/*	$NetBSD: db_watch.c,v 1.23 2006/10/12 01:30:50 christos 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 1.23 2006/10/12 01:30:50 christos 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 boolean_t		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, int have_addr __unused,
    db_expr_t count __unused, const char *modif __unused)
{

	db_delete_watchpoint(db_map_addr(addr), addr);
}

/* Set watchpoint */
/*ARGSUSED*/
void
db_watchpoint_cmd(db_expr_t addr, int have_addr __unused,
    db_expr_t count __unused, const char *modif __unused)
{
	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 __unused, int have_addr __unused,
    db_expr_t count __unused, const char *modif __unused)
{

	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;
}