/*
 * Mach Operating System
 * Copyright (c) 1991,1990 Carnegie Mellon University
 * All Rights Reserved.
 *
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie the
 * rights to redistribute these changes.
 *
 * $FreeBSD: src/sys/ddb/db_break.c,v 1.18 1999/08/28 00:41:05 peter Exp $
 * $DragonFly: src/sys/ddb/db_break.c,v 1.7 2006/12/28 21:24:01 dillon Exp $
 */

/*
 *      Author: David B. Golub, Carnegie Mellon University
 *      Date:   7/90
 */
/*
 * Breakpoints.
 */
#include <sys/param.h>

#include <vm/vm.h>
#include <vm/vm_kern.h>

#include <ddb/ddb.h>
#include <ddb/db_break.h>
#include <ddb/db_access.h>
#include <ddb/db_sym.h>

#define NBREAKPOINTS    100
static struct db_breakpoint     db_break_table[NBREAKPOINTS];
static db_breakpoint_t          db_next_free_breakpoint = &db_break_table[0];
static db_breakpoint_t          db_free_breakpoints = 0;
static db_breakpoint_t          db_breakpoint_list = 0;

static db_breakpoint_t  db_breakpoint_alloc (void);
static void     db_breakpoint_free (db_breakpoint_t bkpt);
static void     db_delete_breakpoint (vm_map_t map, db_addr_t addr);
static db_breakpoint_t  db_find_breakpoint (vm_map_t map, db_addr_t addr);
static void     db_list_breakpoints (void);
static void     db_set_breakpoint (vm_map_t map, db_addr_t addr,
                                       int count);

static db_breakpoint_t
db_breakpoint_alloc(void)
{
        db_breakpoint_t bkpt;

        if ((bkpt = db_free_breakpoints) != 0) {
            db_free_breakpoints = bkpt->link;
            return (bkpt);
        }
        if (db_next_free_breakpoint == &db_break_table[NBREAKPOINTS]) {
            db_printf("All breakpoints used.\n");
            return (0);
        }
        bkpt = db_next_free_breakpoint;
        db_next_free_breakpoint++;

        return (bkpt);
}

static void
db_breakpoint_free(db_breakpoint_t bkpt)
{
        bkpt->link = db_free_breakpoints;
        db_free_breakpoints = bkpt;
}

static void
db_set_breakpoint(vm_map_t map, db_addr_t addr, int count)
{
        db_breakpoint_t bkpt;

        if (db_find_breakpoint(map, addr)) {
            db_printf("Already set.\n");
            return;
        }

        bkpt = db_breakpoint_alloc();
        if (bkpt == 0) {
            db_printf("Too many breakpoints.\n");
            return;
        }

        bkpt->map = map;
        bkpt->address = addr;
        bkpt->flags = 0;
        bkpt->init_count = count;
        bkpt->count = count;

        bkpt->link = db_breakpoint_list;
        db_breakpoint_list = bkpt;
}

static void
db_delete_breakpoint(vm_map_t map, db_addr_t addr)
{
        db_breakpoint_t bkpt;
        db_breakpoint_t *prev;

        for (prev = &db_breakpoint_list;
             (bkpt = *prev) != 0;
             prev = &bkpt->link) {
            if (db_map_equal(bkpt->map, map) &&
                (bkpt->address == addr)) {
                *prev = bkpt->link;
                break;
            }
        }
        if (bkpt == 0) {
            db_printf("Not set.\n");
            return;
        }

        db_breakpoint_free(bkpt);
}

static db_breakpoint_t
db_find_breakpoint(vm_map_t map, db_addr_t addr)
{
        db_breakpoint_t bkpt;

        for (bkpt = db_breakpoint_list;
             bkpt != 0;
             bkpt = bkpt->link)
        {
            if (db_map_equal(bkpt->map, map) &&
                (bkpt->address == addr))
                return (bkpt);
        }
        return (0);
}

db_breakpoint_t
db_find_breakpoint_here(db_addr_t addr)
{
    return db_find_breakpoint(db_map_addr(addr), addr);
}

static boolean_t        db_breakpoints_inserted = TRUE;

void
db_set_breakpoints(void)
{
        db_breakpoint_t bkpt;

        if (!db_breakpoints_inserted) {

            for (bkpt = db_breakpoint_list;
                 bkpt != 0;
                 bkpt = bkpt->link)
                if (db_map_current(bkpt->map)) {
                    bkpt->bkpt_inst = db_get_value(bkpt->address,
                                                   BKPT_SIZE,
                                                   FALSE);
                    db_put_value(bkpt->address,
                                 BKPT_SIZE,
                                 BKPT_SET(bkpt->bkpt_inst));
                }
            db_breakpoints_inserted = TRUE;
        }
}

void
db_clear_breakpoints(void)
{
        db_breakpoint_t bkpt;

        if (db_breakpoints_inserted) {

            for (bkpt = db_breakpoint_list;
                 bkpt != 0;
                 bkpt = bkpt->link)
                if (db_map_current(bkpt->map)) {
                    db_put_value(bkpt->address, BKPT_SIZE, bkpt->bkpt_inst);
                }
            db_breakpoints_inserted = FALSE;
        }
}

#ifdef SOFTWARE_SSTEP
/*
 * Set a temporary breakpoint.
 * The instruction is changed immediately,
 * so the breakpoint does not have to be on the breakpoint list.
 */
db_breakpoint_t
db_set_temp_breakpoint(db_addr_t addr)
{
        db_breakpoint_t bkpt;

        bkpt = db_breakpoint_alloc();
        if (bkpt == 0) {
            db_printf("Too many breakpoints.\n");
            return 0;
        }

        bkpt->map = NULL;
        bkpt->address = addr;
        bkpt->flags = BKPT_TEMP;
        bkpt->init_count = 1;
        bkpt->count = 1;

        bkpt->bkpt_inst = db_get_value(bkpt->address, BKPT_SIZE, FALSE);
        db_put_value(bkpt->address, BKPT_SIZE, BKPT_SET(bkpt->bkpt_inst));
        return bkpt;
}

void
db_delete_temp_breakpoint(db_breakpoint_t bkpt)
{
        db_put_value(bkpt->address, BKPT_SIZE, bkpt->bkpt_inst);
        db_breakpoint_free(bkpt);
}
#endif /* SOFTWARE_SSTEP */

/*
 * List breakpoints.
 */
static void
db_list_breakpoints(void)
{
        db_breakpoint_t bkpt;

        if (db_breakpoint_list == 0) {
            db_printf("No breakpoints set\n");
            return;
        }

        db_printf(" Map      Count    Address\n");
        for (bkpt = db_breakpoint_list;
             bkpt != 0;
             bkpt = bkpt->link) {
            db_printf("%s%8p %5d    ",
                      db_map_current(bkpt->map) ? "*" : " ",
                      (void *)bkpt->map, bkpt->init_count);
            db_printsym(bkpt->address, DB_STGY_PROC);
            db_printf("\n");
        }
}

/* Delete breakpoint */
/*ARGSUSED*/
void
db_delete_cmd(db_expr_t addr, boolean_t have_addr, db_expr_t count, char *modif)
{
        db_delete_breakpoint(db_map_addr(addr), (db_addr_t)addr);
}

/* Set breakpoint with skip count */
/*ARGSUSED*/
void
db_breakpoint_cmd(db_expr_t addr, boolean_t have_addr, db_expr_t count,
                  char *modif)
{
        if (count == -1)
            count = 1;

        db_set_breakpoint(db_map_addr(addr), (db_addr_t)addr, count);
}

/* list breakpoints */
void
db_listbreak_cmd(db_expr_t dummy1, boolean_t dummy2, db_expr_t dummy3,
                 char *dummy4)
{
        db_list_breakpoints();
}

/*
 *      We want ddb to be usable before most of the kernel has been
 *      initialized.  In particular, current_thread() or kernel_map
 *      (or both) may be null.
 */

boolean_t
db_map_equal(vm_map_t map1, vm_map_t map2)
{
        return ((map1 == map2) ||
                ((map1 == NULL) && (map2 == kernel_map)) ||
                ((map1 == kernel_map) && (map2 == NULL)));
}

boolean_t
db_map_current(vm_map_t map)
{
#if 0
        thread_t        thread;

        return ((map == NULL) ||
                (map == kernel_map) ||
                (((thread = current_thread()) != NULL) &&
                 (map == thread->task->map)));
#else
        return (1);
#endif
}

vm_map_t
db_map_addr(vm_offset_t addr)
{
        return kernel_map;
}