/*

 *  i386 emulator main execution loop

 *

 *  Copyright (c) 2003-2005 Fabrice Bellard

 *

 * 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

 */

#include "config.h"

#define CPU_NO_GLOBAL_REGS

#include "exec.h"

#include "disas.h"

#include "tcg.h"

#include "kvm.h"

#if !defined(CONFIG_SOFTMMU)

#undef EAX

#undef ECX

#undef EDX

#undef EBX

#undef ESP

#undef EBP

#undef ESI

#undef EDI

#undef EIP

#include <signal.h>

#ifdef __linux__

#include <sys/ucontext.h>

#endif

#endif

#if defined(__sparc__) && !defined(HOST_SOLARIS)

// Work around ugly bugs in glibc that mangle global register contents

#undef env

#define env cpu_single_env

#endif

int tb_invalidated_flag;

//#define DEBUG_EXEC

//#define DEBUG_SIGNAL

void cpu_loop_exit(void)

{

    /* NOTE: the register at this point must be saved by hand because

       longjmp restore them */

    regs_to_env();

    longjmp(env->jmp_env, 1);

}

/* exit the current TB from a signal handler. The host registers are

   restored in a state compatible with the CPU emulator

 */

void cpu_resume_from_signal(CPUState *env1, void *puc)

{

#if !defined(CONFIG_SOFTMMU)

#ifdef __linux__

    struct ucontext *uc = puc;

#elif defined(__OpenBSD__)

    struct sigcontext *uc = puc;

#endif

#endif

    env = env1;

    /* XXX: restore cpu registers saved in host registers */

#if !defined(CONFIG_SOFTMMU)

    if (puc) {

        /* XXX: use siglongjmp ? */

#ifdef __linux__

        sigprocmask(SIG_SETMASK, &uc->uc_sigmask, NULL);

#elif defined(__OpenBSD__)

        sigprocmask(SIG_SETMASK, &uc->sc_mask, NULL);

#endif

    }

#endif

    env->exception_index = -1;

    longjmp(env->jmp_env, 1);

}

/* Execute the code without caching the generated code. An interpreter

   could be used if available. */

static void cpu_exec_nocache(int max_cycles, TranslationBlock *orig_tb)

{

    unsigned long next_tb;

    TranslationBlock *tb;

    /* Should never happen.

       We only end up here when an existing TB is too long.  */

    if (max_cycles > CF_COUNT_MASK)

        max_cycles = CF_COUNT_MASK;

    tb = tb_gen_code(env, orig_tb->pc, orig_tb->cs_base, orig_tb->flags,

                     max_cycles);

    env->current_tb = tb;

    /* execute the generated code */

    next_tb = tcg_qemu_tb_exec(tb->tc_ptr);

    if ((next_tb & 3) == 2) {

        /* Restore PC.  This may happen if async event occurs before

           the TB starts executing.  */

        cpu_pc_from_tb(env, tb);

    }

    tb_phys_invalidate(tb, -1);

    tb_free(tb);

}

static TranslationBlock *tb_find_slow(target_ulong pc,

                                      target_ulong cs_base,

                                      uint64_t flags)

{

    TranslationBlock *tb, **ptb1;

    unsigned int h;

    target_ulong phys_pc, phys_page1, phys_page2, virt_page2;

    tb_invalidated_flag = 0;

    regs_to_env(); /* XXX: do it just before cpu_gen_code() */

    /* find translated block using physical mappings */

    phys_pc = get_phys_addr_code(env, pc);

    phys_page1 = phys_pc & TARGET_PAGE_MASK;

    phys_page2 = -1;

    h = tb_phys_hash_func(phys_pc);

    ptb1 = &tb_phys_hash[h];

    for(;;) {

        tb = *ptb1;

        if (!tb)

            goto not_found;

        if (tb->pc == pc &&

            tb->page_addr[0] == phys_page1 &&

            tb->cs_base == cs_base &&

            tb->flags == flags) {

            /* check next page if needed */

            if (tb->page_addr[1] != -1) {

                virt_page2 = (pc & TARGET_PAGE_MASK) +

                    TARGET_PAGE_SIZE;

                phys_page2 = get_phys_addr_code(env, virt_page2);

                if (tb->page_addr[1] == phys_page2)

                    goto found;

            } else {

                goto found;

            }

        }

        ptb1 = &tb->phys_hash_next;

    }

 not_found:

   /* if no translated code available, then translate it now */

    tb = tb_gen_code(env, pc, cs_base, flags, 0);

 found:

    /* we add the TB in the virtual pc hash table */

    env->tb_jmp_cache[tb_jmp_cache_hash_func(pc)] = tb;

    return tb;

}

static inline TranslationBlock *tb_find_fast(void)

{

    TranslationBlock *tb;

    target_ulong cs_base, pc;

    int flags;

    /* we record a subset of the CPU state. It will

       always be the same before a given translated block

       is executed. */

    cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags);

    tb = env->tb_jmp_cache[tb_jmp_cache_hash_func(pc)];

    if (unlikely(!tb || tb->pc != pc || tb->cs_base != cs_base ||

                 tb->flags != flags)) {

        tb = tb_find_slow(pc, cs_base, flags);

    }

    return tb;

}

static CPUDebugExcpHandler *debug_excp_handler;

CPUDebugExcpHandler *cpu_set_debug_excp_handler(CPUDebugExcpHandler *handler)

{

    CPUDebugExcpHandler *old_handler = debug_excp_handler;

    debug_excp_handler = handler;

    return old_handler;

}

static void cpu_handle_debug_exception(CPUState *env)

{

    CPUWatchpoint *wp;

    if (!env->watchpoint_hit)

        TAILQ_FOREACH(wp, &env->watchpoints, entry)

            wp->flags &= ~BP_WATCHPOINT_HIT;

    if (debug_excp_handler)

        debug_excp_handler(env);

}

/* main execution loop */

int cpu_exec(CPUState *env1)

{

#define DECLARE_HOST_REGS 1

#include "hostregs_helper.h"

    int ret, interrupt_request;

    TranslationBlock *tb;

    uint8_t *tc_ptr;

    unsigned long next_tb;

    if (cpu_halted(env1) == EXCP_HALTED)

        return EXCP_HALTED;

    cpu_single_env = env1;

    /* first we save global registers */

#define SAVE_HOST_REGS 1

#include "hostregs_helper.h"

    env = env1;

    env_to_regs();

#if defined(TARGET_I386)

    /* put eflags in CPU temporary format */

    CC_SRC = env->eflags & (CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C);

    DF = 1 - (2 * ((env->eflags >> 10) & 1));

    CC_OP = CC_OP_EFLAGS;

    env->eflags &= ~(DF_MASK | CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C);

#elif defined(TARGET_SPARC)

#elif defined(TARGET_M68K)

    env->cc_op = CC_OP_FLAGS;

    env->cc_dest = env->sr & 0xf;

    env->cc_x = (env->sr >> 4) & 1;

#elif defined(TARGET_ALPHA)

#elif defined(TARGET_ARM)

#elif defined(TARGET_PPC)

#elif defined(TARGET_MIPS)

#elif defined(TARGET_SH4)

#elif defined(TARGET_CRIS)

    /* XXXXX */

#else

#error unsupported target CPU

#endif

    env->exception_index = -1;

    /* prepare setjmp context for exception handling */

    for(;;) {

        if (setjmp(env->jmp_env) == 0) {

            env->current_tb = NULL;

            /* if an exception is pending, we execute it here */

            if (env->exception_index >= 0) {

                if (env->exception_index >= EXCP_INTERRUPT) {

                    /* exit request from the cpu execution loop */

                    ret = env->exception_index;

                    if (ret == EXCP_DEBUG)

                        cpu_handle_debug_exception(env);

                    break;

                } else if (env->user_mode_only) {

                    /* if user mode only, we simulate a fake exception

                       which will be handled outside the cpu execution

                       loop */

#if defined(TARGET_I386)

                    do_interrupt_user(env->exception_index,

                                      env->exception_is_int,

                                      env->error_code,

                                      env->exception_next_eip);

                    /* successfully delivered */

                    env->old_exception = -1;

#endif

                    ret = env->exception_index;

                    break;

                } else {

#if defined(TARGET_I386)

                    /* simulate a real cpu exception. On i386, it can

                       trigger new exceptions, but we do not handle

                       double or triple faults yet. */

                    do_interrupt(env->exception_index,

                                 env->exception_is_int,

                                 env->error_code,

                                 env->exception_next_eip, 0);

                    /* successfully delivered */

                    env->old_exception = -1;

#elif defined(TARGET_PPC)

                    do_interrupt(env);

#elif defined(TARGET_MIPS)

                    do_interrupt(env);

#elif defined(TARGET_SPARC)

                    do_interrupt(env);

#elif defined(TARGET_ARM)

                    do_interrupt(env);

#elif defined(TARGET_SH4)

		    do_interrupt(env);

#elif defined(TARGET_ALPHA)

                    do_interrupt(env);

#elif defined(TARGET_CRIS)

                    do_interrupt(env);

#elif defined(TARGET_M68K)

                    do_interrupt(0);

#endif

                }

                env->exception_index = -1;

            }

#ifdef USE_KQEMU

            if (kqemu_is_ok(env) && env->interrupt_request == 0) {

                int ret;

                env->eflags = env->eflags | helper_cc_compute_all(CC_OP) | (DF & DF_MASK);

                ret = kqemu_cpu_exec(env);

                /* put eflags in CPU temporary format */

                CC_SRC = env->eflags & (CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C);

                DF = 1 - (2 * ((env->eflags >> 10) & 1));

                CC_OP = CC_OP_EFLAGS;

                env->eflags &= ~(DF_MASK | CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C);

                if (ret == 1) {

                    /* exception */

                    longjmp(env->jmp_env, 1);

                } else if (ret == 2) {

                    /* softmmu execution needed */

                } else {

                    if (env->interrupt_request != 0) {

                        /* hardware interrupt will be executed just after */

                    } else {

                        /* otherwise, we restart */

                        longjmp(env->jmp_env, 1);

                    }

                }

            }

#endif

            if (kvm_enabled()) {

                kvm_cpu_exec(env);

                longjmp(env->jmp_env, 1);

            }

            next_tb = 0; /* force lookup of first TB */

            for(;;) {

                interrupt_request = env->interrupt_request;

                if (unlikely(interrupt_request)) {

                    if (unlikely(env->singlestep_enabled & SSTEP_NOIRQ)) {

                        /* Mask out external interrupts for this step. */

                        interrupt_request &= ~(CPU_INTERRUPT_HARD |

                                               CPU_INTERRUPT_FIQ |

                                               CPU_INTERRUPT_SMI |

                                               CPU_INTERRUPT_NMI);

                    }

                    if (interrupt_request & CPU_INTERRUPT_DEBUG) {

                        env->interrupt_request &= ~CPU_INTERRUPT_DEBUG;

                        env->exception_index = EXCP_DEBUG;

                        cpu_loop_exit();

                    }

#if defined(TARGET_ARM) || defined(TARGET_SPARC) || defined(TARGET_MIPS) || \

    defined(TARGET_PPC) || defined(TARGET_ALPHA) || defined(TARGET_CRIS)

                    if (interrupt_request & CPU_INTERRUPT_HALT) {

                        env->interrupt_request &= ~CPU_INTERRUPT_HALT;

                        env->halted = 1;

                        env->exception_index = EXCP_HLT;

                        cpu_loop_exit();

                    }

#endif

#if defined(TARGET_I386)

                    if (env->hflags2 & HF2_GIF_MASK) {

                        if ((interrupt_request & CPU_INTERRUPT_SMI) &&

                            !(env->hflags & HF_SMM_MASK)) {

                            svm_check_intercept(SVM_EXIT_SMI);

                            env->interrupt_request &= ~CPU_INTERRUPT_SMI;

                            do_smm_enter();

                            next_tb = 0;

                        } else if ((interrupt_request & CPU_INTERRUPT_NMI) &&

                                   !(env->hflags2 & HF2_NMI_MASK)) {

                            env->interrupt_request &= ~CPU_INTERRUPT_NMI;

                            env->hflags2 |= HF2_NMI_MASK;

                            do_interrupt(EXCP02_NMI, 0, 0, 0, 1);

                            next_tb = 0;

                        } else if ((interrupt_request & CPU_INTERRUPT_HARD) &&

                                   (((env->hflags2 & HF2_VINTR_MASK) && 

                                     (env->hflags2 & HF2_HIF_MASK)) ||

                                    (!(env->hflags2 & HF2_VINTR_MASK) && 

                                     (env->eflags & IF_MASK && 

                                      !(env->hflags & HF_INHIBIT_IRQ_MASK))))) {

                            int intno;

                            svm_check_intercept(SVM_EXIT_INTR);

                            env->interrupt_request &= ~(CPU_INTERRUPT_HARD | CPU_INTERRUPT_VIRQ);

                            intno = cpu_get_pic_interrupt(env);

                            if (loglevel & CPU_LOG_TB_IN_ASM) {

                                fprintf(logfile, "Servicing hardware INT=0x%02x\n", intno);

                            }

                            do_interrupt(intno, 0, 0, 0, 1);

                            /* ensure that no TB jump will be modified as

                               the program flow was changed */

                            next_tb = 0;

#if !defined(CONFIG_USER_ONLY)

                        } else if ((interrupt_request & CPU_INTERRUPT_VIRQ) &&

                                   (env->eflags & IF_MASK) && 

                                   !(env->hflags & HF_INHIBIT_IRQ_MASK)) {

                            int intno;

                            /* FIXME: this should respect TPR */

                            svm_check_intercept(SVM_EXIT_VINTR);

                            intno = ldl_phys(env->vm_vmcb + offsetof(struct vmcb, control.int_vector));

                            if (loglevel & CPU_LOG_TB_IN_ASM)

                                fprintf(logfile, "Servicing virtual hardware INT=0x%02x\n", intno);

                            do_interrupt(intno, 0, 0, 0, 1);

                            env->interrupt_request &= ~CPU_INTERRUPT_VIRQ;

                            next_tb = 0;

#endif

                        }

                    }

#elif defined(TARGET_PPC)

#if 0

                    if ((interrupt_request & CPU_INTERRUPT_RESET)) {

                        cpu_ppc_reset(env);

                    }

#endif

                    if (interrupt_request & CPU_INTERRUPT_HARD) {

                        ppc_hw_interrupt(env);

                        if (env->pending_interrupts == 0)

                            env->interrupt_request &= ~CPU_INTERRUPT_HARD;

                        next_tb = 0;

                    }

#elif defined(TARGET_MIPS)

                    if ((interrupt_request & CPU_INTERRUPT_HARD) &&

                        (env->CP0_Status & env->CP0_Cause & CP0Ca_IP_mask) &&

                        (env->CP0_Status & (1 << CP0St_IE)) &&

                        !(env->CP0_Status & (1 << CP0St_EXL)) &&

                        !(env->CP0_Status & (1 << CP0St_ERL)) &&

                        !(env->hflags & MIPS_HFLAG_DM)) {

                        /* Raise it */

                        env->exception_index = EXCP_EXT_INTERRUPT;

                        env->error_code = 0;

                        do_interrupt(env);

                        next_tb = 0;

                    }

#elif defined(TARGET_SPARC)

                    if ((interrupt_request & CPU_INTERRUPT_HARD) &&

			(env->psret != 0)) {

			int pil = env->interrupt_index & 15;

			int type = env->interrupt_index & 0xf0;

			if (((type == TT_EXTINT) &&

			     (pil == 15 || pil > env->psrpil)) ||

			    type != TT_EXTINT) {

			    env->interrupt_request &= ~CPU_INTERRUPT_HARD;

                            env->exception_index = env->interrupt_index;

                            do_interrupt(env);

			    env->interrupt_index = 0;

#if !defined(TARGET_SPARC64) && !defined(CONFIG_USER_ONLY)

                            cpu_check_irqs(env);

#endif

                        next_tb = 0;

			}

		    } else if (interrupt_request & CPU_INTERRUPT_TIMER) {

			//do_interrupt(0, 0, 0, 0, 0);

			env->interrupt_request &= ~CPU_INTERRUPT_TIMER;

		    }

#elif defined(TARGET_ARM)

                    if (interrupt_request & CPU_INTERRUPT_FIQ

                        && !(env->uncached_cpsr & CPSR_F)) {

                        env->exception_index = EXCP_FIQ;

                        do_interrupt(env);

                        next_tb = 0;

                    }

                    /* ARMv7-M interrupt return works by loading a magic value

                       into the PC.  On real hardware the load causes the

                       return to occur.  The qemu implementation performs the

                       jump normally, then does the exception return when the

                       CPU tries to execute code at the magic address.

                       This will cause the magic PC value to be pushed to

                       the stack if an interrupt occured at the wrong time.

                       We avoid this by disabling interrupts when

                       pc contains a magic address.  */

                    if (interrupt_request & CPU_INTERRUPT_HARD

                        && ((IS_M(env) && env->regs[15] < 0xfffffff0)

                            || !(env->uncached_cpsr & CPSR_I))) {

                        env->exception_index = EXCP_IRQ;

                        do_interrupt(env);

                        next_tb = 0;

                    }

#elif defined(TARGET_SH4)

                    if (interrupt_request & CPU_INTERRUPT_HARD) {

                        do_interrupt(env);

                        next_tb = 0;

                    }

#elif defined(TARGET_ALPHA)

                    if (interrupt_request & CPU_INTERRUPT_HARD) {

                        do_interrupt(env);

                        next_tb = 0;

                    }

#elif defined(TARGET_CRIS)

                    if (interrupt_request & CPU_INTERRUPT_HARD

                        && (env->pregs[PR_CCS] & I_FLAG)) {

                        env->exception_index = EXCP_IRQ;

                        do_interrupt(env);

                        next_tb = 0;

                    }

                    if (interrupt_request & CPU_INTERRUPT_NMI

                        && (env->pregs[PR_CCS] & M_FLAG)) {

                        env->exception_index = EXCP_NMI;

                        do_interrupt(env);

                        next_tb = 0;

                    }

#elif defined(TARGET_M68K)

                    if (interrupt_request & CPU_INTERRUPT_HARD

                        && ((env->sr & SR_I) >> SR_I_SHIFT)

                            < env->pending_level) {

                        /* Real hardware gets the interrupt vector via an

                           IACK cycle at this point.  Current emulated

                           hardware doesn't rely on this, so we

                           provide/save the vector when the interrupt is

                           first signalled.  */

                        env->exception_index = env->pending_vector;

                        do_interrupt(1);

                        next_tb = 0;

                    }

#endif

                   /* Don't use the cached interupt_request value,

                      do_interrupt may have updated the EXITTB flag. */

                    if (env->interrupt_request & CPU_INTERRUPT_EXITTB) {

                        env->interrupt_request &= ~CPU_INTERRUPT_EXITTB;

                        /* ensure that no TB jump will be modified as

                           the program flow was changed */

                        next_tb = 0;

                    }