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/*

 *  CRIS helper routines.

 *

 *  Copyright (c) 2007 AXIS Communications AB

 *  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, see <http://www.gnu.org/licenses/>.

 */

#include "cpu.h"

#include "mmu.h"

#include "qemu/host-utils.h"

//#define CRIS_HELPER_DEBUG

#ifdef CRIS_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)

void do_interrupt (CPUCRISState *env)

{

        env->exception_index = -1;

        env->pregs[PR_ERP] = env->pc;

}

int cpu_cris_handle_mmu_fault(CPUCRISState * env, target_ulong address, int rw,

                              int mmu_idx)

{

        env->exception_index = 0xaa;

        env->pregs[PR_EDA] = address;

        cpu_dump_state(env, stderr, fprintf, 0);

        return 1;

}

#else /* !CONFIG_USER_ONLY */

static void cris_shift_ccs(CPUCRISState *env)

{

        uint32_t ccs;

        /* Apply the ccs shift.  */

        ccs = env->pregs[PR_CCS];

        ccs = ((ccs & 0xc0000000) | ((ccs << 12) >> 2)) & ~0x3ff;

        env->pregs[PR_CCS] = ccs;

}

int cpu_cris_handle_mmu_fault (CPUCRISState *env, target_ulong address, int rw,

                               int mmu_idx)

{

        struct cris_mmu_result res;

        int prot, miss;

        int r = -1;

        target_ulong phy;

        D(printf ("%s addr=%x pc=%x rw=%x\n", __func__, address, env->pc, rw));

        miss = cris_mmu_translate(&res, env, address & TARGET_PAGE_MASK,

                                  rw, mmu_idx, 0);

        if (miss)

        {

                if (env->exception_index == EXCP_BUSFAULT)

                        cpu_abort(env,

                                  "CRIS: Illegal recursive bus fault."

                                 "addr=%x rw=%d\n",

                                 address, rw);

                env->pregs[PR_EDA] = address;

                env->exception_index = EXCP_BUSFAULT;

                env->fault_vector = res.bf_vec;

                r = 1;

        }

        else

        {

                /*

                 * Mask off the cache selection bit. The ETRAX busses do not

                 * see the top bit.

                 */

                phy = res.phy & ~0x80000000;

                prot = res.prot;

                tlb_set_page(env, address & TARGET_PAGE_MASK, phy,

                             prot, mmu_idx, TARGET_PAGE_SIZE);

                r = 0;

        }

        if (r > 0)

            D_LOG("%s returns %d irqreq=%x addr=%x phy=%x vec=%x pc=%x\n",

                  __func__, r, env->interrupt_request, address, res.phy,

                  res.bf_vec, env->pc);

        return r;

}

static void do_interruptv10(CPUCRISState *env)

{

        int ex_vec = -1;

        D_LOG( "exception index=%d interrupt_req=%d\n",

                   env->exception_index,

                   env->interrupt_request);

        assert(!(env->pregs[PR_CCS] & PFIX_FLAG));

        switch (env->exception_index)

        {

                case EXCP_BREAK:

                        /* These exceptions are genereated by the core itself.

                           ERP should point to the insn following the brk.  */

                        ex_vec = env->trap_vector;

                        env->pregs[PRV10_BRP] = env->pc;

                        break;

                case EXCP_NMI:

                        /* NMI is hardwired to vector zero.  */

                        ex_vec = 0;

                        env->pregs[PR_CCS] &= ~M_FLAG_V10;

                        env->pregs[PRV10_BRP] = env->pc;

                        break;

                case EXCP_BUSFAULT:

                        cpu_abort(env, "Unhandled busfault");

                        break;

                default:

                        /* The interrupt controller gives us the vector.  */

                        ex_vec = env->interrupt_vector;

                        /* Normal interrupts are taken between

                           TB's.  env->pc is valid here.  */

                        env->pregs[PR_ERP] = env->pc;

                        break;

        }

        if (env->pregs[PR_CCS] & U_FLAG) {

                /* Swap stack pointers.  */

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

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

        }

        /* Now that we are in kernel mode, load the handlers address.  */

        env->pc = cpu_ldl_code(env, env->pregs[PR_EBP] + ex_vec * 4);

        env->locked_irq = 1;

        env->pregs[PR_CCS] |= F_FLAG_V10; /* set F.  */

        qemu_log_mask(CPU_LOG_INT, "%s isr=%x vec=%x ccs=%x pid=%d erp=%x\n", 

                      __func__, env->pc, ex_vec, 

                      env->pregs[PR_CCS],

                      env->pregs[PR_PID], 

                      env->pregs[PR_ERP]);

}

void do_interrupt(CPUCRISState *env)

{

        int ex_vec = -1;

        if (env->pregs[PR_VR] < 32)

                return do_interruptv10(env);

        D_LOG( "exception index=%d interrupt_req=%d\n",

                   env->exception_index,

                   env->interrupt_request);

        switch (env->exception_index)

        {

                case EXCP_BREAK:

                        /* These exceptions are genereated by the core itself.

                           ERP should point to the insn following the brk.  */

                        ex_vec = env->trap_vector;

                        env->pregs[PR_ERP] = env->pc;

                        break;

                case EXCP_NMI:

                        /* NMI is hardwired to vector zero.  */

                        ex_vec = 0;

                        env->pregs[PR_CCS] &= ~M_FLAG_V32;

                        env->pregs[PR_NRP] = env->pc;

                        break;

                case EXCP_BUSFAULT:

                        ex_vec = env->fault_vector;

                        env->pregs[PR_ERP] = env->pc;

                        break;

                default:

                        /* The interrupt controller gives us the vector.  */

                        ex_vec = env->interrupt_vector;

                        /* Normal interrupts are taken between

                           TB's.  env->pc is valid here.  */

                        env->pregs[PR_ERP] = env->pc;

                        break;

        }

        /* Fill in the IDX field.  */

        env->pregs[PR_EXS] = (ex_vec & 0xff) << 8;

        if (env->dslot) {

                D_LOG("excp isr=%x PC=%x ds=%d SP=%x"

                          " ERP=%x pid=%x ccs=%x cc=%d %x\n",

                          ex_vec, env->pc, env->dslot,

                          env->regs[R_SP],

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

                          env->pregs[PR_CCS],

                          env->cc_op, env->cc_mask);

                /* We loose the btarget, btaken state here so rexec the

                   branch.  */

                env->pregs[PR_ERP] -= env->dslot;

                /* Exception starts with dslot cleared.  */

                env->dslot = 0;

        }

        if (env->pregs[PR_CCS] & U_FLAG) {

                /* Swap stack pointers.  */

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

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

        }

        /* Apply the CRIS CCS shift. Clears U if set.  */

        cris_shift_ccs(env);

        /* Now that we are in kernel mode, load the handlers address.

           This load may not fault, real hw leaves that behaviour as

           undefined.  */

        env->pc = cpu_ldl_code(env, env->pregs[PR_EBP] + ex_vec * 4);

        /* Clear the excption_index to avoid spurios hw_aborts for recursive

           bus faults.  */

        env->exception_index = -1;

        D_LOG("%s isr=%x vec=%x ccs=%x pid=%d erp=%x\n",

                   __func__, env->pc, ex_vec,

                   env->pregs[PR_CCS],

                   env->pregs[PR_PID], 

                   env->pregs[PR_ERP]);

}

hwaddr cpu_get_phys_page_debug(CPUCRISState * env, target_ulong addr)

{

        uint32_t phy = addr;

        struct cris_mmu_result res;

        int miss;

        miss = cris_mmu_translate(&res, env, addr, 0, 0, 1);

        /* If D TLB misses, try I TLB.  */

        if (miss) {

                miss = cris_mmu_translate(&res, env, addr, 2, 0, 1);

        }

        if (!miss)

                phy = res.phy;

        D(fprintf(stderr, "%s %x -> %x\n", __func__, addr, phy));

        return phy;

}

#endif