e500.c

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/*
 * Copyright (C) 2008-2011 Freescale Semiconductor, Inc. All rights reserved.
 *
 * Author: Yu Liu, <[email protected]>
 *
 * Description:
 * This file is derived from arch/powerpc/kvm/44x.c,
 * by Hollis Blanchard <[email protected]>.
 *
 * 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.
 */

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

#include <asm/reg.h>
#include <asm/cputable.h>
#include <asm/tlbflush.h>
#include <asm/kvm_ppc.h>

#include "../mm/mmu_decl.h"
#include "booke.h"
#include "e500.h"

struct id {
    unsigned long val;
    struct id **pentry;
};

#define NUM_TIDS 256

/*
 * This table provide mappings from:
 * (guestAS,guestTID,guestPR) --> ID of physical cpu
 * guestAS  [0..1]
 * guestTID [0..255]
 * guestPR  [0..1]
 * ID       [1..255]
 * Each vcpu keeps one vcpu_id_table.
 */
struct vcpu_id_table {
    struct id id[2][NUM_TIDS][2];
};

/*
 * This table provide reversed mappings of vcpu_id_table:
 * ID --> address of vcpu_id_table item.
 * Each physical core has one pcpu_id_table.
 */
struct pcpu_id_table {
    struct id *entry[NUM_TIDS];
};

static DEFINE_PER_CPU(struct pcpu_id_table, pcpu_sids);

/* This variable keeps last used shadow ID on local core.
 * The valid range of shadow ID is [1..255] */
static DEFINE_PER_CPU(unsigned long, pcpu_last_used_sid);

/*
 * Allocate a free shadow id and setup a valid sid mapping in given entry.
 * A mapping is only valid when vcpu_id_table and pcpu_id_table are match.
 *
 * The caller must have preemption disabled, and keep it that way until
 * it has finished with the returned shadow id (either written into the
 * TLB or arch.shadow_pid, or discarded).
 */
static inline int local_sid_setup_one(struct id *entry)
{
    unsigned long sid;
    int ret = -1;

    sid = ++(__get_cpu_var(pcpu_last_used_sid));
    if (sid < NUM_TIDS) {
        __get_cpu_var(pcpu_sids).entry[sid] = entry;
        entry->val = sid;
        entry->pentry = &__get_cpu_var(pcpu_sids).entry[sid];
        ret = sid;
    }

    /*
     * If sid == NUM_TIDS, we've run out of sids.  We return -1, and
     * the caller will invalidate everything and start over.
     *
     * sid > NUM_TIDS indicates a race, which we disable preemption to
     * avoid.
     */
    WARN_ON(sid > NUM_TIDS);

    return ret;
}

/*
 * Check if given entry contain a valid shadow id mapping.
 * An ID mapping is considered valid only if
 * both vcpu and pcpu know this mapping.
 *
 * The caller must have preemption disabled, and keep it that way until
 * it has finished with the returned shadow id (either written into the
 * TLB or arch.shadow_pid, or discarded).
 */
static inline int local_sid_lookup(struct id *entry)
{
    if (entry && entry->val != 0 &&
        __get_cpu_var(pcpu_sids).entry[entry->val] == entry &&
        entry->pentry == &__get_cpu_var(pcpu_sids).entry[entry->val])
        return entry->val;
    return -1;
}

/* Invalidate all id mappings on local core -- call with preempt disabled */
static inline void local_sid_destroy_all(void)
{
    __get_cpu_var(pcpu_last_used_sid) = 0;
    memset(&__get_cpu_var(pcpu_sids), 0, sizeof(__get_cpu_var(pcpu_sids)));
}

static void *kvmppc_e500_id_table_alloc(struct kvmppc_vcpu_e500 *vcpu_e500)
{
    vcpu_e500->idt = kzalloc(sizeof(struct vcpu_id_table), GFP_KERNEL);
    return vcpu_e500->idt;
}

static void kvmppc_e500_id_table_free(struct kvmppc_vcpu_e500 *vcpu_e500)
{
    kfree(vcpu_e500->idt);
    vcpu_e500->idt = NULL;
}

/* Map guest pid to shadow.
 * We use PID to keep shadow of current guest non-zero PID,
 * and use PID1 to keep shadow of guest zero PID.
 * So that guest tlbe with TID=0 can be accessed at any time */
static void kvmppc_e500_recalc_shadow_pid(struct kvmppc_vcpu_e500 *vcpu_e500)
{
    preempt_disable();
    vcpu_e500->vcpu.arch.shadow_pid = kvmppc_e500_get_sid(vcpu_e500,
            get_cur_as(&vcpu_e500->vcpu),
            get_cur_pid(&vcpu_e500->vcpu),
            get_cur_pr(&vcpu_e500->vcpu), 1);
    vcpu_e500->vcpu.arch.shadow_pid1 = kvmppc_e500_get_sid(vcpu_e500,
            get_cur_as(&vcpu_e500->vcpu), 0,
            get_cur_pr(&vcpu_e500->vcpu), 1);
    preempt_enable();
}

/* Invalidate all mappings on vcpu */
static void kvmppc_e500_id_table_reset_all(struct kvmppc_vcpu_e500 *vcpu_e500)
{
    memset(vcpu_e500->idt, 0, sizeof(struct vcpu_id_table));

    /* Update shadow pid when mappings are changed */
    kvmppc_e500_recalc_shadow_pid(vcpu_e500);
}

/* Invalidate one ID mapping on vcpu */
static inline void kvmppc_e500_id_table_reset_one(
                   struct kvmppc_vcpu_e500 *vcpu_e500,
                   int as, int pid, int pr)
{
    struct vcpu_id_table *idt = vcpu_e500->idt;

    BUG_ON(as >= 2);
    BUG_ON(pid >= NUM_TIDS);
    BUG_ON(pr >= 2);

    idt->id[as][pid][pr].val = 0;
    idt->id[as][pid][pr].pentry = NULL;

    /* Update shadow pid when mappings are changed */
    kvmppc_e500_recalc_shadow_pid(vcpu_e500);
}

/*
 * Map guest (vcpu,AS,ID,PR) to physical core shadow id.
 * This function first lookup if a valid mapping exists,
 * if not, then creates a new one.
 *
 * The caller must have preemption disabled, and keep it that way until
 * it has finished with the returned shadow id (either written into the
 * TLB or arch.shadow_pid, or discarded).
 */
unsigned int kvmppc_e500_get_sid(struct kvmppc_vcpu_e500 *vcpu_e500,
                 unsigned int as, unsigned int gid,
                 unsigned int pr, int avoid_recursion)
{
    struct vcpu_id_table *idt = vcpu_e500->idt;
    int sid;

    BUG_ON(as >= 2);
    BUG_ON(gid >= NUM_TIDS);
    BUG_ON(pr >= 2);

    sid = local_sid_lookup(&idt->id[as][gid][pr]);

    while (sid <= 0) {
        /* No mapping yet */
        sid = local_sid_setup_one(&idt->id[as][gid][pr]);
        if (sid <= 0) {
            _tlbil_all();
            local_sid_destroy_all();
        }

        /* Update shadow pid when mappings are changed */
        if (!avoid_recursion)
            kvmppc_e500_recalc_shadow_pid(vcpu_e500);
    }

    return sid;
}

unsigned int kvmppc_e500_get_tlb_stid(struct kvm_vcpu *vcpu,
                      struct kvm_book3e_206_tlb_entry *gtlbe)
{
    return kvmppc_e500_get_sid(to_e500(vcpu), get_tlb_ts(gtlbe),
                   get_tlb_tid(gtlbe), get_cur_pr(vcpu), 0);
}

void kvmppc_set_pid(struct kvm_vcpu *vcpu, u32 pid)
{
    struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);

    if (vcpu->arch.pid != pid) {
        vcpu_e500->pid[0] = vcpu->arch.pid = pid;
        kvmppc_e500_recalc_shadow_pid(vcpu_e500);
    }
}

/* gtlbe must not be mapped by more than one host tlbe */
void kvmppc_e500_tlbil_one(struct kvmppc_vcpu_e500 *vcpu_e500,
                           struct kvm_book3e_206_tlb_entry *gtlbe)
{
    struct vcpu_id_table *idt = vcpu_e500->idt;
    unsigned int pr, tid, ts, pid;
    u32 val, eaddr;
    unsigned long flags;

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

    preempt_disable();

    /* One guest ID may be mapped to two shadow IDs */
    for (pr = 0; pr < 2; pr++) {
        /*
         * The shadow PID can have a valid mapping on at most one
         * host CPU.  In the common case, it will be valid on this
         * CPU, in which case we do a local invalidation of the
         * specific address.
         *
         * If the shadow PID is not valid on the current host CPU,
         * we invalidate the entire shadow PID.
         */
        pid = local_sid_lookup(&idt->id[ts][tid][pr]);
        if (pid <= 0) {
            kvmppc_e500_id_table_reset_one(vcpu_e500, ts, tid, pr);
            continue;
        }

        /*
         * The guest is invalidating a 4K entry which is in a PID
         * that has a valid shadow mapping on this host CPU.  We
         * search host TLB to invalidate it's shadow TLB entry,
         * similar to __tlbil_va except that we need to look in AS1.
         */
        val = (pid << MAS6_SPID_SHIFT) | MAS6_SAS;
        eaddr = get_tlb_eaddr(gtlbe);

        local_irq_save(flags);

        mtspr(SPRN_MAS6, val);
        asm volatile("tlbsx 0, %[eaddr]" : : [eaddr] "r" (eaddr));
        val = mfspr(SPRN_MAS1);
        if (val & MAS1_VALID) {
            mtspr(SPRN_MAS1, val & ~MAS1_VALID);
            asm volatile("tlbwe");
        }

        local_irq_restore(flags);
    }

    preempt_enable();
}

void kvmppc_e500_tlbil_all(struct kvmppc_vcpu_e500 *vcpu_e500)
{
    kvmppc_e500_id_table_reset_all(vcpu_e500);
}

void kvmppc_mmu_msr_notify(struct kvm_vcpu *vcpu, u32 old_msr)
{
    /* Recalc shadow pid since MSR changes */
    kvmppc_e500_recalc_shadow_pid(to_e500(vcpu));
}

void kvmppc_core_load_host_debugstate(struct kvm_vcpu *vcpu)
{
}

void kvmppc_core_load_guest_debugstate(struct kvm_vcpu *vcpu)
{
}

void kvmppc_core_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
    kvmppc_booke_vcpu_load(vcpu, cpu);

    /* Shadow PID may be expired on local core */
    kvmppc_e500_recalc_shadow_pid(to_e500(vcpu));
}

void kvmppc_core_vcpu_put(struct kvm_vcpu *vcpu)
{
#ifdef CONFIG_SPE
    if (vcpu->arch.shadow_msr & MSR_SPE)
        kvmppc_vcpu_disable_spe(vcpu);
#endif

    kvmppc_booke_vcpu_put(vcpu);
}

int kvmppc_core_check_processor_compat(void)
{
    int r;

    if (strcmp(cur_cpu_spec->cpu_name, "e500v2") == 0)
        r = 0;
    else
        r = -ENOTSUPP;

    return r;
}

static void kvmppc_e500_tlb_setup(struct kvmppc_vcpu_e500 *vcpu_e500)
{
    struct kvm_book3e_206_tlb_entry *tlbe;

    /* Insert large initial mapping for guest. */
    tlbe = get_entry(vcpu_e500, 1, 0);
    tlbe->mas1 = MAS1_VALID | MAS1_TSIZE(BOOK3E_PAGESZ_256M);
    tlbe->mas2 = 0;
    tlbe->mas7_3 = E500_TLB_SUPER_PERM_MASK;

    /* 4K map for serial output. Used by kernel wrapper. */
    tlbe = get_entry(vcpu_e500, 1, 1);
    tlbe->mas1 = MAS1_VALID | MAS1_TSIZE(BOOK3E_PAGESZ_4K);
    tlbe->mas2 = (0xe0004500 & 0xFFFFF000) | MAS2_I | MAS2_G;
    tlbe->mas7_3 = (0xe0004500 & 0xFFFFF000) | E500_TLB_SUPER_PERM_MASK;
}

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

    kvmppc_e500_tlb_setup(vcpu_e500);

    /* Registers init */
    vcpu->arch.pvr = mfspr(SPRN_PVR);
    vcpu_e500->svr = mfspr(SPRN_SVR);

    vcpu->arch.cpu_type = KVM_CPU_E500V2;

    return 0;
}

void kvmppc_core_get_sregs(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_SPE |
                           KVM_SREGS_E_PM;
    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;

    sregs->u.e.ivor_high[0] = vcpu->arch.ivor[BOOKE_IRQPRIO_SPE_UNAVAIL];
    sregs->u.e.ivor_high[1] = vcpu->arch.ivor[BOOKE_IRQPRIO_SPE_FP_DATA];
    sregs->u.e.ivor_high[2] = vcpu->arch.ivor[BOOKE_IRQPRIO_SPE_FP_ROUND];
    sregs->u.e.ivor_high[3] =
        vcpu->arch.ivor[BOOKE_IRQPRIO_PERFORMANCE_MONITOR];

    kvmppc_get_sregs_ivor(vcpu, sregs);
    kvmppc_get_sregs_e500_tlb(vcpu, sregs);
}

int kvmppc_core_set_sregs(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_SPE) {
        vcpu->arch.ivor[BOOKE_IRQPRIO_SPE_UNAVAIL] =
            sregs->u.e.ivor_high[0];
        vcpu->arch.ivor[BOOKE_IRQPRIO_SPE_FP_DATA] =
            sregs->u.e.ivor_high[1];
        vcpu->arch.ivor[BOOKE_IRQPRIO_SPE_FP_ROUND] =
            sregs->u.e.ivor_high[2];
    }

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

    return kvmppc_set_sregs_ivor(vcpu, sregs);
}

struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
{
    struct kvmppc_vcpu_e500 *vcpu_e500;
    struct kvm_vcpu *vcpu;
    int err;

    vcpu_e500 = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
    if (!vcpu_e500) {
        err = -ENOMEM;
        goto out;
    }

    vcpu = &vcpu_e500->vcpu;
    err = kvm_vcpu_init(vcpu, kvm, id);
    if (err)
        goto free_vcpu;

    if (kvmppc_e500_id_table_alloc(vcpu_e500) == NULL)
        goto uninit_vcpu;

    err = kvmppc_e500_tlb_init(vcpu_e500);
    if (err)
        goto uninit_id;

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

    return vcpu;

uninit_tlb:
    kvmppc_e500_tlb_uninit(vcpu_e500);
uninit_id:
    kvmppc_e500_id_table_free(vcpu_e500);
uninit_vcpu:
    kvm_vcpu_uninit(vcpu);
free_vcpu:
    kmem_cache_free(kvm_vcpu_cache, vcpu_e500);
out:
    return ERR_PTR(err);
}

void kvmppc_core_vcpu_free(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);
    kvmppc_e500_id_table_free(vcpu_e500);
    kvm_vcpu_uninit(vcpu);
    kmem_cache_free(kvm_vcpu_cache, vcpu_e500);
}

int kvmppc_core_init_vm(struct kvm *kvm)
{
    return 0;
}

void kvmppc_core_destroy_vm(struct kvm *kvm)
{
}

static int __init kvmppc_e500_init(void)
{
    int r, i;
    unsigned long ivor[3];
    unsigned long max_ivor = 0;

    r = kvmppc_core_check_processor_compat();
    if (r)
        return r;

    r = kvmppc_booke_init();
    if (r)
        return r;

    /* copy extra E500 exception handlers */
    ivor[0] = mfspr(SPRN_IVOR32);
    ivor[1] = mfspr(SPRN_IVOR33);
    ivor[2] = mfspr(SPRN_IVOR34);
    for (i = 0; i < 3; i++) {
        if (ivor[i] > max_ivor)
            max_ivor = ivor[i];

        memcpy((void *)kvmppc_booke_handlers + ivor[i],
               kvmppc_handlers_start + (i + 16) * kvmppc_handler_len,
               kvmppc_handler_len);
    }
    flush_icache_range(kvmppc_booke_handlers,
            kvmppc_booke_handlers + max_ivor + kvmppc_handler_len);

    return kvm_init(NULL, sizeof(struct kvmppc_vcpu_e500), 0, THIS_MODULE);
}

static void __exit kvmppc_e500_exit(void)
{
    kvmppc_booke_exit();
}

module_init(kvmppc_e500_init);
module_exit(kvmppc_e500_exit);