribution, so has no need to
         * set PMHE. The only reason to have it set is if EL3 requires it
         * (and we can't change it).
         */
        if (gic_read_ctlr() & ICC_CTLR_EL1_PMHE_MASK)
                static_branch_enable(&gic_pmr_sync);

        pr_info("Pseudo-NMIs enabled using %s ICC_PMR_EL1 synchronisation\n",
                static_branch_unlikely(&gic_pmr_sync) ? "forced" : "relaxed");

        /*
         * How priority values are used by the GIC depends on two things:
         * the security state of the GIC (controlled by the GICD_CTRL.DS bit)
         * and if Group 0 interrupts can be delivered to Linux in the non-secure
         * world as FIQs (controlled by the SCR_EL3.FIQ bit). These affect the
         * the ICC_PMR_EL1 register and the priority that software assigns to
         * interrupts:
         *
         * GICD_CTRL.DS | SCR_EL3.FIQ | ICC_PMR_EL1 | Group 1 priority
         * -----------------------------------------------------------
         *      1       |      -      |  unchanged  |    unchanged
         * -----------------------------------------------------------
         *      0       |      1      |  non-secure |    non-secure
         * -----------------------------------------------------------
         *      0       |      0      |  unchanged  |    non-secure
         *
         * where non-secure means that the value is right-shifted by one and the
         * MSB bit set, to make it fit in the non-secure priority range.
         *
         * In the first two cases, where ICC_PMR_EL1 and the interrupt priority
         * are both either modified or unchanged, we can use the same set of
         * priorities.
         *
         * In the last case, where only the interrupt priorities are modified to
         * be in the non-secure range, we use a different PMR value to mask IRQs
         * and the rest of the values that we use remain unchanged.
         */
        if (gic_has_group0() && !gic_dist_security_disabled())
                static_branch_enable(&gic_nonsecure_priorities);

        static_branch_enable(&supports_pseudo_nmis);

        if (static_branch_likely(&supports_deactivate_key))
                gic_eoimode1_chip.flags |= IRQCHIP_SUPPORTS_NMI;
        else
                gic_chip.flags |= IRQCHIP_SUPPORTS_NMI;
}

static int __init gic_init_bases(void __iomem *dist_base,
                                 struct redist_region *rdist_regs,
                                 u32 nr_redist_regions,
                                 u64 redist_stride,
                                 struct fwnode_handle *handle)
{
        u32 typer;
        int err;

        if (!is_hyp_mode_available())
                static_branch_disable(&supports_deactivate_key);

        if (static_branch_likely(&supports_deactivate_key))
                pr_info("GIC: Using split EOI/Deactivate mode\n");

        gic_data.fwnode = handle;
        gic_data.dist_base = dist_base;
        gic_data.redist_regions = rdist_regs;
        gic_data.nr_redist_regions = nr_redist_regions;
        gic_data.redist_stride = redist_stride;

        /*
         * Find out how many interrupts are supported.
         */
        typer = readl_relaxed(gic_data.dist_base + GICD_TYPER);
        gic_data.rdists.gicd_typer = typer;

        gic_enable_quirks(readl_relaxed(gic_data.dist_base + GICD_IIDR),
                          gic_quirks, &gic_data);

        pr_info("%d SPIs implemented\n", GIC_LINE_NR - 32);
        pr_info("%d Extended SPIs implemented\n", GIC_ESPI_NR);

        /*
         * ThunderX1 explodes on reading GICD_TYPER2, in violation of the
         * architecture spec (which says that reserved registers are RES0).
         */
        if (!(gic_data.flags & FLAGS_WORKAROUND_CAVIUM_ERRATUM_38539))
                gic_data.rdists.gicd_typer2 = readl_relaxed(gic_data.dist_base + GICD_TYPER2);

        gic_data.domain = irq_domain_create_tree(handle, &gic_irq_domain_ops,
                                                 &gic_data);
        gic_data.rdists.rdist = alloc_percpu(typeof(*gic_data.rdists.rdist));
        gic_data.rdists.has_rvpeid = true;
        gic_data.rdists.has_vlpis = true;
        gic_data.rdists.has_direct_lpi = true;
        gic_data.rdists.has_vpend_valid_dirty = true;

        if (WARN_ON(!gic_data.domain) || WARN_ON(!gic_data.rdists.rdist)) {
                err = -ENOMEM;
                goto out_free;
        }

        irq_domain_update_bus_token(gic_data.domain, DOMAIN_BUS_WIRED);

        gic_data.has_rss = !!(typer & GICD_TYPER_RSS);
        pr_info("Distributor has %sRange Selector support\n",
                gic_data.has_rss ? "" : "no ");

        if (typer & GICD_TYPER_MBIS) {
                err = mbi_init(handle, gic_data.domain);
                if (err)
                        pr_err("Failed to initialize MBIs\n");
        }

        set_handle_irq(gic_handle_irq);

        gic_update_rdist_properties();

        gic_dist_init();
        gic_cpu_init();
        gic_smp_init();
        gic_cpu_pm_init();

        if (gic_dist_supports_lpis()) {
                its_init(handle, &gic_data.rdists, gic_data.domain);
                its_cpu_init();
        } else {
                if (IS_ENABLED(CONFIG_ARM_GIC_V2M))
                        gicv2m_init(handle, gic_data.domain);
        }

        gic_enable_nmi_support();

        return 0;

out_free:
        if (gic_data.domain)
                irq_domain_remove(gic_data.domain);
        free_percpu(gic_data.rdists.rdist);
        return err;
}

static int __init gic_validate_dist_version(void __iomem *dist_base)
{
        u32 reg = readl_relaxed(dist_base + GICD_PIDR2) & GIC_PIDR2_ARCH_MASK;

        if (reg != GIC_PIDR2_ARCH_GICv3 && reg != GIC_PIDR2_ARCH_GICv4)
                return -ENODEV;

        return 0;
}

/* Create all possible partitions at boot time */
static void __init gic_populate_ppi_partitions(struct device_node *gic_node)
{
        struct device_node *parts_node, *child_part;
        int part_idx = 0, i;
        int nr_parts;
        struct partition_affinity *parts;

        parts_node = of_get_child_by_name(gic_node, "ppi-partitions");
        if (!parts_node)
                return;

        gic_data.ppi_descs = kcalloc(gic_data.ppi_nr, sizeof(*gic_data.ppi_descs), GFP_KERNEL);
        if (!gic_data.ppi_descs)
                return;

        nr_parts = of_get_child_count(parts_node);

        if (!nr_parts)
                goto out_put_node;

        parts = kcalloc(nr_parts, sizeof(*parts), GFP_KERNEL);
        if (WARN_ON(!parts))
                goto out_put_node;

        for_each_child_of_node(parts_node, child_part) {
                struct partition_affinity *part;
                int n;

                part = &parts[part_idx];

                part->partition_id = of_node_to_fwnode(child_part);

                pr_info("GIC: PPI partition %pOFn[%d] { ",
                        child_part, part_idx);

                n = of_property_count_elems_of_size(child_part, "affinity",
                                                    sizeof(u32));
                WARN_ON(n <= 0);

                for (i = 0; i < n; i++) {
                        int err, cpu;
                        u32 cpu_phandle;
                        struct device_node *cpu_node;

                        err = of_property_read_u32_index(child_part, "affinity",
                                                         i, &cpu_phandle);
                        if (WARN_ON(err))
                                continue;

                        cpu_node = of_find_node_by_phandle(cpu_phandle);
                        if (WARN_ON(!cpu_node))
                                continue;

                        cpu = of_cpu_node_to_id(cpu_node);
                        if (WARN_ON(cpu < 0))
                                continue;

                        pr_cont("%pOF[%d] ", cpu_node, cpu);

                        cpumask_set_cpu(cpu, &part->mask);
                }

                pr_cont("}\n");
                part_idx++;
        }

        for (i = 0; i < gic_data.ppi_nr; i++) {
                unsigned int irq;
                struct partition_desc *desc;
                struct irq_fwspec ppi_fwspec = {
                        .fwnode         = gic_data.fwnode,
                        .param_count    = 3,
                        .param          = {
                                [0]     = GIC_IRQ_TYPE_PARTITION,
                                [1]     = i,
                                [2]     = IRQ_TYPE_NONE,
                        },
                };

                irq = irq_create_fwspec_mapping(&ppi_fwspec);
                if (WARN_ON(!irq))
                        continue;
                desc = partition_create_desc(gic_data.fwnode, parts, nr_parts,
                                             irq, &partition_domain_ops);
                if (WARN_ON(!desc))
                        continue;

                gic_data.ppi_descs[i] = desc;
        }

out_put_node:
        of_node_put(parts_node);
}

static void __init gic_of_setup_kvm_info(struct device_node *node)
{
        int ret;
        struct resource r;
        u32 gicv_idx;

        gic_v3_kvm_info.type = GIC_V3;

        gic_v3_kvm_info.maint_irq = irq_of_parse_and_map(node, 0);
        if (!gic_v3_kvm_info.maint_irq)
                return;

        if (of_property_read_u32(node, "#redistributor-regions",
                                 &gicv_idx))
                gicv_idx = 1;

        gicv_idx += 3;  /* Also skip GICD, GICC, GICH */
        ret = of_address_to_resource(node, gicv_idx, &r);
        if (!ret)
                gic_v3_kvm_info.vcpu = r;

        gic_v3_kvm_info.has_v4 = gic_data.rdists.has_vlpis;
        gic_v3_kvm_info.has_v4_1 = gic_data.rdists.has_rvpeid;
        gic_set_kvm_info(&gic_v3_kvm_info);
}

static int __init gic_of_init(struct device_node *node, struct device_node *parent)
{
        void __iomem *dist_base;
        struct redist_region *rdist_regs;
        u64 redist_stride;
        u32 nr_redist_regions;
        int err, i;

        dist_base = of_iomap(node, 0);
        if (!dist_base) {
                pr_err("%pOF: unable to map gic dist registers\n", node);
                return -ENXIO;
        }

        err = gic_validate_dist_version(dist_base);
        if (err) {
                pr_err("%pOF: no distributor detected, giving up\n", node);
                goto out_unmap_dist;
        }

        if (of_property_read_u32(node, "#redistributor-regions", &nr_redist_regions))
                nr_redist_regions = 1;

        rdist_regs = kcalloc(nr_redist_regions, sizeof(*rdist_regs),
                             GFP_KERNEL);
        if (!rdist_regs) {
                err = -ENOMEM;
                goto out_unmap_dist;
        }

        for (i = 0; i < nr_redist_regions; i++) {
                struct resource res;
                int ret;

                ret = of_address_to_resource(node, 1 + i, &res);
                rdist_regs[i].redist_base = of_iomap(node, 1 + i);
                if (ret || !rdist_regs[i].redist_base) {
                        pr_err("%pOF: couldn't map region %d\n", node, i);
                        err = -ENODEV;
                        goto out_unmap_rdist;
                }
                rdist_regs[i].phys_base = res.start;
        }

        if (of_property_read_u64(node, "redistributor-stride", &redist_stride))
                redist_stride = 0;

        gic_enable_of_quirks(node, gic_quirks, &gic_data);

        err = gic_init_bases(dist_base, rdist_regs, nr_redist_regions,
                             redist_stride, &node->fwnode);
        if (err)
                goto out_unmap_rdist;

        gic_populate_ppi_partitions(node);

        if (static_branch_likely(&supports_deactivate_key))
                gic_of_setup_kvm_info(node);
        return 0;

out_unmap_rdist:
        for (i = 0; i < nr_redist_regions; i++)
                if (rdist_regs[i].redist_base)
                        iounmap(rdist_regs[i].redist_base);
        kfree(rdist_regs);
out_unmap_dist:
        iounmap(dist_base);
        return err;
}

IRQCHIP_DECLARE(gic_v3, "arm,gic-v3", gic_of_init);

#ifdef CONFIG_ACPI
static struct
{
        void __iomem *dist_base;
        struct redist_region *redist_regs;
        u32 nr_redist_regions;
        bool single_redist;
        int enabled_rdists;
        u32 maint_irq;
        int maint_irq_mode;
        phys_addr_t vcpu_base;
} acpi_data __initdata;

static void __init
gic_acpi_register_redist(phys_addr_t phys_base, void __iomem *redist_base)
{
        static int count = 0;

        acpi_data.redist_regs[count].phys_base = phys_base;
        acpi_data.redist_regs[count].redist_base = redist_base;
        acpi_data.redist_regs[count].single_redist = acpi_data.single_redist;
        count++;
}

static int __init
gic_acpi_parse_madt_redist(union acpi_subtable_headers *header,
                           const unsigned long end)
{
        struct acpi_madt_generic_redistributor *redist =
                        (struct acpi_madt_generic_redistributor *)header;
        void __iomem *redist_base;

        redist_base = ioremap(redist->base_address, redist->length);
        if (!redist_base) {
                pr_err("Couldn't map GICR region @%llx\n", redist->base_address);
                return -ENOMEM;
        }

        gic_acpi_register_redist(redist->base_address, redist_base);
        return 0;
}

static int __init
gic_acpi_parse_madt_gicc(union acpi_subtable_headers *header,
                         const unsigned long end)
{
        struct acpi_madt_generic_interrupt *gicc =
                                (struct acpi_madt_generic_interrupt *)header;
        u32 reg = readl_relaxed(acpi_data.dist_base + GICD_PIDR2) & GIC_PIDR2_ARCH_MASK;
        u32 size = reg == GIC_PIDR2_ARCH_GICv4 ? SZ_64K * 4 : SZ_64K * 2;
        void __iomem *redist_base;

        /* GICC entry which has !ACPI_MADT_ENABLED is not unusable so skip */
        if (!(gicc->flags & ACPI_MADT_ENABLED))
                return 0;

        redist_base = ioremap(gicc->gicr_base_address, size);
        if (!redist_base)
                return -ENOMEM;

        gic_acpi_register_redist(gicc->gicr_base_address, redist_base);
        return 0;
}

static int __init gic_acpi_collect_gicr_base(void)
{
        acpi_tbl_entry_handler redist_parser;
        enum acpi_madt_type type;

        if (acpi_data.single_redist) {
                type = ACPI_MADT_TYPE_GENERIC_INTERRUPT;

                redist_parser = gic_acpi_parse_madt_gicc;
        } else {
                type = ACPI_MADT_TYPE_GENERIC_REDISTRIBUTOR;
                redist_parser = gic_acpi_parse_madt_redist;
        }

        /* Collect redistributor base addresses in GICR entries */
        if (acpi_table_parse_madt(type, redist_parser, 0) > 0)
                return 0;

        pr_info("No valid GICR entries exist\n");
        return -ENODEV;
}

static int __init gic_acpi_match_gicr(union acpi_subtable_headers *header,
                                  const unsigned long end)
{
        /* Subtable presence means that redist exists, that's it */
        return 0;
}

static int __init gic_acpi_match_gicc(union acpi_subtable_headers *header,
                                      const unsigned long end)
{
        struct acpi_madt_generic_interrupt *gicc =
                                (struct acpi_madt_generic_interrupt *)header;

        /*
         * If GICC is enabled and has valid gicr base address, then it means
         * GICR base is presented via GICC
         */
        if ((gicc->flags & ACPI_MADT_ENABLED) && gicc->gicr_base_address) {
                acpi_data.enabled_rdists++;
                return 0;
        }

        /*
         * It's perfectly valid firmware can pass disabled GICC entry, driver
         * should not treat as errors, skip the entry instead of probe fail.
         */
        if (!(gicc->flags & ACPI_MADT_ENABLED))
                return 0;

        return -ENODEV;
}

static int __init gic_acpi_count_gicr_regions(void)
{
        int count;

        /*
         * Count how many redistributor regions we have. It is not allowed
         * to mix redistributor description, GICR and GICC subtables have to be
         * mutually exclusive.
         */
        count = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_REDISTRIBUTOR,
                                      gic_acpi_match_gicr, 0);
        if (count > 0) {
                acpi_data.single_redist = false;
                return count;
        }

        count = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT,
                                      gic_acpi_match_gicc, 0);
        if (count > 0) {
                acpi_data.single_redist = true;
                count = acpi_data.enabled_rdists;
        }

        return count;
}

static bool __init acpi_validate_gic_table(struct acpi_subtable_header *header,
                                           struct acpi_probe_entry *ape)
{
        struct acpi_madt_generic_distributor *dist;
        int count;

        dist = (struct acpi_madt_generic_distributor *)header;
        if (dist->version != ape->driver_data)
                return false;

        /* We need to do that exercise anyway, the sooner the better */
        count = gic_acpi_count_gicr_regions();
        if (count <= 0)
                return false;

        acpi_data.nr_redist_regions = count;
        return true;
}

static int __init gic_acpi_parse_virt_madt_gicc(union acpi_subtable_headers *header,
                                                const unsigned long end)
{
        struct acpi_madt_generic_interrupt *gicc =
                (struct acpi_madt_generic_interrupt *)header;
        int maint_irq_mode;
        static int first_madt = true;

        /* Skip unusable CPUs */
        if (!(gicc->flags & ACPI_MADT_ENABLED))
                return 0;

        maint_irq_mode = (gicc->flags & ACPI_MADT_VGIC_IRQ_MODE) ?
                ACPI_EDGE_SENSITIVE : ACPI_LEVEL_SENSITIVE;

        if (first_madt) {
                first_madt = false;

                acpi_data.maint_irq = gicc->vgic_interrupt;
                acpi_data.maint_irq_mode = maint_irq_mode;
                acpi_data.vcpu_base = gicc->gicv_base_address;

                return 0;
        }

        /*
         * The maintenance interrupt and GICV should be the same for every CPU
         */
        if ((acpi_data.maint_irq != gicc->vgic_interrupt) ||
            (acpi_data.maint_irq_mode != maint_irq_mode) ||
            (acpi_data.vcpu_base != gicc->gicv_base_address))
                return -EINVAL;

        return 0;
}

static bool __init gic_acpi_collect_virt_info(void)
{
        int count;

        count = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT,
                                      gic_acpi_parse_virt_madt_gicc, 0);

        return (count > 0);
}

#define ACPI_GICV3_DIST_MEM_SIZE (SZ_64K)
#define ACPI_GICV2_VCTRL_MEM_SIZE       (SZ_4K)
#define ACPI_GICV2_VCPU_MEM_SIZE        (SZ_8K)

static void __init gic_acpi_setup_kvm_info(void)
{
        int irq;

        if (!gic_acpi_collect_virt_info()) {
                pr_warn("Unable to get hardware information used for virtualization\n");
                return;
        }

        gic_v3_kvm_info.type = GIC_V3;

        irq = acpi_register_gsi(NULL, acpi_data.maint_irq,
                                acpi_data.maint_irq_mode,
                                ACPI_ACTIVE_HIGH);
        if (irq <= 0)
                return;

        gic_v3_kvm_info.maint_irq = irq;

        if (acpi_data.vcpu_base) {
                struct resource *vcpu = &gic_v3_kvm_info.vcpu;

                vcpu->flags = IORESOURCE_MEM;
                vcpu->start = acpi_data.vcpu_base;
                vcpu->end = vcpu->start + ACPI_GICV2_VCPU_MEM_SIZE - 1;
        }

        gic_v3_kvm_info.has_v4 = gic_data.rdists.has_vlpis;
        gic_v3_kvm_info.has_v4_1 = gic_data.rdists.has_rvpeid;
        gic_set_kvm_info(&gic_v3_kvm_info);
}

static int __init
gic_acpi_init(union acpi_subtable_headers *header, const unsigned long end)
{
        struct acpi_madt_generic_distributor *dist;
        struct fwnode_handle *domain_handle;
        size_t size;
        int i, err;

        /* Get distributor base address */
        dist = (struct acpi_madt_generic_distributor *)header;
        acpi_data.dist_base = ioremap(dist->base_address,
                                      ACPI_GICV3_DIST_MEM_SIZE);
        if (!acpi_data.dist_base) {
                pr_err("Unable to map GICD registers\n");
                return -ENOMEM;
        }

        err = gic_validate_dist_version(acpi_data.dist_base);
        if (err) {
                pr_err("No distributor detected at @%p, giving up\n",
                       acpi_data.dist_base);
                goto out_dist_unmap;
        }

        size = sizeof(*acpi_data.redist_regs) * acpi_data.nr_redist_regions;
        acpi_data.redist_regs = kzalloc(size, GFP_KERNEL);
        if (!acpi_data.redist_regs) {
                err = -ENOMEM;
                goto out_dist_unmap;
        }

        err = gic_acpi_collect_gicr_base();
        if (err)
                goto out_redist_unmap;

        domain_handle = irq_domain_alloc_fwnode(&dist->base_address);
        if (!domain_handle) {
                err = -ENOMEM;
                goto out_redist_unmap;
        }

        err = gic_init_bases(acpi_data.dist_base, acpi_data.redist_regs,
                             acpi_data.nr_redist_regions, 0, domain_handle);
        if (err)
                goto out_fwhandle_free;

        acpi_set_irq_model(ACPI_IRQ_MODEL_GIC, domain_handle);

        if (static_branch_likely(&supports_deactivate_key))
                gic_acpi_setup_kvm_info();

        return 0;

out_fwhandle_free:
        irq_domain_free_fwnode(domain_handle);
out_redist_unmap:
        for (i = 0; i < acpi_data.nr_redist_regions; i++)
                if (acpi_data.redist_regs[i].redist_base)
                        iounmap(acpi_data.redist_regs[i].redist_base);
        kfree(acpi_data.redist_regs);
out_dist_unmap:
        iounmap(acpi_data.dist_base);
        return err;
}
IRQCHIP_ACPI_DECLARE(gic_v3, ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR,
                     acpi_validate_gic_table, ACPI_MADT_GIC_VERSION_V3,
                     gic_acpi_init);
IRQCHIP_ACPI_DECLARE(gic_v4, ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR,
                     acpi_validate_gic_table, ACPI_MADT_GIC_VERSION_V4,
                     gic_acpi_init);
IRQCHIP_ACPI_DECLARE(gic_v3_or_v4, ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR,
                     acpi_validate_gic_table, ACPI_MADT_GIC_VERSION_NONE,
                     gic_acpi_init);
#endif