cam_machdep.c revision 228022 
1/*-
2 * Copyright (c) 2011 Marius Strobl <marius@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/sys/sparc64/sparc64/cam_machdep.c 228022 2011-11-27 15:43:40Z marius $");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32
33#include <cam/cam.h>
34#include <cam/cam_ccb.h>
35
36#include <machine/md_var.h>
37
38int
39scsi_da_bios_params(struct ccb_calc_geometry *ccg)
40{
41	uint32_t secs_per_cylinder, size_mb;
42
43	/*
44	 * The VTOC8 disk label only uses 16-bit fields for cylinders, heads
45	 * and sectors so the geometry of large disks has to be adjusted.
46	 * We generally use the sizing used by cam_calc_geometry(9), except
47	 * when it would overflow the cylinders, in which case we use 255
48	 * heads and sectors.  This allows disks up to the 2TB limit of the
49	 * extended VTOC8.
50	 * XXX this doesn't match the sizing used by OpenSolaris, as that
51	 * would exceed the 8-bit ccg->heads and ccg->secs_per_track.
52	 */
53	if (ccg->block_size == 0)
54		return (0);
55	size_mb = (1024L * 1024L) / ccg->block_size;
56	if (size_mb == 0)
57		return (0);
58	size_mb = ccg->volume_size / size_mb;
59	if (ccg->volume_size > (uint64_t)65535 * 255 * 63) {
60		ccg->heads = 255;
61		ccg->secs_per_track = 255;
62	} else if (size_mb > 1024) {
63		ccg->heads = 255;
64		ccg->secs_per_track = 63;
65	} else {
66		ccg->heads = 64;
67		ccg->secs_per_track = 32;
68	}
69	secs_per_cylinder = ccg->heads * ccg->secs_per_track;
70	if (secs_per_cylinder == 0)
71		return (0);
72	ccg->cylinders = ccg->volume_size / secs_per_cylinder;
73	return (1);
74}
75