/*      $NetBSD: db_watch.c,v 1.27 2007/02/22 06:41:01 thorpej Exp $    */

/*
 * 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 "AS IS"
 * 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.
 *
 *      Author: Richard P. Draves, Carnegie Mellon University
 *      Date:   10/90
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: db_watch.c,v 1.27 2007/02/22 06:41:01 thorpej Exp $");

#include <sys/param.h>
#include <sys/proc.h>

#include <machine/db_machdep.h>

#include <ddb/db_break.h>
#include <ddb/db_watch.h>
#include <ddb/db_lex.h>
#include <ddb/db_access.h>
#include <ddb/db_run.h>
#include <ddb/db_sym.h>
#include <ddb/db_output.h>
#include <ddb/db_command.h>
#include <ddb/db_extern.h>

/*
 * Watchpoints.
 */

static bool                     db_watchpoints_inserted = true;

#define NWATCHPOINTS    100
static struct db_watchpoint     db_watch_table[NWATCHPOINTS];
static db_watchpoint_t          db_next_free_watchpoint = &db_watch_table[0];
static db_watchpoint_t          db_free_watchpoints = 0;
static db_watchpoint_t          db_watchpoint_list = 0;

static void             db_delete_watchpoint(struct vm_map *, db_addr_t);
static void             db_list_watchpoints(void);
static void             db_set_watchpoint(struct vm_map *, db_addr_t, vsize_t);
static db_watchpoint_t  db_watchpoint_alloc(void);
static void             db_watchpoint_free(db_watchpoint_t);

db_watchpoint_t
db_watchpoint_alloc(void)
{
        db_watchpoint_t watch;

        if ((watch = db_free_watchpoints) != 0) {
                db_free_watchpoints = watch->link;
                return (watch);
        }
        if (db_next_free_watchpoint == &db_watch_table[NWATCHPOINTS]) {
                db_printf("All watchpoints used.\n");
                return (0);
        }
        watch = db_next_free_watchpoint;
        db_next_free_watchpoint++;

        return (watch);
}

void
db_watchpoint_free(db_watchpoint_t watch)
{
        watch->link = db_free_watchpoints;
        db_free_watchpoints = watch;
}

void
db_set_watchpoint(struct vm_map *map, db_addr_t addr, vsize_t size)
{
        db_watchpoint_t watch;

        if (map == NULL) {
                db_printf("No map.\n");
                return;
        }

        /*
         *      Should we do anything fancy with overlapping regions?
         */

        for (watch = db_watchpoint_list; watch != 0; watch = watch->link)
                if (db_map_equal(watch->map, map) &&
                    (watch->loaddr == addr) &&
                    (watch->hiaddr == addr+size)) {
                        db_printf("Already set.\n");
                        return;
                }

        watch = db_watchpoint_alloc();
        if (watch == 0) {
                db_printf("Too many watchpoints.\n");
                return;
        }

        watch->map = map;
        watch->loaddr = addr;
        watch->hiaddr = addr+size;

        watch->link = db_watchpoint_list;
        db_watchpoint_list = watch;

        db_watchpoints_inserted = false;
}

static void
db_delete_watchpoint(struct vm_map *map, db_addr_t addr)
{
        db_watchpoint_t watch;
        db_watchpoint_t *prev;

        for (prev = &db_watchpoint_list;
             (watch = *prev) != 0;
             prev = &watch->link)
                if (db_map_equal(watch->map, map) &&
                    (watch->loaddr <= addr) &&
                    (addr < watch->hiaddr)) {
                        *prev = watch->link;
                        db_watchpoint_free(watch);
                        return;
                }

        db_printf("Not set.\n");
}

void
db_list_watchpoints(void)
{
        db_watchpoint_t watch;

        if (db_watchpoint_list == 0) {
                db_printf("No watchpoints set\n");
                return;
        }

        db_printf(" Map        Address  Size\n");
        for (watch = db_watchpoint_list; watch != 0; watch = watch->link)
                db_printf("%s%p  %8lx  %lx\n",
                    db_map_current(watch->map) ? "*" : " ",
                    watch->map, (long)watch->loaddr,
                    (long)(watch->hiaddr - watch->loaddr));
}

/* Delete watchpoint */
/*ARGSUSED*/
void
db_deletewatch_cmd(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{

        db_delete_watchpoint(db_map_addr(addr), addr);
}

/* Set watchpoint */
/*ARGSUSED*/
void
db_watchpoint_cmd(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{
        vsize_t size;
        db_expr_t value;

        if (db_expression(&value))
                size = (vsize_t) value;
        else
                size = 4;
        db_skip_to_eol();

        db_set_watchpoint(db_map_addr(addr), addr, size);
}

/* list watchpoints */
/*ARGSUSED*/
void
db_listwatch_cmd(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{

        db_list_watchpoints();
}

void
db_set_watchpoints(void)
{
        db_watchpoint_t watch;

        if (!db_watchpoints_inserted) {
                for (watch = db_watchpoint_list;
                     watch != 0;
                     watch = watch->link) {
                        pmap_protect(watch->map->pmap,
                            trunc_page(watch->loaddr),
                            round_page(watch->hiaddr),
                            VM_PROT_READ);
                        pmap_update(watch->map->pmap);
                }

                db_watchpoints_inserted = true;
        }
}

void
db_clear_watchpoints(void)
{

        db_watchpoints_inserted = false;
}