vscsi.c

Branch :
Show log
Commit
Author : visa
Date : 2020-12-25 12:59:51
Hash : 9b0cf67b
Message : Refactor klist insertion and removal Rename klist_{insert,remove}() to klist_{insert,remove}_locked(). These functions assume that the caller has locked the klist. The current state of locking remains intact because the kernel lock is still used with all klists. Add new functions klist_insert() and klist_remove() that lock the klist internally. This allows some code simplification. OK mpi@
sys/dev/vscsi.c
/*	$OpenBSD: vscsi.c,v 1.58 2020/12/25 12:59:52 visa Exp $ */

/*
 * Copyright (c) 2008 David Gwynne <dlg@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/device.h>
#include <sys/conf.h>
#include <sys/queue.h>
#include <sys/rwlock.h>
#include <sys/pool.h>
#include <sys/task.h>
#include <sys/ioctl.h>
#include <sys/poll.h>
#include <sys/selinfo.h>

#include <scsi/scsi_all.h>
#include <scsi/scsiconf.h>

#include <dev/vscsivar.h>

int		vscsi_match(struct device *, void *, void *);
void		vscsi_attach(struct device *, struct device *, void *);
void		vscsi_shutdown(void *);

struct vscsi_ccb {
	TAILQ_ENTRY(vscsi_ccb)	ccb_entry;
	int			ccb_tag;
	struct scsi_xfer	*ccb_xs;
	size_t			ccb_datalen;
};

TAILQ_HEAD(vscsi_ccb_list, vscsi_ccb);

enum vscsi_state {
	VSCSI_S_CLOSED,
	VSCSI_S_CONFIG,
	VSCSI_S_RUNNING
};

struct vscsi_softc {
	struct device		sc_dev;
	struct scsibus_softc	*sc_scsibus;

	struct mutex		sc_state_mtx;
	enum vscsi_state	sc_state;
	u_int			sc_ref_count;
	struct pool		sc_ccb_pool;

	struct scsi_iopool	sc_iopool;

	struct vscsi_ccb_list	sc_ccb_i2t;
	struct vscsi_ccb_list	sc_ccb_t2i;
	int			sc_ccb_tag;
	struct mutex		sc_poll_mtx;
	struct rwlock		sc_ioc_lock;

	struct selinfo		sc_sel;
	struct mutex		sc_sel_mtx;
};

#define DEVNAME(_s) ((_s)->sc_dev.dv_xname)
#define DEV2SC(_d) ((struct vscsi_softc *)device_lookup(&vscsi_cd, minor(_d)))

struct cfattach vscsi_ca = {
	sizeof(struct vscsi_softc),
	vscsi_match,
	vscsi_attach
};

struct cfdriver vscsi_cd = {
	NULL,
	"vscsi",
	DV_DULL
};

void		vscsi_cmd(struct scsi_xfer *);
int		vscsi_probe(struct scsi_link *);
void		vscsi_free(struct scsi_link *);

struct scsi_adapter vscsi_switch = {
	vscsi_cmd, NULL, vscsi_probe, vscsi_free, NULL
};

int		vscsi_i2t(struct vscsi_softc *, struct vscsi_ioc_i2t *);
int		vscsi_data(struct vscsi_softc *, struct vscsi_ioc_data *, int);
int		vscsi_t2i(struct vscsi_softc *, struct vscsi_ioc_t2i *);
int		vscsi_devevent(struct vscsi_softc *, u_long,
		    struct vscsi_ioc_devevent *);
void		vscsi_devevent_task(void *);
void		vscsi_done(struct vscsi_softc *, struct vscsi_ccb *);

void *		vscsi_ccb_get(void *);
void		vscsi_ccb_put(void *, void *);

void		filt_vscsidetach(struct knote *);
int		filt_vscsiread(struct knote *, long);

const struct filterops vscsi_filtops = {
	.f_flags	= FILTEROP_ISFD,
	.f_attach	= NULL,
	.f_detach	= filt_vscsidetach,
	.f_event	= filt_vscsiread,
};


int
vscsi_match(struct device *parent, void *match, void *aux)
{
	return (1);
}

void
vscsi_attach(struct device *parent, struct device *self, void *aux)
{
	struct vscsi_softc		*sc = (struct vscsi_softc *)self;
	struct scsibus_attach_args	saa;

	printf("\n");

	mtx_init(&sc->sc_state_mtx, IPL_BIO);
	sc->sc_state = VSCSI_S_CLOSED;

	TAILQ_INIT(&sc->sc_ccb_i2t);
	TAILQ_INIT(&sc->sc_ccb_t2i);
	mtx_init(&sc->sc_poll_mtx, IPL_BIO);
	mtx_init(&sc->sc_sel_mtx, IPL_BIO);
	rw_init(&sc->sc_ioc_lock, "vscsiioc");
	scsi_iopool_init(&sc->sc_iopool, sc, vscsi_ccb_get, vscsi_ccb_put);

	saa.saa_adapter = &vscsi_switch;
	saa.saa_adapter_softc = sc;
	saa.saa_adapter_target = SDEV_NO_ADAPTER_TARGET;
	saa.saa_adapter_buswidth = 256;
	saa.saa_luns = 8;
	saa.saa_openings = 16;
	saa.saa_pool = &sc->sc_iopool;
	saa.saa_quirks = saa.saa_flags = 0;
	saa.saa_wwpn = saa.saa_wwnn = 0;

	sc->sc_scsibus = (struct scsibus_softc *)config_found(&sc->sc_dev,
	    &saa, scsiprint);
}

void
vscsi_cmd(struct scsi_xfer *xs)
{
	struct scsi_link		*link = xs->sc_link;
	struct vscsi_softc		*sc = link->bus->sb_adapter_softc;
	struct vscsi_ccb		*ccb = xs->io;
	int				polled = ISSET(xs->flags, SCSI_POLL);
	int				running = 0;

	if (ISSET(xs->flags, SCSI_POLL) && ISSET(xs->flags, SCSI_NOSLEEP)) {
		printf("%s: POLL && NOSLEEP for 0x%02x\n", DEVNAME(sc),
		    xs->cmd.opcode);
		xs->error = XS_DRIVER_STUFFUP;
		scsi_done(xs);
		return;
	}

	ccb->ccb_xs = xs;

	mtx_enter(&sc->sc_state_mtx);
	if (sc->sc_state == VSCSI_S_RUNNING) {
		running = 1;
		TAILQ_INSERT_TAIL(&sc->sc_ccb_i2t, ccb, ccb_entry);
	}
	mtx_leave(&sc->sc_state_mtx);

	if (!running) {
		xs->error = XS_DRIVER_STUFFUP;
		scsi_done(xs);
		return;
	}

	selwakeup(&sc->sc_sel);

	if (polled) {
		mtx_enter(&sc->sc_poll_mtx);
		while (ccb->ccb_xs != NULL)
			msleep_nsec(ccb, &sc->sc_poll_mtx, PRIBIO, "vscsipoll",
			    INFSLP);
		mtx_leave(&sc->sc_poll_mtx);
		scsi_done(xs);
	}
}

void
vscsi_done(struct vscsi_softc *sc, struct vscsi_ccb *ccb)
{
	struct scsi_xfer		*xs = ccb->ccb_xs;

	if (ISSET(xs->flags, SCSI_POLL)) {
		mtx_enter(&sc->sc_poll_mtx);
		ccb->ccb_xs = NULL;
		wakeup(ccb);
		mtx_leave(&sc->sc_poll_mtx);
	} else
		scsi_done(xs);
}

int
vscsi_probe(struct scsi_link *link)
{
	struct vscsi_softc		*sc = link->bus->sb_adapter_softc;
	int				rv = 0;

	mtx_enter(&sc->sc_state_mtx);
	if (sc->sc_state == VSCSI_S_RUNNING)
		sc->sc_ref_count++;
	else
		rv = ENXIO;
	mtx_leave(&sc->sc_state_mtx);

	return (rv);
}

void
vscsi_free(struct scsi_link *link)
{
	struct vscsi_softc		*sc = link->bus->sb_adapter_softc;

	mtx_enter(&sc->sc_state_mtx);
	sc->sc_ref_count--;
	if (sc->sc_state != VSCSI_S_RUNNING && sc->sc_ref_count == 0)
		wakeup(&sc->sc_ref_count);
	mtx_leave(&sc->sc_state_mtx);
}

int
vscsiopen(dev_t dev, int flags, int mode, struct proc *p)
{
	struct vscsi_softc		*sc = DEV2SC(dev);
	enum vscsi_state		state = VSCSI_S_RUNNING;
	int				rv = 0;

	if (sc == NULL)
		return (ENXIO);

	mtx_enter(&sc->sc_state_mtx);
	if (sc->sc_state != VSCSI_S_CLOSED)
		rv = EBUSY;
	else
		sc->sc_state = VSCSI_S_CONFIG;
	mtx_leave(&sc->sc_state_mtx);

	if (rv != 0) {
		device_unref(&sc->sc_dev);
		return (rv);
	}

	pool_init(&sc->sc_ccb_pool, sizeof(struct vscsi_ccb), 0, IPL_BIO, 0,
	    "vscsiccb", NULL);

	/* we need to guarantee some ccbs will be available for the iopool */
	rv = pool_prime(&sc->sc_ccb_pool, 8);
	if (rv != 0) {
		pool_destroy(&sc->sc_ccb_pool);
		state = VSCSI_S_CLOSED;
	}

	/* commit changes */
	mtx_enter(&sc->sc_state_mtx);
	sc->sc_state = state;
	mtx_leave(&sc->sc_state_mtx);

	device_unref(&sc->sc_dev);
	return (rv);
}

int
vscsiioctl(dev_t dev, u_long cmd, caddr_t addr, int flags, struct proc *p)
{
	struct vscsi_softc		*sc = DEV2SC(dev);
	int				read = 0;
	int				err = 0;

	if (sc == NULL)
		return (ENXIO);

	rw_enter_write(&sc->sc_ioc_lock);

	switch (cmd) {
	case VSCSI_I2T:
		err = vscsi_i2t(sc, (struct vscsi_ioc_i2t *)addr);
		break;

	case VSCSI_DATA_READ:
		read = 1;
	case VSCSI_DATA_WRITE:
		err = vscsi_data(sc, (struct vscsi_ioc_data *)addr, read);
		break;

	case VSCSI_T2I:
		err = vscsi_t2i(sc, (struct vscsi_ioc_t2i *)addr);
		break;

	case VSCSI_REQPROBE:
	case VSCSI_REQDETACH:
		err = vscsi_devevent(sc, cmd,
		    (struct vscsi_ioc_devevent *)addr);
		break;

	default:
		err = ENOTTY;
		break;
	}

	rw_exit_write(&sc->sc_ioc_lock);

	device_unref(&sc->sc_dev);
	return (err);
}

int
vscsi_i2t(struct vscsi_softc *sc, struct vscsi_ioc_i2t *i2t)
{
	struct vscsi_ccb		*ccb;
	struct scsi_xfer		*xs;
	struct scsi_link		*link;

	mtx_enter(&sc->sc_state_mtx);
	ccb = TAILQ_FIRST(&sc->sc_ccb_i2t);
	if (ccb != NULL)
		TAILQ_REMOVE(&sc->sc_ccb_i2t, ccb, ccb_entry);
	mtx_leave(&sc->sc_state_mtx);

	if (ccb == NULL)
		return (EAGAIN);

	xs = ccb->ccb_xs;
	link = xs->sc_link;

	i2t->tag = ccb->ccb_tag;
	i2t->target = link->target;
	i2t->lun = link->lun;
	memcpy(&i2t->cmd, &xs->cmd, xs->cmdlen);
	i2t->cmdlen = xs->cmdlen;
	i2t->datalen = xs->datalen;

	switch (xs->flags & (SCSI_DATA_IN | SCSI_DATA_OUT)) {
	case SCSI_DATA_IN:
		i2t->direction = VSCSI_DIR_READ;
		break;
	case SCSI_DATA_OUT:
		i2t->direction = VSCSI_DIR_WRITE;
		break;
	default:
		i2t->direction = VSCSI_DIR_NONE;
		break;
	}

	TAILQ_INSERT_TAIL(&sc->sc_ccb_t2i, ccb, ccb_entry);

	return (0);
}

int
vscsi_data(struct vscsi_softc *sc, struct vscsi_ioc_data *data, int read)
{
	struct vscsi_ccb		*ccb;
	struct scsi_xfer		*xs;
	int				xsread;
	u_int8_t			*buf;
	int				rv = EINVAL;

	TAILQ_FOREACH(ccb, &sc->sc_ccb_t2i, ccb_entry) {
		if (ccb->ccb_tag == data->tag)
			break;
	}
	if (ccb == NULL)
		return (EFAULT);

	xs = ccb->ccb_xs;

	if (data->datalen > xs->datalen - ccb->ccb_datalen)
		return (ENOMEM);

	switch (xs->flags & (SCSI_DATA_IN | SCSI_DATA_OUT)) {
	case SCSI_DATA_IN:
		xsread = 1;
		break;
	case SCSI_DATA_OUT:
		xsread = 0;
		break;
	default:
		return (EINVAL);
	}

	if (read != xsread)
		return (EINVAL);

	buf = xs->data;
	buf += ccb->ccb_datalen;

	if (read)
		rv = copyin(data->data, buf, data->datalen);
	else
		rv = copyout(buf, data->data, data->datalen);

	if (rv == 0)
		ccb->ccb_datalen += data->datalen;

	return (rv);
}

int
vscsi_t2i(struct vscsi_softc *sc, struct vscsi_ioc_t2i *t2i)
{
	struct vscsi_ccb		*ccb;
	struct scsi_xfer		*xs;
	int				rv = 0;

	TAILQ_FOREACH(ccb, &sc->sc_ccb_t2i, ccb_entry) {
		if (ccb->ccb_tag == t2i->tag)
			break;
	}
	if (ccb == NULL)
		return (EFAULT);

	TAILQ_REMOVE(&sc->sc_ccb_t2i, ccb, ccb_entry);

	xs = ccb->ccb_xs;

	xs->resid = xs->datalen - ccb->ccb_datalen;
	xs->status = SCSI_OK;

	switch (t2i->status) {
	case VSCSI_STAT_DONE:
		xs->error = XS_NOERROR;
		break;
	case VSCSI_STAT_SENSE:
		xs->error = XS_SENSE;
		memcpy(&xs->sense, &t2i->sense, sizeof(xs->sense));
		break;
	case VSCSI_STAT_RESET:
		xs->error = XS_RESET;
		break;
	case VSCSI_STAT_ERR:
	default:
		xs->error = XS_DRIVER_STUFFUP;
		break;
	}

	vscsi_done(sc, ccb);

	return (rv);
}

struct vscsi_devevent_task {
	struct vscsi_softc *sc;
	struct task t;
	struct vscsi_ioc_devevent de;
	u_long cmd;
};

int
vscsi_devevent(struct vscsi_softc *sc, u_long cmd,
    struct vscsi_ioc_devevent *de)
{
	struct vscsi_devevent_task *dt;

	dt = malloc(sizeof(*dt), M_TEMP, M_WAITOK | M_CANFAIL);
	if (dt == NULL)
		return (ENOMEM);

	task_set(&dt->t, vscsi_devevent_task, dt);
	dt->sc = sc;
	dt->de = *de;
	dt->cmd = cmd;

	device_ref(&sc->sc_dev);
	task_add(systq, &dt->t);

	return (0);
}

void
vscsi_devevent_task(void *xdt)
{
	struct vscsi_devevent_task *dt = xdt;
	struct vscsi_softc *sc = dt->sc;
	int state;

	mtx_enter(&sc->sc_state_mtx);
	state = sc->sc_state;
	mtx_leave(&sc->sc_state_mtx);

	if (state != VSCSI_S_RUNNING)
		goto gone;

	switch (dt->cmd) {
	case VSCSI_REQPROBE:
		scsi_probe(sc->sc_scsibus, dt->de.target, dt->de.lun);
		break;
	case VSCSI_REQDETACH:
		scsi_detach(sc->sc_scsibus, dt->de.target, dt->de.lun,
		    DETACH_FORCE);
		break;
#ifdef DIAGNOSTIC
	default:
		panic("unexpected vscsi_devevent cmd");
		/* NOTREACHED */
#endif
	}

gone:
	device_unref(&sc->sc_dev);

	free(dt, M_TEMP, sizeof(*dt));
}

int
vscsipoll(dev_t dev, int events, struct proc *p)
{
	struct vscsi_softc		*sc = DEV2SC(dev);
	int				revents = 0;

	if (sc == NULL)
		return (POLLERR);

	if (events & (POLLIN | POLLRDNORM)) {
		mtx_enter(&sc->sc_state_mtx);
		if (!TAILQ_EMPTY(&sc->sc_ccb_i2t))
			revents |= events & (POLLIN | POLLRDNORM);
		mtx_leave(&sc->sc_state_mtx);
	}

	if (revents == 0) {
		if (events & (POLLIN | POLLRDNORM))
			selrecord(p, &sc->sc_sel);
	}

	device_unref(&sc->sc_dev);
	return (revents);
}

int
vscsikqfilter(dev_t dev, struct knote *kn)
{
	struct vscsi_softc *sc = DEV2SC(dev);
	struct klist *klist;

	if (sc == NULL)
		return (ENXIO);

	klist = &sc->sc_sel.si_note;

	switch (kn->kn_filter) {
	case EVFILT_READ:
		kn->kn_fop = &vscsi_filtops;
		break;
	default:
		device_unref(&sc->sc_dev);
		return (EINVAL);
	}

	kn->kn_hook = sc;

	mtx_enter(&sc->sc_sel_mtx);
	klist_insert_locked(klist, kn);
	mtx_leave(&sc->sc_sel_mtx);

	/* device ref is given to the knote in the klist */

	return (0);
}

void
filt_vscsidetach(struct knote *kn)
{
	struct vscsi_softc *sc = kn->kn_hook;
	struct klist *klist = &sc->sc_sel.si_note;

	mtx_enter(&sc->sc_sel_mtx);
	klist_remove_locked(klist, kn);
	mtx_leave(&sc->sc_sel_mtx);

	device_unref(&sc->sc_dev);
}

int
filt_vscsiread(struct knote *kn, long hint)
{
	struct vscsi_softc *sc = kn->kn_hook;
	int event = 0;

	mtx_enter(&sc->sc_state_mtx);
	if (!TAILQ_EMPTY(&sc->sc_ccb_i2t))
		event = 1;
	mtx_leave(&sc->sc_state_mtx);

	return (event);
}

int
vscsiclose(dev_t dev, int flags, int mode, struct proc *p)
{
	struct vscsi_softc		*sc = DEV2SC(dev);
	struct vscsi_ccb		*ccb;

	if (sc == NULL)
		return (ENXIO);

	mtx_enter(&sc->sc_state_mtx);
	KASSERT(sc->sc_state == VSCSI_S_RUNNING);
	sc->sc_state = VSCSI_S_CONFIG;
	mtx_leave(&sc->sc_state_mtx);

	scsi_activate(sc->sc_scsibus, -1, -1, DVACT_DEACTIVATE);

	while ((ccb = TAILQ_FIRST(&sc->sc_ccb_t2i)) != NULL) {
		TAILQ_REMOVE(&sc->sc_ccb_t2i, ccb, ccb_entry);
		ccb->ccb_xs->error = XS_RESET;
		vscsi_done(sc, ccb);
	}

	while ((ccb = TAILQ_FIRST(&sc->sc_ccb_i2t)) != NULL) {
		TAILQ_REMOVE(&sc->sc_ccb_i2t, ccb, ccb_entry);
		ccb->ccb_xs->error = XS_RESET;
		vscsi_done(sc, ccb);
	}

	scsi_req_detach(sc->sc_scsibus, -1, -1, DETACH_FORCE);

	mtx_enter(&sc->sc_state_mtx);
	while (sc->sc_ref_count > 0) {
		msleep_nsec(&sc->sc_ref_count, &sc->sc_state_mtx,
		    PRIBIO, "vscsiref", INFSLP);
	}
	mtx_leave(&sc->sc_state_mtx);

	pool_destroy(&sc->sc_ccb_pool);

	mtx_enter(&sc->sc_state_mtx);
	sc->sc_state = VSCSI_S_CLOSED;
	mtx_leave(&sc->sc_state_mtx);

	device_unref(&sc->sc_dev);
	return (0);
}

void *
vscsi_ccb_get(void *cookie)
{
	struct vscsi_softc		*sc = cookie;
	struct vscsi_ccb		*ccb = NULL;

	ccb = pool_get(&sc->sc_ccb_pool, PR_NOWAIT);
	if (ccb != NULL) {
		ccb->ccb_tag = sc->sc_ccb_tag++;
		ccb->ccb_datalen = 0;
	}

	return (ccb);
}

void
vscsi_ccb_put(void *cookie, void *io)
{
	struct vscsi_softc		*sc = cookie;
	struct vscsi_ccb		*ccb = io;

	pool_put(&sc->sc_ccb_pool, ccb);
}
IABSD.fr/src/sys/dev/vscsi.c

Commit

IABSD.fr/src /sys/dev/vscsi.c
