Files
Arquivotheca.Solaris-2.5/uts/common/io/clone.c
seta75D 7c4988eac0 Init
2021-10-11 19:38:01 -03:00

348 lines
8.1 KiB
C
Executable File

/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/* THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF AT&T */
/* The copyright notice above does not evidence any */
/* actual or intended publication of such source code. */
#ident "@(#)clone.c 1.36 94/09/29 SMI" /* from S5R4 1.10 */
/*
* Clone Driver.
*/
#include "sys/types.h"
#include "sys/param.h"
#include "sys/errno.h"
#include "sys/signal.h"
#include "sys/vfs.h"
#include "sys/vnode.h"
#include "sys/pcb.h"
#include "sys/user.h"
#include "sys/stropts.h"
#include "sys/stream.h"
#include "sys/errno.h"
#include "sys/sysinfo.h"
#include "sys/ddi.h"
#include "sys/systm.h"
#include "sys/conf.h"
#include "sys/debug.h"
#include "sys/cred.h"
#include "sys/mkdev.h"
#include "sys/open.h"
#include "sys/strsubr.h"
#include "sys/sunddi.h"
struct vnode *makespecvp(); /* Device file system */
int clnopen();
static struct module_info clnm_info = { 0, "CLONE", 0, 0, 0, 0 };
static struct qinit clnrinit = { NULL, NULL, clnopen, NULL, NULL,
&clnm_info, NULL };
static struct qinit clnwinit = { NULL, NULL, NULL, NULL, NULL,
&clnm_info, NULL };
struct streamtab clninfo = { &clnrinit, &clnwinit };
/*
* XXX: old conf.c entry had d_open filled plus a d_str filled in?
* XXX: can't see why, thus it's not here.
*/
static int cln_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg,
void **result);
static int cln_identify(dev_info_t *devi);
static int cln_attach(dev_info_t *devi, ddi_attach_cmd_t cmd);
static dev_info_t *cln_dip; /* private copy of devinfo pointer */
#define CLONE_CONF_FLAG (D_NEW|D_MP)
DDI_DEFINE_STREAM_OPS(clone_ops, cln_identify, nulldev, \
cln_attach, nodev, nodev, \
cln_info, CLONE_CONF_FLAG, &clninfo);
#define CBFLAG(maj) (devopsp[(maj)]->devo_cb_ops->cb_flag)
#include <sys/types.h>
#include <sys/conf.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/modctl.h>
extern nodev(), nulldev();
extern dseekneg_flag;
extern struct mod_ops mod_driverops;
extern struct dev_ops clone_ops;
/*
* Module linkage information for the kernel.
*/
static struct modldrv modldrv = {
&mod_driverops, /* Type of module. This one is a pseudo driver */
"Clone Pseudodriver 'clone'",
&clone_ops, /* driver ops */
};
static struct modlinkage modlinkage = {
MODREV_1,
(void *)&modldrv,
NULL
};
int
_init(void)
{
return (mod_install(&modlinkage));
}
int
_fini(void)
{
/*
* Since the clone driver's reference count is unreliable,
* make sure we are never unloaded.
*/
return (EBUSY);
}
int
_info(struct modinfo *modinfop)
{
return (mod_info(&modlinkage, modinfop));
}
static int
cln_identify(dev_info_t *devi)
{
if (strcmp(ddi_get_name(devi), "clone") == 0)
return (DDI_IDENTIFIED);
else
return (DDI_NOT_IDENTIFIED);
}
/* ARGSUSED */
static int
cln_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
{
cln_dip = devi;
return (DDI_SUCCESS);
}
/* ARGSUSED */
static int
cln_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg,
void **result)
{
register int error;
switch (infocmd) {
case DDI_INFO_DEVT2DEVINFO:
if (cln_dip == NULL) {
error = DDI_FAILURE;
} else {
*result = (void *) cln_dip;
error = DDI_SUCCESS;
}
break;
case DDI_INFO_DEVT2INSTANCE:
*result = (void *)0;
error = DDI_SUCCESS;
break;
default:
error = DDI_FAILURE;
}
return (error);
}
/*
* Clone open. Maj is the major device number of the streams
* device to open. Look up the device in the cdevsw[]. Attach
* its qinit structures to the read and write queues and call its
* open with the sflag set to CLONEOPEN. Swap in a new vnode with
* the real device number constructed from either
* a) for old-style drivers:
* maj and the minor returned by the device open, or
* b) for new-style drivers:
* the whole dev passed back as a reference parameter
* from the device open.
*/
int
clnopen(rq, devp, flag, sflag, crp)
register queue_t *rq;
dev_t *devp;
int flag;
int sflag;
cred_t *crp;
{
register struct streamtab *stp;
dev_t newdev;
int error = 0;
klwp_id_t lwp;
major_t maj;
minor_t emaj;
int safety;
struct qinit *rinit, *winit;
u_long qflag, sqtype;
if (sflag)
return (ENXIO);
/*
* Get the device to open.
*/
emaj = getminor(*devp); /* minor is major for a cloned drivers */
maj = etoimajor(emaj); /* get internal major of cloned driver */
if (maj >= devcnt)
return (ENXIO);
/*
* XXX: there is no corresponding release for clone driver opens.
*/
if (ddi_hold_installed_driver(maj) == NULL)
return (ENXIO);
if ((stp = STREAMSTAB(maj)) == NULL) {
ddi_rele_driver(maj);
return (ENXIO);
}
newdev = makedevice(emaj, 0); /* create new style device number */
safety = CBFLAG(maj);
/*
* Save so that we can restore the q on failure.
*/
rinit = rq->q_qinfo;
winit = WR(rq)->q_qinfo;
ASSERT(rq->q_syncq->sq_type == (SQ_CI|SQ_CO));
ASSERT((rq->q_flag & QMT_TYPEMASK) == QMTSAFE);
ASSERT(rq->q_syncq == SQ(rq) && WR(rq)->q_syncq == SQ(rq));
error = devflg_to_qflag(safety, &qflag, &sqtype);
if (error) {
cmn_err(CE_CONT,
"clnopen: bad MT flags in cb_flag: 0x%x",
safety & D_MTSAFETY_MASK);
return (error);
}
/*
* Set the syncq state what qattach started off with. This is safe
* since no other thread can access this queue at this point
* (stream open, close, push, and pop are single threaded
* by the framework.)
*/
leavesq(rq->q_syncq, SQ_OPENCLOSE);
unblockq(rq);
/*
* Substitute the real qinit values for the current ones.
*/
/* setq might sleep in kmem_alloc - avoid holding locks. */
setq(rq, stp->st_rdinit, stp->st_wrinit, stp, &perdev_syncq[maj],
qflag, sqtype);
/*
* Open the attached module or driver.
*/
if (rq->q_flag & QUNSAFE) {
/*
* Do not do an entersq on the queue since
* that would prevent entry of the put and svc procedures
* during a sleep() in the open. Instead we do all what entersq
* does except setting SQ_EXCL.
*/
claimq(rq);
mutex_enter(&unsafe_driver);
insertq(STREAM(rq), rq, 1);
} else {
/*
* If there is an outer perimeter get exclusive access during
* the open procedure.
* Bump up the reference count on the queue.
*/
entersq(rq->q_syncq, SQ_OPENCLOSE);
blockq(rq);
}
/*
* Call the device open with the stream flag CLONEOPEN. The device
* will either fail this or return a minor device number (for old-
* style drivers) or the whole device number (for new-style drivers).
*/
if (rq->q_flag & QOLD) {
int oldev;
/*
* newdev is minor for pre-SVR4 drivers.
* old style drivers get the old device format
* so make sure it fits.
*/
if ((oldev = (o_dev_t)cmpdev(newdev)) == NODEV) {
error = ENXIO;
} else if ((newdev = (*rq->q_qinfo->qi_qopen)(rq, oldev,
flag, CLONEOPEN)) == OPENFAIL) {
lwp = ttolwp(curthread);
error = (lwp->lwp_error == 0 ? ENXIO : lwp->lwp_error);
} else {
/* return new style dev to caller */
*devp = makedevice(emaj, (newdev & OMAXMIN));
}
} else {
if (!(error = (*rq->q_qinfo->qi_qopen)
(rq, &newdev, flag, CLONEOPEN, crp))) {
if ((getmajor(newdev) >= devcnt) ||
!(stp = STREAMSTAB(getmajor(newdev)))) {
(*rq->q_qinfo->qi_qclose)
(rq, flag, crp);
error = ENXIO;
} else {
major_t m = getmajor(newdev);
if (m != maj) {
(void) ddi_hold_installed_driver(m);
}
*devp = newdev;
}
}
}
if (error) {
/*
* open failed; pretty up to look like original
* queue.
*/
if ((rq->q_flag & QUNSAFE)) {
removeq(rq, 1);
rq->q_next = NULL; WR(rq)->q_next = NULL;
releaseq(rq);
mutex_exit(&unsafe_driver);
} else {
/* XXX fix this in qattach as well! */
if (backq(WR(rq)) && backq(WR(rq))->q_next == WR(rq))
qprocsoff(rq);
else
unblockq(rq);
leavesq(rq->q_syncq, SQ_OPENCLOSE);
}
rq->q_next = WR(rq)->q_next = NULL;
flush_syncq(rq->q_syncq, rq);
flush_syncq(WR(rq)->q_syncq, WR(rq));
rq->q_ptr = WR(rq)->q_ptr = NULL;
/* setq might sleep in kmem_alloc - avoid holding locks. */
setq(rq, rinit, winit, NULL, NULL, QMTSAFE, SQ_CI|SQ_CO);
/* Restore back to what qattach will expect */
entersq(rq->q_syncq, SQ_OPENCLOSE);
blockq(rq);
ddi_rele_driver(maj);
}
return (error);
}