// SPDX-License-Identifier: GPL-2.0-only

#include <asm/kvm_ppc.h>
#include <asm/pmc.h>

#include "book3s_hv.h"

static void freeze_pmu(unsigned long mmcr0, unsigned long mmcra)
{
        if (!(mmcr0 & MMCR0_FC))
                goto do_freeze;
        if (mmcra & MMCRA_SAMPLE_ENABLE)
                goto do_freeze;
        if (cpu_has_feature(CPU_FTR_ARCH_31)) {
                if (!(mmcr0 & MMCR0_PMCCEXT))
                        goto do_freeze;
                if (!(mmcra & MMCRA_BHRB_DISABLE))
                        goto do_freeze;
        }
        return;

do_freeze:
        mmcr0 = MMCR0_FC;
        mmcra = 0;
        if (cpu_has_feature(CPU_FTR_ARCH_31)) {
                mmcr0 |= MMCR0_PMCCEXT;
                mmcra = MMCRA_BHRB_DISABLE;
        }

        mtspr(SPRN_MMCR0, mmcr0);
        mtspr(SPRN_MMCRA, mmcra);
        isync();
}

void switch_pmu_to_guest(struct kvm_vcpu *vcpu,
                         struct p9_host_os_sprs *host_os_sprs)
{
        struct lppaca *lp;
        int load_pmu = 1;

        lp = vcpu->arch.vpa.pinned_addr;
        if (lp)
                load_pmu = lp->pmcregs_in_use;

        /* Save host */
        if (ppc_get_pmu_inuse()) {
                /* POWER9, POWER10 do not implement HPMC or SPMC */

                host_os_sprs->mmcr0 = mfspr(SPRN_MMCR0);
                host_os_sprs->mmcra = mfspr(SPRN_MMCRA);

                freeze_pmu(host_os_sprs->mmcr0, host_os_sprs->mmcra);

                host_os_sprs->pmc1 = mfspr(SPRN_PMC1);
                host_os_sprs->pmc2 = mfspr(SPRN_PMC2);
                host_os_sprs->pmc3 = mfspr(SPRN_PMC3);
                host_os_sprs->pmc4 = mfspr(SPRN_PMC4);
                host_os_sprs->pmc5 = mfspr(SPRN_PMC5);
                host_os_sprs->pmc6 = mfspr(SPRN_PMC6);
                host_os_sprs->mmcr1 = mfspr(SPRN_MMCR1);
                host_os_sprs->mmcr2 = mfspr(SPRN_MMCR2);
                host_os_sprs->sdar = mfspr(SPRN_SDAR);
                host_os_sprs->siar = mfspr(SPRN_SIAR);
                host_os_sprs->sier1 = mfspr(SPRN_SIER);

                if (cpu_has_feature(CPU_FTR_ARCH_31)) {
                        host_os_sprs->mmcr3 = mfspr(SPRN_MMCR3);
                        host_os_sprs->sier2 = mfspr(SPRN_SIER2);
                        host_os_sprs->sier3 = mfspr(SPRN_SIER3);
                }
        }

#ifdef CONFIG_PPC_PSERIES
        /* After saving PMU, before loading guest PMU, flip pmcregs_in_use */
        if (kvmhv_on_pseries()) {
                barrier();
                get_lppaca()->pmcregs_in_use = load_pmu;
                barrier();
        }
#endif

        /*
         * Load guest. If the VPA said the PMCs are not in use but the guest
         * tried to access them anyway, HFSCR[PM] will be set by the HFAC
         * fault so we can make forward progress.
         */
        if (load_pmu || (vcpu->arch.hfscr & HFSCR_PM)) {
                mtspr(SPRN_PMC1, vcpu->arch.pmc[0]);
                mtspr(SPRN_PMC2, vcpu->arch.pmc[1]);
                mtspr(SPRN_PMC3, vcpu->arch.pmc[2]);
                mtspr(SPRN_PMC4, vcpu->arch.pmc[3]);
                mtspr(SPRN_PMC5, vcpu->arch.pmc[4]);
                mtspr(SPRN_PMC6, vcpu->arch.pmc[5]);
                mtspr(SPRN_MMCR1, vcpu->arch.mmcr[1]);
                mtspr(SPRN_MMCR2, vcpu->arch.mmcr[2]);
                mtspr(SPRN_SDAR, vcpu->arch.sdar);
                mtspr(SPRN_SIAR, vcpu->arch.siar);
                mtspr(SPRN_SIER, vcpu->arch.sier[0]);

                if (cpu_has_feature(CPU_FTR_ARCH_31)) {
                        mtspr(SPRN_MMCR3, vcpu->arch.mmcr[3]);
                        mtspr(SPRN_SIER2, vcpu->arch.sier[1]);
                        mtspr(SPRN_SIER3, vcpu->arch.sier[2]);
                }

                /* Set MMCRA then MMCR0 last */
                mtspr(SPRN_MMCRA, vcpu->arch.mmcra);
                mtspr(SPRN_MMCR0, vcpu->arch.mmcr[0]);
                /* No isync necessary because we're starting counters */

                if (!vcpu->arch.nested &&
                    (vcpu->arch.hfscr_permitted & HFSCR_PM))
                        vcpu->arch.hfscr |= HFSCR_PM;
        }
}
EXPORT_SYMBOL_GPL(switch_pmu_to_guest);

void switch_pmu_to_host(struct kvm_vcpu *vcpu,
                        struct p9_host_os_sprs *host_os_sprs)
{
        struct lppaca *lp;
        int save_pmu = 1;

        lp = vcpu->arch.vpa.pinned_addr;
        if (lp)
                save_pmu = lp->pmcregs_in_use;
        if (IS_ENABLED(CONFIG_KVM_BOOK3S_HV_NESTED_PMU_WORKAROUND)) {
                /*
                 * Save pmu if this guest is capable of running nested guests.
                 * This is option is for old L1s that do not set their
                 * lppaca->pmcregs_in_use properly when entering their L2.
                 */
                save_pmu |= nesting_enabled(vcpu->kvm);
        }

        if (save_pmu) {
                vcpu->arch.mmcr[0] = mfspr(SPRN_MMCR0);
                vcpu->arch.mmcra = mfspr(SPRN_MMCRA);

                freeze_pmu(vcpu->arch.mmcr[0], vcpu->arch.mmcra);

                vcpu->arch.pmc[0] = mfspr(SPRN_PMC1);
                vcpu->arch.pmc[1] = mfspr(SPRN_PMC2);
                vcpu->arch.pmc[2] = mfspr(SPRN_PMC3);
                vcpu->arch.pmc[3] = mfspr(SPRN_PMC4);
                vcpu->arch.pmc[4] = mfspr(SPRN_PMC5);
                vcpu->arch.pmc[5] = mfspr(SPRN_PMC6);
                vcpu->arch.mmcr[1] = mfspr(SPRN_MMCR1);
                vcpu->arch.mmcr[2] = mfspr(SPRN_MMCR2);
                vcpu->arch.sdar = mfspr(SPRN_SDAR);
                vcpu->arch.siar = mfspr(SPRN_SIAR);
                vcpu->arch.sier[0] = mfspr(SPRN_SIER);

                if (cpu_has_feature(CPU_FTR_ARCH_31)) {
                        vcpu->arch.mmcr[3] = mfspr(SPRN_MMCR3);
                        vcpu->arch.sier[1] = mfspr(SPRN_SIER2);
                        vcpu->arch.sier[2] = mfspr(SPRN_SIER3);
                }

        } else if (vcpu->arch.hfscr & HFSCR_PM) {
                /*
                 * The guest accessed PMC SPRs without specifying they should
                 * be preserved, or it cleared pmcregs_in_use after the last
                 * access. Just ensure they are frozen.
                 */
                freeze_pmu(mfspr(SPRN_MMCR0), mfspr(SPRN_MMCRA));

                /*
                 * Demand-fault PMU register access in the guest.
                 *
                 * This is used to grab the guest's VPA pmcregs_in_use value
                 * and reflect it into the host's VPA in the case of a nested
                 * hypervisor.
                 *
                 * It also avoids having to zero-out SPRs after each guest
                 * exit to avoid side-channels when.
                 *
                 * This is cleared here when we exit the guest, so later HFSCR
                 * interrupt handling can add it back to run the guest with
                 * PM enabled next time.
                 */
                if (!vcpu->arch.nested)
                        vcpu->arch.hfscr &= ~HFSCR_PM;
        } /* otherwise the PMU should still be frozen */

#ifdef CONFIG_PPC_PSERIES
        if (kvmhv_on_pseries()) {
                barrier();
                get_lppaca()->pmcregs_in_use = ppc_get_pmu_inuse();
                barrier();
        }
#endif

        if (ppc_get_pmu_inuse()) {
                mtspr(SPRN_PMC1, host_os_sprs->pmc1);
                mtspr(SPRN_PMC2, host_os_sprs->pmc2);
                mtspr(SPRN_PMC3, host_os_sprs->pmc3);
                mtspr(SPRN_PMC4, host_os_sprs->pmc4);
                mtspr(SPRN_PMC5, host_os_sprs->pmc5);
                mtspr(SPRN_PMC6, host_os_sprs->pmc6);
                mtspr(SPRN_MMCR1, host_os_sprs->mmcr1);
                mtspr(SPRN_MMCR2, host_os_sprs->mmcr2);
                mtspr(SPRN_SDAR, host_os_sprs->sdar);
                mtspr(SPRN_SIAR, host_os_sprs->siar);
                mtspr(SPRN_SIER, host_os_sprs->sier1);

                if (cpu_has_feature(CPU_FTR_ARCH_31)) {
                        mtspr(SPRN_MMCR3, host_os_sprs->mmcr3);
                        mtspr(SPRN_SIER2, host_os_sprs->sier2);
                        mtspr(SPRN_SIER3, host_os_sprs->sier3);
                }

                /* Set MMCRA then MMCR0 last */
                mtspr(SPRN_MMCRA, host_os_sprs->mmcra);
                mtspr(SPRN_MMCR0, host_os_sprs->mmcr0);
                isync();
        }
}
EXPORT_SYMBOL_GPL(switch_pmu_to_host);