/*

 *  PowerPC emulation special registers manipulation helpers for qemu.

 *

 *  Copyright (c) 2003-2007 Jocelyn Mayer

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

#if !defined(__HELPER_REGS_H__)

#define __HELPER_REGS_H__

/* Swap temporary saved registers with GPRs */

static always_inline void hreg_swap_gpr_tgpr (CPUPPCState *env)

{

    target_ulong tmp;

    tmp = env->gpr[0];

    env->gpr[0] = env->tgpr[0];

    env->tgpr[0] = tmp;

    tmp = env->gpr[1];

    env->gpr[1] = env->tgpr[1];

    env->tgpr[1] = tmp;

    tmp = env->gpr[2];

    env->gpr[2] = env->tgpr[2];

    env->tgpr[2] = tmp;

    tmp = env->gpr[3];

    env->gpr[3] = env->tgpr[3];

    env->tgpr[3] = tmp;

}

static always_inline void hreg_compute_mem_idx (CPUPPCState *env)

{

    /* Precompute MMU index */

    if (msr_pr == 0 && msr_hv != 0) {

        env->mmu_idx = 2;

    } else {

        env->mmu_idx = 1 - msr_pr;

    }

}

static always_inline void hreg_compute_hflags (CPUPPCState *env)

{

    target_ulong hflags_mask;

    /* We 'forget' FE0 & FE1: we'll never generate imprecise exceptions */

    hflags_mask = (1 << MSR_VR) | (1 << MSR_AP) | (1 << MSR_SA) |

        (1 << MSR_PR) | (1 << MSR_FP) | (1 << MSR_SE) | (1 << MSR_BE) |

        (1 << MSR_LE);

    hflags_mask |= (1ULL << MSR_CM) | (1ULL << MSR_SF) | MSR_HVB;

    hreg_compute_mem_idx(env);

    env->hflags = env->msr & hflags_mask;

    /* Merge with hflags coming from other registers */

    env->hflags |= env->hflags_nmsr;

}

static always_inline int hreg_store_msr (CPUPPCState *env, target_ulong value,

                                         int alter_hv)

{

    int excp;

    excp = 0;

    value &= env->msr_mask;

#if !defined (CONFIG_USER_ONLY)

    if (!alter_hv) {

        /* mtmsr cannot alter the hypervisor state */

        value &= ~MSR_HVB;

        value |= env->msr & MSR_HVB;

    }

    if (((value >> MSR_IR) & 1) != msr_ir ||

        ((value >> MSR_DR) & 1) != msr_dr) {

        /* Flush all tlb when changing translation mode */

        tlb_flush(env, 1);

        excp = POWERPC_EXCP_NONE;

        env->interrupt_request |= CPU_INTERRUPT_EXITTB;

    }

    if (unlikely((env->flags & POWERPC_FLAG_TGPR) &&

                 ((value ^ env->msr) & (1 << MSR_TGPR)))) {

        /* Swap temporary saved registers with GPRs */

        hreg_swap_gpr_tgpr(env);

    }

    if (unlikely((value >> MSR_EP) & 1) != msr_ep) {

        /* Change the exception prefix on PowerPC 601 */

        env->excp_prefix = ((value >> MSR_EP) & 1) * 0xFFF00000;

    }

#endif

    env->msr = value;

    hreg_compute_hflags(env);

#if !defined (CONFIG_USER_ONLY)

    if (unlikely(msr_pow == 1)) {

        if ((*env->check_pow)(env)) {

            env->halted = 1;

            excp = EXCP_HALTED;

        }

    }

#endif

    return excp;

}

#endif /* !defined(__HELPER_REGS_H__) */