/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright 2012 Michael Ellerman, IBM Corporation.
 * Copyright 2012 Benjamin Herrenschmidt, IBM Corporation
 */

#ifndef _KVM_PPC_BOOK3S_XICS_H
#define _KVM_PPC_BOOK3S_XICS_H

#ifdef CONFIG_KVM_XICS
/*
 * We use a two-level tree to store interrupt source information.
 * There are up to 1024 ICS nodes, each of which can represent
 * 1024 sources.
 */
#define KVMPPC_XICS_MAX_ICS_ID  1023
#define KVMPPC_XICS_ICS_SHIFT   10
#define KVMPPC_XICS_IRQ_PER_ICS (1 << KVMPPC_XICS_ICS_SHIFT)
#define KVMPPC_XICS_SRC_MASK    (KVMPPC_XICS_IRQ_PER_ICS - 1)

/*
 * Interrupt source numbers below this are reserved, for example
 * 0 is "no interrupt", and 2 is used for IPIs.
 */
#define KVMPPC_XICS_FIRST_IRQ   16
#define KVMPPC_XICS_NR_IRQS     ((KVMPPC_XICS_MAX_ICS_ID + 1) * \
                                 KVMPPC_XICS_IRQ_PER_ICS)

/* Priority value to use for disabling an interrupt */
#define MASKED  0xff

#define PQ_PRESENTED    1
#define PQ_QUEUED       2

/* State for one irq source */
struct ics_irq_state {
        u32 number;
        u32 server;
        u32 pq_state;
        u8  priority;
        u8  saved_priority;
        u8  resend;
        u8  masked_pending;
        u8  lsi;                /* level-sensitive interrupt */
        u8  exists;
        int intr_cpu;
        u32 host_irq;
};

/* Atomic ICP state, updated with a single compare & swap */
union kvmppc_icp_state {
        unsigned long raw;
        struct {
                u8 out_ee:1;
                u8 need_resend:1;
                u8 cppr;
                u8 mfrr;
                u8 pending_pri;
                u32 xisr;
        };
};

/* One bit per ICS */
#define ICP_RESEND_MAP_SIZE     (KVMPPC_XICS_MAX_ICS_ID / BITS_PER_LONG + 1)

struct kvmppc_icp {
        struct kvm_vcpu *vcpu;
        unsigned long server_num;
        union kvmppc_icp_state state;
        unsigned long resend_map[ICP_RESEND_MAP_SIZE];

        /* Real mode might find something too hard, here's the action
         * it might request from virtual mode
         */
#define XICS_RM_KICK_VCPU       0x1
#define XICS_RM_CHECK_RESEND    0x2
#define XICS_RM_NOTIFY_EOI      0x8
        u32 rm_action;
        struct kvm_vcpu *rm_kick_target;
        struct kvmppc_icp *rm_resend_icp;
        u32  rm_reject;
        u32  rm_eoied_irq;

        /* Counters for each reason we exited real mode */
        unsigned long n_rm_kick_vcpu;
        unsigned long n_rm_check_resend;
        unsigned long n_rm_notify_eoi;
        /* Counters for handling ICP processing in real mode */
        unsigned long n_check_resend;
        unsigned long n_reject;

        /* Debug stuff for real mode */
        union kvmppc_icp_state rm_dbgstate;
        struct kvm_vcpu *rm_dbgtgt;
};

struct kvmppc_ics {
        arch_spinlock_t lock;
        u16 icsid;
        struct ics_irq_state irq_state[KVMPPC_XICS_IRQ_PER_ICS];
};

struct kvmppc_xics {
        struct kvm *kvm;
        struct kvm_device *dev;
        struct dentry *dentry;
        u32 max_icsid;
        bool real_mode;
        bool real_mode_dbg;
        u32 err_noics;
        u32 err_noicp;
        struct kvmppc_ics *ics[KVMPPC_XICS_MAX_ICS_ID + 1];
};

static inline struct kvmppc_icp *kvmppc_xics_find_server(struct kvm *kvm,
                                                         u32 nr)
{
        struct kvm_vcpu *vcpu = NULL;
        unsigned long i;

        kvm_for_each_vcpu(i, vcpu, kvm) {
                if (vcpu->arch.icp && nr == vcpu->arch.icp->server_num)
                        return vcpu->arch.icp;
        }
        return NULL;
}

static inline struct kvmppc_ics *kvmppc_xics_find_ics(struct kvmppc_xics *xics,
                                                      u32 irq, u16 *source)
{
        u32 icsid = irq >> KVMPPC_XICS_ICS_SHIFT;
        u16 src = irq & KVMPPC_XICS_SRC_MASK;
        struct kvmppc_ics *ics;

        if (source)
                *source = src;
        if (icsid > KVMPPC_XICS_MAX_ICS_ID)
                return NULL;
        ics = xics->ics[icsid];
        if (!ics)
                return NULL;
        return ics;
}

extern unsigned long xics_rm_h_xirr(struct kvm_vcpu *vcpu);
extern unsigned long xics_rm_h_xirr_x(struct kvm_vcpu *vcpu);
extern int xics_rm_h_ipi(struct kvm_vcpu *vcpu, unsigned long server,
                         unsigned long mfrr);
extern int xics_rm_h_cppr(struct kvm_vcpu *vcpu, unsigned long cppr);
extern int xics_rm_h_eoi(struct kvm_vcpu *vcpu, unsigned long xirr);

#endif /* CONFIG_KVM_XICS */
#endif /* _KVM_PPC_BOOK3S_XICS_H */