freebsd-dev/sys/cam/scsi/scsi_target.c
Alexander Motin 227d67aa54 Merge CAM locking changes from the projects/camlock branch to radically
reduce lock congestion and improve SMP scalability of the SCSI/ATA stack,
preparing the ground for the coming next GEOM direct dispatch support.

Replace big per-SIM locks with bunch of smaller ones:
 - per-LUN locks to protect device and peripheral drivers state;
 - per-target locks to protect list of LUNs on target;
 - per-bus locks to protect reference counting;
 - per-send queue locks to protect queue of CCBs to be sent;
 - per-done queue locks to protect queue of completed CCBs;
 - remaining per-SIM locks now protect only HBA driver internals.

While holding LUN lock it is allowed (while not recommended for performance
reasons) to take SIM lock.  The opposite acquisition order is forbidden.
All the other locks are leaf locks, that can be taken anywhere, but should
not be cascaded.  Many functions, such as: xpt_action(), xpt_done(),
xpt_async(), xpt_create_path(), etc. are no longer require (but allow) SIM
lock to be held.

To keep compatibility and solve cases where SIM lock can't be dropped, all
xpt_async() calls in addition to xpt_done() calls are queued to completion
threads for async processing in clean environment without SIM lock held.

Instead of single CAM SWI thread, used for commands completion processing
before, use multiple (depending on number of CPUs) threads.  Load balanced
between them using "hash" of the device B:T:L address.

HBA drivers that can drop SIM lock during completion processing and have
sufficient number of completion threads to efficiently scale to multiple
CPUs can use new function xpt_done_direct() to avoid extra context switch.
Make ahci(4) driver to use this mechanism depending on hardware setup.

Sponsored by:	iXsystems, Inc.
MFC after:	2 months
2013-10-21 12:00:26 +00:00

1155 lines
32 KiB
C

/*-
* Generic SCSI Target Kernel Mode Driver
*
* Copyright (c) 2002 Nate Lawson.
* Copyright (c) 1998, 1999, 2001, 2002 Justin T. Gibbs.
* 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,
* without modification, immediately at the beginning of the file.
* 2. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* 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 <sys/kernel.h>
#include <sys/conf.h>
#include <sys/malloc.h>
#include <sys/poll.h>
#include <sys/vnode.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/devicestat.h>
#include <sys/proc.h>
/* Includes to support callout */
#include <sys/types.h>
#include <sys/systm.h>
#include <cam/cam.h>
#include <cam/cam_ccb.h>
#include <cam/cam_periph.h>
#include <cam/cam_xpt_periph.h>
#include <cam/cam_sim.h>
#include <cam/scsi/scsi_targetio.h>
/* Transaction information attached to each CCB sent by the user */
struct targ_cmd_descr {
struct cam_periph_map_info mapinfo;
TAILQ_ENTRY(targ_cmd_descr) tqe;
union ccb *user_ccb;
int priority;
int func_code;
};
/* Offset into the private CCB area for storing our descriptor */
#define targ_descr periph_priv.entries[1].ptr
TAILQ_HEAD(descr_queue, targ_cmd_descr);
typedef enum {
TARG_STATE_RESV = 0x00, /* Invalid state */
TARG_STATE_OPENED = 0x01, /* Device opened, softc initialized */
TARG_STATE_LUN_ENABLED = 0x02 /* Device enabled for a path */
} targ_state;
/* Per-instance device software context */
struct targ_softc {
/* CCBs (CTIOs, ATIOs, INOTs) pending on the controller */
struct ccb_queue pending_ccb_queue;
/* Command descriptors awaiting CTIO resources from the XPT */
struct descr_queue work_queue;
/* Command descriptors that have been aborted back to the user. */
struct descr_queue abort_queue;
/*
* Queue of CCBs that have been copied out to userland, but our
* userland daemon has not yet seen.
*/
struct ccb_queue user_ccb_queue;
struct cam_periph *periph;
struct cam_path *path;
targ_state state;
struct selinfo read_select;
struct devstat device_stats;
};
static d_open_t targopen;
static d_read_t targread;
static d_write_t targwrite;
static d_ioctl_t targioctl;
static d_poll_t targpoll;
static d_kqfilter_t targkqfilter;
static void targreadfiltdetach(struct knote *kn);
static int targreadfilt(struct knote *kn, long hint);
static struct filterops targread_filtops = {
.f_isfd = 1,
.f_detach = targreadfiltdetach,
.f_event = targreadfilt,
};
static struct cdevsw targ_cdevsw = {
.d_version = D_VERSION,
.d_flags = D_NEEDGIANT,
.d_open = targopen,
.d_read = targread,
.d_write = targwrite,
.d_ioctl = targioctl,
.d_poll = targpoll,
.d_name = "targ",
.d_kqfilter = targkqfilter
};
static cam_status targendislun(struct cam_path *path, int enable,
int grp6_len, int grp7_len);
static cam_status targenable(struct targ_softc *softc,
struct cam_path *path,
int grp6_len, int grp7_len);
static cam_status targdisable(struct targ_softc *softc);
static periph_ctor_t targctor;
static periph_dtor_t targdtor;
static periph_start_t targstart;
static int targusermerge(struct targ_softc *softc,
struct targ_cmd_descr *descr,
union ccb *ccb);
static int targsendccb(struct targ_softc *softc, union ccb *ccb,
struct targ_cmd_descr *descr);
static void targdone(struct cam_periph *periph,
union ccb *done_ccb);
static int targreturnccb(struct targ_softc *softc,
union ccb *ccb);
static union ccb * targgetccb(struct targ_softc *softc, xpt_opcode type,
int priority);
static void targfreeccb(struct targ_softc *softc, union ccb *ccb);
static struct targ_cmd_descr *
targgetdescr(struct targ_softc *softc);
static periph_init_t targinit;
static void targasync(void *callback_arg, u_int32_t code,
struct cam_path *path, void *arg);
static void abort_all_pending(struct targ_softc *softc);
static void notify_user(struct targ_softc *softc);
static int targcamstatus(cam_status status);
static size_t targccblen(xpt_opcode func_code);
static struct periph_driver targdriver =
{
targinit, "targ",
TAILQ_HEAD_INITIALIZER(targdriver.units), /* generation */ 0
};
PERIPHDRIVER_DECLARE(targ, targdriver);
static MALLOC_DEFINE(M_TARG, "TARG", "TARG data");
/* Disable LUN if enabled and teardown softc */
static void
targcdevdtor(void *data)
{
struct targ_softc *softc;
struct cam_periph *periph;
softc = data;
if (softc->periph == NULL) {
printf("%s: destroying non-enabled target\n", __func__);
free(softc, M_TARG);
return;
}
/*
* Acquire a hold on the periph so that it doesn't go away before
* we are ready at the end of the function.
*/
periph = softc->periph;
cam_periph_acquire(periph);
cam_periph_lock(periph);
(void)targdisable(softc);
if (softc->periph != NULL) {
cam_periph_invalidate(softc->periph);
softc->periph = NULL;
}
cam_periph_unlock(periph);
cam_periph_release(periph);
free(softc, M_TARG);
}
/*
* Create softc and initialize it. There is no locking here because a
* periph doesn't get created until an ioctl is issued to do so, and
* that can't happen until this method returns.
*/
static int
targopen(struct cdev *dev, int flags, int fmt, struct thread *td)
{
struct targ_softc *softc;
/* Allocate its softc, initialize it */
softc = malloc(sizeof(*softc), M_TARG,
M_WAITOK | M_ZERO);
softc->state = TARG_STATE_OPENED;
softc->periph = NULL;
softc->path = NULL;
TAILQ_INIT(&softc->pending_ccb_queue);
TAILQ_INIT(&softc->work_queue);
TAILQ_INIT(&softc->abort_queue);
TAILQ_INIT(&softc->user_ccb_queue);
knlist_init_mtx(&softc->read_select.si_note, NULL);
devfs_set_cdevpriv(softc, targcdevdtor);
return (0);
}
/* Enable/disable LUNs, set debugging level */
static int
targioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flag, struct thread *td)
{
struct targ_softc *softc;
cam_status status;
devfs_get_cdevpriv((void **)&softc);
switch (cmd) {
case TARGIOCENABLE:
{
struct ioc_enable_lun *new_lun;
struct cam_path *path;
new_lun = (struct ioc_enable_lun *)addr;
status = xpt_create_path(&path, /*periph*/NULL,
new_lun->path_id,
new_lun->target_id,
new_lun->lun_id);
if (status != CAM_REQ_CMP) {
printf("Couldn't create path, status %#x\n", status);
break;
}
xpt_path_lock(path);
status = targenable(softc, path, new_lun->grp6_len,
new_lun->grp7_len);
xpt_path_unlock(path);
xpt_free_path(path);
break;
}
case TARGIOCDISABLE:
if (softc->periph == NULL) {
status = CAM_DEV_NOT_THERE;
break;
}
cam_periph_lock(softc->periph);
status = targdisable(softc);
cam_periph_unlock(softc->periph);
break;
case TARGIOCDEBUG:
{
struct ccb_debug cdbg;
/* If no periph available, disallow debugging changes */
if ((softc->state & TARG_STATE_LUN_ENABLED) == 0) {
status = CAM_DEV_NOT_THERE;
break;
}
bzero(&cdbg, sizeof cdbg);
if (*((int *)addr) != 0)
cdbg.flags = CAM_DEBUG_PERIPH;
else
cdbg.flags = CAM_DEBUG_NONE;
xpt_setup_ccb(&cdbg.ccb_h, softc->path, CAM_PRIORITY_NORMAL);
cdbg.ccb_h.func_code = XPT_DEBUG;
cdbg.ccb_h.cbfcnp = targdone;
xpt_action((union ccb *)&cdbg);
status = cdbg.ccb_h.status & CAM_STATUS_MASK;
break;
}
default:
status = CAM_PROVIDE_FAIL;
break;
}
return (targcamstatus(status));
}
/* Writes are always ready, reads wait for user_ccb_queue or abort_queue */
static int
targpoll(struct cdev *dev, int poll_events, struct thread *td)
{
struct targ_softc *softc;
int revents;
devfs_get_cdevpriv((void **)&softc);
/* Poll for write() is always ok. */
revents = poll_events & (POLLOUT | POLLWRNORM);
if ((poll_events & (POLLIN | POLLRDNORM)) != 0) {
/* Poll for read() depends on user and abort queues. */
cam_periph_lock(softc->periph);
if (!TAILQ_EMPTY(&softc->user_ccb_queue) ||
!TAILQ_EMPTY(&softc->abort_queue)) {
revents |= poll_events & (POLLIN | POLLRDNORM);
}
cam_periph_unlock(softc->periph);
/* Only sleep if the user didn't poll for write. */
if (revents == 0)
selrecord(td, &softc->read_select);
}
return (revents);
}
static int
targkqfilter(struct cdev *dev, struct knote *kn)
{
struct targ_softc *softc;
devfs_get_cdevpriv((void **)&softc);
kn->kn_hook = (caddr_t)softc;
kn->kn_fop = &targread_filtops;
knlist_add(&softc->read_select.si_note, kn, 0);
return (0);
}
static void
targreadfiltdetach(struct knote *kn)
{
struct targ_softc *softc;
softc = (struct targ_softc *)kn->kn_hook;
knlist_remove(&softc->read_select.si_note, kn, 0);
}
/* Notify the user's kqueue when the user queue or abort queue gets a CCB */
static int
targreadfilt(struct knote *kn, long hint)
{
struct targ_softc *softc;
int retval;
softc = (struct targ_softc *)kn->kn_hook;
cam_periph_lock(softc->periph);
retval = !TAILQ_EMPTY(&softc->user_ccb_queue) ||
!TAILQ_EMPTY(&softc->abort_queue);
cam_periph_unlock(softc->periph);
return (retval);
}
/* Send the HBA the enable/disable message */
static cam_status
targendislun(struct cam_path *path, int enable, int grp6_len, int grp7_len)
{
struct ccb_en_lun en_ccb;
cam_status status;
/* Tell the lun to begin answering selects */
xpt_setup_ccb(&en_ccb.ccb_h, path, CAM_PRIORITY_NORMAL);
en_ccb.ccb_h.func_code = XPT_EN_LUN;
/* Don't need support for any vendor specific commands */
en_ccb.grp6_len = grp6_len;
en_ccb.grp7_len = grp7_len;
en_ccb.enable = enable ? 1 : 0;
xpt_action((union ccb *)&en_ccb);
status = en_ccb.ccb_h.status & CAM_STATUS_MASK;
if (status != CAM_REQ_CMP) {
xpt_print(path, "%sable lun CCB rejected, status %#x\n",
enable ? "en" : "dis", status);
}
return (status);
}
/* Enable target mode on a LUN, given its path */
static cam_status
targenable(struct targ_softc *softc, struct cam_path *path, int grp6_len,
int grp7_len)
{
struct cam_periph *periph;
struct ccb_pathinq cpi;
cam_status status;
if ((softc->state & TARG_STATE_LUN_ENABLED) != 0)
return (CAM_LUN_ALRDY_ENA);
/* Make sure SIM supports target mode */
xpt_setup_ccb(&cpi.ccb_h, path, CAM_PRIORITY_NORMAL);
cpi.ccb_h.func_code = XPT_PATH_INQ;
xpt_action((union ccb *)&cpi);
status = cpi.ccb_h.status & CAM_STATUS_MASK;
if (status != CAM_REQ_CMP) {
printf("pathinq failed, status %#x\n", status);
goto enable_fail;
}
if ((cpi.target_sprt & PIT_PROCESSOR) == 0) {
printf("controller does not support target mode\n");
status = CAM_FUNC_NOTAVAIL;
goto enable_fail;
}
/* Destroy any periph on our path if it is disabled */
periph = cam_periph_find(path, "targ");
if (periph != NULL) {
struct targ_softc *del_softc;
del_softc = (struct targ_softc *)periph->softc;
if ((del_softc->state & TARG_STATE_LUN_ENABLED) == 0) {
cam_periph_invalidate(del_softc->periph);
del_softc->periph = NULL;
} else {
printf("Requested path still in use by targ%d\n",
periph->unit_number);
status = CAM_LUN_ALRDY_ENA;
goto enable_fail;
}
}
/* Create a periph instance attached to this path */
status = cam_periph_alloc(targctor, NULL, targdtor, targstart,
"targ", CAM_PERIPH_BIO, path, targasync, 0, softc);
if (status != CAM_REQ_CMP) {
printf("cam_periph_alloc failed, status %#x\n", status);
goto enable_fail;
}
/* Ensure that the periph now exists. */
if (cam_periph_find(path, "targ") == NULL) {
panic("targenable: succeeded but no periph?");
/* NOTREACHED */
}
/* Send the enable lun message */
status = targendislun(path, /*enable*/1, grp6_len, grp7_len);
if (status != CAM_REQ_CMP) {
printf("enable lun failed, status %#x\n", status);
goto enable_fail;
}
softc->state |= TARG_STATE_LUN_ENABLED;
enable_fail:
return (status);
}
/* Disable this softc's target instance if enabled */
static cam_status
targdisable(struct targ_softc *softc)
{
cam_status status;
if ((softc->state & TARG_STATE_LUN_ENABLED) == 0)
return (CAM_REQ_CMP);
CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targdisable\n"));
/* Abort any ccbs pending on the controller */
abort_all_pending(softc);
/* Disable this lun */
status = targendislun(softc->path, /*enable*/0,
/*grp6_len*/0, /*grp7_len*/0);
if (status == CAM_REQ_CMP)
softc->state &= ~TARG_STATE_LUN_ENABLED;
else
printf("Disable lun failed, status %#x\n", status);
return (status);
}
/* Initialize a periph (called from cam_periph_alloc) */
static cam_status
targctor(struct cam_periph *periph, void *arg)
{
struct targ_softc *softc;
/* Store pointer to softc for periph-driven routines */
softc = (struct targ_softc *)arg;
periph->softc = softc;
softc->periph = periph;
softc->path = periph->path;
return (CAM_REQ_CMP);
}
static void
targdtor(struct cam_periph *periph)
{
struct targ_softc *softc;
struct ccb_hdr *ccb_h;
struct targ_cmd_descr *descr;
softc = (struct targ_softc *)periph->softc;
/*
* targdisable() aborts CCBs back to the user and leaves them
* on user_ccb_queue and abort_queue in case the user is still
* interested in them. We free them now.
*/
while ((ccb_h = TAILQ_FIRST(&softc->user_ccb_queue)) != NULL) {
TAILQ_REMOVE(&softc->user_ccb_queue, ccb_h, periph_links.tqe);
targfreeccb(softc, (union ccb *)ccb_h);
}
while ((descr = TAILQ_FIRST(&softc->abort_queue)) != NULL) {
TAILQ_REMOVE(&softc->abort_queue, descr, tqe);
free(descr, M_TARG);
}
softc->periph = NULL;
softc->path = NULL;
periph->softc = NULL;
}
/* Receive CCBs from user mode proc and send them to the HBA */
static int
targwrite(struct cdev *dev, struct uio *uio, int ioflag)
{
union ccb *user_ccb;
struct targ_softc *softc;
struct targ_cmd_descr *descr;
int write_len, error;
int func_code, priority;
devfs_get_cdevpriv((void **)&softc);
write_len = error = 0;
CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
("write - uio_resid %zd\n", uio->uio_resid));
while (uio->uio_resid >= sizeof(user_ccb) && error == 0) {
union ccb *ccb;
error = uiomove((caddr_t)&user_ccb, sizeof(user_ccb), uio);
if (error != 0) {
CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
("write - uiomove failed (%d)\n", error));
break;
}
priority = fuword32(&user_ccb->ccb_h.pinfo.priority);
if (priority == CAM_PRIORITY_NONE) {
error = EINVAL;
break;
}
func_code = fuword32(&user_ccb->ccb_h.func_code);
switch (func_code) {
case XPT_ACCEPT_TARGET_IO:
case XPT_IMMED_NOTIFY:
case XPT_IMMEDIATE_NOTIFY:
cam_periph_lock(softc->periph);
ccb = targgetccb(softc, func_code, priority);
descr = (struct targ_cmd_descr *)ccb->ccb_h.targ_descr;
descr->user_ccb = user_ccb;
descr->func_code = func_code;
CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
("Sent ATIO/INOT (%p)\n", user_ccb));
xpt_action(ccb);
TAILQ_INSERT_TAIL(&softc->pending_ccb_queue,
&ccb->ccb_h,
periph_links.tqe);
cam_periph_unlock(softc->periph);
break;
default:
cam_periph_lock(softc->periph);
if ((func_code & XPT_FC_QUEUED) != 0) {
CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
("Sending queued ccb %#x (%p)\n",
func_code, user_ccb));
descr = targgetdescr(softc);
descr->user_ccb = user_ccb;
descr->priority = priority;
descr->func_code = func_code;
TAILQ_INSERT_TAIL(&softc->work_queue,
descr, tqe);
xpt_schedule(softc->periph, priority);
} else {
CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
("Sending inline ccb %#x (%p)\n",
func_code, user_ccb));
ccb = targgetccb(softc, func_code, priority);
descr = (struct targ_cmd_descr *)
ccb->ccb_h.targ_descr;
descr->user_ccb = user_ccb;
descr->priority = priority;
descr->func_code = func_code;
if (targusermerge(softc, descr, ccb) != EFAULT)
targsendccb(softc, ccb, descr);
targreturnccb(softc, ccb);
}
cam_periph_unlock(softc->periph);
break;
}
write_len += sizeof(user_ccb);
}
/*
* If we've successfully taken in some amount of
* data, return success for that data first. If
* an error is persistent, it will be reported
* on the next write.
*/
if (error != 0 && write_len == 0)
return (error);
if (write_len == 0 && uio->uio_resid != 0)
return (ENOSPC);
return (0);
}
/* Process requests (descrs) via the periph-supplied CCBs */
static void
targstart(struct cam_periph *periph, union ccb *start_ccb)
{
struct targ_softc *softc;
struct targ_cmd_descr *descr, *next_descr;
int error;
softc = (struct targ_softc *)periph->softc;
CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targstart %p\n", start_ccb));
descr = TAILQ_FIRST(&softc->work_queue);
if (descr == NULL) {
xpt_release_ccb(start_ccb);
} else {
TAILQ_REMOVE(&softc->work_queue, descr, tqe);
next_descr = TAILQ_FIRST(&softc->work_queue);
/* Initiate a transaction using the descr and supplied CCB */
error = targusermerge(softc, descr, start_ccb);
if (error == 0)
error = targsendccb(softc, start_ccb, descr);
if (error != 0) {
xpt_print(periph->path,
"targsendccb failed, err %d\n", error);
xpt_release_ccb(start_ccb);
suword(&descr->user_ccb->ccb_h.status,
CAM_REQ_CMP_ERR);
TAILQ_INSERT_TAIL(&softc->abort_queue, descr, tqe);
notify_user(softc);
}
/* If we have more work to do, stay scheduled */
if (next_descr != NULL)
xpt_schedule(periph, next_descr->priority);
}
}
static int
targusermerge(struct targ_softc *softc, struct targ_cmd_descr *descr,
union ccb *ccb)
{
struct ccb_hdr *u_ccbh, *k_ccbh;
size_t ccb_len;
int error;
u_ccbh = &descr->user_ccb->ccb_h;
k_ccbh = &ccb->ccb_h;
/*
* There are some fields in the CCB header that need to be
* preserved, the rest we get from the user ccb. (See xpt_merge_ccb)
*/
xpt_setup_ccb(k_ccbh, softc->path, descr->priority);
k_ccbh->retry_count = fuword32(&u_ccbh->retry_count);
k_ccbh->func_code = descr->func_code;
k_ccbh->flags = fuword32(&u_ccbh->flags);
k_ccbh->timeout = fuword32(&u_ccbh->timeout);
ccb_len = targccblen(k_ccbh->func_code) - sizeof(struct ccb_hdr);
error = copyin(u_ccbh + 1, k_ccbh + 1, ccb_len);
if (error != 0) {
k_ccbh->status = CAM_REQ_CMP_ERR;
return (error);
}
/* Translate usermode abort_ccb pointer to its kernel counterpart */
if (k_ccbh->func_code == XPT_ABORT) {
struct ccb_abort *cab;
struct ccb_hdr *ccb_h;
cab = (struct ccb_abort *)ccb;
TAILQ_FOREACH(ccb_h, &softc->pending_ccb_queue,
periph_links.tqe) {
struct targ_cmd_descr *ab_descr;
ab_descr = (struct targ_cmd_descr *)ccb_h->targ_descr;
if (ab_descr->user_ccb == cab->abort_ccb) {
CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
("Changing abort for %p to %p\n",
cab->abort_ccb, ccb_h));
cab->abort_ccb = (union ccb *)ccb_h;
break;
}
}
/* CCB not found, set appropriate status */
if (ccb_h == NULL) {
k_ccbh->status = CAM_PATH_INVALID;
error = ESRCH;
}
}
return (error);
}
/* Build and send a kernel CCB formed from descr->user_ccb */
static int
targsendccb(struct targ_softc *softc, union ccb *ccb,
struct targ_cmd_descr *descr)
{
struct cam_periph_map_info *mapinfo;
struct ccb_hdr *ccb_h;
int error;
ccb_h = &ccb->ccb_h;
mapinfo = &descr->mapinfo;
mapinfo->num_bufs_used = 0;
/*
* There's no way for the user to have a completion
* function, so we put our own completion function in here.
* We also stash in a reference to our descriptor so targreturnccb()
* can find our mapping info.
*/
ccb_h->cbfcnp = targdone;
ccb_h->targ_descr = descr;
if ((ccb_h->func_code == XPT_CONT_TARGET_IO) ||
(ccb_h->func_code == XPT_DEV_MATCH)) {
error = cam_periph_mapmem(ccb, mapinfo);
/*
* cam_periph_mapmem returned an error, we can't continue.
* Return the error to the user.
*/
if (error) {
ccb_h->status = CAM_REQ_CMP_ERR;
mapinfo->num_bufs_used = 0;
return (error);
}
}
/*
* Once queued on the pending CCB list, this CCB will be protected
* by our error recovery handler.
*/
CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("sendccb %p\n", ccb));
if (XPT_FC_IS_QUEUED(ccb)) {
TAILQ_INSERT_TAIL(&softc->pending_ccb_queue, ccb_h,
periph_links.tqe);
}
xpt_action(ccb);
return (0);
}
/* Completion routine for CCBs (called at splsoftcam) */
static void
targdone(struct cam_periph *periph, union ccb *done_ccb)
{
struct targ_softc *softc;
cam_status status;
CAM_DEBUG(periph->path, CAM_DEBUG_PERIPH, ("targdone %p\n", done_ccb));
softc = (struct targ_softc *)periph->softc;
TAILQ_REMOVE(&softc->pending_ccb_queue, &done_ccb->ccb_h,
periph_links.tqe);
status = done_ccb->ccb_h.status & CAM_STATUS_MASK;
/* If we're no longer enabled, throw away CCB */
if ((softc->state & TARG_STATE_LUN_ENABLED) == 0) {
targfreeccb(softc, done_ccb);
return;
}
/* abort_all_pending() waits for pending queue to be empty */
if (TAILQ_EMPTY(&softc->pending_ccb_queue))
wakeup(&softc->pending_ccb_queue);
switch (done_ccb->ccb_h.func_code) {
/* All FC_*_QUEUED CCBs go back to userland */
case XPT_IMMED_NOTIFY:
case XPT_IMMEDIATE_NOTIFY:
case XPT_ACCEPT_TARGET_IO:
case XPT_CONT_TARGET_IO:
TAILQ_INSERT_TAIL(&softc->user_ccb_queue, &done_ccb->ccb_h,
periph_links.tqe);
cam_periph_unlock(softc->periph);
notify_user(softc);
cam_periph_lock(softc->periph);
break;
default:
panic("targdone: impossible xpt opcode %#x",
done_ccb->ccb_h.func_code);
/* NOTREACHED */
}
}
/* Return CCBs to the user from the user queue and abort queue */
static int
targread(struct cdev *dev, struct uio *uio, int ioflag)
{
struct descr_queue *abort_queue;
struct targ_cmd_descr *user_descr;
struct targ_softc *softc;
struct ccb_queue *user_queue;
struct ccb_hdr *ccb_h;
union ccb *user_ccb;
int read_len, error;
error = 0;
read_len = 0;
devfs_get_cdevpriv((void **)&softc);
user_queue = &softc->user_ccb_queue;
abort_queue = &softc->abort_queue;
CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targread\n"));
/* If no data is available, wait or return immediately */
cam_periph_lock(softc->periph);
ccb_h = TAILQ_FIRST(user_queue);
user_descr = TAILQ_FIRST(abort_queue);
while (ccb_h == NULL && user_descr == NULL) {
if ((ioflag & IO_NDELAY) == 0) {
error = cam_periph_sleep(softc->periph, user_queue,
PRIBIO | PCATCH, "targrd", 0);
ccb_h = TAILQ_FIRST(user_queue);
user_descr = TAILQ_FIRST(abort_queue);
if (error != 0) {
if (error == ERESTART) {
continue;
} else {
goto read_fail;
}
}
} else {
cam_periph_unlock(softc->periph);
return (EAGAIN);
}
}
/* Data is available so fill the user's buffer */
while (ccb_h != NULL) {
struct targ_cmd_descr *descr;
if (uio->uio_resid < sizeof(user_ccb))
break;
TAILQ_REMOVE(user_queue, ccb_h, periph_links.tqe);
descr = (struct targ_cmd_descr *)ccb_h->targ_descr;
user_ccb = descr->user_ccb;
CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
("targread ccb %p (%p)\n", ccb_h, user_ccb));
error = targreturnccb(softc, (union ccb *)ccb_h);
if (error != 0)
goto read_fail;
cam_periph_unlock(softc->periph);
error = uiomove((caddr_t)&user_ccb, sizeof(user_ccb), uio);
cam_periph_lock(softc->periph);
if (error != 0)
goto read_fail;
read_len += sizeof(user_ccb);
ccb_h = TAILQ_FIRST(user_queue);
}
/* Flush out any aborted descriptors */
while (user_descr != NULL) {
if (uio->uio_resid < sizeof(user_ccb))
break;
TAILQ_REMOVE(abort_queue, user_descr, tqe);
user_ccb = user_descr->user_ccb;
CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
("targread aborted descr %p (%p)\n",
user_descr, user_ccb));
suword(&user_ccb->ccb_h.status, CAM_REQ_ABORTED);
cam_periph_unlock(softc->periph);
error = uiomove((caddr_t)&user_ccb, sizeof(user_ccb), uio);
cam_periph_lock(softc->periph);
if (error != 0)
goto read_fail;
read_len += sizeof(user_ccb);
user_descr = TAILQ_FIRST(abort_queue);
}
/*
* If we've successfully read some amount of data, don't report an
* error. If the error is persistent, it will be reported on the
* next read().
*/
if (read_len == 0 && uio->uio_resid != 0)
error = ENOSPC;
read_fail:
cam_periph_unlock(softc->periph);
return (error);
}
/* Copy completed ccb back to the user */
static int
targreturnccb(struct targ_softc *softc, union ccb *ccb)
{
struct targ_cmd_descr *descr;
struct ccb_hdr *u_ccbh;
size_t ccb_len;
int error;
CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targreturnccb %p\n", ccb));
descr = (struct targ_cmd_descr *)ccb->ccb_h.targ_descr;
u_ccbh = &descr->user_ccb->ccb_h;
/* Copy out the central portion of the ccb_hdr */
copyout(&ccb->ccb_h.retry_count, &u_ccbh->retry_count,
offsetof(struct ccb_hdr, periph_priv) -
offsetof(struct ccb_hdr, retry_count));
/* Copy out the rest of the ccb (after the ccb_hdr) */
ccb_len = targccblen(ccb->ccb_h.func_code) - sizeof(struct ccb_hdr);
if (descr->mapinfo.num_bufs_used != 0)
cam_periph_unmapmem(ccb, &descr->mapinfo);
error = copyout(&ccb->ccb_h + 1, u_ccbh + 1, ccb_len);
if (error != 0) {
xpt_print(softc->path,
"targreturnccb - CCB copyout failed (%d)\n", error);
}
/* Free CCB or send back to devq. */
targfreeccb(softc, ccb);
return (error);
}
static union ccb *
targgetccb(struct targ_softc *softc, xpt_opcode type, int priority)
{
union ccb *ccb;
int ccb_len;
ccb_len = targccblen(type);
ccb = malloc(ccb_len, M_TARG, M_NOWAIT);
CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("getccb %p\n", ccb));
if (ccb == NULL) {
return (ccb);
}
xpt_setup_ccb(&ccb->ccb_h, softc->path, priority);
ccb->ccb_h.func_code = type;
ccb->ccb_h.cbfcnp = targdone;
ccb->ccb_h.targ_descr = targgetdescr(softc);
if (ccb->ccb_h.targ_descr == NULL) {
free (ccb, M_TARG);
ccb = NULL;
}
return (ccb);
}
static void
targfreeccb(struct targ_softc *softc, union ccb *ccb)
{
CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH, ("targfreeccb descr %p and\n",
ccb->ccb_h.targ_descr));
free(ccb->ccb_h.targ_descr, M_TARG);
switch (ccb->ccb_h.func_code) {
case XPT_ACCEPT_TARGET_IO:
case XPT_IMMED_NOTIFY:
case XPT_IMMEDIATE_NOTIFY:
CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH, ("freeing ccb %p\n", ccb));
free(ccb, M_TARG);
break;
default:
/* Send back CCB if we got it from the periph */
if (XPT_FC_IS_QUEUED(ccb)) {
CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH,
("returning queued ccb %p\n", ccb));
xpt_release_ccb(ccb);
} else {
CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH,
("freeing ccb %p\n", ccb));
free(ccb, M_TARG);
}
break;
}
}
static struct targ_cmd_descr *
targgetdescr(struct targ_softc *softc)
{
struct targ_cmd_descr *descr;
descr = malloc(sizeof(*descr), M_TARG,
M_NOWAIT);
if (descr) {
descr->mapinfo.num_bufs_used = 0;
}
return (descr);
}
static void
targinit(void)
{
struct cdev *dev;
/* Add symbolic link to targ0 for compatibility. */
dev = make_dev(&targ_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "targ");
make_dev_alias(dev, "targ0");
}
static void
targasync(void *callback_arg, u_int32_t code, struct cam_path *path, void *arg)
{
/* All events are handled in usermode by INOTs */
panic("targasync() called, should be an INOT instead");
}
/* Cancel all pending requests and CCBs awaiting work. */
static void
abort_all_pending(struct targ_softc *softc)
{
struct targ_cmd_descr *descr;
struct ccb_abort cab;
struct ccb_hdr *ccb_h;
CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("abort_all_pending\n"));
/* First abort the descriptors awaiting resources */
while ((descr = TAILQ_FIRST(&softc->work_queue)) != NULL) {
CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
("Aborting descr from workq %p\n", descr));
TAILQ_REMOVE(&softc->work_queue, descr, tqe);
TAILQ_INSERT_TAIL(&softc->abort_queue, descr, tqe);
}
/*
* Then abort all pending CCBs.
* targdone() will return the aborted CCB via user_ccb_queue
*/
xpt_setup_ccb(&cab.ccb_h, softc->path, CAM_PRIORITY_NORMAL);
cab.ccb_h.func_code = XPT_ABORT;
cab.ccb_h.status = CAM_REQ_CMP_ERR;
TAILQ_FOREACH(ccb_h, &softc->pending_ccb_queue, periph_links.tqe) {
CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
("Aborting pending CCB %p\n", ccb_h));
cab.abort_ccb = (union ccb *)ccb_h;
xpt_action((union ccb *)&cab);
if (cab.ccb_h.status != CAM_REQ_CMP) {
xpt_print(cab.ccb_h.path,
"Unable to abort CCB, status %#x\n",
cab.ccb_h.status);
}
}
/* If we aborted at least one pending CCB ok, wait for it. */
if (cab.ccb_h.status == CAM_REQ_CMP) {
cam_periph_sleep(softc->periph, &softc->pending_ccb_queue,
PRIBIO | PCATCH, "tgabrt", 0);
}
/* If we aborted anything from the work queue, wakeup user. */
if (!TAILQ_EMPTY(&softc->user_ccb_queue)
|| !TAILQ_EMPTY(&softc->abort_queue)) {
cam_periph_unlock(softc->periph);
notify_user(softc);
cam_periph_lock(softc->periph);
}
}
/* Notify the user that data is ready */
static void
notify_user(struct targ_softc *softc)
{
/*
* Notify users sleeping via poll(), kqueue(), and
* blocking read().
*/
selwakeuppri(&softc->read_select, PRIBIO);
KNOTE_UNLOCKED(&softc->read_select.si_note, 0);
wakeup(&softc->user_ccb_queue);
}
/* Convert CAM status to errno values */
static int
targcamstatus(cam_status status)
{
switch (status & CAM_STATUS_MASK) {
case CAM_REQ_CMP: /* CCB request completed without error */
return (0);
case CAM_REQ_INPROG: /* CCB request is in progress */
return (EINPROGRESS);
case CAM_REQ_CMP_ERR: /* CCB request completed with an error */
return (EIO);
case CAM_PROVIDE_FAIL: /* Unable to provide requested capability */
return (ENOTTY);
case CAM_FUNC_NOTAVAIL: /* The requested function is not available */
return (ENOTSUP);
case CAM_LUN_ALRDY_ENA: /* LUN is already enabled for target mode */
return (EADDRINUSE);
case CAM_PATH_INVALID: /* Supplied Path ID is invalid */
case CAM_DEV_NOT_THERE: /* SCSI Device Not Installed/there */
return (ENOENT);
case CAM_REQ_ABORTED: /* CCB request aborted by the host */
return (ECANCELED);
case CAM_CMD_TIMEOUT: /* Command timeout */
return (ETIMEDOUT);
case CAM_REQUEUE_REQ: /* Requeue to preserve transaction ordering */
return (EAGAIN);
case CAM_REQ_INVALID: /* CCB request was invalid */
return (EINVAL);
case CAM_RESRC_UNAVAIL: /* Resource Unavailable */
return (ENOMEM);
case CAM_BUSY: /* CAM subsystem is busy */
case CAM_UA_ABORT: /* Unable to abort CCB request */
return (EBUSY);
default:
return (ENXIO);
}
}
static size_t
targccblen(xpt_opcode func_code)
{
int len;
/* Codes we expect to see as a target */
switch (func_code) {
case XPT_CONT_TARGET_IO:
case XPT_SCSI_IO:
len = sizeof(struct ccb_scsiio);
break;
case XPT_ACCEPT_TARGET_IO:
len = sizeof(struct ccb_accept_tio);
break;
case XPT_IMMED_NOTIFY:
len = sizeof(struct ccb_immed_notify);
break;
case XPT_IMMEDIATE_NOTIFY:
len = sizeof(struct ccb_immediate_notify);
break;
case XPT_REL_SIMQ:
len = sizeof(struct ccb_relsim);
break;
case XPT_PATH_INQ:
len = sizeof(struct ccb_pathinq);
break;
case XPT_DEBUG:
len = sizeof(struct ccb_debug);
break;
case XPT_ABORT:
len = sizeof(struct ccb_abort);
break;
case XPT_EN_LUN:
len = sizeof(struct ccb_en_lun);
break;
default:
len = sizeof(union ccb);
break;
}
return (len);
}