/*
 * Copyright (C) 2015, 2016 ARM Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#ifndef __KVM_ARM_VGIC_H
#define __KVM_ARM_VGIC_H

#include <linux/kernel.h>
#include <linux/kvm.h>
#include <linux/irqreturn.h>
#include <linux/spinlock.h>
#include <linux/static_key.h>
#include <linux/types.h>
#include <kvm/iodev.h>
#include <linux/list.h>
#include <linux/jump_label.h>

#include <linux/irqchip/arm-gic-v4.h>

#define VGIC_V3_MAX_CPUS        255
#define VGIC_V2_MAX_CPUS        8
#define VGIC_NR_IRQS_LEGACY     256
#define VGIC_NR_SGIS            16
#define VGIC_NR_PPIS            16
#define VGIC_NR_PRIVATE_IRQS    (VGIC_NR_SGIS + VGIC_NR_PPIS)
#define VGIC_MAX_PRIVATE        (VGIC_NR_PRIVATE_IRQS - 1)
#define VGIC_MAX_SPI            1019
#define VGIC_MAX_RESERVED       1023
#define VGIC_MIN_LPI            8192
#define KVM_IRQCHIP_NUM_PINS    (1020 - 32)

#define irq_is_ppi(irq) ((irq) >= VGIC_NR_SGIS && (irq) < VGIC_NR_PRIVATE_IRQS)
#define irq_is_spi(irq) ((irq) >= VGIC_NR_PRIVATE_IRQS && \
                         (irq) <= VGIC_MAX_SPI)

enum vgic_type {
        VGIC_V2,                /* Good ol' GICv2 */
        VGIC_V3,                /* New fancy GICv3 */
};

/* same for all guests, as depending only on the _host's_ GIC model */
struct vgic_global {
        /* type of the host GIC */
        enum vgic_type          type;

        /* Physical address of vgic virtual cpu interface */
        phys_addr_t             vcpu_base;

        /* GICV mapping */
        void __iomem            *vcpu_base_va;

        /* virtual control interface mapping */
        void __iomem            *vctrl_base;

        /* Number of implemented list registers */
        int                     nr_lr;

        /* Maintenance IRQ number */
        unsigned int            maint_irq;

        /* maximum number of VCPUs allowed (GICv2 limits us to 8) */
        int                     max_gic_vcpus;

        /* Only needed for the legacy KVM_CREATE_IRQCHIP */
        bool                    can_emulate_gicv2;

        /* Hardware has GICv4? */
        bool                    has_gicv4;

        /* GIC system register CPU interface */
        struct static_key_false gicv3_cpuif;

        u32                     ich_vtr_el2;
};

extern struct vgic_global kvm_vgic_global_state;

#define VGIC_V2_MAX_LRS         (1 << 6)
#define VGIC_V3_MAX_LRS         16
#define VGIC_V3_LR_INDEX(lr)    (VGIC_V3_MAX_LRS - 1 - lr)

enum vgic_irq_config {
        VGIC_CONFIG_EDGE = 0,
        VGIC_CONFIG_LEVEL
};

struct vgic_irq {
        spinlock_t irq_lock;            /* Protects the content of the struct */
        struct list_head lpi_list;      /* Used to link all LPIs together */
        struct list_head ap_list;

        struct kvm_vcpu *vcpu;          /* SGIs and PPIs: The VCPU
                                         * SPIs and LPIs: The VCPU whose ap_list
                                         * this is queued on.
                                         */

        struct kvm_vcpu *target_vcpu;   /* The VCPU that this interrupt should
                                         * be sent to, as a result of the
                                         * targets reg (v2) or the
                                         * affinity reg (v3).
                                         */

        u32 intid;                      /* Guest visible INTID */
        bool line_level;                /* Level only */
        bool pending_latch;             /* The pending latch state used to calculate
                                         * the pending state for both level
                                         * and edge triggered IRQs. */
        bool active;                    /* not used for LPIs */
        bool enabled;
        bool hw;                        /* Tied to HW IRQ */
        struct kref refcount;           /* Used for LPIs */
        u32 hwintid;                    /* HW INTID number */
        unsigned int host_irq;          /* linux irq corresponding to hwintid */
        union {
                u8 targets;                     /* GICv2 target VCPUs mask */
                u32 mpidr;                      /* GICv3 target VCPU */
        };
        u8 source;                      /* GICv2 SGIs only */
        u8 priority;
        enum vgic_irq_config config;    /* Level or edge */

        /*
         * Callback function pointer to in-kernel devices that can tell us the
         * state of the input level of mapped level-triggered IRQ faster than
         * peaking into the physical GIC.
         *
         * Always called in non-preemptible section and the functions can use
         * kvm_arm_get_running_vcpu() to get the vcpu pointer for private
         * IRQs.
         */
        bool (*get_input_level)(int vintid);

        void *owner;                    /* Opaque pointer to reserve an interrupt
                                           for in-kernel devices. */
};

struct vgic_register_region;
struct vgic_its;

enum iodev_type {
        IODEV_CPUIF,
        IODEV_DIST,
        IODEV_REDIST,
        IODEV_ITS
};

struct vgic_io_device {
        gpa_t base_addr;
        union {
                struct kvm_vcpu *redist_vcpu;
                struct vgic_its *its;
        };
        const struct vgic_register_region *regions;
        enum iodev_type iodev_type;
        int nr_regions;
        struct kvm_io_device dev;
};

struct vgic_its {
        /* The base address of the ITS control register frame */
        gpa_t                   vgic_its_base;

        bool                    enabled;
        struct vgic_io_device   iodev;
        struct kvm_device       *dev;

        /* These registers correspond to GITS_BASER{0,1} */
        u64                     baser_device_table;
        u64                     baser_coll_table;

        /* Protects the command queue */
        struct mutex            cmd_lock;
        u64                     cbaser;
        u32                     creadr;
        u32                     cwriter;

        /* migration ABI revision in use */
        u32                     abi_rev;

        /* Protects the device and collection lists */
        struct mutex            its_lock;
        struct list_head        device_list;
        struct list_head        collection_list;
};

struct vgic_state_iter;

struct vgic_dist {
        bool                    in_kernel;
        bool                    ready;
        bool                    initialized;

        /* vGIC model the kernel emulates for the guest (GICv2 or GICv3) */
        u32                     vgic_model;

        /* Do injected MSIs require an additional device ID? */
        bool                    msis_require_devid;

        int                     nr_spis;

        /* TODO: Consider moving to global state */
        /* Virtual control interface mapping */
        void __iomem            *vctrl_base;

        /* base addresses in guest physical address space: */
        gpa_t                   vgic_dist_base;         /* distributor */
        union {
                /* either a GICv2 CPU interface */
                gpa_t                   vgic_cpu_base;
                /* or a number of GICv3 redistributor regions */
                struct {
                        gpa_t           vgic_redist_base;
                        gpa_t           vgic_redist_free_offset;
                };
        };

        /* distributor enabled */
        bool                    enabled;

        struct vgic_irq         *spis;

        struct vgic_io_device   dist_iodev;

        bool                    has_its;

        /*
         * Contains the attributes and gpa of the LPI configuration table.
         * Since we report GICR_TYPER.CommonLPIAff as 0b00, we can share
         * one address across all redistributors.
         * GICv3 spec: 6.1.2 "LPI Configuration tables"
         */
        u64                     propbaser;

        /* Protects the lpi_list and the count value below. */
        spinlock_t              lpi_list_lock;
        struct list_head        lpi_list_head;
        int                     lpi_list_count;

        /* used by vgic-debug */
        struct vgic_state_iter *iter;

        /*
         * GICv4 ITS per-VM data, containing the IRQ domain, the VPE
         * array, the property table pointer as well as allocation
         * data. This essentially ties the Linux IRQ core and ITS
         * together, and avoids leaking KVM's data structures anywhere
         * else.
         */
        struct its_vm           its_vm;
};

struct vgic_v2_cpu_if {
        u32             vgic_hcr;
        u32             vgic_vmcr;
        u64             vgic_elrsr;     /* Saved only */
        u32             vgic_apr;
        u32             vgic_lr[VGIC_V2_MAX_LRS];
};

struct vgic_v3_cpu_if {
        u32             vgic_hcr;
        u32             vgic_vmcr;
        u32             vgic_sre;       /* Restored only, change ignored */
        u32             vgic_elrsr;     /* Saved only */
        u32             vgic_ap0r[4];
        u32             vgic_ap1r[4];
        u64             vgic_lr[VGIC_V3_MAX_LRS];

        /*
         * GICv4 ITS per-VPE data, containing the doorbell IRQ, the
         * pending table pointer, the its_vm pointer and a few other
         * HW specific things. As for the its_vm structure, this is
         * linking the Linux IRQ subsystem and the ITS together.
         */
        struct its_vpe  its_vpe;
};

struct vgic_cpu {
        /* CPU vif control registers for world switch */
        union {
                struct vgic_v2_cpu_if   vgic_v2;
                struct vgic_v3_cpu_if   vgic_v3;
        };

        unsigned int used_lrs;
        struct vgic_irq private_irqs[VGIC_NR_PRIVATE_IRQS];

        spinlock_t ap_list_lock;        /* Protects the ap_list */

        /*
         * List of IRQs that this VCPU should consider because they are either
         * Active or Pending (hence the name; AP list), or because they recently
         * were one of the two and need to be migrated off this list to another
         * VCPU.
         */
        struct list_head ap_list_head;

        /*
         * Members below are used with GICv3 emulation only and represent
         * parts of the redistributor.
         */
        struct vgic_io_device   rd_iodev;
        struct vgic_io_device   sgi_iodev;

        /* Contains the attributes and gpa of the LPI pending tables. */
        u64 pendbaser;

        bool lpis_enabled;

        /* Cache guest priority bits */
        u32 num_pri_bits;

        /* Cache guest interrupt ID bits */
        u32 num_id_bits;
};

extern struct static_key_false vgic_v2_cpuif_trap;
extern struct static_key_false vgic_v3_cpuif_trap;

int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write);
void kvm_vgic_early_init(struct kvm *kvm);
int kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu);
int kvm_vgic_create(struct kvm *kvm, u32 type);
void kvm_vgic_destroy(struct kvm *kvm);
void kvm_vgic_vcpu_early_init(struct kvm_vcpu *vcpu);
void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu);
int kvm_vgic_map_resources(struct kvm *kvm);
int kvm_vgic_hyp_init(void);
void kvm_vgic_init_cpu_hardware(void);

int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int intid,
                        bool level, void *owner);
int kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu, unsigned int host_irq,
                          u32 vintid, bool (*get_input_level)(int vindid));
int kvm_vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, unsigned int vintid);
bool kvm_vgic_map_is_active(struct kvm_vcpu *vcpu, unsigned int vintid);

int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);

void kvm_vgic_load(struct kvm_vcpu *vcpu);
void kvm_vgic_put(struct kvm_vcpu *vcpu);

#define irqchip_in_kernel(k)    (!!((k)->arch.vgic.in_kernel))
#define vgic_initialized(k)     ((k)->arch.vgic.initialized)
#define vgic_ready(k)           ((k)->arch.vgic.ready)
#define vgic_valid_spi(k, i)    (((i) >= VGIC_NR_PRIVATE_IRQS) && \
                        ((i) < (k)->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS))

bool kvm_vcpu_has_pending_irqs(struct kvm_vcpu *vcpu);
void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu);
void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu);
void kvm_vgic_reset_mapped_irq(struct kvm_vcpu *vcpu, u32 vintid);

void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64 reg);

/**
 * kvm_vgic_get_max_vcpus - Get the maximum number of VCPUs allowed by HW
 *
 * The host's GIC naturally limits the maximum amount of VCPUs a guest
 * can use.
 */
static inline int kvm_vgic_get_max_vcpus(void)
{
        return kvm_vgic_global_state.max_gic_vcpus;
}

int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi);

/**
 * kvm_vgic_setup_default_irq_routing:
 * Setup a default flat gsi routing table mapping all SPIs
 */
int kvm_vgic_setup_default_irq_routing(struct kvm *kvm);

int kvm_vgic_set_owner(struct kvm_vcpu *vcpu, unsigned int intid, void *owner);

struct kvm_kernel_irq_routing_entry;

int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int irq,
                               struct kvm_kernel_irq_routing_entry *irq_entry);

int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int irq,
                                 struct kvm_kernel_irq_routing_entry *irq_entry);

void kvm_vgic_v4_enable_doorbell(struct kvm_vcpu *vcpu);
void kvm_vgic_v4_disable_doorbell(struct kvm_vcpu *vcpu);

#endif /* __KVM_ARM_VGIC_H */