1/*
2 * Platform dependent support for IO probing.
3 *
4 * Copyright (c) 2000-2002 Silicon Graphics, Inc.  All rights reserved.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of version 2 of the GNU General Public License
8 * as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it would be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
13 *
14 * Further, this software is distributed without any warranty that it is
15 * free of the rightful claim of any third person regarding infringement
16 * or the like.  Any license provided herein, whether implied or
17 * otherwise, applies only to this software file.  Patent licenses, if
18 * any, provided herein do not apply to combinations of this program with
19 * other software, or any other product whatsoever.
20 *
21 * You should have received a copy of the GNU General Public
22 * License along with this program; if not, write the Free Software
23 * Foundation, Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
24 *
25 * Contact information:  Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
26 * Mountain View, CA  94043, or:
27 *
28 * http://www.sgi.com
29 *
30 * For further information regarding this notice, see:
31 *
32 * http://oss.sgi.com/projects/GenInfo/NoticeExplan
33 */
34
35#include <asm/sn/sn_sal.h>
36
37/**
38 * ia64_sn_probe_io_slot - test a memory location for readability
39 * @paddr: physical address to probe
40 * @size: number bytes to read (1,2,4,8)
41 * @data_ptr: address to store value read by probe (-1 returned if probe fails)
42 *
43 * This function will probe a physical address to determine if
44 * the address can be read. If reading the address causes a BUS
45 * error, an error is returned. If the probe succeeds, the contents
46 * of the memory location is returned.
47 *
48 * Return values:
49 *  0 - probe successful
50 *  1 - probe failed (generated MCA)
51 *  2 - Bad arg
52 * <0 - PAL error
53 */
54u64
55ia64_sn_probe_io_slot(long paddr, long size, void *data_ptr)
56{
57	struct ia64_sal_retval isrv;
58
59	SAL_CALL(isrv, SN_SAL_PROBE, paddr, size, 0, 0, 0, 0, 0);
60
61	if (data_ptr) {
62		switch (size) {
63			case 1:
64				*((u8*)data_ptr) = (u8)isrv.v0;
65				break;
66			case 2:
67				*((u16*)data_ptr) = (u16)isrv.v0;
68				break;
69			case 4:
70				*((u32*)data_ptr) = (u32)isrv.v0;
71				break;
72			case 8:
73				*((u64*)data_ptr) = (u64)isrv.v0;
74				break;
75			default:
76				isrv.status = 2;
77		}
78	}
79
80	return isrv.status;
81}
82