/*
 * 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, write to the Free Software
 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * Copyright IBM Corp. 2008
 *
 * Authors: Hollis Blanchard <hollisb@us.ibm.com>
 */

#include <asm/kvm_ppc.h>
#include <asm/dcr.h>
#include <asm/dcr-regs.h>
#include <asm/disassemble.h>
#include <asm/kvm_44x.h>
#include "timing.h"

#include "booke.h"
#include "44x_tlb.h"

#define XOP_MFDCR   323
#define XOP_MTDCR   451
#define XOP_TLBSX   914
#define XOP_ICCCI   966
#define XOP_TLBWE   978

int kvmppc_core_emulate_op(struct kvm_run *run, struct kvm_vcpu *vcpu,
                           unsigned int inst, int *advance)
{
        int emulated = EMULATE_DONE;
        int dcrn;
        int ra;
        int rb;
        int rc;
        int rs;
        int rt;
        int ws;

        switch (get_op(inst)) {
        case 31:
                switch (get_xop(inst)) {

                case XOP_MFDCR:
                        dcrn = get_dcrn(inst);
                        rt = get_rt(inst);

                        /* The guest may access CPR0 registers to determine the timebase
                         * frequency, and it must know the real host frequency because it
                         * can directly access the timebase registers.
                         *
                         * It would be possible to emulate those accesses in userspace,
                         * but userspace can really only figure out the end frequency.
                         * We could decompose that into the factors that compute it, but
                         * that's tricky math, and it's easier to just report the real
                         * CPR0 values.
                         */
                        switch (dcrn) {
                        case DCRN_CPR0_CONFIG_ADDR:
                                vcpu->arch.gpr[rt] = vcpu->arch.cpr0_cfgaddr;
                                break;
                        case DCRN_CPR0_CONFIG_DATA:
                                local_irq_disable();
                                mtdcr(DCRN_CPR0_CONFIG_ADDR,
                                          vcpu->arch.cpr0_cfgaddr);
                                vcpu->arch.gpr[rt] = mfdcr(DCRN_CPR0_CONFIG_DATA);
                                local_irq_enable();
                                break;
                        default:
                                run->dcr.dcrn = dcrn;
                                run->dcr.data =  0;
                                run->dcr.is_write = 0;
                                vcpu->arch.io_gpr = rt;
                                vcpu->arch.dcr_needed = 1;
                                kvmppc_account_exit(vcpu, DCR_EXITS);
                                emulated = EMULATE_DO_DCR;
                        }

                        break;

                case XOP_MTDCR:
                        dcrn = get_dcrn(inst);
                        rs = get_rs(inst);

                        /* emulate some access in kernel */
                        switch (dcrn) {
                        case DCRN_CPR0_CONFIG_ADDR:
                                vcpu->arch.cpr0_cfgaddr = vcpu->arch.gpr[rs];
                                break;
                        default:
                                run->dcr.dcrn = dcrn;
                                run->dcr.data = vcpu->arch.gpr[rs];
                                run->dcr.is_write = 1;
                                vcpu->arch.dcr_needed = 1;
                                kvmppc_account_exit(vcpu, DCR_EXITS);
                                emulated = EMULATE_DO_DCR;
                        }

                        break;

                case XOP_TLBWE:
                        ra = get_ra(inst);
                        rs = get_rs(inst);
                        ws = get_ws(inst);
                        emulated = kvmppc_44x_emul_tlbwe(vcpu, ra, rs, ws);
                        break;

                case XOP_TLBSX:
                        rt = get_rt(inst);
                        ra = get_ra(inst);
                        rb = get_rb(inst);
                        rc = get_rc(inst);
                        emulated = kvmppc_44x_emul_tlbsx(vcpu, rt, ra, rb, rc);
                        break;

                case XOP_ICCCI:
                        break;

                default:
                        emulated = EMULATE_FAIL;
                }

                break;

        default:
                emulated = EMULATE_FAIL;
        }

        if (emulated == EMULATE_FAIL)
                emulated = kvmppc_booke_emulate_op(run, vcpu, inst, advance);

        return emulated;
}

int kvmppc_core_emulate_mtspr(struct kvm_vcpu *vcpu, int sprn, int rs)
{
        int emulated = EMULATE_DONE;

        switch (sprn) {
        case SPRN_PID:
                kvmppc_set_pid(vcpu, vcpu->arch.gpr[rs]); break;
        case SPRN_MMUCR:
                vcpu->arch.mmucr = vcpu->arch.gpr[rs]; break;
        case SPRN_CCR0:
                vcpu->arch.ccr0 = vcpu->arch.gpr[rs]; break;
        case SPRN_CCR1:
                vcpu->arch.ccr1 = vcpu->arch.gpr[rs]; break;
        default:
                emulated = kvmppc_booke_emulate_mtspr(vcpu, sprn, rs);
        }

        kvmppc_set_exit_type(vcpu, EMULATED_MTSPR_EXITS);
        return emulated;
}

int kvmppc_core_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt)
{
        int emulated = EMULATE_DONE;

        switch (sprn) {
        case SPRN_PID:
                vcpu->arch.gpr[rt] = vcpu->arch.pid; break;
        case SPRN_MMUCR:
                vcpu->arch.gpr[rt] = vcpu->arch.mmucr; break;
        case SPRN_CCR0:
                vcpu->arch.gpr[rt] = vcpu->arch.ccr0; break;
        case SPRN_CCR1:
                vcpu->arch.gpr[rt] = vcpu->arch.ccr1; break;
        default:
                emulated = kvmppc_booke_emulate_mfspr(vcpu, sprn, rt);
        }

        kvmppc_set_exit_type(vcpu, EMULATED_MFSPR_EXITS);
        return emulated;
}