[dragonfly.git] / sys / dev / raid / mfi / mfi_syspd.c

/*-
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *            Copyright 1994-2009 The FreeBSD Project.
 *            All rights reserved.
 *
 * 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 FREEBSD PROJECT``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 FREEBSD PROJECT 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.
 *
 * The views and conclusions contained in the software and documentation
 * are those of the authors and should not be interpreted as representing
 * official policies,either expressed or implied, of the FreeBSD Project.
 *
 * $FreeBSD: src/sys/dev/mfi/mfi_pddisk.c,v 1.2.2.6 2007/08/24 17:29:18 jhb Exp $
 * FreeBSD projects/head_mfi/ r232888
 */

#include "opt_mfi.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/malloc.h>
#include <sys/uio.h>

#include <sys/bio.h>
#include <sys/buf2.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/disk.h>

#include <vm/vm.h>
#include <vm/pmap.h>

#include <machine/md_var.h>
#include <sys/rman.h>

#include <dev/raid/mfi/mfireg.h>
#include <dev/raid/mfi/mfi_ioctl.h>
#include <dev/raid/mfi/mfivar.h>

static int	mfi_syspd_probe(device_t dev);
static int	mfi_syspd_attach(device_t dev);
static int	mfi_syspd_detach(device_t dev);

static d_open_t		mfi_syspd_open;
static d_close_t	mfi_syspd_close;
static d_strategy_t	mfi_syspd_strategy;
static d_dump_t		mfi_syspd_dump;

static struct dev_ops mfi_syspd_ops = {
	{ "mfisyspd", 0, D_DISK },
	.d_open = mfi_syspd_open,
	.d_close = mfi_syspd_close,
	.d_strategy = mfi_syspd_strategy,
	.d_dump = mfi_syspd_dump,
};

static devclass_t	mfi_syspd_devclass;

static device_method_t mfi_syspd_methods[] = {
	DEVMETHOD(device_probe,		mfi_syspd_probe),
	DEVMETHOD(device_attach,	mfi_syspd_attach),
	DEVMETHOD(device_detach,	mfi_syspd_detach),
	{ 0, 0 }
};

static driver_t mfi_syspd_driver = {
	"mfisyspd",
	mfi_syspd_methods,
	sizeof(struct mfi_system_pd)
};

DRIVER_MODULE(mfisyspd, mfi, mfi_syspd_driver, mfi_syspd_devclass, NULL, NULL);

static int
mfi_syspd_probe(device_t dev)
{

	return (0);
}

static int
mfi_syspd_attach(device_t dev)
{
	struct mfi_system_pd *sc;
	struct mfi_pd_info *pd_info;
	struct disk_info info;
	uint64_t sectors;
	uint32_t secsize;

	sc = device_get_softc(dev);
	pd_info = device_get_ivars(dev);

	sc->pd_dev = dev;
	sc->pd_id = pd_info->ref.v.device_id;
	sc->pd_unit = device_get_unit(dev);
	sc->pd_info = pd_info;
	sc->pd_controller = device_get_softc(device_get_parent(dev));
	sc->pd_flags = MFI_DISK_FLAGS_SYSPD;

	sectors = pd_info->raw_size;
	secsize = MFI_SECTOR_LEN;
	lockmgr(&sc->pd_controller->mfi_io_lock, LK_EXCLUSIVE);
	TAILQ_INSERT_TAIL(&sc->pd_controller->mfi_syspd_tqh, sc, pd_link);
	lockmgr(&sc->pd_controller->mfi_io_lock, LK_RELEASE);
	device_printf(dev, "%juMB (%ju sectors) SYSPD volume\n",
		      sectors / (1024 * 1024 / secsize), sectors);

	devstat_add_entry(&sc->pd_devstat, "mfisyspd", device_get_unit(dev),
	    MFI_SECTOR_LEN, DEVSTAT_NO_ORDERED_TAGS,
	    DEVSTAT_TYPE_STORARRAY | DEVSTAT_TYPE_IF_OTHER,
	    DEVSTAT_PRIORITY_ARRAY);

	sc->pd_dev_t = disk_create(sc->pd_unit, &sc->pd_disk, &mfi_syspd_ops);
	sc->pd_dev_t->si_drv1 = sc;
	sc->pd_dev_t->si_iosize_max = sc->pd_controller->mfi_max_io *
	    secsize;

	bzero(&info, sizeof(info));
	info.d_media_blksize = secsize; /* mandatory */
	info.d_media_blocks = sectors;

	if (info.d_media_blocks >= (1 * 1024 * 1024)) {
		info.d_nheads = 255;
		info.d_secpertrack = 63;
	} else {
		info.d_nheads = 64;
		info.d_secpertrack = 32;
	}

	disk_setdiskinfo(&sc->pd_disk, &info);

	return (0);
}

static int
mfi_syspd_detach(device_t dev)
{
	struct mfi_system_pd *sc;

	sc = device_get_softc(dev);
	lockmgr(&sc->pd_controller->mfi_io_lock, LK_EXCLUSIVE);
	if ((sc->pd_flags & MFI_DISK_FLAGS_OPEN) &&
	    (sc->pd_controller->mfi_keep_deleted_volumes ||
	    sc->pd_controller->mfi_detaching)) {
		lockmgr(&sc->pd_controller->mfi_io_lock, LK_RELEASE);
		return (EBUSY);
	}
	lockmgr(&sc->pd_controller->mfi_io_lock, LK_RELEASE);

	disk_destroy(&sc->pd_disk);
	devstat_remove_entry(&sc->pd_devstat);
	lockmgr(&sc->pd_controller->mfi_io_lock, LK_EXCLUSIVE);
	TAILQ_REMOVE(&sc->pd_controller->mfi_syspd_tqh, sc, pd_link);
	lockmgr(&sc->pd_controller->mfi_io_lock, LK_RELEASE);
	kfree(sc->pd_info, M_MFIBUF);
	return (0);
}

static int
mfi_syspd_open(struct dev_open_args *ap)
{
	struct mfi_system_pd *sc = ap->a_head.a_dev->si_drv1;
	int error;

	lockmgr(&sc->pd_controller->mfi_io_lock, LK_EXCLUSIVE);
	if (sc->pd_flags & MFI_DISK_FLAGS_DISABLED)
		error = ENXIO;
	else {
		sc->pd_flags |= MFI_DISK_FLAGS_OPEN;
		error = 0;
	}
	lockmgr(&sc->pd_controller->mfi_io_lock, LK_RELEASE);
	return (error);
}

static int
mfi_syspd_close(struct dev_close_args *ap)
{
	struct mfi_system_pd *sc = ap->a_head.a_dev->si_drv1;

	lockmgr(&sc->pd_controller->mfi_io_lock, LK_EXCLUSIVE);
	sc->pd_flags &= ~MFI_DISK_FLAGS_OPEN;
	lockmgr(&sc->pd_controller->mfi_io_lock, LK_RELEASE);

	return (0);
}

int
mfi_syspd_disable(struct mfi_system_pd *sc)
{

	KKASSERT(lockstatus(&sc->pd_controller->mfi_io_lock, curthread) != 0);
	if (sc->pd_flags & MFI_DISK_FLAGS_OPEN) {
		if (sc->pd_controller->mfi_delete_busy_volumes)
			return (0);
		device_printf(sc->pd_dev,
		    "Unable to delete busy syspd device\n");
		return (EBUSY);
	}
	sc->pd_flags |= MFI_DISK_FLAGS_DISABLED;
	return (0);
}

void
mfi_syspd_enable(struct mfi_system_pd *sc)
{

	KKASSERT(lockstatus(&sc->pd_controller->mfi_io_lock, curthread) != 0);
	sc->pd_flags &= ~MFI_DISK_FLAGS_DISABLED;
}

static int
mfi_syspd_strategy(struct dev_strategy_args *ap)
{
	struct bio *bio = ap->a_bio;
	struct buf *bp = bio->bio_buf;
	struct mfi_system_pd *sc = ap->a_head.a_dev->si_drv1;
	struct mfi_softc *controller = sc->pd_controller;

	if (sc == NULL) {
		bp->b_error = EINVAL;
		bp->b_flags |= B_ERROR;
		bp->b_resid = bp->b_bcount;
		biodone(bio);
		return (0);
	}

	if (controller->hw_crit_error) {
		bp->b_error = EBUSY;
		return (0);
	}

	if (controller->issuepend_done == 0) {
		bp->b_error = EBUSY;
		return (0);
	}

	/*
	 * XXX swildner
	 *
	 * If it's a null transfer, do nothing. FreeBSD's original driver
	 * doesn't have this, but that caused hard error messages (even
	 * though everything else continued to work fine). Interestingly,
	 * only when HAMMER was used.
	 *
	 * Several others of our RAID drivers have this check, such as
	 * aac(4) and ida(4), so we insert it here, too.
	 *
	 * The cause of null transfers is yet unknown.
	 */
	if (bp->b_bcount == 0) {
		bp->b_resid = bp->b_bcount;
		biodone(bio);
		return (0);
	}

	bio->bio_driver_info = sc;
	lockmgr(&controller->mfi_io_lock, LK_EXCLUSIVE);
	mfi_enqueue_bio(controller, bio);
	devstat_start_transaction(&sc->pd_devstat);
	mfi_startio(controller);
	lockmgr(&controller->mfi_io_lock, LK_RELEASE);
	return (0);
}

static int
mfi_syspd_dump(struct dev_dump_args *ap)
{
	cdev_t dev = ap->a_head.a_dev;
	off_t offset = ap->a_offset;
	void *virt = ap->a_virtual;
	size_t len = ap->a_length;
	struct mfi_system_pd *sc;
	struct mfi_softc *parent_sc;
	int error;

	sc = dev->si_drv1;
	parent_sc = sc->pd_controller;

	if (len > 0) {
		if ((error = mfi_dump_syspd_blocks(parent_sc,
		    sc->pd_id, offset / MFI_SECTOR_LEN, virt, len)) != 0)
			return (error);
	} else {
		/* mfi_sync_cache(parent_sc, sc->ld_id); */
	}
	return (0);
}
Commit	Line	Data
17566092 SW	1	/*-
	2	* Redistribution and use in source and binary forms, with or without
	3	* modification, are permitted provided that the following conditions
	4	* are met:
	5	*
	6	* Copyright 1994-2009 The FreeBSD Project.
	7	* All rights reserved.
	8	*
	9	* 1. Redistributions of source code must retain the above copyright
	10	* notice, this list of conditions and the following disclaimer.
	11	* 2. Redistributions in binary form must reproduce the above copyright
	12	* notice, this list of conditions and the following disclaimer in the
	13	* documentation and/or other materials provided with the distribution.
	14	*
	15	* THIS SOFTWARE IS PROVIDED BY THE FREEBSD PROJECT``AS IS'' AND
	16	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
	17	* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	18	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FREEBSD PROJECT OR
	19	* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
	20	* EXEMPLARY,OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
	21	* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
	22	* PROFITS; OR BUSINESS INTERRUPTION)HOWEVER CAUSED AND ON ANY THEORY
	23	* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
	24	* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
	25	* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	26	*
	27	* The views and conclusions contained in the software and documentation
	28	* are those of the authors and should not be interpreted as representing
	29	* official policies,either expressed or implied, of the FreeBSD Project.
	30	*
	31	* $FreeBSD: src/sys/dev/mfi/mfi_pddisk.c,v 1.2.2.6 2007/08/24 17:29:18 jhb Exp $
590ba11d	32	* FreeBSD projects/head_mfi/ r232888
17566092 SW	33	*/
	34
	35	#include "opt_mfi.h"
	36
	37	#include <sys/param.h>
	38	#include <sys/systm.h>
	39	#include <sys/kernel.h>
	40	#include <sys/module.h>
	41	#include <sys/malloc.h>
	42	#include <sys/uio.h>
	43
	44	#include <sys/bio.h>
	45	#include <sys/buf2.h>
	46	#include <sys/bus.h>
	47	#include <sys/conf.h>
	48	#include <sys/disk.h>
	49
	50	#include <vm/vm.h>
	51	#include <vm/pmap.h>
	52
	53	#include <machine/md_var.h>
	54	#include <sys/rman.h>
	55
	56	#include <dev/raid/mfi/mfireg.h>
	57	#include <dev/raid/mfi/mfi_ioctl.h>
	58	#include <dev/raid/mfi/mfivar.h>
	59
	60	static int mfi_syspd_probe(device_t dev);
	61	static int mfi_syspd_attach(device_t dev);
	62	static int mfi_syspd_detach(device_t dev);
	63
	64	static d_open_t mfi_syspd_open;
	65	static d_close_t mfi_syspd_close;
	66	static d_strategy_t mfi_syspd_strategy;
	67	static d_dump_t mfi_syspd_dump;
	68
	69	static struct dev_ops mfi_syspd_ops = {
	70	{ "mfisyspd", 0, D_DISK },
	71	.d_open = mfi_syspd_open,
	72	.d_close = mfi_syspd_close,
	73	.d_strategy = mfi_syspd_strategy,
	74	.d_dump = mfi_syspd_dump,
	75	};
	76
	77	static devclass_t mfi_syspd_devclass;
	78
	79	static device_method_t mfi_syspd_methods[] = {
	80	DEVMETHOD(device_probe, mfi_syspd_probe),
	81	DEVMETHOD(device_attach, mfi_syspd_attach),
	82	DEVMETHOD(device_detach, mfi_syspd_detach),
	83	{ 0, 0 }
	84	};
	85
	86	static driver_t mfi_syspd_driver = {
	87	"mfisyspd",
	88	mfi_syspd_methods,
	89	sizeof(struct mfi_system_pd)
	90	};
	91
8515b7f9	92	DRIVER_MODULE(mfisyspd, mfi, mfi_syspd_driver, mfi_syspd_devclass, NULL, NULL);
17566092 SW	93
	94	static int
	95	mfi_syspd_probe(device_t dev)
	96	{
	97
	98	return (0);
	99	}
	100
	101	static int
	102	mfi_syspd_attach(device_t dev)
	103	{
	104	struct mfi_system_pd *sc;
	105	struct mfi_pd_info *pd_info;
	106	struct disk_info info;
	107	uint64_t sectors;
	108	uint32_t secsize;
	109
	110	sc = device_get_softc(dev);
	111	pd_info = device_get_ivars(dev);
	112
	113	sc->pd_dev = dev;
	114	sc->pd_id = pd_info->ref.v.device_id;
	115	sc->pd_unit = device_get_unit(dev);
	116	sc->pd_info = pd_info;
	117	sc->pd_controller = device_get_softc(device_get_parent(dev));
	118	sc->pd_flags = MFI_DISK_FLAGS_SYSPD;
	119
	120	sectors = pd_info->raw_size;
	121	secsize = MFI_SECTOR_LEN;
	122	lockmgr(&sc->pd_controller->mfi_io_lock, LK_EXCLUSIVE);
	123	TAILQ_INSERT_TAIL(&sc->pd_controller->mfi_syspd_tqh, sc, pd_link);
	124	lockmgr(&sc->pd_controller->mfi_io_lock, LK_RELEASE);
	125	device_printf(dev, "%juMB (%ju sectors) SYSPD volume\n",
	126	sectors / (1024 * 1024 / secsize), sectors);
	127
	128	devstat_add_entry(&sc->pd_devstat, "mfisyspd", device_get_unit(dev),
	129	MFI_SECTOR_LEN, DEVSTAT_NO_ORDERED_TAGS,
	130	DEVSTAT_TYPE_STORARRAY \| DEVSTAT_TYPE_IF_OTHER,
	131	DEVSTAT_PRIORITY_ARRAY);
	132
9049decf SW	133	sc->pd_dev_t = disk_create(sc->pd_unit, &sc->pd_disk, &mfi_syspd_ops);
	134	sc->pd_dev_t->si_drv1 = sc;
	135	sc->pd_dev_t->si_iosize_max = sc->pd_controller->mfi_max_io *
17566092 SW	136	secsize;
	137
	138	bzero(&info, sizeof(info));
	139	info.d_media_blksize = secsize; /* mandatory */
	140	info.d_media_blocks = sectors;
	141
	142	if (info.d_media_blocks >= (1 * 1024 * 1024)) {
	143	info.d_nheads = 255;
	144	info.d_secpertrack = 63;
	145	} else {
	146	info.d_nheads = 64;
	147	info.d_secpertrack = 32;
	148	}
	149
	150	disk_setdiskinfo(&sc->pd_disk, &info);
	151
17566092 SW	152	return (0);
	153	}
	154
	155	static int
	156	mfi_syspd_detach(device_t dev)
	157	{
	158	struct mfi_system_pd *sc;
	159
	160	sc = device_get_softc(dev);
17566092 SW	161	lockmgr(&sc->pd_controller->mfi_io_lock, LK_EXCLUSIVE);
	162	if ((sc->pd_flags & MFI_DISK_FLAGS_OPEN) &&
	163	(sc->pd_controller->mfi_keep_deleted_volumes \|\|
	164	sc->pd_controller->mfi_detaching)) {
	165	lockmgr(&sc->pd_controller->mfi_io_lock, LK_RELEASE);
17566092 SW	166	return (EBUSY);
	167	}
	168	lockmgr(&sc->pd_controller->mfi_io_lock, LK_RELEASE);
	169
	170	disk_destroy(&sc->pd_disk);
	171	devstat_remove_entry(&sc->pd_devstat);
	172	lockmgr(&sc->pd_controller->mfi_io_lock, LK_EXCLUSIVE);
	173	TAILQ_REMOVE(&sc->pd_controller->mfi_syspd_tqh, sc, pd_link);
	174	lockmgr(&sc->pd_controller->mfi_io_lock, LK_RELEASE);
	175	kfree(sc->pd_info, M_MFIBUF);
	176	return (0);
	177	}
	178
	179	static int
	180	mfi_syspd_open(struct dev_open_args *ap)
	181	{
	182	struct mfi_system_pd *sc = ap->a_head.a_dev->si_drv1;
	183	int error;
	184
	185	lockmgr(&sc->pd_controller->mfi_io_lock, LK_EXCLUSIVE);
	186	if (sc->pd_flags & MFI_DISK_FLAGS_DISABLED)
	187	error = ENXIO;
	188	else {
	189	sc->pd_flags \|= MFI_DISK_FLAGS_OPEN;
	190	error = 0;
	191	}
	192	lockmgr(&sc->pd_controller->mfi_io_lock, LK_RELEASE);
	193	return (error);
	194	}
	195
	196	static int
	197	mfi_syspd_close(struct dev_close_args *ap)
	198	{
	199	struct mfi_system_pd *sc = ap->a_head.a_dev->si_drv1;
	200
	201	lockmgr(&sc->pd_controller->mfi_io_lock, LK_EXCLUSIVE);
	202	sc->pd_flags &= ~MFI_DISK_FLAGS_OPEN;
	203	lockmgr(&sc->pd_controller->mfi_io_lock, LK_RELEASE);
	204
	205	return (0);
	206	}
	207
	208	int
	209	mfi_syspd_disable(struct mfi_system_pd *sc)
	210	{
	211
17566092 SW	212	KKASSERT(lockstatus(&sc->pd_controller->mfi_io_lock, curthread) != 0);
	213	if (sc->pd_flags & MFI_DISK_FLAGS_OPEN) {
	214	if (sc->pd_controller->mfi_delete_busy_volumes)
	215	return (0);
590ba11d SW	216	device_printf(sc->pd_dev,
590ba11d SW	217	"Unable to delete busy syspd device\n");
17566092 SW	218	return (EBUSY);
	219	}
	220	sc->pd_flags \|= MFI_DISK_FLAGS_DISABLED;
	221	return (0);
	222	}
	223
	224	void
	225	mfi_syspd_enable(struct mfi_system_pd *sc)
	226	{
	227
17566092 SW	228	KKASSERT(lockstatus(&sc->pd_controller->mfi_io_lock, curthread) != 0);
	229	sc->pd_flags &= ~MFI_DISK_FLAGS_DISABLED;
	230	}
	231
	232	static int
	233	mfi_syspd_strategy(struct dev_strategy_args *ap)
	234	{
	235	struct bio *bio = ap->a_bio;
	236	struct buf *bp = bio->bio_buf;
	237	struct mfi_system_pd *sc = ap->a_head.a_dev->si_drv1;
590ba11d	238	struct mfi_softc *controller = sc->pd_controller;
17566092 SW	239
	240	if (sc == NULL) {
	241	bp->b_error = EINVAL;
	242	bp->b_flags \|= B_ERROR;
	243	bp->b_resid = bp->b_bcount;
	244	biodone(bio);
	245	return (0);
	246	}
	247
590ba11d SW	248	if (controller->hw_crit_error) {
	249	bp->b_error = EBUSY;
	250	return (0);
	251	}
	252
	253	if (controller->issuepend_done == 0) {
	254	bp->b_error = EBUSY;
	255	return (0);
	256	}
	257
17566092 SW	258	/*
	259	* XXX swildner
	260	*
	261	* If it's a null transfer, do nothing. FreeBSD's original driver
	262	* doesn't have this, but that caused hard error messages (even
	263	* though everything else continued to work fine). Interestingly,
	264	* only when HAMMER was used.
	265	*
	266	* Several others of our RAID drivers have this check, such as
	267	* aac(4) and ida(4), so we insert it here, too.
	268	*
	269	* The cause of null transfers is yet unknown.
	270	*/
	271	if (bp->b_bcount == 0) {
	272	bp->b_resid = bp->b_bcount;
	273	biodone(bio);
	274	return (0);
	275	}
	276
17566092 SW	277	bio->bio_driver_info = sc;
	278	lockmgr(&controller->mfi_io_lock, LK_EXCLUSIVE);
	279	mfi_enqueue_bio(controller, bio);
	280	devstat_start_transaction(&sc->pd_devstat);
	281	mfi_startio(controller);
	282	lockmgr(&controller->mfi_io_lock, LK_RELEASE);
	283	return (0);
	284	}
	285
17566092 SW	286	static int
	287	mfi_syspd_dump(struct dev_dump_args *ap)
	288	{
	289	cdev_t dev = ap->a_head.a_dev;
	290	off_t offset = ap->a_offset;
	291	void *virt = ap->a_virtual;
	292	size_t len = ap->a_length;
	293	struct mfi_system_pd *sc;
	294	struct mfi_softc *parent_sc;
	295	int error;
	296
	297	sc = dev->si_drv1;
	298	parent_sc = sc->pd_controller;
	299
	300	if (len > 0) {
590ba11d SW	301	if ((error = mfi_dump_syspd_blocks(parent_sc,
590ba11d SW	302	sc->pd_id, offset / MFI_SECTOR_LEN, virt, len)) != 0)
17566092 SW	303	return (error);
	304	} else {
	305	/* mfi_sync_cache(parent_sc, sc->ld_id); */
	306	}
	307	return (0);
	308	}