For sparc64 also adjust the geometry of da(4) driven disks to not overflow

the 16-bit cylinders field of the VTOC8 disk label (at around 502GB). The
geometry chosen for disks above that limit allows to use disks up to 2TB,
which is the limit of the extended VTOC8 format. The geometry used for
disks smaller than the 16-bit cylinders limit stays the same as used by
cam_calc_geometry(9) for extended translation.
Thanks to Hans-Joerg Sirtl for providing hardware for testing this change.

MFC after:	3 days

2 files changed, 78 insertions, 3 deletions

diff --git a/sys/sparc64/include/md_var.h b/sys/sparc64/include/md_var.h
index 8503b43..6a0a2f6 100644
--- a/sys/sparc64/include/md_var.h
+++ b/sys/sparc64/include/md_var.h
@@ -65,10 +65,11 @@ extern	cpu_block_copy_t *cpu_block_copy;
 extern	cpu_block_zero_t *cpu_block_zero;
 
 /*
- * Given that the Sun disk label only uses 16-bit fields for cylinders,
- * heads and sectors we might need to adjust the geometry of large IDE
- * disks.
+ * Given that the VTOC8 disk label only uses 16-bit fields for cylinders,
+ * heads and sectors we might need to adjust the geometry of large disks.
  */
+struct ccb_calc_geometry;
+int scsi_da_bios_params(struct ccb_calc_geometry *ccg);
 struct disk;
 void sparc64_ata_disk_firmware_geom_adjust(struct disk *disk);
 #define	ata_disk_firmware_geom_adjust(disk)				\
diff --git a/sys/sparc64/sparc64/cam_machdep.c b/sys/sparc64/sparc64/cam_machdep.c
new file mode 100644
index 0000000..91a3cce
--- /dev/null
+++ b/sys/sparc64/sparc64/cam_machdep.c
@@ -0,0 +1,74 @@
+/*-
+ * Copyright (c) 2011 Marius Strobl <marius@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/systm.h>
+
+#include <cam/cam.h>
+#include <cam/cam_ccb.h>
+
+#include <machine/md_var.h>
+
+int
+scsi_da_bios_params(struct ccb_calc_geometry *ccg)
+{
+	uint32_t secs_per_cylinder, size_mb;
+
+	/*
+	 * The VTOC8 disk label only uses 16-bit fields for cylinders, heads
+	 * and sectors so the geometry of large disks has to be adjusted.
+	 * We generally use the sizing used by cam_calc_geometry(9), except
+	 * when it would overflow the cylinders, in which case we use 255
+	 * heads and sectors.  This allows disks up to the 2TB limit of the
+	 * extended VTOC8.
+	 * XXX this doesn't match the sizing used by OpenSolaris, as that
+	 * would exceed the 8-bit ccg->heads and ccg->secs_per_track.
+	 */
+	if (ccg->block_size == 0)
+		return (0);
+	size_mb = (1024L * 1024L) / ccg->block_size;
+	if (size_mb == 0)
+		return (0);
+	size_mb = ccg->volume_size / size_mb;
+	if (ccg->volume_size > (uint64_t)65535 * 255 * 63) {
+		ccg->heads = 255;
+		ccg->secs_per_track = 255;
+	} else if (size_mb > 1024) {
+		ccg->heads = 255;
+		ccg->secs_per_track = 63;
+	} else {
+		ccg->heads = 64;
+		ccg->secs_per_track = 32;
+	}
+	secs_per_cylinder = ccg->heads * ccg->secs_per_track;
+	if (secs_per_cylinder == 0)
+		return (0);
+	ccg->cylinders = ccg->volume_size / secs_per_cylinder;
+	return (1);
+}