// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright The Asahi Linux Contributors
 *
 * Based on irq-lpc32xx:
 *   Copyright 2015-2016 Vladimir Zapolskiy <vz@mleia.com>
 * Based on irq-bcm2836:
 *   Copyright 2015 Broadcom
 */

/*
 * AIC is a fairly simple interrupt controller with the following features:
 *
 * - 896 level-triggered hardware IRQs
 *   - Single mask bit per IRQ
 *   - Per-IRQ affinity setting
 *   - Automatic masking on event delivery (auto-ack)
 *   - Software triggering (ORed with hw line)
 * - 2 per-CPU IPIs (meant as "self" and "other", but they are
 *   interchangeable if not symmetric)
 * - Automatic prioritization (single event/ack register per CPU, lower IRQs =
 *   higher priority)
 * - Automatic masking on ack
 * - Default "this CPU" register view and explicit per-CPU views
 *
 * In addition, this driver also handles FIQs, as these are routed to the same
 * IRQ vector. These are used for Fast IPIs, the ARMv8 timer IRQs, and
 * performance counters (TODO).
 *
 * Implementation notes:
 *
 * - This driver creates two IRQ domains, one for HW IRQs and internal FIQs,
 *   and one for IPIs.
 * - Since Linux needs more than 2 IPIs, we implement a software IRQ controller
 *   and funnel all IPIs into one per-CPU IPI (the second "self" IPI is unused).
 * - FIQ hwirq numbers are assigned after true hwirqs, and are per-cpu.
 * - DT bindings use 3-cell form (like GIC):
 *   - <0 nr flags> - hwirq #nr
 *   - <1 nr flags> - FIQ #nr
 *     - nr=0  Physical HV timer
 *     - nr=1  Virtual HV timer
 *     - nr=2  Physical guest timer
 *     - nr=3  Virtual guest timer
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/bits.h>
#include <linux/bitfield.h>
#include <linux/cpuhotplug.h>
#include <linux/io.h>
#include <linux/irqchip.h>
#include <linux/irqchip/arm-vgic-info.h>
#include <linux/irqdomain.h>
#include <linux/jump_label.h>
#include <linux/limits.h>
#include <linux/of_address.h>
#include <linux/slab.h>
#include <asm/apple_m1_pmu.h>
#include <asm/cputype.h>
#include <asm/exception.h>
#include <asm/sysreg.h>
#include <asm/virt.h>

#include <dt-bindings/interrupt-controller/apple-aic.h>

/*
 * AIC v1 registers (MMIO)
 */

#define AIC_INFO                0x0004
#define AIC_INFO_NR_IRQ         GENMASK(15, 0)

#define AIC_CONFIG              0x0010

#define AIC_WHOAMI              0x2000
#define AIC_EVENT               0x2004
#define AIC_EVENT_DIE           GENMASK(31, 24)
#define AIC_EVENT_TYPE          GENMASK(23, 16)
#define AIC_EVENT_NUM           GENMASK(15, 0)

#define AIC_EVENT_TYPE_FIQ      0 /* Software use */
#define AIC_EVENT_TYPE_IRQ      1
#define AIC_EVENT_TYPE_IPI      4
#define AIC_EVENT_IPI_OTHER     1
#define AIC_EVENT_IPI_SELF      2

#define AIC_IPI_SEND            0x2008
#define AIC_IPI_ACK             0x200c
#define AIC_IPI_MASK_SET        0x2024
#define AIC_IPI_MASK_CLR        0x2028

#define AIC_IPI_SEND_CPU(cpu)   BIT(cpu)

#define AIC_IPI_OTHER           BIT(0)
#define AIC_IPI_SELF            BIT(31)

#define AIC_TARGET_CPU          0x3000

#define AIC_CPU_IPI_SET(cpu)    (0x5008 + ((cpu) << 7))
#define AIC_CPU_IPI_CLR(cpu)    (0x500c + ((cpu) << 7))
#define AIC_CPU_IPI_MASK_SET(cpu) (0x5024 + ((cpu) << 7))
#define AIC_CPU_IPI_MASK_CLR(cpu) (0x5028 + ((cpu) << 7))

#define AIC_MAX_IRQ             0x400

/*
 * AIC v2 registers (MMIO)
 */

#define AIC2_VERSION            0x0000
#define AIC2_VERSION_VER        GENMASK(7, 0)

#define AIC2_INFO1              0x0004
#define AIC2_INFO1_NR_IRQ       GENMASK(15, 0)
#define AIC2_INFO1_LAST_DIE     GENMASK(27, 24)

#define AIC2_INFO2              0x0008

#define AIC2_INFO3              0x000c
#define AIC2_INFO3_MAX_IRQ      GENMASK(15, 0)
#define AIC2_INFO3_MAX_DIE      GENMASK(27, 24)

#define AIC2_RESET              0x0010
#define AIC2_RESET_RESET        BIT(0)

#define AIC2_CONFIG             0x0014
#define AIC2_CONFIG_ENABLE      BIT(0)
#define AIC2_CONFIG_PREFER_PCPU BIT(28)

#define AIC2_TIMEOUT            0x0028
#define AIC2_CLUSTER_PRIO       0x0030
#define AIC2_DELAY_GROUPS       0x0100

#define AIC2_IRQ_CFG            0x2000

/*
 * AIC2 registers are laid out like this, starting at AIC2_IRQ_CFG:
 *
 * Repeat for each die:
 *   IRQ_CFG: u32 * MAX_IRQS
 *   SW_SET: u32 * (MAX_IRQS / 32)
 *   SW_CLR: u32 * (MAX_IRQS / 32)
 *   MASK_SET: u32 * (MAX_IRQS / 32)
 *   MASK_CLR: u32 * (MAX_IRQS / 32)
 *   HW_STATE: u32 * (MAX_IRQS / 32)
 *
 * This is followed by a set of event registers, each 16K page aligned.
 * The first one is the AP event register we will use. Unfortunately,
 * the actual implemented die count is not specified anywhere in the
 * capability registers, so we have to explicitly specify the event
 * register as a second reg entry in the device tree to remain
 * forward-compatible.
 */

#define AIC2_IRQ_CFG_TARGET     GENMASK(3, 0)
#define AIC2_IRQ_CFG_DELAY_IDX  GENMASK(7, 5)

#define MASK_REG(x)             (4 * ((x) >> 5))
#define MASK_BIT(x)             BIT((x) & GENMASK(4, 0))

/*
 * IMP-DEF sysregs that control FIQ sources
 */

/* IPI request registers */
#define SYS_IMP_APL_IPI_RR_LOCAL_EL1    sys_reg(3, 5, 15, 0, 0)
#define SYS_IMP_APL_IPI_RR_GLOBAL_EL1   sys_reg(3, 5, 15, 0, 1)
#define IPI_RR_CPU                      GENMASK(7, 0)
/* Cluster only used for the GLOBAL register */
#define IPI_RR_CLUSTER                  GENMASK(23, 16)
#define IPI_RR_TYPE                     GENMASK(29, 28)
#define IPI_RR_IMMEDIATE                0
#define IPI_RR_RETRACT                  1
#define IPI_RR_DEFERRED                 2
#define IPI_RR_NOWAKE                   3

/* IPI status register */
#define SYS_IMP_APL_IPI_SR_EL1          sys_reg(3, 5, 15, 1, 1)
#define IPI_SR_PENDING                  BIT(0)

/* Guest timer FIQ enable register */
#define SYS_IMP_APL_VM_TMR_FIQ_ENA_EL2  sys_reg(3, 5, 15, 1, 3)
#define VM_TMR_FIQ_ENABLE_V             BIT(0)
#define VM_TMR_FIQ_ENABLE_P             BIT(1)

/* Deferred IPI countdown register */
#define SYS_IMP_APL_IPI_CR_EL1          sys_reg(3, 5, 15, 3, 1)

/* Uncore PMC control register */
#define SYS_IMP_APL_UPMCR0_EL1          sys_reg(3, 7, 15, 0, 4)
#define UPMCR0_IMODE                    GENMASK(18, 16)
#define UPMCR0_IMODE_OFF                0
#define UPMCR0_IMODE_AIC                2
#define UPMCR0_IMODE_HALT               3
#define UPMCR0_IMODE_FIQ                4

/* Uncore PMC status register */
#define SYS_IMP_APL_UPMSR_EL1           sys_reg(3, 7, 15, 6, 4)
#define UPMSR_IACT                      BIT(0)

/* MPIDR fields */
#define MPIDR_CPU(x)                    MPIDR_AFFINITY_LEVEL(x, 0)
#define MPIDR_CLUSTER(x)                MPIDR_AFFINITY_LEVEL(x, 1)

#define AIC_IRQ_HWIRQ(die, irq) (FIELD_PREP(AIC_EVENT_DIE, die) | \
                                 FIELD_PREP(AIC_EVENT_TYPE, AIC_EVENT_TYPE_IRQ) | \
                                 FIELD_PREP(AIC_EVENT_NUM, irq))
#define AIC_FIQ_HWIRQ(x)        (FIELD_PREP(AIC_EVENT_TYPE, AIC_EVENT_TYPE_FIQ) | \
                                 FIELD_PREP(AIC_EVENT_NUM, x))
#define AIC_HWIRQ_IRQ(x)        FIELD_GET(AIC_EVENT_NUM, x)
#define AIC_HWIRQ_DIE(x)        FIELD_GET(AIC_EVENT_DIE, x)
#define AIC_NR_SWIPI            32

/*
 * FIQ hwirq index definitions: FIQ sources use the DT binding defines
 * directly, except that timers are special. At the irqchip level, the
 * two timer types are represented by their access method: _EL0 registers
 * or _EL02 registers. In the DT binding, the timers are represented
 * by their purpose (HV or guest). This mapping is for when the kernel is
 * running at EL2 (with VHE). When the kernel is running at EL1, the
 * mapping differs and aic_irq_domain_translate() performs the remapping.
 */
enum fiq_hwirq {
        /* Must be ordered as in apple-aic.h */
        AIC_TMR_EL0_PHYS        = AIC_TMR_HV_PHYS,
        AIC_TMR_EL0_VIRT        = AIC_TMR_HV_VIRT,
        AIC_TMR_EL02_PHYS       = AIC_TMR_GUEST_PHYS,
        AIC_TMR_EL02_VIRT       = AIC_TMR_GUEST_VIRT,
        AIC_CPU_PMU_Effi        = AIC_CPU_PMU_E,
        AIC_CPU_PMU_Perf        = AIC_CPU_PMU_P,
        /* No need for this to be discovered from DT */
        AIC_VGIC_MI,
        AIC_NR_FIQ
};

/* True if UNCORE/UNCORE2 and Sn_... IPI registers are present and used (A11+) */
static DEFINE_STATIC_KEY_TRUE(use_fast_ipi);
/* True if SYS_IMP_APL_IPI_RR_LOCAL_EL1 exists for local fast IPIs (M1+) */
static DEFINE_STATIC_KEY_TRUE(use_local_fast_ipi);

struct aic_info {
        int version;

        /* Register offsets */
        u32 event;
        u32 target_cpu;
        u32 irq_cfg;
        u32 sw_set;
        u32 sw_clr;
        u32 mask_set;
        u32 mask_clr;

        u32 die_stride;

        /* Features */
        bool fast_ipi;
        bool local_fast_ipi;
};

static const struct aic_info aic1_info __initconst = {
        .version        = 1,

        .event          = AIC_EVENT,
        .target_cpu     = AIC_TARGET_CPU,
};

static const struct aic_info aic1_fipi_info __initconst = {
        .version        = 1,

        .event          = AIC_EVENT,
        .target_cpu     = AIC_TARGET_CPU,

        .fast_ipi       = true,
};

static const struct aic_info aic1_local_fipi_info __initconst = {
        .version        = 1,

        .event          = AIC_EVENT,
        .target_cpu     = AIC_TARGET_CPU,

        .fast_ipi       = true,
        .local_fast_ipi = true,
};

static const struct aic_info aic2_info __initconst = {
        .version        = 2,

        .irq_cfg        = AIC2_IRQ_CFG,

        .fast_ipi       = true,
        .local_fast_ipi = true,
};

static const struct of_device_id aic_info_match[] = {
        {
                .compatible = "apple,t8103-aic",
                .data = &aic1_local_fipi_info,
        },
        {
                .compatible = "apple,t8015-aic",
                .data = &aic1_fipi_info,
        },
        {
                .compatible = "apple,aic",
                .data = &aic1_info,
        },
        {
                .compatible = "apple,aic2",
                .data = &aic2_info,
        },
        {}
};

struct aic_irq_chip {
        void __iomem *base;
        void __iomem *event;
        struct irq_domain *hw_domain;
        struct {
                cpumask_t aff;
        } *fiq_aff[AIC_NR_FIQ];

        int nr_irq;
        int max_irq;
        int nr_die;
        int max_die;

        struct aic_info info;
};

static DEFINE_PER_CPU(uint32_t, aic_fiq_unmasked);

static struct aic_irq_chip *aic_irqc;

static void aic_handle_ipi(struct pt_regs *regs);

static u32 aic_ic_read(struct aic_irq_chip *ic, u32 reg)
{
        return readl_relaxed(ic->base + reg);
}

static void aic_ic_write(struct aic_irq_chip *ic, u32 reg, u32 val)
{
        writel_relaxed(val, ic->base + reg);
}

/*
 * IRQ irqchip
 */

static void aic_irq_mask(struct irq_data *d)
{
        irq_hw_number_t hwirq = irqd_to_hwirq(d);
        struct aic_irq_chip *ic = irq_data_get_irq_chip_data(d);

        u32 off = AIC_HWIRQ_DIE(hwirq) * ic->info.die_stride;
        u32 irq = AIC_HWIRQ_IRQ(hwirq);

        aic_ic_write(ic, ic->info.mask_set + off + MASK_REG(irq), MASK_BIT(irq));
}

static void aic_irq_unmask(struct irq_data *d)
{
        irq_hw_number_t hwirq = irqd_to_hwirq(d);
        struct aic_irq_chip *ic = irq_data_get_irq_chip_data(d);

        u32 off = AIC_HWIRQ_DIE(hwirq) * ic->info.die_stride;
        u32 irq = AIC_HWIRQ_IRQ(hwirq);

        aic_ic_write(ic, ic->info.mask_clr + off + MASK_REG(irq), MASK_BIT(irq));
}

static void aic_irq_eoi(struct irq_data *d)
{
        /*
         * Reading the interrupt reason automatically acknowledges and masks
         * the IRQ, so we just unmask it here if needed.
         */
        if (!irqd_irq_masked(d))
                aic_irq_unmask(d);
}

static void __exception_irq_entry aic_handle_irq(struct pt_regs *regs)
{
        struct aic_irq_chip *ic = aic_irqc;
        u32 event, type, irq;

        do {
                /*
                 * We cannot use a relaxed read here, as reads from DMA buffers
                 * need to be ordered after the IRQ fires.
                 */
                event = readl(ic->event + ic->info.event);
                type = FIELD_GET(AIC_EVENT_TYPE, event);
                irq = FIELD_GET(AIC_EVENT_NUM, event);

                if (type == AIC_EVENT_TYPE_IRQ)
                        generic_handle_domain_irq(aic_irqc->hw_domain, event);
                else if (type == AIC_EVENT_TYPE_IPI && irq == 1)
                        aic_handle_ipi(regs);
                else if (event != 0)
                        pr_err_ratelimited("Unknown IRQ event %d, %d\n", type, irq);
        } while (event);

        /*
         * vGIC maintenance interrupts end up here too, so we need to check
         * for them separately. It should however only trigger when NV is
         * in use, and be cleared when coming back from the handler.
         */
        if (is_kernel_in_hyp_mode() &&
            (read_sysreg_s(SYS_ICH_HCR_EL2) & ICH_HCR_EL2_En) &&
            read_sysreg_s(SYS_ICH_MISR_EL2) != 0) {
                u64 val;

                generic_handle_domain_irq(aic_irqc->hw_domain,
                                          AIC_FIQ_HWIRQ(AIC_VGIC_MI));

                if (unlikely((read_sysreg_s(SYS_ICH_HCR_EL2) & ICH_HCR_EL2_En) &&
                             (val = read_sysreg_s(SYS_ICH_MISR_EL2)))) {
                        pr_err_ratelimited("vGIC IRQ fired and not handled by KVM (MISR=%llx), disabling.\n",
                                           val);
                        sysreg_clear_set_s(SYS_ICH_HCR_EL2, ICH_HCR_EL2_En, 0);
                }
        }
}

static int aic_irq_set_affinity(struct irq_data *d,
                                const struct cpumask *mask_val, bool force)
{
        irq_hw_number_t hwirq = irqd_to_hwirq(d);
        struct aic_irq_chip *ic = irq_data_get_irq_chip_data(d);
        int cpu;

        BUG_ON(!ic->info.target_cpu);

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

        aic_ic_write(ic, ic->info.target_cpu + AIC_HWIRQ_IRQ(hwirq) * 4, BIT(cpu));
        irq_data_update_effective_affinity(d, cpumask_of(cpu));

        return IRQ_SET_MASK_OK;
}

static int aic_irq_set_type(struct irq_data *d, unsigned int type)
{
        /*
         * Some IRQs (e.g. MSIs) implicitly have edge semantics, and we don't
         * have a way to find out the type of any given IRQ, so just allow both.
         */
        return (type == IRQ_TYPE_LEVEL_HIGH || type == IRQ_TYPE_EDGE_RISING) ? 0 : -EINVAL;
}

static struct irq_chip aic_chip = {
        .name = "AIC",
        .irq_mask = aic_irq_mask,
        .irq_unmask = aic_irq_unmask,
        .irq_eoi = aic_irq_eoi,
        .irq_set_affinity = aic_irq_set_affinity,
        .irq_set_type = aic_irq_set_type,
};

static struct irq_chip aic2_chip = {
        .name = "AIC2",
        .irq_mask = aic_irq_mask,
        .irq_unmask = aic_irq_unmask,
        .irq_eoi = aic_irq_eoi,
        .irq_set_type = aic_irq_set_type,
};

/*
 * FIQ irqchip
 */

static unsigned long aic_fiq_get_idx(struct irq_data *d)
{
        return AIC_HWIRQ_IRQ(irqd_to_hwirq(d));
}

static void aic_fiq_set_mask(struct irq_data *d)
{
        /* Only the guest timers have real mask bits, unfortunately. */
        switch (aic_fiq_get_idx(d)) {
        case AIC_TMR_EL02_PHYS:
                sysreg_clear_set_s(SYS_IMP_APL_VM_TMR_FIQ_ENA_EL2, VM_TMR_FIQ_ENABLE_P, 0);
                isb();
                break;
        case AIC_TMR_EL02_VIRT:
                sysreg_clear_set_s(SYS_IMP_APL_VM_TMR_FIQ_ENA_EL2, VM_TMR_FIQ_ENABLE_V, 0);
                isb();
                break;
        default:
                break;
        }
}

static void aic_fiq_clear_mask(struct irq_data *d)
{
        switch (aic_fiq_get_idx(d)) {
        case AIC_TMR_EL02_PHYS:
                sysreg_clear_set_s(SYS_IMP_APL_VM_TMR_FIQ_ENA_EL2, 0, VM_TMR_FIQ_ENABLE_P);
                isb();
                break;
        case AIC_TMR_EL02_VIRT:
                sysreg_clear_set_s(SYS_IMP_APL_VM_TMR_FIQ_ENA_EL2, 0, VM_TMR_FIQ_ENABLE_V);
                isb();
                break;
        default:
                break;
        }
}

static void aic_fiq_mask(struct irq_data *d)
{
        aic_fiq_set_mask(d);
        __this_cpu_and(aic_fiq_unmasked, ~BIT(aic_fiq_get_idx(d)));
}

static void aic_fiq_unmask(struct irq_data *d)
{
        aic_fiq_clear_mask(d);
        __this_cpu_or(aic_fiq_unmasked, BIT(aic_fiq_get_idx(d)));
}

static void aic_fiq_eoi(struct irq_data *d)
{
        /* We mask to ack (where we can), so we need to unmask at EOI. */
        if (__this_cpu_read(aic_fiq_unmasked) & BIT(aic_fiq_get_idx(d)))
                aic_fiq_clear_mask(d);
}

#define TIMER_FIRING(x)                                                        \
        (((x) & (ARCH_TIMER_CTRL_ENABLE | ARCH_TIMER_CTRL_IT_MASK |            \
                 ARCH_TIMER_CTRL_IT_STAT)) ==                                  \
         (ARCH_TIMER_CTRL_ENABLE | ARCH_TIMER_CTRL_IT_STAT))

static void __exception_irq_entry aic_handle_fiq(struct pt_regs *regs)
{
        /*
         * It would be really nice if we had a system register that lets us get
         * the FIQ source state without having to peek down into sources...
         * but such a register does not seem to exist.
         *
         * So, we have these potential sources to test for:
         *  - Fast IPIs (not yet used)
         *  - The 4 timers (CNTP, CNTV for each of HV and guest)
         *  - Per-core PMCs (not yet supported)
         *  - Per-cluster uncore PMCs (not yet supported)
         *
         * Since not dealing with any of these results in a FIQ storm,
         * we check for everything here, even things we don't support yet.
         */

        if (static_branch_likely(&use_fast_ipi) &&
            (read_sysreg_s(SYS_IMP_APL_IPI_SR_EL1) & IPI_SR_PENDING))
                aic_handle_ipi(regs);

        if (TIMER_FIRING(read_sysreg(cntp_ctl_el0)))
                generic_handle_domain_irq(aic_irqc->hw_domain,
                                          AIC_FIQ_HWIRQ(AIC_TMR_EL0_PHYS));

        if (TIMER_FIRING(read_sysreg(cntv_ctl_el0)))
                generic_handle_domain_irq(aic_irqc->hw_domain,
                                          AIC_FIQ_HWIRQ(AIC_TMR_EL0_VIRT));

        if (is_kernel_in_hyp_mode()) {
                uint64_t enabled = read_sysreg_s(SYS_IMP_APL_VM_TMR_FIQ_ENA_EL2);

                if ((enabled & VM_TMR_FIQ_ENABLE_P) &&
                    TIMER_FIRING(read_sysreg_s(SYS_CNTP_CTL_EL02)))
                        generic_handle_domain_irq(aic_irqc->hw_domain,
                                                  AIC_FIQ_HWIRQ(AIC_TMR_EL02_PHYS));

                if ((enabled & VM_TMR_FIQ_ENABLE_V) &&
                    TIMER_FIRING(read_sysreg_s(SYS_CNTV_CTL_EL02)))
                        generic_handle_domain_irq(aic_irqc->hw_domain,
                                                  AIC_FIQ_HWIRQ(AIC_TMR_EL02_VIRT));
        }

        if ((read_sysreg_s(SYS_IMP_APL_PMCR0_EL1) & (PMCR0_IMODE | PMCR0_IACT)) ==
                        (FIELD_PREP(PMCR0_IMODE, PMCR0_IMODE_FIQ) | PMCR0_IACT))
                generic_handle_domain_irq(aic_irqc->hw_domain,
                                          AIC_FIQ_HWIRQ(AIC_CPU_PMU_P));

        if (static_branch_likely(&use_fast_ipi) &&
            (FIELD_GET(UPMCR0_IMODE, read_sysreg_s(SYS_IMP_APL_UPMCR0_EL1)) == UPMCR0_IMODE_FIQ) &&
            (read_sysreg_s(SYS_IMP_APL_UPMSR_EL1) & UPMSR_IACT)) {
                /* Same story with uncore PMCs */
                pr_err_ratelimited("Uncore PMC FIQ fired. Masking.\n");
                sysreg_clear_set_s(SYS_IMP_APL_UPMCR0_EL1, UPMCR0_IMODE,
                                   FIELD_PREP(UPMCR0_IMODE, UPMCR0_IMODE_OFF));
        }
}

static int aic_fiq_set_type(struct irq_data *d, unsigned int type)
{
        return (type == IRQ_TYPE_LEVEL_HIGH) ? 0 : -EINVAL;
}

static struct irq_chip fiq_chip = {
        .name = "AIC-FIQ",
        .irq_mask = aic_fiq_mask,
        .irq_unmask = aic_fiq_unmask,
        .irq_ack = aic_fiq_set_mask,
        .irq_eoi = aic_fiq_eoi,
        .irq_set_type = aic_fiq_set_type,
};

/*
 * Main IRQ domain
 */

static int aic_irq_domain_map(struct irq_domain *id, unsigned int irq,
                              irq_hw_number_t hw)
{
        struct aic_irq_chip *ic = id->host_data;
        u32 type = FIELD_GET(AIC_EVENT_TYPE, hw);
        struct irq_chip *chip = &aic_chip;

        if (ic->info.version == 2)
                chip = &aic2_chip;

        if (type == AIC_EVENT_TYPE_IRQ) {
                irq_domain_set_info(id, irq, hw, chip, id->host_data,
                                    handle_fasteoi_irq, NULL, NULL);
                irqd_set_single_target(irq_desc_get_irq_data(irq_to_desc(irq)));
        } else {
                irq_set_percpu_devid(irq);
                irq_domain_set_info(id, irq, hw, &fiq_chip, id->host_data,
                                    handle_percpu_devid_irq, NULL, NULL);
        }

        return 0;
}

static int aic_irq_get_fwspec_info(struct irq_fwspec *fwspec, struct irq_fwspec_info *info)
{
        const struct cpumask *mask;
        u32 intid;

        info->flags = 0;
        info->affinity = NULL;

        if (fwspec->param[0] != AIC_FIQ)
                return 0;

        if (fwspec->param_count == 3)
                intid = fwspec->param[1];
        else
                intid = fwspec->param[2];

        if (aic_irqc->fiq_aff[intid])
                mask = &aic_irqc->fiq_aff[intid]->aff;
        else
                mask = cpu_possible_mask;

        info->affinity = mask;
        info->flags = IRQ_FWSPEC_INFO_AFFINITY_VALID;

        return 0;
}

static int aic_irq_domain_translate(struct irq_domain *id,
                                    struct irq_fwspec *fwspec,
                                    unsigned long *hwirq,
                                    unsigned int *type)
{
        struct aic_irq_chip *ic = id->host_data;
        u32 *args;
        u32 die = 0;

        if (fwspec->param_count < 3 || fwspec->param_count > 4 ||
            !is_of_node(fwspec->fwnode))
                return -EINVAL;

        args = &fwspec->param[1];

        if (fwspec->param_count == 4) {
                die = args[0];
                args++;
        }

        switch (fwspec->param[0]) {
        case AIC_IRQ:
                if (die >= ic->nr_die)
                        return -EINVAL;
                if (args[0] >= ic->nr_irq)
                        return -EINVAL;
                *hwirq = AIC_IRQ_HWIRQ(die, args[0]);
                break;
        case AIC_FIQ:
                if (die != 0)
                        return -EINVAL;
                if (args[0] >= AIC_NR_FIQ)
                        return -EINVAL;
                *hwirq = AIC_FIQ_HWIRQ(args[0]);

                /*
                 * In EL1 the non-redirected registers are the guest's,
                 * not EL2's, so remap the hwirqs to match.
                 */
                if (!is_kernel_in_hyp_mode()) {
                        switch (args[0]) {
                        case AIC_TMR_GUEST_PHYS:
                                *hwirq = AIC_FIQ_HWIRQ(AIC_TMR_EL0_PHYS);
                                break;
                        case AIC_TMR_GUEST_VIRT:
                                *hwirq = AIC_FIQ_HWIRQ(AIC_TMR_EL0_VIRT);
                                break;
                        case AIC_TMR_HV_PHYS:
                        case AIC_TMR_HV_VIRT:
                                return -ENOENT;
                        default:
                                break;
                        }
                }

                /* Merge the two PMUs on a single interrupt */
                if (*hwirq == AIC_CPU_PMU_E)
                        *hwirq = AIC_CPU_PMU_P;
                break;
        default:
                return -EINVAL;
        }

        *type = args[1] & IRQ_TYPE_SENSE_MASK;

        return 0;
}

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

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

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

        return 0;
}

static void aic_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 const struct irq_domain_ops aic_irq_domain_ops = {
        .translate              = aic_irq_domain_translate,
        .alloc                  = aic_irq_domain_alloc,
        .free                   = aic_irq_domain_free,
        .get_fwspec_info        = aic_irq_get_fwspec_info,
};

/*
 * IPI irqchip
 */

static void aic_ipi_send_fast(int cpu)
{
        u64 mpidr = cpu_logical_map(cpu);
        u64 my_mpidr = read_cpuid_mpidr();
        u64 cluster = MPIDR_CLUSTER(mpidr);
        u64 idx = MPIDR_CPU(mpidr);

        if (static_branch_likely(&use_local_fast_ipi) && MPIDR_CLUSTER(my_mpidr) == cluster) {
                write_sysreg_s(FIELD_PREP(IPI_RR_CPU, idx), SYS_IMP_APL_IPI_RR_LOCAL_EL1);
        } else {
                write_sysreg_s(FIELD_PREP(IPI_RR_CPU, idx) | FIELD_PREP(IPI_RR_CLUSTER, cluster),
                               SYS_IMP_APL_IPI_RR_GLOBAL_EL1);
        }
        isb();
}

static void aic_handle_ipi(struct pt_regs *regs)
{
        /*
         * Ack the IPI. We need to order this after the AIC event read, but
         * that is enforced by normal MMIO ordering guarantees.
         *
         * For the Fast IPI case, this needs to be ordered before the vIPI
         * handling below, so we need to isb();
         */
        if (static_branch_likely(&use_fast_ipi)) {
                write_sysreg_s(IPI_SR_PENDING, SYS_IMP_APL_IPI_SR_EL1);
                isb();
        } else {
                aic_ic_write(aic_irqc, AIC_IPI_ACK, AIC_IPI_OTHER);
        }

        ipi_mux_process();

        /*
         * No ordering needed here; at worst this just changes the timing of
         * when the next IPI will be delivered.
         */
        if (!static_branch_likely(&use_fast_ipi))
                aic_ic_write(aic_irqc, AIC_IPI_MASK_CLR, AIC_IPI_OTHER);
}

static void aic_ipi_send_single(unsigned int cpu)
{
        if (static_branch_likely(&use_fast_ipi))
                aic_ipi_send_fast(cpu);
        else
                aic_ic_write(aic_irqc, AIC_IPI_SEND, AIC_IPI_SEND_CPU(cpu));
}

static int __init aic_init_smp(struct aic_irq_chip *irqc, struct device_node *node)
{
        int base_ipi;

        base_ipi = ipi_mux_create(AIC_NR_SWIPI, aic_ipi_send_single);
        if (WARN_ON(base_ipi <= 0))
                return -ENODEV;

        set_smp_ipi_range(base_ipi, AIC_NR_SWIPI);

        return 0;
}

static int aic_init_cpu(unsigned int cpu)
{
        /* Mask all hard-wired per-CPU IRQ/FIQ sources */

        /* Pending Fast IPI FIQs */
        if (static_branch_likely(&use_fast_ipi))
                write_sysreg_s(IPI_SR_PENDING, SYS_IMP_APL_IPI_SR_EL1);

        /* Timer FIQs */
        sysreg_clear_set(cntp_ctl_el0, 0, ARCH_TIMER_CTRL_IT_MASK);
        sysreg_clear_set(cntv_ctl_el0, 0, ARCH_TIMER_CTRL_IT_MASK);

        /* EL2-only (VHE mode) IRQ sources */
        if (is_kernel_in_hyp_mode()) {
                /* Guest timers */
                sysreg_clear_set_s(SYS_IMP_APL_VM_TMR_FIQ_ENA_EL2,
                                   VM_TMR_FIQ_ENABLE_V | VM_TMR_FIQ_ENABLE_P, 0);

                /* vGIC maintenance IRQ */
                sysreg_clear_set_s(SYS_ICH_HCR_EL2, ICH_HCR_EL2_En, 0);
        }

        /* PMC FIQ */
        sysreg_clear_set_s(SYS_IMP_APL_PMCR0_EL1, PMCR0_IMODE | PMCR0_IACT,
                           FIELD_PREP(PMCR0_IMODE, PMCR0_IMODE_OFF));

        /* Uncore PMC FIQ */
        if (static_branch_likely(&use_fast_ipi)) {
                sysreg_clear_set_s(SYS_IMP_APL_UPMCR0_EL1, UPMCR0_IMODE,
                                   FIELD_PREP(UPMCR0_IMODE, UPMCR0_IMODE_OFF));
        }

        /* Commit all of the above */
        isb();

        if (aic_irqc->info.version == 1) {
                /*
                 * Make sure the kernel's idea of logical CPU order is the same as AIC's
                 * If we ever end up with a mismatch here, we will have to introduce
                 * a mapping table similar to what other irqchip drivers do.
                 */
                WARN_ON(aic_ic_read(aic_irqc, AIC_WHOAMI) != smp_processor_id());

                /*
                 * Always keep IPIs unmasked at the hardware level (except auto-masking
                 * by AIC during processing). We manage masks at the vIPI level.
                 * These registers only exist on AICv1, AICv2 always uses fast IPIs.
                 */
                aic_ic_write(aic_irqc, AIC_IPI_ACK, AIC_IPI_SELF | AIC_IPI_OTHER);
                if (static_branch_likely(&use_fast_ipi)) {
                        aic_ic_write(aic_irqc, AIC_IPI_MASK_SET, AIC_IPI_SELF | AIC_IPI_OTHER);
                } else {
                        aic_ic_write(aic_irqc, AIC_IPI_MASK_SET, AIC_IPI_SELF);
                        aic_ic_write(aic_irqc, AIC_IPI_MASK_CLR, AIC_IPI_OTHER);
                }
        }

        /* Initialize the local mask state */
        __this_cpu_write(aic_fiq_unmasked, 0);

        return 0;
}

static struct gic_kvm_info vgic_info __initdata = {
        .type                   = GIC_V3,
        .no_maint_irq_mask      = true,
        .no_hw_deactivation     = true,
};

static void build_fiq_affinity(struct aic_irq_chip *ic, struct device_node *aff)
{
        int i, n;
        u32 fiq;

        if (of_property_read_u32(aff, "apple,fiq-index", &fiq) ||
            WARN_ON(fiq >= AIC_NR_FIQ) || ic->fiq_aff[fiq])
                return;

        n = of_property_count_elems_of_size(aff, "cpus", sizeof(u32));
        if (WARN_ON(n < 0))
                return;

        ic->fiq_aff[fiq] = kzalloc_obj(*ic->fiq_aff[fiq]);
        if (!ic->fiq_aff[fiq])
                return;

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

                if (of_property_read_u32_index(aff, "cpus", i, &cpu_phandle))
                        continue;

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

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

                cpumask_set_cpu(cpu, &ic->fiq_aff[fiq]->aff);
        }
}

static int __init aic_of_ic_init(struct device_node *node, struct device_node *parent)
{
        int i, die;
        u32 off, start_off;
        void __iomem *regs;
        struct aic_irq_chip *irqc;
        struct device_node *affs;
        const struct of_device_id *match;

        regs = of_iomap(node, 0);
        if (WARN_ON(!regs))
                return -EIO;

        irqc = kzalloc_obj(*irqc);
        if (!irqc) {
                iounmap(regs);
                return -ENOMEM;
        }

        irqc->base = regs;

        match = of_match_node(aic_info_match, node);
        if (!match)
                goto err_unmap;

        irqc->info = *(struct aic_info *)match->data;

        aic_irqc = irqc;

        switch (irqc->info.version) {
        case 1: {
                u32 info;

                info = aic_ic_read(irqc, AIC_INFO);
                irqc->nr_irq = FIELD_GET(AIC_INFO_NR_IRQ, info);
                irqc->max_irq = AIC_MAX_IRQ;
                irqc->nr_die = irqc->max_die = 1;

                off = start_off = irqc->info.target_cpu;
                off += sizeof(u32) * irqc->max_irq; /* TARGET_CPU */

                irqc->event = irqc->base;

                break;
        }
        case 2: {
                u32 info1, info3;

                info1 = aic_ic_read(irqc, AIC2_INFO1);
                info3 = aic_ic_read(irqc, AIC2_INFO3);

                irqc->nr_irq = FIELD_GET(AIC2_INFO1_NR_IRQ, info1);
                irqc->max_irq = FIELD_GET(AIC2_INFO3_MAX_IRQ, info3);
                irqc->nr_die = FIELD_GET(AIC2_INFO1_LAST_DIE, info1) + 1;
                irqc->max_die = FIELD_GET(AIC2_INFO3_MAX_DIE, info3);

                off = start_off = irqc->info.irq_cfg;
                off += sizeof(u32) * irqc->max_irq; /* IRQ_CFG */

                irqc->event = of_iomap(node, 1);
                if (WARN_ON(!irqc->event))
                        goto err_unmap;

                break;
        }
        }

        irqc->info.sw_set = off;
        off += sizeof(u32) * (irqc->max_irq >> 5); /* SW_SET */
        irqc->info.sw_clr = off;
        off += sizeof(u32) * (irqc->max_irq >> 5); /* SW_CLR */
        irqc->info.mask_set = off;
        off += sizeof(u32) * (irqc->max_irq >> 5); /* MASK_SET */
        irqc->info.mask_clr = off;
        off += sizeof(u32) * (irqc->max_irq >> 5); /* MASK_CLR */
        off += sizeof(u32) * (irqc->max_irq >> 5); /* HW_STATE */

        if (!irqc->info.fast_ipi)
                static_branch_disable(&use_fast_ipi);

        if (!irqc->info.local_fast_ipi)
                static_branch_disable(&use_local_fast_ipi);

        irqc->info.die_stride = off - start_off;

        irqc->hw_domain = irq_domain_create_tree(of_fwnode_handle(node),
                                                 &aic_irq_domain_ops, irqc);
        if (WARN_ON(!irqc->hw_domain))
                goto err_unmap;

        irq_domain_update_bus_token(irqc->hw_domain, DOMAIN_BUS_WIRED);

        if (aic_init_smp(irqc, node))
                goto err_remove_domain;

        affs = of_get_child_by_name(node, "affinities");
        if (affs) {
                struct device_node *chld;

                for_each_child_of_node(affs, chld)
                        build_fiq_affinity(irqc, chld);
        }
        of_node_put(affs);

        set_handle_irq(aic_handle_irq);
        set_handle_fiq(aic_handle_fiq);

        off = 0;
        for (die = 0; die < irqc->nr_die; die++) {
                for (i = 0; i < BITS_TO_U32(irqc->nr_irq); i++)
                        aic_ic_write(irqc, irqc->info.mask_set + off + i * 4, U32_MAX);
                for (i = 0; i < BITS_TO_U32(irqc->nr_irq); i++)
                        aic_ic_write(irqc, irqc->info.sw_clr + off + i * 4, U32_MAX);
                if (irqc->info.target_cpu)
                        for (i = 0; i < irqc->nr_irq; i++)
                                aic_ic_write(irqc, irqc->info.target_cpu + off + i * 4, 1);
                off += irqc->info.die_stride;
        }

        if (irqc->info.version == 2) {
                u32 config = aic_ic_read(irqc, AIC2_CONFIG);

                config |= AIC2_CONFIG_ENABLE;
                aic_ic_write(irqc, AIC2_CONFIG, config);
        }

        if (!is_kernel_in_hyp_mode())
                pr_info("Kernel running in EL1, mapping interrupts");

        if (static_branch_likely(&use_fast_ipi))
                pr_info("Using Fast IPIs");

        cpuhp_setup_state(CPUHP_AP_IRQ_APPLE_AIC_STARTING,
                          "irqchip/apple-aic/ipi:starting",
                          aic_init_cpu, NULL);

        if (is_kernel_in_hyp_mode()) {
                struct irq_fwspec mi = {
                        .fwnode         = of_fwnode_handle(node),
                        .param_count    = 3,
                        .param          = {
                                [0]     = AIC_FIQ, /* This is a lie */
                                [1]     = AIC_VGIC_MI,
                                [2]     = IRQ_TYPE_LEVEL_HIGH,
                        },
                };

                vgic_info.maint_irq = irq_create_fwspec_mapping(&mi);
                WARN_ON(!vgic_info.maint_irq);
        }

        vgic_set_kvm_info(&vgic_info);

        pr_info("Initialized with %d/%d IRQs * %d/%d die(s), %d FIQs, %d vIPIs",
                irqc->nr_irq, irqc->max_irq, irqc->nr_die, irqc->max_die, AIC_NR_FIQ, AIC_NR_SWIPI);

        return 0;

err_remove_domain:
        irq_domain_remove(irqc->hw_domain);
err_unmap:
        if (irqc->event && irqc->event != irqc->base)
                iounmap(irqc->event);
        iounmap(irqc->base);
        kfree(irqc);
        return -ENODEV;
}

IRQCHIP_DECLARE(apple_aic, "apple,aic", aic_of_ic_init);
IRQCHIP_DECLARE(apple_aic2, "apple,aic2", aic_of_ic_init);