// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2010,2012 Freescale Semiconductor, Inc. All rights reserved.
 *
 * Author: Varun Sethi, <varun.sethi@freescale.com>
 *
 * Description:
 * This file is derived from arch/powerpc/kvm/e500.c,
 * by Yu Liu <yu.liu@freescale.com>.
 */

#include <linux/kvm_host.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/export.h>
#include <linux/miscdevice.h>
#include <linux/module.h>

#include <asm/reg.h>
#include <asm/cputable.h>
#include <asm/kvm_ppc.h>
#include <asm/dbell.h>
#include <asm/ppc-opcode.h>

#include "booke.h"
#include "e500.h"

void kvmppc_set_pending_interrupt(struct kvm_vcpu *vcpu, enum int_class type)
{
        enum ppc_dbell dbell_type;
        unsigned long tag;

        switch (type) {
        case INT_CLASS_NONCRIT:
                dbell_type = PPC_G_DBELL;
                break;
        case INT_CLASS_CRIT:
                dbell_type = PPC_G_DBELL_CRIT;
                break;
        case INT_CLASS_MC:
                dbell_type = PPC_G_DBELL_MC;
                break;
        default:
                WARN_ONCE(1, "%s: unknown int type %d\n", __func__, type);
                return;
        }

        preempt_disable();
        tag = PPC_DBELL_LPID(get_lpid(vcpu)) | vcpu->vcpu_id;
        mb();
        ppc_msgsnd(dbell_type, 0, tag);
        preempt_enable();
}

/* gtlbe must not be mapped by more than one host tlb entry */
void kvmppc_e500_tlbil_one(struct kvmppc_vcpu_e500 *vcpu_e500,
                           struct kvm_book3e_206_tlb_entry *gtlbe)
{
        unsigned int tid, ts;
        gva_t eaddr;
        u32 val;
        unsigned long flags;

        ts = get_tlb_ts(gtlbe);
        tid = get_tlb_tid(gtlbe);

        /* We search the host TLB to invalidate its shadow TLB entry */
        val = (tid << 16) | ts;
        eaddr = get_tlb_eaddr(gtlbe);

        local_irq_save(flags);

        mtspr(SPRN_MAS6, val);
        mtspr(SPRN_MAS5, MAS5_SGS | get_lpid(&vcpu_e500->vcpu));

        asm volatile("tlbsx 0, %[eaddr]\n" : : [eaddr] "r" (eaddr));
        val = mfspr(SPRN_MAS1);
        if (val & MAS1_VALID) {
                mtspr(SPRN_MAS1, val & ~MAS1_VALID);
                asm volatile("tlbwe");
        }
        mtspr(SPRN_MAS5, 0);
        /* NOTE: tlbsx also updates mas8, so clear it for host tlbwe */
        mtspr(SPRN_MAS8, 0);
        isync();

        local_irq_restore(flags);
}

void kvmppc_e500_tlbil_all(struct kvmppc_vcpu_e500 *vcpu_e500)
{
        unsigned long flags;

        local_irq_save(flags);
        mtspr(SPRN_MAS5, MAS5_SGS | get_lpid(&vcpu_e500->vcpu));
        /*
         * clang-17 and older could not assemble tlbilxlpid.
         * https://github.com/ClangBuiltLinux/linux/issues/1891
         */
        asm volatile (PPC_TLBILX_LPID);
        mtspr(SPRN_MAS5, 0);
        local_irq_restore(flags);
}

void kvmppc_set_pid(struct kvm_vcpu *vcpu, u32 pid)
{
        vcpu->arch.pid = pid;
}

void kvmppc_mmu_msr_notify(struct kvm_vcpu *vcpu, u32 old_msr)
{
}

/* We use two lpids per VM */
static DEFINE_PER_CPU(struct kvm_vcpu *[KVMPPC_NR_LPIDS], last_vcpu_of_lpid);

static void kvmppc_core_vcpu_load_e500mc(struct kvm_vcpu *vcpu, int cpu)
{
        struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);

        kvmppc_booke_vcpu_load(vcpu, cpu);

        mtspr(SPRN_LPID, get_lpid(vcpu));
        mtspr(SPRN_EPCR, vcpu->arch.shadow_epcr);
        mtspr(SPRN_GPIR, vcpu->vcpu_id);
        mtspr(SPRN_MSRP, vcpu->arch.shadow_msrp);
        vcpu->arch.eplc = EPC_EGS | (get_lpid(vcpu) << EPC_ELPID_SHIFT);
        vcpu->arch.epsc = vcpu->arch.eplc;
        mtspr(SPRN_EPLC, vcpu->arch.eplc);
        mtspr(SPRN_EPSC, vcpu->arch.epsc);

        mtspr(SPRN_GIVPR, vcpu->arch.ivpr);
        mtspr(SPRN_GIVOR2, vcpu->arch.ivor[BOOKE_IRQPRIO_DATA_STORAGE]);
        mtspr(SPRN_GIVOR8, vcpu->arch.ivor[BOOKE_IRQPRIO_SYSCALL]);
        mtspr(SPRN_GSPRG0, (unsigned long)vcpu->arch.shared->sprg0);
        mtspr(SPRN_GSPRG1, (unsigned long)vcpu->arch.shared->sprg1);
        mtspr(SPRN_GSPRG2, (unsigned long)vcpu->arch.shared->sprg2);
        mtspr(SPRN_GSPRG3, (unsigned long)vcpu->arch.shared->sprg3);

        mtspr(SPRN_GSRR0, vcpu->arch.shared->srr0);
        mtspr(SPRN_GSRR1, vcpu->arch.shared->srr1);

        mtspr(SPRN_GEPR, vcpu->arch.epr);
        mtspr(SPRN_GDEAR, vcpu->arch.shared->dar);
        mtspr(SPRN_GESR, vcpu->arch.shared->esr);

        if (vcpu->arch.oldpir != mfspr(SPRN_PIR) ||
            __this_cpu_read(last_vcpu_of_lpid[get_lpid(vcpu)]) != vcpu) {
                kvmppc_e500_tlbil_all(vcpu_e500);
                __this_cpu_write(last_vcpu_of_lpid[get_lpid(vcpu)], vcpu);
        }
}

static void kvmppc_core_vcpu_put_e500mc(struct kvm_vcpu *vcpu)
{
        vcpu->arch.eplc = mfspr(SPRN_EPLC);
        vcpu->arch.epsc = mfspr(SPRN_EPSC);

        vcpu->arch.shared->sprg0 = mfspr(SPRN_GSPRG0);
        vcpu->arch.shared->sprg1 = mfspr(SPRN_GSPRG1);
        vcpu->arch.shared->sprg2 = mfspr(SPRN_GSPRG2);
        vcpu->arch.shared->sprg3 = mfspr(SPRN_GSPRG3);

        vcpu->arch.shared->srr0 = mfspr(SPRN_GSRR0);
        vcpu->arch.shared->srr1 = mfspr(SPRN_GSRR1);

        vcpu->arch.epr = mfspr(SPRN_GEPR);
        vcpu->arch.shared->dar = mfspr(SPRN_GDEAR);
        vcpu->arch.shared->esr = mfspr(SPRN_GESR);

        vcpu->arch.oldpir = mfspr(SPRN_PIR);

        kvmppc_booke_vcpu_put(vcpu);
}

static int kvmppc_e500mc_check_processor_compat(void)
{
        int r;

        if (strcmp(cur_cpu_spec->cpu_name, "e500mc") == 0)
                r = 0;
        else if (strcmp(cur_cpu_spec->cpu_name, "e5500") == 0)
                r = 0;
#ifdef CONFIG_ALTIVEC
        /*
         * Since guests have the privilege to enable AltiVec, we need AltiVec
         * support in the host to save/restore their context.
         * Don't use CPU_FTR_ALTIVEC to identify cores with AltiVec unit
         * because it's cleared in the absence of CONFIG_ALTIVEC!
         */
        else if (strcmp(cur_cpu_spec->cpu_name, "e6500") == 0)
                r = 0;
#endif
        else
                r = -ENOTSUPP;

        return r;
}

int kvmppc_core_vcpu_setup(struct kvm_vcpu *vcpu)
{
        struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);

        vcpu->arch.shadow_epcr = SPRN_EPCR_DSIGS | SPRN_EPCR_DGTMI | \
                                 SPRN_EPCR_DUVD;
#ifdef CONFIG_64BIT
        vcpu->arch.shadow_epcr |= SPRN_EPCR_ICM;
#endif
        vcpu->arch.shadow_msrp = MSRP_UCLEP | MSRP_PMMP;

        vcpu->arch.pvr = mfspr(SPRN_PVR);
        vcpu_e500->svr = mfspr(SPRN_SVR);

        vcpu->arch.cpu_type = KVM_CPU_E500MC;

        return 0;
}

static int kvmppc_core_get_sregs_e500mc(struct kvm_vcpu *vcpu,
                                        struct kvm_sregs *sregs)
{
        struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);

        sregs->u.e.features |= KVM_SREGS_E_ARCH206_MMU | KVM_SREGS_E_PM |
                               KVM_SREGS_E_PC;
        sregs->u.e.impl_id = KVM_SREGS_E_IMPL_FSL;

        sregs->u.e.impl.fsl.features = 0;
        sregs->u.e.impl.fsl.svr = vcpu_e500->svr;
        sregs->u.e.impl.fsl.hid0 = vcpu_e500->hid0;
        sregs->u.e.impl.fsl.mcar = vcpu_e500->mcar;

        kvmppc_get_sregs_e500_tlb(vcpu, sregs);

        sregs->u.e.ivor_high[3] =
                vcpu->arch.ivor[BOOKE_IRQPRIO_PERFORMANCE_MONITOR];
        sregs->u.e.ivor_high[4] = vcpu->arch.ivor[BOOKE_IRQPRIO_DBELL];
        sregs->u.e.ivor_high[5] = vcpu->arch.ivor[BOOKE_IRQPRIO_DBELL_CRIT];

        return kvmppc_get_sregs_ivor(vcpu, sregs);
}

static int kvmppc_core_set_sregs_e500mc(struct kvm_vcpu *vcpu,
                                        struct kvm_sregs *sregs)
{
        struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
        int ret;

        if (sregs->u.e.impl_id == KVM_SREGS_E_IMPL_FSL) {
                vcpu_e500->svr = sregs->u.e.impl.fsl.svr;
                vcpu_e500->hid0 = sregs->u.e.impl.fsl.hid0;
                vcpu_e500->mcar = sregs->u.e.impl.fsl.mcar;
        }

        ret = kvmppc_set_sregs_e500_tlb(vcpu, sregs);
        if (ret < 0)
                return ret;

        if (!(sregs->u.e.features & KVM_SREGS_E_IVOR))
                return 0;

        if (sregs->u.e.features & KVM_SREGS_E_PM) {
                vcpu->arch.ivor[BOOKE_IRQPRIO_PERFORMANCE_MONITOR] =
                        sregs->u.e.ivor_high[3];
        }

        if (sregs->u.e.features & KVM_SREGS_E_PC) {
                vcpu->arch.ivor[BOOKE_IRQPRIO_DBELL] =
                        sregs->u.e.ivor_high[4];
                vcpu->arch.ivor[BOOKE_IRQPRIO_DBELL_CRIT] =
                        sregs->u.e.ivor_high[5];
        }

        return kvmppc_set_sregs_ivor(vcpu, sregs);
}

static int kvmppc_get_one_reg_e500mc(struct kvm_vcpu *vcpu, u64 id,
                              union kvmppc_one_reg *val)
{
        int r = 0;

        switch (id) {
        case KVM_REG_PPC_SPRG9:
                *val = get_reg_val(id, vcpu->arch.sprg9);
                break;
        default:
                r = kvmppc_get_one_reg_e500_tlb(vcpu, id, val);
        }

        return r;
}

static int kvmppc_set_one_reg_e500mc(struct kvm_vcpu *vcpu, u64 id,
                              union kvmppc_one_reg *val)
{
        int r = 0;

        switch (id) {
        case KVM_REG_PPC_SPRG9:
                vcpu->arch.sprg9 = set_reg_val(id, *val);
                break;
        default:
                r = kvmppc_set_one_reg_e500_tlb(vcpu, id, val);
        }

        return r;
}

static int kvmppc_core_vcpu_create_e500mc(struct kvm_vcpu *vcpu)
{
        struct kvmppc_vcpu_e500 *vcpu_e500;
        int err;

        BUILD_BUG_ON(offsetof(struct kvmppc_vcpu_e500, vcpu) != 0);
        vcpu_e500 = to_e500(vcpu);

        /* Invalid PIR value -- this LPID doesn't have valid state on any cpu */
        vcpu->arch.oldpir = 0xffffffff;

        err = kvmppc_e500_tlb_init(vcpu_e500);
        if (err)
                return err;

        vcpu->arch.shared = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
        if (!vcpu->arch.shared) {
                err = -ENOMEM;
                goto uninit_tlb;
        }

        return 0;

uninit_tlb:
        kvmppc_e500_tlb_uninit(vcpu_e500);
        return err;
}

static void kvmppc_core_vcpu_free_e500mc(struct kvm_vcpu *vcpu)
{
        struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);

        free_page((unsigned long)vcpu->arch.shared);
        kvmppc_e500_tlb_uninit(vcpu_e500);
}

static int kvmppc_core_init_vm_e500mc(struct kvm *kvm)
{
        int lpid;

        lpid = kvmppc_alloc_lpid();
        if (lpid < 0)
                return lpid;

        /*
         * Use two lpids per VM on cores with two threads like e6500. Use
         * even numbers to speedup vcpu lpid computation with consecutive lpids
         * per VM. vm1 will use lpids 2 and 3, vm2 lpids 4 and 5, and so on.
         */
        if (threads_per_core == 2)
                lpid <<= 1;

        kvm->arch.lpid = lpid;
        return 0;
}

static void kvmppc_core_destroy_vm_e500mc(struct kvm *kvm)
{
        int lpid = kvm->arch.lpid;

        if (threads_per_core == 2)
                lpid >>= 1;

        kvmppc_free_lpid(lpid);
}

static struct kvmppc_ops kvm_ops_e500mc = {
        .get_sregs = kvmppc_core_get_sregs_e500mc,
        .set_sregs = kvmppc_core_set_sregs_e500mc,
        .get_one_reg = kvmppc_get_one_reg_e500mc,
        .set_one_reg = kvmppc_set_one_reg_e500mc,
        .vcpu_load   = kvmppc_core_vcpu_load_e500mc,
        .vcpu_put    = kvmppc_core_vcpu_put_e500mc,
        .vcpu_create = kvmppc_core_vcpu_create_e500mc,
        .vcpu_free   = kvmppc_core_vcpu_free_e500mc,
        .init_vm = kvmppc_core_init_vm_e500mc,
        .destroy_vm = kvmppc_core_destroy_vm_e500mc,
        .emulate_op = kvmppc_core_emulate_op_e500,
        .emulate_mtspr = kvmppc_core_emulate_mtspr_e500,
        .emulate_mfspr = kvmppc_core_emulate_mfspr_e500,
        .create_vcpu_debugfs = kvmppc_create_vcpu_debugfs_e500,
};

static int __init kvmppc_e500mc_init(void)
{
        int r;

        r = kvmppc_e500mc_check_processor_compat();
        if (r)
                goto err_out;

        r = kvmppc_booke_init();
        if (r)
                goto err_out;

        /*
         * Use two lpids per VM on dual threaded processors like e6500
         * to workarround the lack of tlb write conditional instruction.
         * Expose half the number of available hardware lpids to the lpid
         * allocator.
         */
        kvmppc_init_lpid(KVMPPC_NR_LPIDS/threads_per_core);

        r = kvm_init(sizeof(struct kvmppc_vcpu_e500), 0, THIS_MODULE);
        if (r)
                goto err_out;
        kvm_ops_e500mc.owner = THIS_MODULE;
        kvmppc_pr_ops = &kvm_ops_e500mc;

err_out:
        return r;
}

static void __exit kvmppc_e500mc_exit(void)
{
        kvmppc_pr_ops = NULL;
        kvmppc_booke_exit();
}

module_init(kvmppc_e500mc_init);
module_exit(kvmppc_e500mc_exit);
MODULE_ALIAS_MISCDEV(KVM_MINOR);
MODULE_ALIAS("devname:kvm");