xref: /onnv-gate/usr/src/uts/common/io/devpoll.c (revision 0:68f95e015346)
1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24*0Sstevel@tonic-gate  * Use is subject to license terms.
25*0Sstevel@tonic-gate  */
26*0Sstevel@tonic-gate 
27*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
28*0Sstevel@tonic-gate 
29*0Sstevel@tonic-gate #include <sys/types.h>
30*0Sstevel@tonic-gate #include <sys/devops.h>
31*0Sstevel@tonic-gate #include <sys/conf.h>
32*0Sstevel@tonic-gate #include <sys/modctl.h>
33*0Sstevel@tonic-gate #include <sys/sunddi.h>
34*0Sstevel@tonic-gate #include <sys/stat.h>
35*0Sstevel@tonic-gate #include <sys/poll_impl.h>
36*0Sstevel@tonic-gate #include <sys/errno.h>
37*0Sstevel@tonic-gate #include <sys/kmem.h>
38*0Sstevel@tonic-gate #include <sys/mkdev.h>
39*0Sstevel@tonic-gate #include <sys/debug.h>
40*0Sstevel@tonic-gate #include <sys/file.h>
41*0Sstevel@tonic-gate #include <sys/sysmacros.h>
42*0Sstevel@tonic-gate #include <sys/systm.h>
43*0Sstevel@tonic-gate #include <sys/bitmap.h>
44*0Sstevel@tonic-gate #include <sys/devpoll.h>
45*0Sstevel@tonic-gate #include <sys/rctl.h>
46*0Sstevel@tonic-gate #include <sys/resource.h>
47*0Sstevel@tonic-gate 
48*0Sstevel@tonic-gate #define	RESERVED	1
49*0Sstevel@tonic-gate 
50*0Sstevel@tonic-gate /* local data struct */
51*0Sstevel@tonic-gate static	dp_entry_t	**devpolltbl; 	/* dev poll entries */
52*0Sstevel@tonic-gate static	size_t		dptblsize;
53*0Sstevel@tonic-gate 
54*0Sstevel@tonic-gate static	kmutex_t	devpoll_lock;	/* lock protecting dev tbl */
55*0Sstevel@tonic-gate int			devpoll_init;	/* is /dev/poll initialized already */
56*0Sstevel@tonic-gate 
57*0Sstevel@tonic-gate /* device local functions */
58*0Sstevel@tonic-gate 
59*0Sstevel@tonic-gate static int dpopen(dev_t *devp, int flag, int otyp, cred_t *credp);
60*0Sstevel@tonic-gate static int dpwrite(dev_t dev, struct uio *uiop, cred_t *credp);
61*0Sstevel@tonic-gate static int dpioctl(dev_t dev, int cmd, intptr_t arg, int mode, cred_t *credp,
62*0Sstevel@tonic-gate     int *rvalp);
63*0Sstevel@tonic-gate static int dppoll(dev_t dev, short events, int anyyet, short *reventsp,
64*0Sstevel@tonic-gate     struct pollhead **phpp);
65*0Sstevel@tonic-gate static int dpclose(dev_t dev, int flag, int otyp, cred_t *credp);
66*0Sstevel@tonic-gate static dev_info_t *dpdevi;
67*0Sstevel@tonic-gate 
68*0Sstevel@tonic-gate 
69*0Sstevel@tonic-gate static struct cb_ops    dp_cb_ops = {
70*0Sstevel@tonic-gate 	dpopen,			/* open */
71*0Sstevel@tonic-gate 	dpclose,		/* close */
72*0Sstevel@tonic-gate 	nodev,			/* strategy */
73*0Sstevel@tonic-gate 	nodev,			/* print */
74*0Sstevel@tonic-gate 	nodev,			/* dump */
75*0Sstevel@tonic-gate 	nodev,			/* read */
76*0Sstevel@tonic-gate 	dpwrite,		/* write */
77*0Sstevel@tonic-gate 	dpioctl,		/* ioctl */
78*0Sstevel@tonic-gate 	nodev,			/* devmap */
79*0Sstevel@tonic-gate 	nodev,			/* mmap */
80*0Sstevel@tonic-gate 	nodev,			/* segmap */
81*0Sstevel@tonic-gate 	dppoll,			/* poll */
82*0Sstevel@tonic-gate 	nodev,			/* prop_op */
83*0Sstevel@tonic-gate 	(struct streamtab *)0,	/* streamtab */
84*0Sstevel@tonic-gate 	D_NEW | D_MP		/* flags */
85*0Sstevel@tonic-gate };
86*0Sstevel@tonic-gate 
87*0Sstevel@tonic-gate static int dpattach(dev_info_t *, ddi_attach_cmd_t);
88*0Sstevel@tonic-gate static int dpdetach(dev_info_t *, ddi_detach_cmd_t);
89*0Sstevel@tonic-gate static int dpinfo(dev_info_t *, ddi_info_cmd_t, void *, void **);
90*0Sstevel@tonic-gate 
91*0Sstevel@tonic-gate static struct dev_ops dp_ops = {
92*0Sstevel@tonic-gate 	DEVO_REV,		/* devo_rev */
93*0Sstevel@tonic-gate 	0,			/* refcnt */
94*0Sstevel@tonic-gate 	dpinfo,			/* info */
95*0Sstevel@tonic-gate 	nulldev,		/* identify */
96*0Sstevel@tonic-gate 	nulldev,		/* probe */
97*0Sstevel@tonic-gate 	dpattach,		/* attach */
98*0Sstevel@tonic-gate 	dpdetach,		/* detach */
99*0Sstevel@tonic-gate 	nodev,			/* reset */
100*0Sstevel@tonic-gate 	&dp_cb_ops,		/* driver operations */
101*0Sstevel@tonic-gate 	(struct bus_ops *)NULL, /* bus operations */
102*0Sstevel@tonic-gate 	nulldev			/* power */
103*0Sstevel@tonic-gate };
104*0Sstevel@tonic-gate 
105*0Sstevel@tonic-gate 
106*0Sstevel@tonic-gate static struct modldrv modldrv = {
107*0Sstevel@tonic-gate 	&mod_driverops,		/* type of module - a driver */
108*0Sstevel@tonic-gate 	"Dev Poll driver %I%",
109*0Sstevel@tonic-gate 	&dp_ops,
110*0Sstevel@tonic-gate };
111*0Sstevel@tonic-gate 
112*0Sstevel@tonic-gate static struct modlinkage modlinkage = {
113*0Sstevel@tonic-gate 	MODREV_1,
114*0Sstevel@tonic-gate 	(void *)&modldrv,
115*0Sstevel@tonic-gate 	NULL
116*0Sstevel@tonic-gate };
117*0Sstevel@tonic-gate 
118*0Sstevel@tonic-gate /*
119*0Sstevel@tonic-gate  * Locking Design
120*0Sstevel@tonic-gate  *
121*0Sstevel@tonic-gate  * The /dev/poll driver shares most of its code with poll sys call whose
122*0Sstevel@tonic-gate  * code is in common/syscall/poll.c. In poll(2) design, the pollcache
123*0Sstevel@tonic-gate  * structure is per lwp. An implicit assumption is made there that some
124*0Sstevel@tonic-gate  * portion of pollcache will never be touched by other lwps. E.g., in
125*0Sstevel@tonic-gate  * poll(2) design, no lwp will ever need to grow bitmap of other lwp.
126*0Sstevel@tonic-gate  * This assumption is not true for /dev/poll; hence the need for extra
127*0Sstevel@tonic-gate  * locking.
128*0Sstevel@tonic-gate  *
129*0Sstevel@tonic-gate  * To allow more paralellism, each /dev/poll file descriptor (indexed by
130*0Sstevel@tonic-gate  * minor number) has its own lock. Since read (dpioctl) is a much more
131*0Sstevel@tonic-gate  * frequent operation than write, we want to allow multiple reads on same
132*0Sstevel@tonic-gate  * /dev/poll fd. However, we prevent writes from being starved by giving
133*0Sstevel@tonic-gate  * priority to write operation. Theoretically writes can starve reads as
134*0Sstevel@tonic-gate  * well. But in pratical sense this is not important because (1) writes
135*0Sstevel@tonic-gate  * happens less often than reads, and (2) write operation defines the
136*0Sstevel@tonic-gate  * content of poll fd a cache set. If writes happens so often that they
137*0Sstevel@tonic-gate  * can starve reads, that means the cached set is very unstable. It may
138*0Sstevel@tonic-gate  * not make sense to read an unstable cache set anyway. Therefore, the
139*0Sstevel@tonic-gate  * writers starving readers case is not handled in this design.
140*0Sstevel@tonic-gate  */
141*0Sstevel@tonic-gate 
142*0Sstevel@tonic-gate int
143*0Sstevel@tonic-gate _init()
144*0Sstevel@tonic-gate {
145*0Sstevel@tonic-gate 	int	error;
146*0Sstevel@tonic-gate 
147*0Sstevel@tonic-gate 	dptblsize = DEVPOLLSIZE;
148*0Sstevel@tonic-gate 	devpolltbl = kmem_zalloc(sizeof (caddr_t) * dptblsize, KM_SLEEP);
149*0Sstevel@tonic-gate 	mutex_init(&devpoll_lock, NULL, MUTEX_DEFAULT, NULL);
150*0Sstevel@tonic-gate 	devpoll_init = 1;
151*0Sstevel@tonic-gate 	if ((error = mod_install(&modlinkage)) != 0) {
152*0Sstevel@tonic-gate 		mutex_destroy(&devpoll_lock);
153*0Sstevel@tonic-gate 		kmem_free(devpolltbl, sizeof (caddr_t) * dptblsize);
154*0Sstevel@tonic-gate 		devpoll_init = 0;
155*0Sstevel@tonic-gate 	}
156*0Sstevel@tonic-gate 	return (error);
157*0Sstevel@tonic-gate }
158*0Sstevel@tonic-gate 
159*0Sstevel@tonic-gate int
160*0Sstevel@tonic-gate _fini()
161*0Sstevel@tonic-gate {
162*0Sstevel@tonic-gate 	int error;
163*0Sstevel@tonic-gate 
164*0Sstevel@tonic-gate 	if ((error = mod_remove(&modlinkage)) != 0) {
165*0Sstevel@tonic-gate 		return (error);
166*0Sstevel@tonic-gate 	}
167*0Sstevel@tonic-gate 	mutex_destroy(&devpoll_lock);
168*0Sstevel@tonic-gate 	kmem_free(devpolltbl, sizeof (caddr_t) * dptblsize);
169*0Sstevel@tonic-gate 	return (0);
170*0Sstevel@tonic-gate }
171*0Sstevel@tonic-gate 
172*0Sstevel@tonic-gate int
173*0Sstevel@tonic-gate _info(struct modinfo *modinfop)
174*0Sstevel@tonic-gate {
175*0Sstevel@tonic-gate 	return (mod_info(&modlinkage, modinfop));
176*0Sstevel@tonic-gate }
177*0Sstevel@tonic-gate 
178*0Sstevel@tonic-gate /*ARGSUSED*/
179*0Sstevel@tonic-gate static int
180*0Sstevel@tonic-gate dpattach(dev_info_t *devi, ddi_attach_cmd_t cmd)
181*0Sstevel@tonic-gate {
182*0Sstevel@tonic-gate 	if (ddi_create_minor_node(devi, "poll", S_IFCHR, 0, DDI_PSEUDO, NULL)
183*0Sstevel@tonic-gate 	    == DDI_FAILURE) {
184*0Sstevel@tonic-gate 		ddi_remove_minor_node(devi, NULL);
185*0Sstevel@tonic-gate 		return (DDI_FAILURE);
186*0Sstevel@tonic-gate 	}
187*0Sstevel@tonic-gate 	dpdevi = devi;
188*0Sstevel@tonic-gate 	return (DDI_SUCCESS);
189*0Sstevel@tonic-gate }
190*0Sstevel@tonic-gate 
191*0Sstevel@tonic-gate static int
192*0Sstevel@tonic-gate dpdetach(dev_info_t *devi, ddi_detach_cmd_t cmd)
193*0Sstevel@tonic-gate {
194*0Sstevel@tonic-gate 	if (cmd != DDI_DETACH)
195*0Sstevel@tonic-gate 		return (DDI_FAILURE);
196*0Sstevel@tonic-gate 
197*0Sstevel@tonic-gate 	ddi_remove_minor_node(devi, NULL);
198*0Sstevel@tonic-gate 	return (DDI_SUCCESS);
199*0Sstevel@tonic-gate }
200*0Sstevel@tonic-gate 
201*0Sstevel@tonic-gate /* ARGSUSED */
202*0Sstevel@tonic-gate static int
203*0Sstevel@tonic-gate dpinfo(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result)
204*0Sstevel@tonic-gate {
205*0Sstevel@tonic-gate 	int error;
206*0Sstevel@tonic-gate 
207*0Sstevel@tonic-gate 	switch (infocmd) {
208*0Sstevel@tonic-gate 	case DDI_INFO_DEVT2DEVINFO:
209*0Sstevel@tonic-gate 		*result = (void *)dpdevi;
210*0Sstevel@tonic-gate 		error = DDI_SUCCESS;
211*0Sstevel@tonic-gate 		break;
212*0Sstevel@tonic-gate 	case DDI_INFO_DEVT2INSTANCE:
213*0Sstevel@tonic-gate 		*result = (void *)0;
214*0Sstevel@tonic-gate 		error = DDI_SUCCESS;
215*0Sstevel@tonic-gate 		break;
216*0Sstevel@tonic-gate 	default:
217*0Sstevel@tonic-gate 		error = DDI_FAILURE;
218*0Sstevel@tonic-gate 	}
219*0Sstevel@tonic-gate 	return (error);
220*0Sstevel@tonic-gate }
221*0Sstevel@tonic-gate 
222*0Sstevel@tonic-gate /*
223*0Sstevel@tonic-gate  * dp_pcache_poll has similar logic to pcache_poll() in poll.c. The major
224*0Sstevel@tonic-gate  * differences are: (1) /dev/poll requires scanning the bitmap starting at
225*0Sstevel@tonic-gate  * where it was stopped last time, instead of always starting from 0,
226*0Sstevel@tonic-gate  * (2) since user may not have cleaned up the cached fds when they are
227*0Sstevel@tonic-gate  * closed, some polldats in cache may refer to closed or reused fds. We
228*0Sstevel@tonic-gate  * need to check for those cases.
229*0Sstevel@tonic-gate  *
230*0Sstevel@tonic-gate  * NOTE: Upon closing an fd, automatic poll cache cleanup is done for
231*0Sstevel@tonic-gate  *	 poll(2) caches but NOT for /dev/poll caches. So expect some
232*0Sstevel@tonic-gate  *	 stale entries!
233*0Sstevel@tonic-gate  */
234*0Sstevel@tonic-gate static int
235*0Sstevel@tonic-gate dp_pcache_poll(pollfd_t *pfdp, pollcache_t *pcp, nfds_t nfds, int *fdcntp)
236*0Sstevel@tonic-gate {
237*0Sstevel@tonic-gate 	int		start, ostart, end;
238*0Sstevel@tonic-gate 	int		fdcnt, fd;
239*0Sstevel@tonic-gate 	boolean_t 	done;
240*0Sstevel@tonic-gate 	file_t		*fp;
241*0Sstevel@tonic-gate 	short		revent;
242*0Sstevel@tonic-gate 	boolean_t	no_wrap;
243*0Sstevel@tonic-gate 	pollhead_t	*php;
244*0Sstevel@tonic-gate 	polldat_t	*pdp;
245*0Sstevel@tonic-gate 	int		error = 0;
246*0Sstevel@tonic-gate 
247*0Sstevel@tonic-gate 	ASSERT(MUTEX_HELD(&pcp->pc_lock));
248*0Sstevel@tonic-gate 	if (pcp->pc_bitmap == NULL) {
249*0Sstevel@tonic-gate 		/*
250*0Sstevel@tonic-gate 		 * No Need to search because no poll fd
251*0Sstevel@tonic-gate 		 * has been cached.
252*0Sstevel@tonic-gate 		 */
253*0Sstevel@tonic-gate 		return (error);
254*0Sstevel@tonic-gate 	}
255*0Sstevel@tonic-gate retry:
256*0Sstevel@tonic-gate 	start = ostart = pcp->pc_mapstart;
257*0Sstevel@tonic-gate 	end = pcp->pc_mapend;
258*0Sstevel@tonic-gate 	php = NULL;
259*0Sstevel@tonic-gate 
260*0Sstevel@tonic-gate 	if (start == 0) {
261*0Sstevel@tonic-gate 		/*
262*0Sstevel@tonic-gate 		 * started from every begining, no need to wrap around.
263*0Sstevel@tonic-gate 		 */
264*0Sstevel@tonic-gate 		no_wrap = B_TRUE;
265*0Sstevel@tonic-gate 	} else {
266*0Sstevel@tonic-gate 		no_wrap = B_FALSE;
267*0Sstevel@tonic-gate 	}
268*0Sstevel@tonic-gate 	done = B_FALSE;
269*0Sstevel@tonic-gate 	fdcnt = 0;
270*0Sstevel@tonic-gate 	while ((fdcnt < nfds) && !done) {
271*0Sstevel@tonic-gate 		php = NULL;
272*0Sstevel@tonic-gate 		revent = 0;
273*0Sstevel@tonic-gate 		/*
274*0Sstevel@tonic-gate 		 * Examine the bit map in a circular fashion
275*0Sstevel@tonic-gate 		 * to avoid starvation. Always resume from
276*0Sstevel@tonic-gate 		 * last stop. Scan till end of the map. Then
277*0Sstevel@tonic-gate 		 * wrap around.
278*0Sstevel@tonic-gate 		 */
279*0Sstevel@tonic-gate 		fd = bt_getlowbit(pcp->pc_bitmap, start, end);
280*0Sstevel@tonic-gate 		ASSERT(fd <= end);
281*0Sstevel@tonic-gate 		if (fd >= 0) {
282*0Sstevel@tonic-gate 			if (fd == end) {
283*0Sstevel@tonic-gate 				if (no_wrap) {
284*0Sstevel@tonic-gate 					done = B_TRUE;
285*0Sstevel@tonic-gate 				} else {
286*0Sstevel@tonic-gate 					start = 0;
287*0Sstevel@tonic-gate 					end = ostart - 1;
288*0Sstevel@tonic-gate 					no_wrap = B_TRUE;
289*0Sstevel@tonic-gate 				}
290*0Sstevel@tonic-gate 			} else {
291*0Sstevel@tonic-gate 				start = fd + 1;
292*0Sstevel@tonic-gate 			}
293*0Sstevel@tonic-gate 			pdp = pcache_lookup_fd(pcp, fd);
294*0Sstevel@tonic-gate 			ASSERT(pdp != NULL);
295*0Sstevel@tonic-gate 			ASSERT(pdp->pd_fd == fd);
296*0Sstevel@tonic-gate 			if (pdp->pd_fp == NULL) {
297*0Sstevel@tonic-gate 				/*
298*0Sstevel@tonic-gate 				 * The fd is POLLREMOVed. This fd is
299*0Sstevel@tonic-gate 				 * logically no longer cached. So move
300*0Sstevel@tonic-gate 				 * on to the next one.
301*0Sstevel@tonic-gate 				 */
302*0Sstevel@tonic-gate 				continue;
303*0Sstevel@tonic-gate 			}
304*0Sstevel@tonic-gate 			if ((fp = getf(fd)) == NULL) {
305*0Sstevel@tonic-gate 				/*
306*0Sstevel@tonic-gate 				 * The fd has been closed, but user has not
307*0Sstevel@tonic-gate 				 * done a POLLREMOVE on this fd yet. Instead
308*0Sstevel@tonic-gate 				 * of cleaning it here implicitly, we return
309*0Sstevel@tonic-gate 				 * POLLNVAL. This is consistent with poll(2)
310*0Sstevel@tonic-gate 				 * polling a closed fd. Hope this will remind
311*0Sstevel@tonic-gate 				 * user to do a POLLREMOVE.
312*0Sstevel@tonic-gate 				 */
313*0Sstevel@tonic-gate 				pfdp[fdcnt].fd = fd;
314*0Sstevel@tonic-gate 				pfdp[fdcnt].revents = POLLNVAL;
315*0Sstevel@tonic-gate 				fdcnt++;
316*0Sstevel@tonic-gate 				continue;
317*0Sstevel@tonic-gate 			}
318*0Sstevel@tonic-gate 			if (fp != pdp->pd_fp) {
319*0Sstevel@tonic-gate 				/*
320*0Sstevel@tonic-gate 				 * user is polling on a cached fd which was
321*0Sstevel@tonic-gate 				 * closed and then reused. Unfortunately
322*0Sstevel@tonic-gate 				 * there is no good way to inform user.
323*0Sstevel@tonic-gate 				 * If the file struct is also reused, we
324*0Sstevel@tonic-gate 				 * may not be able to detect the fd reuse
325*0Sstevel@tonic-gate 				 * at all.  As long as this does not
326*0Sstevel@tonic-gate 				 * cause system failure and/or memory leak,
327*0Sstevel@tonic-gate 				 * we will play along. Man page states if
328*0Sstevel@tonic-gate 				 * user does not clean up closed fds, polling
329*0Sstevel@tonic-gate 				 * results will be indeterministic.
330*0Sstevel@tonic-gate 				 *
331*0Sstevel@tonic-gate 				 * XXX - perhaps log the detection of fd
332*0Sstevel@tonic-gate 				 *	 reuse?
333*0Sstevel@tonic-gate 				 */
334*0Sstevel@tonic-gate 				pdp->pd_fp = fp;
335*0Sstevel@tonic-gate 			}
336*0Sstevel@tonic-gate 			/*
337*0Sstevel@tonic-gate 			 * XXX - pollrelock() logic needs to know which
338*0Sstevel@tonic-gate 			 * which pollcache lock to grab. It'd be a
339*0Sstevel@tonic-gate 			 * cleaner solution if we could pass pcp as
340*0Sstevel@tonic-gate 			 * an arguement in VOP_POLL interface instead
341*0Sstevel@tonic-gate 			 * of implicitly passing it using thread_t
342*0Sstevel@tonic-gate 			 * struct. On the other hand, changing VOP_POLL
343*0Sstevel@tonic-gate 			 * interface will require all driver/file system
344*0Sstevel@tonic-gate 			 * poll routine to change. May want to revisit
345*0Sstevel@tonic-gate 			 * the tradeoff later.
346*0Sstevel@tonic-gate 			 */
347*0Sstevel@tonic-gate 			curthread->t_pollcache = pcp;
348*0Sstevel@tonic-gate 			error = VOP_POLL(fp->f_vnode, pdp->pd_events, 0,
349*0Sstevel@tonic-gate 			    &revent, &php);
350*0Sstevel@tonic-gate 			curthread->t_pollcache = NULL;
351*0Sstevel@tonic-gate 			releasef(fd);
352*0Sstevel@tonic-gate 			if (error != 0) {
353*0Sstevel@tonic-gate 				break;
354*0Sstevel@tonic-gate 			}
355*0Sstevel@tonic-gate 			/*
356*0Sstevel@tonic-gate 			 * layered devices (e.g. console driver)
357*0Sstevel@tonic-gate 			 * may change the vnode and thus the pollhead
358*0Sstevel@tonic-gate 			 * pointer out from underneath us.
359*0Sstevel@tonic-gate 			 */
360*0Sstevel@tonic-gate 			if (php != NULL && pdp->pd_php != NULL &&
361*0Sstevel@tonic-gate 			    php != pdp->pd_php) {
362*0Sstevel@tonic-gate 				pollhead_delete(pdp->pd_php, pdp);
363*0Sstevel@tonic-gate 				pdp->pd_php = php;
364*0Sstevel@tonic-gate 				pollhead_insert(php, pdp);
365*0Sstevel@tonic-gate 				/*
366*0Sstevel@tonic-gate 				 * The bit should still be set.
367*0Sstevel@tonic-gate 				 */
368*0Sstevel@tonic-gate 				ASSERT(BT_TEST(pcp->pc_bitmap, fd));
369*0Sstevel@tonic-gate 				goto retry;
370*0Sstevel@tonic-gate 			}
371*0Sstevel@tonic-gate 
372*0Sstevel@tonic-gate 			if (revent != 0) {
373*0Sstevel@tonic-gate 				pfdp[fdcnt].fd = fd;
374*0Sstevel@tonic-gate 				pfdp[fdcnt].events = pdp->pd_events;
375*0Sstevel@tonic-gate 				pfdp[fdcnt].revents = revent;
376*0Sstevel@tonic-gate 				fdcnt++;
377*0Sstevel@tonic-gate 			} else if (php != NULL) {
378*0Sstevel@tonic-gate 				/*
379*0Sstevel@tonic-gate 				 * We clear a bit or cache a poll fd if
380*0Sstevel@tonic-gate 				 * the driver returns a poll head ptr,
381*0Sstevel@tonic-gate 				 * which is expected in the case of 0
382*0Sstevel@tonic-gate 				 * revents. Some buggy driver may return
383*0Sstevel@tonic-gate 				 * NULL php pointer with 0 revents. In
384*0Sstevel@tonic-gate 				 * this case, we just treat the driver as
385*0Sstevel@tonic-gate 				 * "noncachable" and not clearing the bit
386*0Sstevel@tonic-gate 				 * in bitmap.
387*0Sstevel@tonic-gate 				 */
388*0Sstevel@tonic-gate 				if ((pdp->pd_php != NULL) &&
389*0Sstevel@tonic-gate 				    ((pcp->pc_flag & T_POLLWAKE) == 0)) {
390*0Sstevel@tonic-gate 					BT_CLEAR(pcp->pc_bitmap, fd);
391*0Sstevel@tonic-gate 				}
392*0Sstevel@tonic-gate 				if (pdp->pd_php == NULL) {
393*0Sstevel@tonic-gate 					pollhead_insert(php, pdp);
394*0Sstevel@tonic-gate 					pdp->pd_php = php;
395*0Sstevel@tonic-gate 				}
396*0Sstevel@tonic-gate 			}
397*0Sstevel@tonic-gate 		} else {
398*0Sstevel@tonic-gate 			/*
399*0Sstevel@tonic-gate 			 * No bit set in the range. Check for wrap around.
400*0Sstevel@tonic-gate 			 */
401*0Sstevel@tonic-gate 			if (!no_wrap) {
402*0Sstevel@tonic-gate 				start = 0;
403*0Sstevel@tonic-gate 				end = ostart - 1;
404*0Sstevel@tonic-gate 				no_wrap = B_TRUE;
405*0Sstevel@tonic-gate 			} else {
406*0Sstevel@tonic-gate 				done = B_TRUE;
407*0Sstevel@tonic-gate 			}
408*0Sstevel@tonic-gate 		}
409*0Sstevel@tonic-gate 	}
410*0Sstevel@tonic-gate 
411*0Sstevel@tonic-gate 	if (!done) {
412*0Sstevel@tonic-gate 		pcp->pc_mapstart = start;
413*0Sstevel@tonic-gate 	}
414*0Sstevel@tonic-gate 	ASSERT(*fdcntp == 0);
415*0Sstevel@tonic-gate 	*fdcntp = fdcnt;
416*0Sstevel@tonic-gate 	return (error);
417*0Sstevel@tonic-gate }
418*0Sstevel@tonic-gate 
419*0Sstevel@tonic-gate /*ARGSUSED*/
420*0Sstevel@tonic-gate static int
421*0Sstevel@tonic-gate dpopen(dev_t *devp, int flag, int otyp, cred_t *credp)
422*0Sstevel@tonic-gate {
423*0Sstevel@tonic-gate 	minor_t		minordev;
424*0Sstevel@tonic-gate 	dp_entry_t	*dpep;
425*0Sstevel@tonic-gate 	pollcache_t	*pcp;
426*0Sstevel@tonic-gate 
427*0Sstevel@tonic-gate 	ASSERT(devpoll_init);
428*0Sstevel@tonic-gate 	ASSERT(dptblsize <= MAXMIN);
429*0Sstevel@tonic-gate 	mutex_enter(&devpoll_lock);
430*0Sstevel@tonic-gate 	for (minordev = 0; minordev < dptblsize; minordev++) {
431*0Sstevel@tonic-gate 		if (devpolltbl[minordev] == NULL) {
432*0Sstevel@tonic-gate 			devpolltbl[minordev] = (dp_entry_t *)RESERVED;
433*0Sstevel@tonic-gate 			break;
434*0Sstevel@tonic-gate 		}
435*0Sstevel@tonic-gate 	}
436*0Sstevel@tonic-gate 	if (minordev == dptblsize) {
437*0Sstevel@tonic-gate 		dp_entry_t	**newtbl;
438*0Sstevel@tonic-gate 		size_t		oldsize;
439*0Sstevel@tonic-gate 
440*0Sstevel@tonic-gate 		/*
441*0Sstevel@tonic-gate 		 * Used up every entry in the existing devpoll table.
442*0Sstevel@tonic-gate 		 * Grow the table by DEVPOLLSIZE.
443*0Sstevel@tonic-gate 		 */
444*0Sstevel@tonic-gate 		if ((oldsize = dptblsize) >= MAXMIN) {
445*0Sstevel@tonic-gate 			mutex_exit(&devpoll_lock);
446*0Sstevel@tonic-gate 			return (ENXIO);
447*0Sstevel@tonic-gate 		}
448*0Sstevel@tonic-gate 		dptblsize += DEVPOLLSIZE;
449*0Sstevel@tonic-gate 		if (dptblsize > MAXMIN) {
450*0Sstevel@tonic-gate 			dptblsize = MAXMIN;
451*0Sstevel@tonic-gate 		}
452*0Sstevel@tonic-gate 		newtbl = kmem_zalloc(sizeof (caddr_t) * dptblsize, KM_SLEEP);
453*0Sstevel@tonic-gate 		bcopy(devpolltbl, newtbl, sizeof (caddr_t) * oldsize);
454*0Sstevel@tonic-gate 		kmem_free(devpolltbl, sizeof (caddr_t) * oldsize);
455*0Sstevel@tonic-gate 		devpolltbl = newtbl;
456*0Sstevel@tonic-gate 		devpolltbl[minordev] = (dp_entry_t *)RESERVED;
457*0Sstevel@tonic-gate 	}
458*0Sstevel@tonic-gate 	mutex_exit(&devpoll_lock);
459*0Sstevel@tonic-gate 
460*0Sstevel@tonic-gate 	dpep = kmem_zalloc(sizeof (dp_entry_t), KM_SLEEP);
461*0Sstevel@tonic-gate 	/*
462*0Sstevel@tonic-gate 	 * allocate a pollcache skeleton here. Delay allocating bitmap
463*0Sstevel@tonic-gate 	 * structures until dpwrite() time, since we don't know the
464*0Sstevel@tonic-gate 	 * optimal size yet.
465*0Sstevel@tonic-gate 	 */
466*0Sstevel@tonic-gate 	pcp = pcache_alloc();
467*0Sstevel@tonic-gate 	dpep->dpe_pcache = pcp;
468*0Sstevel@tonic-gate 	pcp->pc_pid = curproc->p_pid;
469*0Sstevel@tonic-gate 	*devp = makedevice(getmajor(*devp), minordev);  /* clone the driver */
470*0Sstevel@tonic-gate 	mutex_enter(&devpoll_lock);
471*0Sstevel@tonic-gate 	ASSERT(minordev < dptblsize);
472*0Sstevel@tonic-gate 	ASSERT(devpolltbl[minordev] == (dp_entry_t *)RESERVED);
473*0Sstevel@tonic-gate 	devpolltbl[minordev] = dpep;
474*0Sstevel@tonic-gate 	mutex_exit(&devpoll_lock);
475*0Sstevel@tonic-gate 	return (0);
476*0Sstevel@tonic-gate }
477*0Sstevel@tonic-gate 
478*0Sstevel@tonic-gate /*
479*0Sstevel@tonic-gate  * Write to dev/poll add/remove fd's to/from a cached poll fd set,
480*0Sstevel@tonic-gate  * or change poll events for a watched fd.
481*0Sstevel@tonic-gate  */
482*0Sstevel@tonic-gate /*ARGSUSED*/
483*0Sstevel@tonic-gate static int
484*0Sstevel@tonic-gate dpwrite(dev_t dev, struct uio *uiop, cred_t *credp)
485*0Sstevel@tonic-gate {
486*0Sstevel@tonic-gate 	minor_t 	minor;
487*0Sstevel@tonic-gate 	dp_entry_t	*dpep;
488*0Sstevel@tonic-gate 	pollcache_t	*pcp;
489*0Sstevel@tonic-gate 	pollfd_t	*pollfdp, *pfdp;
490*0Sstevel@tonic-gate 	int		error;
491*0Sstevel@tonic-gate 	ssize_t		uiosize;
492*0Sstevel@tonic-gate 	nfds_t		pollfdnum;
493*0Sstevel@tonic-gate 	struct pollhead	*php = NULL;
494*0Sstevel@tonic-gate 	polldat_t	*pdp;
495*0Sstevel@tonic-gate 	int		fd;
496*0Sstevel@tonic-gate 	file_t		*fp;
497*0Sstevel@tonic-gate 
498*0Sstevel@tonic-gate 	minor = getminor(dev);
499*0Sstevel@tonic-gate 
500*0Sstevel@tonic-gate 	mutex_enter(&devpoll_lock);
501*0Sstevel@tonic-gate 	ASSERT(minor < dptblsize);
502*0Sstevel@tonic-gate 	dpep = devpolltbl[minor];
503*0Sstevel@tonic-gate 	ASSERT(dpep != NULL);
504*0Sstevel@tonic-gate 	mutex_exit(&devpoll_lock);
505*0Sstevel@tonic-gate 	pcp = dpep->dpe_pcache;
506*0Sstevel@tonic-gate 	if (curproc->p_pid != pcp->pc_pid) {
507*0Sstevel@tonic-gate 		return (EACCES);
508*0Sstevel@tonic-gate 	}
509*0Sstevel@tonic-gate 	uiosize = uiop->uio_resid;
510*0Sstevel@tonic-gate 	pollfdnum = uiosize / sizeof (pollfd_t);
511*0Sstevel@tonic-gate 	mutex_enter(&curproc->p_lock);
512*0Sstevel@tonic-gate 	if (pollfdnum > (uint_t)rctl_enforced_value(
513*0Sstevel@tonic-gate 	    rctlproc_legacy[RLIMIT_NOFILE], curproc->p_rctls, curproc)) {
514*0Sstevel@tonic-gate 		(void) rctl_action(rctlproc_legacy[RLIMIT_NOFILE],
515*0Sstevel@tonic-gate 		    curproc->p_rctls, curproc, RCA_SAFE);
516*0Sstevel@tonic-gate 		mutex_exit(&curproc->p_lock);
517*0Sstevel@tonic-gate 		return (set_errno(EINVAL));
518*0Sstevel@tonic-gate 	}
519*0Sstevel@tonic-gate 	mutex_exit(&curproc->p_lock);
520*0Sstevel@tonic-gate 	/*
521*0Sstevel@tonic-gate 	 * Copy in the pollfd array.  Walk through the array and add
522*0Sstevel@tonic-gate 	 * each polled fd to the cached set.
523*0Sstevel@tonic-gate 	 */
524*0Sstevel@tonic-gate 	pollfdp = kmem_alloc(uiosize, KM_SLEEP);
525*0Sstevel@tonic-gate 
526*0Sstevel@tonic-gate 	/*
527*0Sstevel@tonic-gate 	 * Although /dev/poll uses the write(2) interface to cache fds, it's
528*0Sstevel@tonic-gate 	 * not supposed to function as a seekable device. To prevent offset
529*0Sstevel@tonic-gate 	 * from growing and eventually exceed the maximum, reset the offset
530*0Sstevel@tonic-gate 	 * here for every call.
531*0Sstevel@tonic-gate 	 */
532*0Sstevel@tonic-gate 	uiop->uio_loffset = 0;
533*0Sstevel@tonic-gate 	if ((error = uiomove((caddr_t)pollfdp, uiosize, UIO_WRITE, uiop))
534*0Sstevel@tonic-gate 	    != 0) {
535*0Sstevel@tonic-gate 		kmem_free(pollfdp, uiosize);
536*0Sstevel@tonic-gate 		return (error);
537*0Sstevel@tonic-gate 	}
538*0Sstevel@tonic-gate 	/*
539*0Sstevel@tonic-gate 	 * We are about to enter the core portion of dpwrite(). Make sure this
540*0Sstevel@tonic-gate 	 * write has exclusive access in this portion of the code, i.e., no
541*0Sstevel@tonic-gate 	 * other writers in this code and no other readers in dpioctl.
542*0Sstevel@tonic-gate 	 */
543*0Sstevel@tonic-gate 	mutex_enter(&dpep->dpe_lock);
544*0Sstevel@tonic-gate 	dpep->dpe_writerwait++;
545*0Sstevel@tonic-gate 	while (dpep->dpe_refcnt != 0) {
546*0Sstevel@tonic-gate 		if (!cv_wait_sig_swap(&dpep->dpe_cv, &dpep->dpe_lock)) {
547*0Sstevel@tonic-gate 			dpep->dpe_writerwait--;
548*0Sstevel@tonic-gate 			mutex_exit(&dpep->dpe_lock);
549*0Sstevel@tonic-gate 			kmem_free(pollfdp, uiosize);
550*0Sstevel@tonic-gate 			return (set_errno(EINTR));
551*0Sstevel@tonic-gate 		}
552*0Sstevel@tonic-gate 	}
553*0Sstevel@tonic-gate 	dpep->dpe_writerwait--;
554*0Sstevel@tonic-gate 	dpep->dpe_flag |= DP_WRITER_PRESENT;
555*0Sstevel@tonic-gate 	dpep->dpe_refcnt++;
556*0Sstevel@tonic-gate 	mutex_exit(&dpep->dpe_lock);
557*0Sstevel@tonic-gate 
558*0Sstevel@tonic-gate 	mutex_enter(&pcp->pc_lock);
559*0Sstevel@tonic-gate 	if (pcp->pc_bitmap == NULL) {
560*0Sstevel@tonic-gate 		pcache_create(pcp, pollfdnum);
561*0Sstevel@tonic-gate 	}
562*0Sstevel@tonic-gate 	for (pfdp = pollfdp; pfdp < pollfdp + pollfdnum; pfdp++) {
563*0Sstevel@tonic-gate 		fd = pfdp->fd;
564*0Sstevel@tonic-gate 		if ((uint_t)fd >= P_FINFO(curproc)->fi_nfiles)
565*0Sstevel@tonic-gate 			continue;
566*0Sstevel@tonic-gate 		pdp = pcache_lookup_fd(pcp, fd);
567*0Sstevel@tonic-gate 		if (pfdp->events != POLLREMOVE) {
568*0Sstevel@tonic-gate 			if (pdp == NULL) {
569*0Sstevel@tonic-gate 				pdp = pcache_alloc_fd(0);
570*0Sstevel@tonic-gate 				pdp->pd_fd = fd;
571*0Sstevel@tonic-gate 				pdp->pd_pcache = pcp;
572*0Sstevel@tonic-gate 				pcache_insert_fd(pcp, pdp, pollfdnum);
573*0Sstevel@tonic-gate 			}
574*0Sstevel@tonic-gate 			ASSERT(pdp->pd_fd == fd);
575*0Sstevel@tonic-gate 			ASSERT(pdp->pd_pcache == pcp);
576*0Sstevel@tonic-gate 			if (fd >= pcp->pc_mapsize) {
577*0Sstevel@tonic-gate 				mutex_exit(&pcp->pc_lock);
578*0Sstevel@tonic-gate 				pcache_grow_map(pcp, fd);
579*0Sstevel@tonic-gate 				mutex_enter(&pcp->pc_lock);
580*0Sstevel@tonic-gate 			}
581*0Sstevel@tonic-gate 			if (fd > pcp->pc_mapend) {
582*0Sstevel@tonic-gate 				pcp->pc_mapend = fd;
583*0Sstevel@tonic-gate 			}
584*0Sstevel@tonic-gate 			if ((fp = getf(fd)) == NULL) {
585*0Sstevel@tonic-gate 				/*
586*0Sstevel@tonic-gate 				 * The fd is not valid. Since we can't pass
587*0Sstevel@tonic-gate 				 * this error back in the write() call, set
588*0Sstevel@tonic-gate 				 * the bit in bitmap to force DP_POLL ioctl
589*0Sstevel@tonic-gate 				 * to examine it.
590*0Sstevel@tonic-gate 				 */
591*0Sstevel@tonic-gate 				BT_SET(pcp->pc_bitmap, fd);
592*0Sstevel@tonic-gate 				pdp->pd_events |= pfdp->events;
593*0Sstevel@tonic-gate 				continue;
594*0Sstevel@tonic-gate 			}
595*0Sstevel@tonic-gate 			/*
596*0Sstevel@tonic-gate 			 * Don't do VOP_POLL for an already cached fd with
597*0Sstevel@tonic-gate 			 * same poll events.
598*0Sstevel@tonic-gate 			 */
599*0Sstevel@tonic-gate 			if ((pdp->pd_events == pfdp->events) &&
600*0Sstevel@tonic-gate 			    (pdp->pd_fp != NULL)) {
601*0Sstevel@tonic-gate 				/*
602*0Sstevel@tonic-gate 				 * the events are already cached
603*0Sstevel@tonic-gate 				 */
604*0Sstevel@tonic-gate 				releasef(fd);
605*0Sstevel@tonic-gate 				continue;
606*0Sstevel@tonic-gate 			}
607*0Sstevel@tonic-gate 
608*0Sstevel@tonic-gate 			/*
609*0Sstevel@tonic-gate 			 * do VOP_POLL and cache this poll fd.
610*0Sstevel@tonic-gate 			 */
611*0Sstevel@tonic-gate 			/*
612*0Sstevel@tonic-gate 			 * XXX - pollrelock() logic needs to know which
613*0Sstevel@tonic-gate 			 * which pollcache lock to grab. It'd be a
614*0Sstevel@tonic-gate 			 * cleaner solution if we could pass pcp as
615*0Sstevel@tonic-gate 			 * an arguement in VOP_POLL interface instead
616*0Sstevel@tonic-gate 			 * of implicitly passing it using thread_t
617*0Sstevel@tonic-gate 			 * struct. On the other hand, changing VOP_POLL
618*0Sstevel@tonic-gate 			 * interface will require all driver/file system
619*0Sstevel@tonic-gate 			 * poll routine to change. May want to revisit
620*0Sstevel@tonic-gate 			 * the tradeoff later.
621*0Sstevel@tonic-gate 			 */
622*0Sstevel@tonic-gate 			curthread->t_pollcache = pcp;
623*0Sstevel@tonic-gate 			error = VOP_POLL(fp->f_vnode, pfdp->events, 0,
624*0Sstevel@tonic-gate 			    &pfdp->revents, &php);
625*0Sstevel@tonic-gate 			curthread->t_pollcache = NULL;
626*0Sstevel@tonic-gate 			/*
627*0Sstevel@tonic-gate 			 * We always set the bit when this fd is cached.
628*0Sstevel@tonic-gate 			 * So we don't have to worry about missing a
629*0Sstevel@tonic-gate 			 * pollwakeup between VOP_POLL and pollhead_insert.
630*0Sstevel@tonic-gate 			 * This forces the first DP_POLL to poll this fd.
631*0Sstevel@tonic-gate 			 * Real performance gain comes from subsequent
632*0Sstevel@tonic-gate 			 * DP_POLL.
633*0Sstevel@tonic-gate 			 */
634*0Sstevel@tonic-gate 			BT_SET(pcp->pc_bitmap, fd);
635*0Sstevel@tonic-gate 			if (error != 0) {
636*0Sstevel@tonic-gate 				releasef(fd);
637*0Sstevel@tonic-gate 				break;
638*0Sstevel@tonic-gate 			}
639*0Sstevel@tonic-gate 			pdp->pd_fp = fp;
640*0Sstevel@tonic-gate 			pdp->pd_events |= pfdp->events;
641*0Sstevel@tonic-gate 			if (php != NULL) {
642*0Sstevel@tonic-gate 				if (pdp->pd_php == NULL) {
643*0Sstevel@tonic-gate 					pollhead_insert(php, pdp);
644*0Sstevel@tonic-gate 					pdp->pd_php = php;
645*0Sstevel@tonic-gate 				} else {
646*0Sstevel@tonic-gate 					if (pdp->pd_php != php) {
647*0Sstevel@tonic-gate 						pollhead_delete(pdp->pd_php,
648*0Sstevel@tonic-gate 						    pdp);
649*0Sstevel@tonic-gate 						pollhead_insert(php, pdp);
650*0Sstevel@tonic-gate 						pdp->pd_php = php;
651*0Sstevel@tonic-gate 					}
652*0Sstevel@tonic-gate 				}
653*0Sstevel@tonic-gate 
654*0Sstevel@tonic-gate 			}
655*0Sstevel@tonic-gate 			releasef(fd);
656*0Sstevel@tonic-gate 		} else {
657*0Sstevel@tonic-gate 			if (pdp == NULL) {
658*0Sstevel@tonic-gate 				continue;
659*0Sstevel@tonic-gate 			}
660*0Sstevel@tonic-gate 			ASSERT(pdp->pd_fd == fd);
661*0Sstevel@tonic-gate 			pdp->pd_fp = NULL;
662*0Sstevel@tonic-gate 			pdp->pd_events = 0;
663*0Sstevel@tonic-gate 			ASSERT(pdp->pd_thread == NULL);
664*0Sstevel@tonic-gate 			if (pdp->pd_php != NULL) {
665*0Sstevel@tonic-gate 				pollhead_delete(pdp->pd_php, pdp);
666*0Sstevel@tonic-gate 				pdp->pd_php = NULL;
667*0Sstevel@tonic-gate 			}
668*0Sstevel@tonic-gate 			BT_CLEAR(pcp->pc_bitmap, fd);
669*0Sstevel@tonic-gate 		}
670*0Sstevel@tonic-gate 	}
671*0Sstevel@tonic-gate 	mutex_exit(&pcp->pc_lock);
672*0Sstevel@tonic-gate 	mutex_enter(&dpep->dpe_lock);
673*0Sstevel@tonic-gate 	dpep->dpe_flag &= ~DP_WRITER_PRESENT;
674*0Sstevel@tonic-gate 	ASSERT(dpep->dpe_refcnt == 1);
675*0Sstevel@tonic-gate 	dpep->dpe_refcnt--;
676*0Sstevel@tonic-gate 	cv_broadcast(&dpep->dpe_cv);
677*0Sstevel@tonic-gate 	mutex_exit(&dpep->dpe_lock);
678*0Sstevel@tonic-gate 	kmem_free(pollfdp, uiosize);
679*0Sstevel@tonic-gate 	return (error);
680*0Sstevel@tonic-gate }
681*0Sstevel@tonic-gate 
682*0Sstevel@tonic-gate /*ARGSUSED*/
683*0Sstevel@tonic-gate static int
684*0Sstevel@tonic-gate dpioctl(dev_t dev, int cmd, intptr_t arg, int mode, cred_t *credp, int *rvalp)
685*0Sstevel@tonic-gate {
686*0Sstevel@tonic-gate 	timestruc_t	now;
687*0Sstevel@tonic-gate 	timestruc_t	rqtime;
688*0Sstevel@tonic-gate 	timestruc_t	*rqtp = NULL;
689*0Sstevel@tonic-gate 	int		timecheck = 0;
690*0Sstevel@tonic-gate 	minor_t 	minor;
691*0Sstevel@tonic-gate 	dp_entry_t	*dpep;
692*0Sstevel@tonic-gate 	pollcache_t	*pcp;
693*0Sstevel@tonic-gate 	int 		error = 0;
694*0Sstevel@tonic-gate 	STRUCT_DECL(dvpoll, dvpoll);
695*0Sstevel@tonic-gate 
696*0Sstevel@tonic-gate 	if (cmd == DP_POLL) {
697*0Sstevel@tonic-gate 		/* do this now, before we sleep on DP_WRITER_PRESENT below */
698*0Sstevel@tonic-gate 		timecheck = timechanged;
699*0Sstevel@tonic-gate 		gethrestime(&now);
700*0Sstevel@tonic-gate 	}
701*0Sstevel@tonic-gate 	minor = getminor(dev);
702*0Sstevel@tonic-gate 	mutex_enter(&devpoll_lock);
703*0Sstevel@tonic-gate 	ASSERT(minor < dptblsize);
704*0Sstevel@tonic-gate 	dpep = devpolltbl[minor];
705*0Sstevel@tonic-gate 	mutex_exit(&devpoll_lock);
706*0Sstevel@tonic-gate 	ASSERT(dpep != NULL);
707*0Sstevel@tonic-gate 	pcp = dpep->dpe_pcache;
708*0Sstevel@tonic-gate 	if (curproc->p_pid != pcp->pc_pid)
709*0Sstevel@tonic-gate 		return (EACCES);
710*0Sstevel@tonic-gate 
711*0Sstevel@tonic-gate 	mutex_enter(&dpep->dpe_lock);
712*0Sstevel@tonic-gate 	while ((dpep->dpe_flag & DP_WRITER_PRESENT) ||
713*0Sstevel@tonic-gate 	    (dpep->dpe_writerwait != 0)) {
714*0Sstevel@tonic-gate 		if (!cv_wait_sig_swap(&dpep->dpe_cv, &dpep->dpe_lock)) {
715*0Sstevel@tonic-gate 			mutex_exit(&dpep->dpe_lock);
716*0Sstevel@tonic-gate 			return (EINTR);
717*0Sstevel@tonic-gate 		}
718*0Sstevel@tonic-gate 	}
719*0Sstevel@tonic-gate 	dpep->dpe_refcnt++;
720*0Sstevel@tonic-gate 	mutex_exit(&dpep->dpe_lock);
721*0Sstevel@tonic-gate 
722*0Sstevel@tonic-gate 	switch (cmd) {
723*0Sstevel@tonic-gate 	case	DP_POLL:
724*0Sstevel@tonic-gate 	{
725*0Sstevel@tonic-gate 		pollstate_t *ps;
726*0Sstevel@tonic-gate 		nfds_t	nfds;
727*0Sstevel@tonic-gate 		int	fdcnt = 0;
728*0Sstevel@tonic-gate 		int	time_out;
729*0Sstevel@tonic-gate 		int	rval;
730*0Sstevel@tonic-gate 
731*0Sstevel@tonic-gate 		STRUCT_INIT(dvpoll, mode);
732*0Sstevel@tonic-gate 		error = copyin((caddr_t)arg, STRUCT_BUF(dvpoll),
733*0Sstevel@tonic-gate 		    STRUCT_SIZE(dvpoll));
734*0Sstevel@tonic-gate 		if (error) {
735*0Sstevel@tonic-gate 			DP_REFRELE(dpep);
736*0Sstevel@tonic-gate 			return (EFAULT);
737*0Sstevel@tonic-gate 		}
738*0Sstevel@tonic-gate 
739*0Sstevel@tonic-gate 		time_out = STRUCT_FGET(dvpoll, dp_timeout);
740*0Sstevel@tonic-gate 		if (time_out > 0) {
741*0Sstevel@tonic-gate 			/*
742*0Sstevel@tonic-gate 			 * Determine the future time of the requested timeout.
743*0Sstevel@tonic-gate 			 */
744*0Sstevel@tonic-gate 			rqtp = &rqtime;
745*0Sstevel@tonic-gate 			rqtp->tv_sec = time_out / MILLISEC;
746*0Sstevel@tonic-gate 			rqtp->tv_nsec = (time_out % MILLISEC) * MICROSEC;
747*0Sstevel@tonic-gate 			timespecadd(rqtp, &now);
748*0Sstevel@tonic-gate 		}
749*0Sstevel@tonic-gate 
750*0Sstevel@tonic-gate 		if ((nfds = STRUCT_FGET(dvpoll, dp_nfds)) == 0) {
751*0Sstevel@tonic-gate 			/*
752*0Sstevel@tonic-gate 			 * We are just using DP_POLL to sleep, so
753*0Sstevel@tonic-gate 			 * we don't any of the devpoll apparatus.
754*0Sstevel@tonic-gate 			 * Do not check for signals if we have a zero timeout.
755*0Sstevel@tonic-gate 			 */
756*0Sstevel@tonic-gate 			DP_REFRELE(dpep);
757*0Sstevel@tonic-gate 			if (time_out == 0)
758*0Sstevel@tonic-gate 				return (0);
759*0Sstevel@tonic-gate 			mutex_enter(&curthread->t_delay_lock);
760*0Sstevel@tonic-gate 			while ((rval = cv_waituntil_sig(&curthread->t_delay_cv,
761*0Sstevel@tonic-gate 			    &curthread->t_delay_lock, rqtp, timecheck)) > 0)
762*0Sstevel@tonic-gate 				continue;
763*0Sstevel@tonic-gate 			mutex_exit(&curthread->t_delay_lock);
764*0Sstevel@tonic-gate 			return ((rval == 0)? EINTR : 0);
765*0Sstevel@tonic-gate 		}
766*0Sstevel@tonic-gate 
767*0Sstevel@tonic-gate 		/*
768*0Sstevel@tonic-gate 		 * XXX It'd be nice not to have to alloc each time.
769*0Sstevel@tonic-gate 		 * But it requires another per thread structure hook.
770*0Sstevel@tonic-gate 		 * Do it later if there is data suggest that.
771*0Sstevel@tonic-gate 		 */
772*0Sstevel@tonic-gate 		if ((ps = curthread->t_pollstate) == NULL) {
773*0Sstevel@tonic-gate 			curthread->t_pollstate = pollstate_create();
774*0Sstevel@tonic-gate 			ps = curthread->t_pollstate;
775*0Sstevel@tonic-gate 		}
776*0Sstevel@tonic-gate 		if (ps->ps_dpbufsize < nfds) {
777*0Sstevel@tonic-gate 			struct proc *p = ttoproc(curthread);
778*0Sstevel@tonic-gate 			/*
779*0Sstevel@tonic-gate 			 * The maximum size should be no large than
780*0Sstevel@tonic-gate 			 * current maximum open file count.
781*0Sstevel@tonic-gate 			 */
782*0Sstevel@tonic-gate 			mutex_enter(&p->p_lock);
783*0Sstevel@tonic-gate 			if (nfds >= p->p_fno_ctl) {
784*0Sstevel@tonic-gate 				mutex_exit(&p->p_lock);
785*0Sstevel@tonic-gate 				DP_REFRELE(dpep);
786*0Sstevel@tonic-gate 				return (EINVAL);
787*0Sstevel@tonic-gate 			}
788*0Sstevel@tonic-gate 			mutex_exit(&p->p_lock);
789*0Sstevel@tonic-gate 			kmem_free(ps->ps_dpbuf, sizeof (pollfd_t) *
790*0Sstevel@tonic-gate 			    ps->ps_dpbufsize);
791*0Sstevel@tonic-gate 			ps->ps_dpbuf = kmem_zalloc(sizeof (pollfd_t) *
792*0Sstevel@tonic-gate 			    nfds, KM_SLEEP);
793*0Sstevel@tonic-gate 			ps->ps_dpbufsize = nfds;
794*0Sstevel@tonic-gate 		}
795*0Sstevel@tonic-gate 
796*0Sstevel@tonic-gate 		mutex_enter(&pcp->pc_lock);
797*0Sstevel@tonic-gate 		for (;;) {
798*0Sstevel@tonic-gate 			pcp->pc_flag = 0;
799*0Sstevel@tonic-gate 			error = dp_pcache_poll(ps->ps_dpbuf, pcp, nfds, &fdcnt);
800*0Sstevel@tonic-gate 			if (fdcnt > 0 || error != 0)
801*0Sstevel@tonic-gate 				break;
802*0Sstevel@tonic-gate 
803*0Sstevel@tonic-gate 			/*
804*0Sstevel@tonic-gate 			 * A pollwake has happened since we polled cache.
805*0Sstevel@tonic-gate 			 */
806*0Sstevel@tonic-gate 			if (pcp->pc_flag & T_POLLWAKE)
807*0Sstevel@tonic-gate 				continue;
808*0Sstevel@tonic-gate 
809*0Sstevel@tonic-gate 			/*
810*0Sstevel@tonic-gate 			 * Sleep until we are notified, signalled, or timed out.
811*0Sstevel@tonic-gate 			 * Do not check for signals if we have a zero timeout.
812*0Sstevel@tonic-gate 			 */
813*0Sstevel@tonic-gate 			if (time_out == 0)	/* immediate timeout */
814*0Sstevel@tonic-gate 				break;
815*0Sstevel@tonic-gate 			rval = cv_waituntil_sig(&pcp->pc_cv, &pcp->pc_lock,
816*0Sstevel@tonic-gate 				rqtp, timecheck);
817*0Sstevel@tonic-gate 			/*
818*0Sstevel@tonic-gate 			 * If we were awakened by a signal or timeout
819*0Sstevel@tonic-gate 			 * then break the loop, else poll again.
820*0Sstevel@tonic-gate 			 */
821*0Sstevel@tonic-gate 			if (rval <= 0) {
822*0Sstevel@tonic-gate 				if (rval == 0)	/* signal */
823*0Sstevel@tonic-gate 					error = EINTR;
824*0Sstevel@tonic-gate 				break;
825*0Sstevel@tonic-gate 			}
826*0Sstevel@tonic-gate 		}
827*0Sstevel@tonic-gate 		mutex_exit(&pcp->pc_lock);
828*0Sstevel@tonic-gate 
829*0Sstevel@tonic-gate 		if (error == 0 && fdcnt > 0) {
830*0Sstevel@tonic-gate 			if (copyout(ps->ps_dpbuf, STRUCT_FGETP(dvpoll,
831*0Sstevel@tonic-gate 			    dp_fds), sizeof (pollfd_t) * fdcnt)) {
832*0Sstevel@tonic-gate 				DP_REFRELE(dpep);
833*0Sstevel@tonic-gate 				return (EFAULT);
834*0Sstevel@tonic-gate 			}
835*0Sstevel@tonic-gate 			*rvalp = fdcnt;
836*0Sstevel@tonic-gate 		}
837*0Sstevel@tonic-gate 		break;
838*0Sstevel@tonic-gate 	}
839*0Sstevel@tonic-gate 
840*0Sstevel@tonic-gate 	case	DP_ISPOLLED:
841*0Sstevel@tonic-gate 	{
842*0Sstevel@tonic-gate 		pollfd_t	pollfd;
843*0Sstevel@tonic-gate 		polldat_t	*pdp;
844*0Sstevel@tonic-gate 
845*0Sstevel@tonic-gate 		STRUCT_INIT(dvpoll, mode);
846*0Sstevel@tonic-gate 		error = copyin((caddr_t)arg, &pollfd, sizeof (pollfd_t));
847*0Sstevel@tonic-gate 		if (error) {
848*0Sstevel@tonic-gate 			DP_REFRELE(dpep);
849*0Sstevel@tonic-gate 			return (EFAULT);
850*0Sstevel@tonic-gate 		}
851*0Sstevel@tonic-gate 		mutex_enter(&pcp->pc_lock);
852*0Sstevel@tonic-gate 		if (pcp->pc_hash == NULL) {
853*0Sstevel@tonic-gate 			/*
854*0Sstevel@tonic-gate 			 * No Need to search because no poll fd
855*0Sstevel@tonic-gate 			 * has been cached.
856*0Sstevel@tonic-gate 			 */
857*0Sstevel@tonic-gate 			mutex_exit(&pcp->pc_lock);
858*0Sstevel@tonic-gate 			DP_REFRELE(dpep);
859*0Sstevel@tonic-gate 			return (0);
860*0Sstevel@tonic-gate 		}
861*0Sstevel@tonic-gate 		if (pollfd.fd < 0) {
862*0Sstevel@tonic-gate 			mutex_exit(&pcp->pc_lock);
863*0Sstevel@tonic-gate 			break;
864*0Sstevel@tonic-gate 		}
865*0Sstevel@tonic-gate 		pdp = pcache_lookup_fd(pcp, pollfd.fd);
866*0Sstevel@tonic-gate 		if ((pdp != NULL) && (pdp->pd_fd == pollfd.fd) &&
867*0Sstevel@tonic-gate 		    (pdp->pd_fp != NULL)) {
868*0Sstevel@tonic-gate 			pollfd.revents = pdp->pd_events;
869*0Sstevel@tonic-gate 			if (copyout(&pollfd, (caddr_t)arg, sizeof (pollfd_t))) {
870*0Sstevel@tonic-gate 				mutex_exit(&pcp->pc_lock);
871*0Sstevel@tonic-gate 				DP_REFRELE(dpep);
872*0Sstevel@tonic-gate 				return (EFAULT);
873*0Sstevel@tonic-gate 			}
874*0Sstevel@tonic-gate 			*rvalp = 1;
875*0Sstevel@tonic-gate 		}
876*0Sstevel@tonic-gate 		mutex_exit(&pcp->pc_lock);
877*0Sstevel@tonic-gate 		break;
878*0Sstevel@tonic-gate 	}
879*0Sstevel@tonic-gate 
880*0Sstevel@tonic-gate 	default:
881*0Sstevel@tonic-gate 		DP_REFRELE(dpep);
882*0Sstevel@tonic-gate 		return (EINVAL);
883*0Sstevel@tonic-gate 	}
884*0Sstevel@tonic-gate 	DP_REFRELE(dpep);
885*0Sstevel@tonic-gate 	return (error);
886*0Sstevel@tonic-gate }
887*0Sstevel@tonic-gate 
888*0Sstevel@tonic-gate /*ARGSUSED*/
889*0Sstevel@tonic-gate static int
890*0Sstevel@tonic-gate dppoll(dev_t dev, short events, int anyyet, short *reventsp,
891*0Sstevel@tonic-gate     struct pollhead **phpp)
892*0Sstevel@tonic-gate {
893*0Sstevel@tonic-gate 	/*
894*0Sstevel@tonic-gate 	 * Polling on a /dev/poll fd is not fully supported yet.
895*0Sstevel@tonic-gate 	 */
896*0Sstevel@tonic-gate 	*reventsp = POLLERR;
897*0Sstevel@tonic-gate 	return (0);
898*0Sstevel@tonic-gate }
899*0Sstevel@tonic-gate 
900*0Sstevel@tonic-gate /*
901*0Sstevel@tonic-gate  * devpoll close should do enough clean up before the pollcache is deleted,
902*0Sstevel@tonic-gate  * i.e., it should ensure no one still references the pollcache later.
903*0Sstevel@tonic-gate  * There is no "permission" check in here. Any process having the last
904*0Sstevel@tonic-gate  * reference of this /dev/poll fd can close.
905*0Sstevel@tonic-gate  */
906*0Sstevel@tonic-gate /*ARGSUSED*/
907*0Sstevel@tonic-gate static int
908*0Sstevel@tonic-gate dpclose(dev_t dev, int flag, int otyp, cred_t *credp)
909*0Sstevel@tonic-gate {
910*0Sstevel@tonic-gate 	minor_t 	minor;
911*0Sstevel@tonic-gate 	dp_entry_t	*dpep;
912*0Sstevel@tonic-gate 	pollcache_t	*pcp;
913*0Sstevel@tonic-gate 	int		i;
914*0Sstevel@tonic-gate 	polldat_t	**hashtbl;
915*0Sstevel@tonic-gate 	polldat_t	*pdp;
916*0Sstevel@tonic-gate 
917*0Sstevel@tonic-gate 	minor = getminor(dev);
918*0Sstevel@tonic-gate 
919*0Sstevel@tonic-gate 	mutex_enter(&devpoll_lock);
920*0Sstevel@tonic-gate 	dpep = devpolltbl[minor];
921*0Sstevel@tonic-gate 	ASSERT(dpep != NULL);
922*0Sstevel@tonic-gate 	devpolltbl[minor] = NULL;
923*0Sstevel@tonic-gate 	mutex_exit(&devpoll_lock);
924*0Sstevel@tonic-gate 	pcp = dpep->dpe_pcache;
925*0Sstevel@tonic-gate 	ASSERT(pcp != NULL);
926*0Sstevel@tonic-gate 	/*
927*0Sstevel@tonic-gate 	 * At this point, no other lwp can access this pollcache via the
928*0Sstevel@tonic-gate 	 * /dev/poll fd. This pollcache is going away, so do the clean
929*0Sstevel@tonic-gate 	 * up without the pc_lock.
930*0Sstevel@tonic-gate 	 */
931*0Sstevel@tonic-gate 	hashtbl = pcp->pc_hash;
932*0Sstevel@tonic-gate 	for (i = 0; i < pcp->pc_hashsize; i++) {
933*0Sstevel@tonic-gate 		for (pdp = hashtbl[i]; pdp; pdp = pdp->pd_hashnext) {
934*0Sstevel@tonic-gate 			if (pdp->pd_php != NULL) {
935*0Sstevel@tonic-gate 				pollhead_delete(pdp->pd_php, pdp);
936*0Sstevel@tonic-gate 				pdp->pd_php = NULL;
937*0Sstevel@tonic-gate 				pdp->pd_fp = NULL;
938*0Sstevel@tonic-gate 			}
939*0Sstevel@tonic-gate 		}
940*0Sstevel@tonic-gate 	}
941*0Sstevel@tonic-gate 	/*
942*0Sstevel@tonic-gate 	 * pollwakeup() may still interact with this pollcache. Wait until
943*0Sstevel@tonic-gate 	 * it is done.
944*0Sstevel@tonic-gate 	 */
945*0Sstevel@tonic-gate 	mutex_enter(&pcp->pc_no_exit);
946*0Sstevel@tonic-gate 	ASSERT(pcp->pc_busy >= 0);
947*0Sstevel@tonic-gate 	while (pcp->pc_busy > 0)
948*0Sstevel@tonic-gate 		cv_wait(&pcp->pc_busy_cv, &pcp->pc_no_exit);
949*0Sstevel@tonic-gate 	mutex_exit(&pcp->pc_no_exit);
950*0Sstevel@tonic-gate 	pcache_destroy(pcp);
951*0Sstevel@tonic-gate 	ASSERT(dpep->dpe_refcnt == 0);
952*0Sstevel@tonic-gate 	kmem_free(dpep, sizeof (dp_entry_t));
953*0Sstevel@tonic-gate 	return (0);
954*0Sstevel@tonic-gate }
955