include: gcc 7's cpp has problems with the line continuations in .x files

[unleashed.git] / kernel / os / driver.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
/*
 * Copyright (c) 2017 by Delphix. All rights reserved.
 */

#include <sys/types.h>
#include <sys/t_lock.h>
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/systm.h>
#include <sys/sysmacros.h>
#include <sys/buf.h>
#include <sys/cred.h>
#include <sys/user.h>
#include <sys/stat.h>
#include <sys/uio.h>
#include <sys/vnode.h>
#include <sys/fs/snode.h>
#include <sys/open.h>
#include <sys/kmem.h>
#include <sys/file.h>
#include <sys/debug.h>

/* Don't #include <sys/ddi.h> - it #undef's getmajor() */

#include <sys/sunddi.h>
#include <sys/sunndi.h>
#include <sys/sunpm.h>
#include <sys/ddi_impldefs.h>
#include <sys/ndi_impldefs.h>
#include <sys/esunddi.h>
#include <sys/autoconf.h>
#include <sys/modctl.h>
#include <sys/epm.h>
#include <sys/dacf.h>
#include <sys/sunmdi.h>
#include <sys/instance.h>
#include <sys/sdt.h>

static void i_attach_ctlop(dev_info_t *, ddi_attach_cmd_t, ddi_pre_post_t, int);
static void i_detach_ctlop(dev_info_t *, ddi_detach_cmd_t, ddi_pre_post_t, int);

/* decide what to do when a double dev_lclose is detected */
#ifdef  DEBUG
int             dev_lclose_ce = CE_PANIC;
#else   /* DEBUG */
int             dev_lclose_ce = CE_WARN;
#endif  /* DEBUG */

/*
 * Configuration-related entry points for nexus and leaf drivers
 */
int
devi_identify(dev_info_t *devi)
{
        struct dev_ops *ops;
        int (*fn)(dev_info_t *);

        if ((ops = ddi_get_driver(devi)) == NULL ||
            (fn = ops->devo_identify) == NULL)
                return (-1);

        return ((*fn)(devi));
}

int
devi_probe(dev_info_t *devi)
{
        int rv, probe_failed;
        pm_ppm_cookie_t ppm_cookie;
        struct dev_ops *ops;
        int (*fn)(dev_info_t *);

        ops = ddi_get_driver(devi);
        ASSERT(ops);

        pm_pre_probe(devi, &ppm_cookie);

        /*
         * probe(9E) in 2.0 implies that you can get
         * away with not writing one of these .. so we
         * pretend we're 'nulldev' if we don't find one (sigh).
         */
        if ((fn = ops->devo_probe) == NULL) {
                if (ddi_dev_is_sid(devi) == DDI_SUCCESS)
                        rv = DDI_PROBE_DONTCARE;
                else
                        rv = DDI_PROBE_FAILURE;
        } else
                rv = (*fn)(devi);

        switch (rv) {
        case DDI_PROBE_DONTCARE:
        case DDI_PROBE_SUCCESS:
                probe_failed = 0;
                break;
        default:
                probe_failed = 1;
                break;
        }
        pm_post_probe(&ppm_cookie, rv, probe_failed);

        return (rv);
}


/*
 * devi_attach()
 *      attach a device instance to the system if the driver supplies an
 *      attach(9E) entrypoint.
 */
int
devi_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
{
        struct dev_ops *ops;
        int error;
        int (*fn)(dev_info_t *, ddi_attach_cmd_t);
        pm_ppm_cookie_t pc;

        if ((error = mdi_pre_attach(devi, cmd)) != DDI_SUCCESS) {
                return (error);
        }

        pm_pre_attach(devi, &pc, cmd);

        if ((cmd == DDI_RESUME || cmd == DDI_PM_RESUME) &&
            e_ddi_parental_suspend_resume(devi)) {
                error = e_ddi_resume(devi, cmd);
                goto done;
        }
        ops = ddi_get_driver(devi);
        ASSERT(ops);
        if ((fn = ops->devo_attach) == NULL) {
                error = DDI_FAILURE;
                goto done;
        }

        /*
         * Call the driver's attach(9e) entrypoint
         */
        i_attach_ctlop(devi, cmd, DDI_PRE, 0);
        error = (*fn)(devi, cmd);
        i_attach_ctlop(devi, cmd, DDI_POST, error);

done:
        pm_post_attach(&pc, error);
        mdi_post_attach(devi, cmd, error);

        return (error);
}

/*
 * devi_detach()
 *      detach a device instance from the system if the driver supplies a
 *      detach(9E) entrypoint.
 */
int
devi_detach(dev_info_t *devi, ddi_detach_cmd_t cmd)
{
        struct dev_ops *ops;
        int error;
        int (*fn)(dev_info_t *, ddi_detach_cmd_t);
        pm_ppm_cookie_t pc;

        ASSERT(cmd == DDI_SUSPEND || cmd == DDI_PM_SUSPEND ||
            cmd == DDI_DETACH);

        if ((cmd == DDI_SUSPEND || cmd == DDI_PM_SUSPEND) &&
            e_ddi_parental_suspend_resume(devi)) {
                return (e_ddi_suspend(devi, cmd));
        }
        ops = ddi_get_driver(devi);
        ASSERT(ops);
        if ((fn = ops->devo_detach) == NULL)
                return (DDI_FAILURE);

        if ((error = mdi_pre_detach(devi, cmd)) != DDI_SUCCESS) {
                return (error);
        }
        i_detach_ctlop(devi, cmd, DDI_PRE, 0);
        pm_pre_detach(devi, cmd, &pc);

        /*
         * Call the driver's detach routine
         */
        error = (*fn)(devi, cmd);

        pm_post_detach(&pc, error);
        i_detach_ctlop(devi, cmd, DDI_POST, error);
        mdi_post_detach(devi, cmd, error);

        return (error);
}

static void
i_attach_ctlop(dev_info_t *devi, ddi_attach_cmd_t cmd, ddi_pre_post_t w,
    int ret)
{
        int error;
        struct attachspec as;
        dev_info_t *pdip = ddi_get_parent(devi);

        as.cmd = cmd;
        as.when = w;
        as.pdip = pdip;
        as.result = ret;
        (void) ddi_ctlops(devi, devi, DDI_CTLOPS_ATTACH, &as, &error);
}

static void
i_detach_ctlop(dev_info_t *devi, ddi_detach_cmd_t cmd, ddi_pre_post_t w,
    int ret)
{
        int error;
        struct detachspec ds;
        dev_info_t *pdip = ddi_get_parent(devi);

        ds.cmd = cmd;
        ds.when = w;
        ds.pdip = pdip;
        ds.result = ret;
        (void) ddi_ctlops(devi, devi, DDI_CTLOPS_DETACH, &ds, &error);
}

/*
 * This entry point not defined by Solaris 2.0 DDI/DKI, so
 * its inclusion here is somewhat moot.
 */
int
devi_reset(dev_info_t *devi, ddi_reset_cmd_t cmd)
{
        struct dev_ops *ops;
        int (*fn)(dev_info_t *, ddi_reset_cmd_t);

        if ((ops = ddi_get_driver(devi)) == NULL ||
            (fn = ops->devo_reset) == NULL)
                return (DDI_FAILURE);

        return ((*fn)(devi, cmd));
}

int
devi_quiesce(dev_info_t *devi)
{
        struct dev_ops *ops;
        int (*fn)(dev_info_t *);

        if (((ops = ddi_get_driver(devi)) == NULL) ||
            (ops->devo_rev < 4) || ((fn = ops->devo_quiesce) == NULL))
                return (DDI_FAILURE);

        return ((*fn)(devi));
}

/*
 * Leaf driver entry points. The following [cb]dev_* functions are *not* part
 * of the DDI, please use functions defined in <sys/sunldi.h> and driver_lyr.c.
 */
int
dev_open(dev_t *devp, int flag, int type, struct cred *cred)
{
        struct cb_ops   *cb;

        cb = devopsp[getmajor(*devp)]->devo_cb_ops;
        return ((*cb->cb_open)(devp, flag, type, cred));
}

int
dev_close(dev_t dev, int flag, int type, struct cred *cred)
{
        struct cb_ops   *cb;

        cb = (devopsp[getmajor(dev)])->devo_cb_ops;
        return ((*cb->cb_close)(dev, flag, type, cred));
}

/*
 * New Leaf driver open entry point.  We make a vnode and go through specfs
 * in order to obtain open close exclusions guarantees.  Note that we drop
 * OTYP_LYR if it was specified - we are going through specfs and it provides
 * last close semantics (FKLYR is provided to open(9E)).  Also, since
 * spec_open will drive attach via e_ddi_hold_devi_by_dev for a makespecvp
 * vnode with no SDIP_SET on the common snode, the dev_lopen caller no longer
 * needs to call ddi_hold_installed_driver.
 */
int
dev_lopen(dev_t *devp, int flag, int otype, struct cred *cred)
{
        struct vnode    *vp;
        int             error;
        struct vnode    *cvp;

        vp = makespecvp(*devp, (otype == OTYP_BLK) ? VBLK : VCHR);
        error = fop_open(&vp, flag | FKLYR, cred, NULL);
        if (error == 0) {
                /* Pick up the (possibly) new dev_t value. */
                *devp = vp->v_rdev;

                /*
                 * Place extra hold on the common vnode, which contains the
                 * open count, so that it is not destroyed by the VN_RELE of
                 * the shadow makespecvp vnode below.
                 */
                cvp = STOV(VTOCS(vp));
                VN_HOLD(cvp);
        }

        /* release the shadow makespecvp vnode. */
        VN_RELE(vp);
        return (error);
}

/*
 * Leaf driver close entry point.  We make a vnode and go through specfs in
 * order to obtain open close exclusions guarantees.  Note that we drop
 * OTYP_LYR if it was specified - we are going through specfs and it provides
 * last close semantics (FLKYR is provided to close(9E)).
 */
int
dev_lclose(dev_t dev, int flag, int otype, struct cred *cred)
{
        struct vnode    *vp;
        int             error;
        struct vnode    *cvp;
        char            *funcname;
        ulong_t         offset;

        vp = makespecvp(dev, (otype == OTYP_BLK) ? VBLK : VCHR);
        error = fop_close(vp, flag | FKLYR, 1, 0, cred, NULL);

        /*
         * Release the extra dev_lopen hold on the common vnode. We inline a
         * VN_RELE(cvp) call so that we can detect more dev_lclose calls than
         * dev_lopen calls without panic. See vn_rele.  If our inline of
         * vn_rele called fop_inactive(cvp, CRED(), ...) we would panic on the
         * "release the makespecvp vnode" VN_RELE(vp) that follows  - so
         * instead we diagnose this situation.  Note that the driver has
         * still seen a double close(9E), but that would have occurred with
         * the old dev_close implementation too.
         */
        cvp = STOV(VTOCS(vp));
        mutex_enter(&cvp->v_lock);
        switch (cvp->v_count) {
        default:
                VN_RELE_LOCKED(cvp);
                break;

        case 0:
                VTOS(vp)->s_commonvp = NULL;    /* avoid panic */
                /*FALLTHROUGH*/
        case 1:
                /*
                 * The following message indicates a serious problem in the
                 * identified driver, the driver should be fixed. If obtaining
                 * a panic dump is needed to diagnose the driver problem then
                 * adding "set dev_lclose_ce=3" to /etc/system will cause a
                 * panic when this occurs.
                 */
                funcname = modgetsymname((uintptr_t)caller(), &offset);
                cmn_err(dev_lclose_ce, "dev_lclose: extra close of dev_t 0x%lx "
                    "from %s`%s()", dev, mod_containing_pc(caller()),
                    funcname ? funcname : "unknown...");
                break;
        }
        mutex_exit(&cvp->v_lock);

        /* release the makespecvp vnode. */
        VN_RELE(vp);
        return (error);
}

/*
 * Returns -1 or the instance number of the given dev_t as
 * interpreted by the device driver.  The code may load the driver
 * but it does not attach any instances.
 *
 * Instance is supposed to be a int but drivers have assumed that
 * the pointer was a pointer to "void *" instead of a pointer to
 * "int *" so we now explicitly pass a pointer to "void *" and then
 * cast the result to an int when returning the value.
 */
int
dev_to_instance(dev_t dev)
{
        major_t         major = getmajor(dev);
        struct dev_ops  *ops;
        void            *vinstance;
        int             error;

        /* verify that the driver is loaded */
        if ((ops = mod_hold_dev_by_major(major)) == NULL)
                return (-1);
        ASSERT(CB_DRV_INSTALLED(ops));

        /* verify that it supports the getinfo(9E) entry point */
        if (ops->devo_getinfo == NULL) {
                mod_rele_dev_by_major(major);
                return (-1);
        }

        /* ask the driver to extract the instance number from the devt */
        error = (*ops->devo_getinfo)(NULL, DDI_INFO_DEVT2INSTANCE,
            (void *)dev, &vinstance);

        /* release the driver */
        mod_rele_dev_by_major(major);

        if (error != DDI_SUCCESS)
                return (-1);

        return ((int)(uintptr_t)vinstance);
}

int
bdev_strategy(struct buf *bp)
{
        struct dev_ops *ops;

        ops = devopsp[getmajor(bp->b_edev)];

        /*
         * Before we hit the io:::start probe, we need to fill in the b_dip
         * field of the buf structure.  This should be -- for the most part --
         * incredibly cheap.  If you're in this code looking to bum cycles,
         * there is almost certainly bigger game further down the I/O path...
         */
        (void) ops->devo_getinfo(NULL, DDI_INFO_DEVT2DEVINFO,
            (void *)bp->b_edev, (void **)&bp->b_dip);

        DTRACE_IO1(start, struct buf *, bp);
        bp->b_flags |= B_STARTED;

        return (ops->devo_cb_ops->cb_strategy(bp));
}

int
bdev_print(dev_t dev, caddr_t str)
{
        struct cb_ops   *cb;

        cb = devopsp[getmajor(dev)]->devo_cb_ops;
        return ((*cb->cb_print)(dev, str));
}

/*
 * Return number of DEV_BSIZE byte blocks.
 */
int
bdev_size(dev_t dev)
{
        uint_t          nblocks;
        uint_t          blksize;

        if ((nblocks = e_ddi_getprop(dev, VBLK, "nblocks",
            DDI_PROP_NOTPROM | DDI_PROP_DONTPASS, -1)) == -1)
                return (-1);

        /* Get blksize, default to DEV_BSIZE */
        if ((blksize = e_ddi_getprop(dev, VBLK, "blksize",
            DDI_PROP_NOTPROM | DDI_PROP_DONTPASS, -1)) == -1)
                blksize = e_ddi_getprop(DDI_DEV_T_ANY, VBLK, "device-blksize",
                    DDI_PROP_NOTPROM | DDI_PROP_DONTPASS, DEV_BSIZE);

        if (blksize >= DEV_BSIZE)
                return (nblocks * (blksize / DEV_BSIZE));
        else
                return (nblocks / (DEV_BSIZE / blksize));
}

/*
 * Same for 64-bit Nblocks property
 */
uint64_t
bdev_Size(dev_t dev)
{
        uint64_t        nblocks;
        uint_t          blksize;

        if ((nblocks = e_ddi_getprop_int64(dev, VBLK, "Nblocks",
            DDI_PROP_NOTPROM | DDI_PROP_DONTPASS, -1)) == -1)
                return (-1);

        /* Get blksize, default to DEV_BSIZE */
        if ((blksize = e_ddi_getprop(dev, VBLK, "blksize",
            DDI_PROP_NOTPROM | DDI_PROP_DONTPASS, -1)) == -1)
                blksize = e_ddi_getprop(DDI_DEV_T_ANY, VBLK, "device-blksize",
                    DDI_PROP_NOTPROM | DDI_PROP_DONTPASS, DEV_BSIZE);

        if (blksize >= DEV_BSIZE)
                return (nblocks * (blksize / DEV_BSIZE));
        else
                return (nblocks / (DEV_BSIZE / blksize));
}

int
bdev_dump(dev_t dev, caddr_t addr, daddr_t blkno, int blkcnt)
{
        struct cb_ops   *cb;

        cb = devopsp[getmajor(dev)]->devo_cb_ops;
        return ((*cb->cb_dump)(dev, addr, blkno, blkcnt));
}

int
cdev_read(dev_t dev, struct uio *uiop, struct cred *cred)
{
        struct cb_ops   *cb;

        cb = devopsp[getmajor(dev)]->devo_cb_ops;
        return ((*cb->cb_read)(dev, uiop, cred));
}

int
cdev_write(dev_t dev, struct uio *uiop, struct cred *cred)
{
        struct cb_ops   *cb;

        cb = devopsp[getmajor(dev)]->devo_cb_ops;
        return ((*cb->cb_write)(dev, uiop, cred));
}

int
cdev_ioctl(dev_t dev, int cmd, intptr_t arg, int mode, struct cred *cred,
    int *rvalp)
{
        struct cb_ops   *cb;

        cb = devopsp[getmajor(dev)]->devo_cb_ops;
        return ((*cb->cb_ioctl)(dev, cmd, arg, mode, cred, rvalp));
}

int
cdev_devmap(dev_t dev, devmap_cookie_t dhp, offset_t off, size_t len,
    size_t *maplen, uint_t mode)
{
        struct cb_ops   *cb;

        cb = devopsp[getmajor(dev)]->devo_cb_ops;
        return ((*cb->cb_devmap)(dev, dhp, off, len, maplen, mode));
}

int
cdev_mmap(int (*mapfunc)(dev_t, off_t, int), dev_t dev, off_t off, int prot)
{
        return ((*mapfunc)(dev, off, prot));
}

int
cdev_segmap(dev_t dev, off_t off, struct as *as, caddr_t *addrp, off_t len,
    uint_t prot, uint_t maxprot, uint_t flags, cred_t *credp)
{
        struct cb_ops   *cb;

        cb = devopsp[getmajor(dev)]->devo_cb_ops;
        return ((*cb->cb_segmap)(dev, off, as, addrp,
            len, prot, maxprot, flags, credp));
}

int
cdev_poll(dev_t dev, short events, int anyyet, short *reventsp,
    struct pollhead **pollhdrp)
{
        struct cb_ops   *cb;

        cb = devopsp[getmajor(dev)]->devo_cb_ops;
        return ((*cb->cb_chpoll)(dev, events, anyyet, reventsp, pollhdrp));
}

/*
 * A 'size' property can be provided by a VCHR device.
 *
 * Since it's defined as zero for STREAMS devices, so we avoid the
 * overhead of looking it up.  Note also that we don't force an
 * unused driver into memory simply to ask about it's size.  We also
 * don't bother to ask it its size unless it's already been attached
 * (the attach routine is the earliest place the property will be created)
 *
 * XXX  In an ideal world, we'd call this at fop_getattr() time.
 */
int
cdev_size(dev_t dev)
{
        major_t maj;
        struct devnames *dnp;

        if ((maj = getmajor(dev)) >= devcnt)
                return (0);

        dnp = &(devnamesp[maj]);
        LOCK_DEV_OPS(&dnp->dn_lock);
        if (devopsp[maj] && devopsp[maj]->devo_cb_ops &&
            !devopsp[maj]->devo_cb_ops->cb_str) {
                UNLOCK_DEV_OPS(&dnp->dn_lock);
                return (e_ddi_getprop(dev, VCHR, "size",
                    DDI_PROP_NOTPROM | DDI_PROP_DONTPASS, 0));
        }
        UNLOCK_DEV_OPS(&dnp->dn_lock);
        return (0);
}

/*
 * same for 64-bit Size property
 */
uint64_t
cdev_Size(dev_t dev)
{
        major_t maj;
        struct devnames *dnp;

        if ((maj = getmajor(dev)) >= devcnt)
                return (0);

        dnp = &(devnamesp[maj]);
        LOCK_DEV_OPS(&dnp->dn_lock);
        if (devopsp[maj] && devopsp[maj]->devo_cb_ops &&
            !devopsp[maj]->devo_cb_ops->cb_str) {
                UNLOCK_DEV_OPS(&dnp->dn_lock);
                return (e_ddi_getprop_int64(dev, VCHR, "Size",
                    DDI_PROP_NOTPROM | DDI_PROP_DONTPASS, 0));
        }
        UNLOCK_DEV_OPS(&dnp->dn_lock);
        return (0);
}

/*
 * XXX  This routine is poorly named, because block devices can and do
 *      have properties (see bdev_size() above).
 *
 * XXX  fix the comment in devops.h that claims that cb_prop_op
 *      is character-only.
 */
int
cdev_prop_op(dev_t dev, dev_info_t *dip, ddi_prop_op_t prop_op, int mod_flags,
    char *name, caddr_t valuep, int *lengthp)
{
        struct cb_ops   *cb;

        if ((cb = devopsp[DEVI(dip)->devi_major]->devo_cb_ops) == NULL)
                return (DDI_PROP_NOT_FOUND);

        return ((*cb->cb_prop_op)(dev, dip, prop_op, mod_flags,
            name, valuep, lengthp));
}