/**

  * $Id$

  * 

  * SH4 translation core module. This part handles the non-target-specific

  * section of the translation.

  *

  * Copyright (c) 2005 Nathan Keynes.

  *

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

  * it under the terms of the GNU General Public License as published by

  * the Free Software Foundation; either version 2 of the License, or

  * (at your option) any later version.

  *

  * 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.

  */

 #include <assert.h>

 #include <setjmp.h>

 #include "eventq.h"

 #include "syscall.h"

 #include "clock.h"

 #include "sh4/sh4core.h"

 #include "sh4/sh4trans.h"

 #include "sh4/xltcache.h"

 static jmp_buf xlat_jmp_buf;

 static gboolean xlat_running = FALSE;

 gboolean sh4_xlat_is_running()

 {

     return xlat_running;

 }

 /**

  * Execute a timeslice using translated code only (ie translate/execute loop)

  */

 uint32_t sh4_xlat_run_slice( uint32_t nanosecs ) 

 {

     sh4r.slice_cycle = 0;

     if( sh4r.sh4_state != SH4_STATE_RUNNING ) {

 	if( sh4r.event_pending < nanosecs ) {

 	    sh4r.sh4_state = SH4_STATE_RUNNING;

 	    sh4r.slice_cycle = sh4r.event_pending;

 	}

     }

     switch( setjmp(xlat_jmp_buf) ) {

     case XLAT_EXIT_BREAKPOINT:

 	sh4_clear_breakpoint( sh4r.pc, BREAK_ONESHOT );

 	/* fallthrough */

     case XLAT_EXIT_HALT:

 	if( sh4r.sh4_state != SH4_STATE_STANDBY ) {

 	    TMU_run_slice( sh4r.slice_cycle );

 	    SCIF_run_slice( sh4r.slice_cycle );

 	    dreamcast_stop();

 	    return sh4r.slice_cycle;

 	}

     case XLAT_EXIT_SYSRESET:

 	dreamcast_reset();

 	break;

     }

     xlat_running = TRUE;

     void * (*code)() = NULL;

     while( sh4r.slice_cycle < nanosecs ) {

 	if( sh4r.event_pending <= sh4r.slice_cycle ) {

 	    if( sh4r.event_types & PENDING_EVENT ) {

 		event_execute();

 	    }

 	    /* Eventq execute may (quite likely) deliver an immediate IRQ */

 	    if( sh4r.event_types & PENDING_IRQ ) {

 		sh4_accept_interrupt();

 		code = NULL;

 	    }

 	}

 	if( code == NULL ) {

 	    if( sh4r.pc > 0xFFFFFF00 ) {

 		syscall_invoke( sh4r.pc );

 		sh4r.in_delay_slot = 0;

 		sh4r.pc = sh4r.pr;

 	    }

 	    code = xlat_get_code_by_vma( sh4r.pc );

 	    if( code == NULL ) {

 		code = sh4_translate_basic_block( sh4r.pc );

 	    }

 	}

 	code = code();

     }

     xlat_running = FALSE;

     sh4_starting = FALSE;

     if( sh4r.sh4_state != SH4_STATE_STANDBY ) {

 	TMU_run_slice( nanosecs );

 	SCIF_run_slice( nanosecs );

     }

     return nanosecs;

 }

 uint8_t *xlat_output;

 struct xlat_recovery_record xlat_recovery[MAX_RECOVERY_SIZE];

 uint32_t xlat_recovery_posn;

 /**

  * Translate a linear basic block, ie all instructions from the start address

  * (inclusive) until the next branch/jump instruction or the end of the page

  * is reached.

  * @return the address of the translated block

  * eg due to lack of buffer space.

  */

 void * sh4_translate_basic_block( sh4addr_t start )

 {

     sh4addr_t pc = start;

     sh4addr_t lastpc = (pc&0xFFFFF000)+0x1000;

     int done, i;

     xlat_cache_block_t block = xlat_start_block( start );

     xlat_output = (uint8_t *)block->code;

     xlat_recovery_posn = 0;

     uint8_t *eob = xlat_output + block->size;

     if( GET_ICACHE_END() < lastpc ) {

 	lastpc = GET_ICACHE_END();

     }

     sh4_translate_begin_block(pc);

     do {

 	/* check for breakpoints at this pc */

 	for( i=0; i<sh4_breakpoint_count; i++ ) {

 	    if( sh4_breakpoints[i].address == pc ) {

 		sh4_translate_emit_breakpoint(pc);

 		break;

 	    }

 	}

 	if( eob - xlat_output < MAX_INSTRUCTION_SIZE ) {

 	    uint8_t *oldstart = block->code;

 	    block = xlat_extend_block( xlat_output - oldstart + MAX_INSTRUCTION_SIZE );

 	    xlat_output = block->code + (xlat_output - oldstart);

 	    eob = block->code + block->size;

 	}

 	done = sh4_translate_instruction( pc ); 

 	assert( xlat_output <= eob );

 	pc += 2;

 	if ( pc >= lastpc ) {

 	    done = 2;

 	}

     } while( !done );

     pc += (done - 2);

     if( eob - xlat_output < EPILOGUE_SIZE ) {

 	uint8_t *oldstart = block->code;

 	block = xlat_extend_block( xlat_output - oldstart + EPILOGUE_SIZE );

 	xlat_output = block->code + (xlat_output - oldstart);

     }	

     sh4_translate_end_block(pc);

     /* Write the recovery records onto the end of the code block */

     uint32_t recovery_size = sizeof(struct xlat_recovery_record)*xlat_recovery_posn;

     uint32_t finalsize = xlat_output - block->code + recovery_size;

     if( finalsize > block->size ) {

 	uint8_t *oldstart = block->code;

 	block = xlat_extend_block( finalsize );

 	xlat_output = block->code + (xlat_output - oldstart);

     }

     memcpy( xlat_output, xlat_recovery, recovery_size);

     block->recover_table_offset = xlat_output - (uint8_t *)block->code;

     block->recover_table_size = xlat_recovery_posn;

     xlat_commit_block( finalsize, pc-start );

     return block->code;

 }

 /**

  * "Execute" the supplied recovery record. Currently this only updates

  * sh4r.pc and sh4r.slice_cycle according to the currently executing

  * instruction. In future this may be more sophisticated (ie will

  * call into generated code).

  */

 void sh4_translate_run_recovery( xlat_recovery_record_t recovery )

 {

     sh4r.slice_cycle += (recovery->sh4_icount * sh4_cpu_period);

     sh4r.pc += (recovery->sh4_icount<<1);

 }

 void sh4_translate_unwind_stack( gboolean abort_after, unwind_thunk_t thunk )

 {

     void *pc = xlat_get_native_pc();

     assert( pc != NULL );

     void *code = xlat_get_code( sh4r.pc );

     xlat_recovery_record_t recover = xlat_get_recovery(code, pc, TRUE);

     if( recover != NULL ) {

 	// Can be null if there is no recovery necessary

 	sh4_translate_run_recovery(recover);

     }

     if( thunk != NULL ) {

 	thunk();

     }

     // finally longjmp back into sh4_xlat_run_slice

     xlat_running = FALSE;

     longjmp(xlat_jmp_buf, XLAT_EXIT_CONTINUE);

 } 

 void sh4_translate_exit( int exit_code )

 {

     void *pc = xlat_get_native_pc();

     if( pc != NULL ) {

 	// could be null if we're not actually running inside the translator

 	void *code = xlat_get_code( sh4r.pc );

 	xlat_recovery_record_t recover = xlat_get_recovery(code, pc, TRUE);

 	if( recover != NULL ) {

 	    // Can be null if there is no recovery necessary

 	    sh4_translate_run_recovery(recover);

 	}

     }

     // finally longjmp back into sh4_xlat_run_slice

     xlat_running = FALSE;

     longjmp(xlat_jmp_buf, exit_code);

 }

 void sh4_translate_breakpoint_hit(uint32_t pc)

 {

     if( sh4_starting && sh4r.slice_cycle == 0 && pc == sh4r.pc ) {

 	return;

     }

     sh4_translate_exit( XLAT_EXIT_BREAKPOINT );

 }

 /**

  * Exit the current block at the end of the current instruction, flush the

  * translation cache (completely) and return control to sh4_xlat_run_slice.

  *

  * As a special case, if the current instruction is actually the last 

  * instruction in the block (ie it's in a delay slot), this function 

  * returns to allow normal completion of the translation block. Otherwise

  * this function never returns.

  *

  * Must only be invoked (indirectly) from within translated code.

  */

 void sh4_translate_flush_cache()

 {

     void *pc = xlat_get_native_pc();

     assert( pc != NULL );

     void *code = xlat_get_code( sh4r.pc );

     xlat_recovery_record_t recover = xlat_get_recovery(code, pc, TRUE);

     if( recover != NULL ) {

 	// Can be null if there is no recovery necessary

 	sh4_translate_run_recovery(recover);

 	xlat_flush_cache();

 	xlat_running = FALSE;

 	longjmp(xlat_jmp_buf, XLAT_EXIT_CONTINUE);

     } else {

 	xlat_flush_cache();

 	return;

     }

 }

 void *xlat_get_code_by_vma( sh4vma_t vma )

 {

     void *result = NULL;

     if( IS_IN_ICACHE(vma) ) {

 	result = xlat_get_code( GET_ICACHE_PHYS(vma) );

     }

     if( vma > 0xFFFFFF00 ) {

 	// lxdream hook

 	return NULL;

     }

     if( !mmu_update_icache(vma) ) {

 	// fault - off to the fault handler

 	if( !mmu_update_icache(sh4r.pc) ) {

 	    // double fault - halt

 	    ERROR( "Double fault - halting" );

 	    dreamcast_stop();

 	    return NULL;

 	}

     }

     assert( IS_IN_ICACHE(sh4r.pc) );

     result = xlat_get_code( GET_ICACHE_PHYS(sh4r.pc) );

     return result;

 }