Archipelago » qemu

/*

 *  CRIS helper routines

 *

 *  Copyright (c) 2007 AXIS Communications

 *  Written by Edgar E. Iglesias

 *

 * 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., 51 Franklin Street, Fifth Floor, Boston MA  02110-1301 USA

 */

#include <assert.h>

#include "exec.h"

#include "mmu.h"

#include "helper.h"

#include "host-utils.h"

//#define CRIS_OP_HELPER_DEBUG

#ifdef CRIS_OP_HELPER_DEBUG

#define D(x) x

#define D_LOG(...) qemu_log(__VA__ARGS__)

#else

#define D(x)

#define D_LOG(...) do { } while (0)

#endif

#if !defined(CONFIG_USER_ONLY)

#define MMUSUFFIX _mmu

#define SHIFT 0

#include "softmmu_template.h"

#define SHIFT 1

#include "softmmu_template.h"

#define SHIFT 2

#include "softmmu_template.h"

#define SHIFT 3

#include "softmmu_template.h"

/* Try to fill the TLB and return an exception if error. If retaddr is

   NULL, it means that the function was called in C code (i.e. not

   from generated code or from helper.c) */

/* XXX: fix it to restore all registers */

void tlb_fill (target_ulong addr, int is_write, int mmu_idx, void *retaddr)

{

    TranslationBlock *tb;

    CPUState *saved_env;

    unsigned long pc;

    int ret;

    /* XXX: hack to restore env in all cases, even if not called from

       generated code */

    saved_env = env;

    env = cpu_single_env;

    D_LOG("%s pc=%x tpc=%x ra=%x\n", __func__, 

             env->pc, env->debug1, retaddr);

    ret = cpu_cris_handle_mmu_fault(env, addr, is_write, mmu_idx, 1);

    if (unlikely(ret)) {

        if (retaddr) {

            /* now we have a real cpu fault */

            pc = (unsigned long)retaddr;

            tb = tb_find_pc(pc);

            if (tb) {

                /* the PC is inside the translated code. It means that we have

                   a virtual CPU fault */

                cpu_restore_state(tb, env, pc, NULL);

                /* Evaluate flags after retranslation.  */

                helper_top_evaluate_flags();

            }

        }

        cpu_loop_exit();

    }

    env = saved_env;

}

#endif

void helper_raise_exception(uint32_t index)

{

        env->exception_index = index;

        cpu_loop_exit();

}

void helper_tlb_flush_pid(uint32_t pid)

{

#if !defined(CONFIG_USER_ONLY)

        pid &= 0xff;

        if (pid != (env->pregs[PR_PID] & 0xff))

                cris_mmu_flush_pid(env, env->pregs[PR_PID]);

#endif

}

void helper_spc_write(uint32_t new_spc)

{

#if !defined(CONFIG_USER_ONLY)

        tlb_flush_page(env, env->pregs[PR_SPC]);

        tlb_flush_page(env, new_spc);

#endif

}

void helper_dump(uint32_t a0, uint32_t a1, uint32_t a2)

{

        qemu_log("%s: a0=%x a1=%x\n", __func__, a0, a1);

}

/* Used by the tlb decoder.  */

#define EXTRACT_FIELD(src, start, end) \

            (((src) >> start) & ((1 << (end - start + 1)) - 1))

void helper_movl_sreg_reg (uint32_t sreg, uint32_t reg)

{

        uint32_t srs;

        srs = env->pregs[PR_SRS];

        srs &= 3;

        env->sregs[srs][sreg] = env->regs[reg];

#if !defined(CONFIG_USER_ONLY)

        if (srs == 1 || srs == 2) {

                if (sreg == 6) {

                        /* Writes to tlb-hi write to mm_cause as a side 

                           effect.  */

                        env->sregs[SFR_RW_MM_TLB_HI] = env->regs[reg];

                        env->sregs[SFR_R_MM_CAUSE] = env->regs[reg];

                }

                else if (sreg == 5) {

                        uint32_t set;

                        uint32_t idx;

                        uint32_t lo, hi;

                        uint32_t vaddr;

                        int tlb_v;

                        idx = set = env->sregs[SFR_RW_MM_TLB_SEL];

                        set >>= 4;

                        set &= 3;

                        idx &= 15;

                        /* We've just made a write to tlb_lo.  */

                        lo = env->sregs[SFR_RW_MM_TLB_LO];

                        /* Writes are done via r_mm_cause.  */

                        hi = env->sregs[SFR_R_MM_CAUSE];

                        vaddr = EXTRACT_FIELD(env->tlbsets[srs-1][set][idx].hi,

                                              13, 31);

                        vaddr <<= TARGET_PAGE_BITS;

                        tlb_v = EXTRACT_FIELD(env->tlbsets[srs-1][set][idx].lo,

                                            3, 3);

                        env->tlbsets[srs - 1][set][idx].lo = lo;

                        env->tlbsets[srs - 1][set][idx].hi = hi;

                        D_LOG("tlb flush vaddr=%x v=%d pc=%x\n", 

                                  vaddr, tlb_v, env->pc);

                        tlb_flush_page(env, vaddr);

                }

        }

#endif

}

void helper_movl_reg_sreg (uint32_t reg, uint32_t sreg)

{

        uint32_t srs;

        env->pregs[PR_SRS] &= 3;

        srs = env->pregs[PR_SRS];

#if !defined(CONFIG_USER_ONLY)

        if (srs == 1 || srs == 2)

        {

                uint32_t set;

                uint32_t idx;

                uint32_t lo, hi;

                idx = set = env->sregs[SFR_RW_MM_TLB_SEL];

                set >>= 4;

                set &= 3;

                idx &= 15;

                /* Update the mirror regs.  */

                hi = env->tlbsets[srs - 1][set][idx].hi;

                lo = env->tlbsets[srs - 1][set][idx].lo;

                env->sregs[SFR_RW_MM_TLB_HI] = hi;

                env->sregs[SFR_RW_MM_TLB_LO] = lo;

        }

#endif

        env->regs[reg] = env->sregs[srs][sreg];

}

static void cris_ccs_rshift(CPUState *env)

{

        uint32_t ccs;

        /* Apply the ccs shift.  */

        ccs = env->pregs[PR_CCS];

        ccs = (ccs & 0xc0000000) | ((ccs & 0x0fffffff) >> 10);

        if (ccs & U_FLAG)

        {

                /* Enter user mode.  */

                env->ksp = env->regs[R_SP];

                env->regs[R_SP] = env->pregs[PR_USP];

        }

        env->pregs[PR_CCS] = ccs;

}

void helper_rfe(void)

{

        int rflag = env->pregs[PR_CCS] & R_FLAG;

        D_LOG("rfe: erp=%x pid=%x ccs=%x btarget=%x\n", 

                 env->pregs[PR_ERP], env->pregs[PR_PID],

                 env->pregs[PR_CCS],

                 env->btarget);

        cris_ccs_rshift(env);

        /* RFE sets the P_FLAG only if the R_FLAG is not set.  */

        if (!rflag)

                env->pregs[PR_CCS] |= P_FLAG;

}

void helper_rfn(void)

{

        int rflag = env->pregs[PR_CCS] & R_FLAG;

        D_LOG("rfn: erp=%x pid=%x ccs=%x btarget=%x\n", 

                 env->pregs[PR_ERP], env->pregs[PR_PID],

                 env->pregs[PR_CCS],

                 env->btarget);

        cris_ccs_rshift(env);

        /* Set the P_FLAG only if the R_FLAG is not set.  */

        if (!rflag)

                env->pregs[PR_CCS] |= P_FLAG;

    /* Always set the M flag.  */

    env->pregs[PR_CCS] |= M_FLAG;

}

uint32_t helper_lz(uint32_t t0)

{

        return clz32(t0);

}

uint32_t helper_btst(uint32_t t0, uint32_t t1, uint32_t ccs)

{

        /* FIXME: clean this up.  */

        /* des ref:

           The N flag is set according to the selected bit in the dest reg.

           The Z flag is set if the selected bit and all bits to the right are

           zero.

           The X flag is cleared.

           Other flags are left untouched.

           The destination reg is not affected.*/

        unsigned int fz, sbit, bset, mask, masked_t0;

        sbit = t1 & 31;

        bset = !!(t0 & (1 << sbit));

        mask = sbit == 31 ? -1 : (1 << (sbit + 1)) - 1;

        masked_t0 = t0 & mask;

        fz = !(masked_t0 | bset);

        /* Clear the X, N and Z flags.  */

        ccs = ccs & ~(X_FLAG | N_FLAG | Z_FLAG);

        /* Set the N and Z flags accordingly.  */

        ccs |= (bset << 3) | (fz << 2);

        return ccs;

}

static inline uint32_t evaluate_flags_writeback(uint32_t flags, uint32_t ccs)

{

        unsigned int x, z, mask;

        /* Extended arithmetics, leave the z flag alone.  */

        x = env->cc_x;

        mask = env->cc_mask | X_FLAG;

        if (x) {

                z = flags & Z_FLAG;

                mask = mask & ~z;

        }

        flags &= mask;

        /* all insn clear the x-flag except setf or clrf.  */

        ccs &= ~mask;

        ccs |= flags;

        return ccs;

}

uint32_t helper_evaluate_flags_muls(uint32_t ccs, uint32_t res, uint32_t mof)

{

        uint32_t flags = 0;

        int64_t tmp;

        int dneg;

        dneg = ((int32_t)res) < 0;

        tmp = mof;

        tmp <<= 32;

        tmp |= res;

        if (tmp == 0)

                flags |= Z_FLAG;

        else if (tmp < 0)

                flags |= N_FLAG;

        if ((dneg && mof != -1)

            || (!dneg && mof != 0))

                flags |= V_FLAG;

        return evaluate_flags_writeback(flags, ccs);

}

uint32_t helper_evaluate_flags_mulu(uint32_t ccs, uint32_t res, uint32_t mof)

{

        uint32_t flags = 0;

        uint64_t tmp;

        tmp = mof;

        tmp <<= 32;

        tmp |= res;

        if (tmp == 0)

                flags |= Z_FLAG;

        else if (tmp >> 63)

                flags |= N_FLAG;

        if (mof)

                flags |= V_FLAG;

        return evaluate_flags_writeback(flags, ccs);

}

uint32_t helper_evaluate_flags_mcp(uint32_t ccs,

                                   uint32_t src, uint32_t dst, uint32_t res)

{

        uint32_t flags = 0;

        src = src & 0x80000000;

        dst = dst & 0x80000000;

        if ((res & 0x80000000L) != 0L)

        {

                flags |= N_FLAG;

                if (!src && !dst)

                        flags |= V_FLAG;

                else if (src & dst)

                        flags |= R_FLAG;

        }

        else

        {

                if (res == 0L)

                        flags |= Z_FLAG;

                if (src & dst) 

                        flags |= V_FLAG;

                if (dst | src) 

                        flags |= R_FLAG;

        }

        return evaluate_flags_writeback(flags, ccs);

}

uint32_t helper_evaluate_flags_alu_4(uint32_t ccs,

                                     uint32_t src, uint32_t dst, uint32_t res)

{

        uint32_t flags = 0;

        src = src & 0x80000000;

        dst = dst & 0x80000000;

        if ((res & 0x80000000L) != 0L)

        {

                flags |= N_FLAG;

                if (!src && !dst)

                        flags |= V_FLAG;

                else if (src & dst)

                        flags |= C_FLAG;

        }

        else

        {

                if (res == 0L)

                        flags |= Z_FLAG;

                if (src & dst) 

                        flags |= V_FLAG;

                if (dst | src) 

                        flags |= C_FLAG;

        }

        return evaluate_flags_writeback(flags, ccs);

}

uint32_t helper_evaluate_flags_sub_4(uint32_t ccs,

                                     uint32_t src, uint32_t dst, uint32_t res)

{

        uint32_t flags = 0;

        src = (~src) & 0x80000000;

        dst = dst & 0x80000000;

        if ((res & 0x80000000L) != 0L)

        {

                flags |= N_FLAG;

                if (!src && !dst)

                        flags |= V_FLAG;

                else if (src & dst)

                        flags |= C_FLAG;

        }

        else

        {

                if (res == 0L)

                        flags |= Z_FLAG;

                if (src & dst) 

                        flags |= V_FLAG;

                if (dst | src) 

                        flags |= C_FLAG;

        }

        flags ^= C_FLAG;

        return evaluate_flags_writeback(flags, ccs);

}

uint32_t helper_evaluate_flags_move_4(uint32_t ccs, uint32_t res)

{

        uint32_t flags = 0;

        if ((int32_t)res < 0)

                flags |= N_FLAG;

        else if (res == 0L)

                flags |= Z_FLAG;

        return evaluate_flags_writeback(flags, ccs);

}

uint32_t helper_evaluate_flags_move_2(uint32_t ccs, uint32_t res)

{

        uint32_t flags = 0;

        if ((int16_t)res < 0L)

                flags |= N_FLAG;

        else if (res == 0)

                flags |= Z_FLAG;

        return evaluate_flags_writeback(flags, ccs);

}

/* TODO: This is expensive. We could split things up and only evaluate part of

   CCR on a need to know basis. For now, we simply re-evaluate everything.  */

void  helper_evaluate_flags(void)

{

        uint32_t src, dst, res;

        uint32_t flags = 0;

        src = env->cc_src;

        dst = env->cc_dest;

        res = env->cc_result;

        if (env->cc_op == CC_OP_SUB || env->cc_op == CC_OP_CMP)

                src = ~src;

        /* Now, evaluate the flags. This stuff is based on

           Per Zander's CRISv10 simulator.  */

        switch (env->cc_size)

        {

                case 1:

                        if ((res & 0x80L) != 0L)

                        {

                                flags |= N_FLAG;

                                if (((src & 0x80L) == 0L)

                                    && ((dst & 0x80L) == 0L))

                                {

                                        flags |= V_FLAG;

                                }

                                else if (((src & 0x80L) != 0L)

                                         && ((dst & 0x80L) != 0L))

                                {

                                        flags |= C_FLAG;

                                }

                        }

                        else

                        {

                                if ((res & 0xFFL) == 0L)

                                {

                                        flags |= Z_FLAG;

                                }

                                if (((src & 0x80L) != 0L)

                                    && ((dst & 0x80L) != 0L))

                                {

                                        flags |= V_FLAG;

                                }

                                if ((dst & 0x80L) != 0L

                                    || (src & 0x80L) != 0L)

                                {

                                        flags |= C_FLAG;

                                }

                        }

                        break;

                case 2:

                        if ((res & 0x8000L) != 0L)

                        {

                                flags |= N_FLAG;

                                if (((src & 0x8000L) == 0L)

                                    && ((dst & 0x8000L) == 0L))

                                {

                                        flags |= V_FLAG;

                                }

                                else if (((src & 0x8000L) != 0L)

                                         && ((dst & 0x8000L) != 0L))

                                {

                                        flags |= C_FLAG;

                                }

                        }

                        else

                        {

                                if ((res & 0xFFFFL) == 0L)

                                {

                                        flags |= Z_FLAG;

                                }

                                if (((src & 0x8000L) != 0L)

                                    && ((dst & 0x8000L) != 0L))

                                {

                                        flags |= V_FLAG;

                                }

                                if ((dst & 0x8000L) != 0L

                                    || (src & 0x8000L) != 0L)

                                {

                                        flags |= C_FLAG;

                                }

                        }

                        break;

                case 4:

                        if ((res & 0x80000000L) != 0L)

                        {

                                flags |= N_FLAG;

                                if (((src & 0x80000000L) == 0L)

                                    && ((dst & 0x80000000L) == 0L))

                                {

                                        flags |= V_FLAG;

                                }

                                else if (((src & 0x80000000L) != 0L) &&

                                         ((dst & 0x80000000L) != 0L))

                                {

                                        flags |= C_FLAG;

                                }

                        }

                        else

                        {

                                if (res == 0L)

                                        flags |= Z_FLAG;

                                if (((src & 0x80000000L) != 0L)

                                    && ((dst & 0x80000000L) != 0L))

                                        flags |= V_FLAG;

                                if ((dst & 0x80000000L) != 0L

                                    || (src & 0x80000000L) != 0L)

                                        flags |= C_FLAG;

                        }

                        break;

                default:

                        break;

        }

        if (env->cc_op == CC_OP_SUB || env->cc_op == CC_OP_CMP)

                flags ^= C_FLAG;

        env->pregs[PR_CCS] = evaluate_flags_writeback(flags, env->pregs[PR_CCS]);

}

void helper_top_evaluate_flags(void)

{

        switch (env->cc_op)

        {

                case CC_OP_MCP:

                        env->pregs[PR_CCS] = helper_evaluate_flags_mcp(

                                        env->pregs[PR_CCS], env->cc_src,

                                        env->cc_dest, env->cc_result);

                        break;

                case CC_OP_MULS:

                        env->pregs[PR_CCS] = helper_evaluate_flags_muls(

                                        env->pregs[PR_CCS], env->cc_result,

                                        env->pregs[PR_MOF]);

                        break;

                case CC_OP_MULU:

                        env->pregs[PR_CCS] = helper_evaluate_flags_mulu(

                                        env->pregs[PR_CCS], env->cc_result,

                                        env->pregs[PR_MOF]);

                        break;

                case CC_OP_MOVE:

                case CC_OP_AND:

                case CC_OP_OR:

                case CC_OP_XOR:

                case CC_OP_ASR:

                case CC_OP_LSR:

                case CC_OP_LSL:

                switch (env->cc_size)

                {

                        case 4:

                                env->pregs[PR_CCS] =

                                        helper_evaluate_flags_move_4(

                                                        env->pregs[PR_CCS],

                                                        env->cc_result);

                                break;

                        case 2:

                                env->pregs[PR_CCS] =

                                        helper_evaluate_flags_move_2(

                                                        env->pregs[PR_CCS],

                                                        env->cc_result);

                                break;

                        default:

                                helper_evaluate_flags();

                                break;

                }

                break;

                case CC_OP_FLAGS:

                        /* live.  */

                        break;

                case CC_OP_SUB:

                case CC_OP_CMP:

                        if (env->cc_size == 4)

                                env->pregs[PR_CCS] =

                                        helper_evaluate_flags_sub_4(

                                                env->pregs[PR_CCS],

                                                env->cc_src, env->cc_dest,

                                                env->cc_result);

                        else

                                helper_evaluate_flags();

                        break;

                default:

                {

                        switch (env->cc_size)

                        {

                        case 4:

                                env->pregs[PR_CCS] =

                                        helper_evaluate_flags_alu_4(

                                                env->pregs[PR_CCS],

                                                env->cc_src, env->cc_dest,

                                                env->cc_result);

                                break;

                        default:

                                helper_evaluate_flags();

                                break;

                        }

                }

                break;

        }

}