xref: /titanic_41/usr/src/uts/common/os/dacf_clnt.c (revision c037192b037119c9fd354732fc29b38ce097d356)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 /*
29  * DACF (Device Autoconfiguration Framework) client code.
30  *
31  * DACF has two clients. the first is dacf modules which implement
32  * configuration operations; the second is the set of hooks in the kernel
33  * which do rule matching and invoke configuration operations.
34  *
35  * This file implements the second part, the kernel hooks.
36  *
37  * Currently implemented are post-attach and pre-detach handlers, and the hook
38  * for ddi_create_minor_common() which sets up post-attach and pre-detach
39  * reservations.
40  *
41  * This code depends on the core dacf code (in dacf.c) but the converse should
42  * never be true.
43  *
44  * This file also implements '__kernel', the kernel-supplied dacf module.
45  * For now, this is pretty much empty, except under DEBUG, in which case it
46  * contains some debugging code.
47  */
48 
49 #include <sys/param.h>
50 #include <sys/modctl.h>
51 #include <sys/sysmacros.h>
52 #include <sys/kmem.h>
53 #include <sys/cmn_err.h>
54 #include <sys/pathname.h>
55 #include <sys/ddi_impldefs.h>
56 #include <sys/sunddi.h>
57 #include <sys/autoconf.h>
58 #include <sys/modhash.h>
59 #include <sys/dacf_impl.h>
60 #include <sys/systm.h>
61 #include <sys/debug.h>
62 
63 /*
64  * dacfc_match_create_minor()
65  * 	Check to see if this minor node creation sequence matches a dacf
66  * 	(device autoconfiguration framework) rule.  If so make a reservation
67  * 	for the operation to be invoked at post-attach and/or pre-detach time.
68  */
69 void
70 dacfc_match_create_minor(char *name, char *node_type, dev_info_t *dip,
71     struct ddi_minor_data *dmdp, int flag)
72 {
73 	dacf_rule_t *r;
74 	char *dev_path, *dev_pathp, *drv_mname = NULL;
75 	dacf_rsrvlist_t *pa_rsrv, *pd_rsrv;
76 
77 	/*
78 	 * Check the dacf rule for non-clone devices or for network devices.
79 	 */
80 	if ((flag & CLONE_DEV) && (strcmp(node_type, DDI_NT_NET) != 0)) {
81 		return;
82 	}
83 
84 	/*
85 	 * Because dacf currently only implements post-attach and pre-detach
86 	 * processing, we only care about minor nodes created during attach.
87 	 * However, there is no restriction on drivers about when to create
88 	 * minor nodes.
89 	 */
90 	if (!DEVI_IS_ATTACHING(dmdp->dip)) {
91 		return;
92 	}
93 
94 	dev_path = kmem_alloc(MAXPATHLEN, KM_SLEEP);
95 	dev_pathp = ddi_pathname(dip, dev_path);
96 	pa_rsrv = kmem_alloc(sizeof (dacf_rsrvlist_t), KM_SLEEP);
97 	pd_rsrv = kmem_alloc(sizeof (dacf_rsrvlist_t), KM_SLEEP);
98 
99 	if (name) {
100 		const char *drv_name = ddi_driver_name(dip);
101 		if (drv_name == NULL)
102 			drv_name = "???";
103 		drv_mname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
104 		(void) snprintf(drv_mname, MAXPATHLEN, "%s:%s", drv_name, name);
105 	}
106 
107 	mutex_enter(&dacf_lock);
108 
109 	/*
110 	 * Ensure that we don't wind up in a 'matching loop' against a devinfo
111 	 * node, which could cause deadlock.  This could happen as follows:
112 	 *
113 	 * 	We match (just below)
114 	 * 	We invoke a task (later, at the end of devi_attach)
115 	 *	   this means we have taken the per-devinfo lock
116 	 * 	The task invoke winds up causing the same driver (that has
117 	 *	   just finished attaching) to create another minor node.
118 	 * 	We try to re-acquire the per-devinfo list lock again in the
119 	 *	   process of making another reservation
120 	 */
121 	mutex_enter(&(DEVI(dip)->devi_lock));
122 	if (DEVI_IS_INVOKING_DACF(dip)) {
123 		mutex_exit(&(DEVI(dip)->devi_lock));
124 		cmn_err(CE_WARN,
125 		    "!dacf detected deadlock, aborting matching procedure\n");
126 		mutex_exit(&dacf_lock);
127 		kmem_free(pa_rsrv, sizeof (dacf_rsrvlist_t));
128 		kmem_free(pd_rsrv, sizeof (dacf_rsrvlist_t));
129 		kmem_free(dev_path, MAXPATHLEN);
130 		if (drv_mname) {
131 			kmem_free(drv_mname, MAXPATHLEN);
132 		}
133 		return;
134 	}
135 	mutex_exit(&(DEVI(dip)->devi_lock));
136 
137 	/*
138 	 * Do rule matching.  It's possible to construct two rules that would
139 	 * match against the same minor node, so we match from most to least
140 	 * specific:
141 	 * 	device path
142 	 * 	minor node name (concatenation of drv_name:name
143 	 * 	node type
144 	 *
145 	 * Future additions to the set of device-specifiers should be
146 	 * sensitive to this ordering.
147 	 */
148 
149 	/*
150 	 * post-attach matching
151 	 */
152 	r = NULL;
153 	if (dev_pathp) {
154 		r = dacf_match(DACF_OPID_POSTATTACH, DACF_DS_DEV_PATH,
155 		    dev_pathp);
156 	}
157 	if (!r && drv_mname) {
158 		r = dacf_match(DACF_OPID_POSTATTACH, DACF_DS_DRV_MNAME,
159 		    drv_mname);
160 	}
161 	if (!r && node_type) {
162 		r = dacf_match(DACF_OPID_POSTATTACH, DACF_DS_MIN_NT, node_type);
163 	}
164 	if (r) {
165 		dacf_rsrv_make(pa_rsrv, r, dmdp, &(DEVI(dip)->devi_dacf_tasks));
166 
167 		if (dacfdebug & DACF_DBG_MSGS)
168 			printf("dacf: made 'post-attach' reservation for "
169 			    "%s, %s, %s\n", name, node_type, dev_pathp);
170 	} else {
171 		kmem_free(pa_rsrv, sizeof (dacf_rsrvlist_t));
172 	}
173 
174 	/*
175 	 * pre-detach matching
176 	 */
177 	r = NULL;
178 	if (dev_pathp) {
179 		r = dacf_match(DACF_OPID_PREDETACH, DACF_DS_DEV_PATH,
180 		    dev_pathp);
181 	}
182 	if (!r && drv_mname) {
183 		r = dacf_match(DACF_OPID_PREDETACH, DACF_DS_DRV_MNAME,
184 		    drv_mname);
185 	}
186 	if (!r && node_type) {
187 		r = dacf_match(DACF_OPID_PREDETACH, DACF_DS_MIN_NT, node_type);
188 	}
189 	if (r) {
190 		dacf_rsrv_make(pd_rsrv, r, dmdp, &(DEVI(dip)->devi_dacf_tasks));
191 
192 		if (dacfdebug & DACF_DBG_MSGS) {
193 			printf("dacf: made 'pre-detach' reservation for "
194 			    "%s, %s, %s\n", name, node_type, dev_pathp);
195 		}
196 	} else {
197 		kmem_free(pd_rsrv, sizeof (dacf_rsrvlist_t));
198 	}
199 
200 	mutex_exit(&dacf_lock);
201 	kmem_free(dev_path, MAXPATHLEN);
202 	if (drv_mname) {
203 		kmem_free(drv_mname, MAXPATHLEN);
204 	}
205 }
206 
207 /*
208  * dacfc_postattach()
209  * 	autoconfiguration for post-attach events.
210  *
211  * 	strategy: try to configure.  If some of the configuration operations
212  * 	fail, emit a warning.
213  */
214 int
215 dacfc_postattach(dev_info_t *devi)
216 {
217 	int err = DACF_SUCCESS;
218 	char *path, *pathp;
219 	dacf_rsrvlist_t **opsp, *op;
220 	ASSERT(MUTEX_HELD(&dacf_lock));
221 
222 	/*
223 	 * Instruct dacf_process_rsrvs() to invoke each POSTATTACH op.
224 	 */
225 	opsp = &DEVI(devi)->devi_dacf_tasks;
226 	dacf_process_rsrvs(opsp, DACF_OPID_POSTATTACH, DACF_PROC_INVOKE);
227 
228 	/*
229 	 * Check to see that all POSTATTACH's succeeded.
230 	 */
231 	for (op = *opsp; op != NULL; op = op->rsrv_next) {
232 		if (op->rsrv_rule->r_opid != DACF_OPID_POSTATTACH)
233 			continue;
234 		if (op->rsrv_result == DACF_SUCCESS)
235 			continue;
236 		if (dacfdebug & DACF_DBG_DEVI) {
237 			cmn_err(CE_WARN, "op failed, err = %d\n",
238 			    op->rsrv_result);
239 		}
240 		err = DACF_FAILURE;
241 		break;
242 	}
243 
244 	/*
245 	 * If one or more postattach's failed, give up.
246 	 */
247 	if ((err == DACF_FAILURE) && (dacfdebug & DACF_DBG_DEVI)) {
248 		path = kmem_alloc(MAXPATHLEN, KM_SLEEP);
249 		if ((pathp = ddi_pathname(devi, path)) == NULL)
250 			pathp = "<unknown>";
251 		cmn_err(CE_WARN, "%s attached, but failed to auto-configure",
252 		    pathp);
253 		kmem_free(path, MAXPATHLEN);
254 	}
255 
256 	return (err);
257 }
258 
259 /*
260  * dacfc_predetach()
261  * 	auto-unconfiguration for pre-detach events.
262  *
263  * 	strategy: call the pre-detach operation for all matching reservations.
264  * 	If any of these fail, make (one) attempt to reconfigure things back
265  * 	into a sane state.  if that fails, our state is uncertain.
266  */
267 int
268 dacfc_predetach(dev_info_t *devi)
269 {
270 	int err = DDI_SUCCESS;
271 	char *path, *pathp;
272 	dacf_rsrvlist_t **opsp, *op;
273 	ASSERT(MUTEX_HELD(&dacf_lock));
274 
275 	/*
276 	 * Instruct dacf_process_rsrvs() to invoke each PREDETACH op.
277 	 */
278 	opsp = &DEVI(devi)->devi_dacf_tasks;
279 	dacf_process_rsrvs(opsp, DACF_OPID_PREDETACH, DACF_PROC_INVOKE);
280 
281 	/*
282 	 * Check to see that all PREDETACH's succeeded.
283 	 */
284 	for (op = *opsp; op != NULL; op = op->rsrv_next) {
285 		if (op->rsrv_rule->r_opid != DACF_OPID_PREDETACH)
286 			continue;
287 		if (op->rsrv_result == 0)
288 			continue;
289 		err = DDI_FAILURE;
290 		break;
291 	}
292 
293 	/*
294 	 * If one or more predetach's failed, make one attempt to fix things
295 	 * by re-running all of the POST-ATTACH operations.  If any of those
296 	 * fail, give up.
297 	 */
298 	if (err == DDI_FAILURE) {
299 		int pa_err;
300 
301 		if (dacfdebug & DACF_DBG_DEVI) {
302 			path = kmem_alloc(MAXPATHLEN, KM_SLEEP);
303 			if ((pathp = ddi_pathname(devi, path)) == NULL)
304 				pathp = "<unknown>";
305 			cmn_err(CE_WARN, "%s failed to auto-unconfigure, "
306 			    "attempting to reconfigure...", pathp);
307 			kmem_free(path, MAXPATHLEN);
308 		}
309 
310 		pa_err = dacfc_postattach(devi);
311 
312 		if (dacfdebug & DACF_DBG_DEVI) {
313 			path = kmem_alloc(MAXPATHLEN, KM_SLEEP);
314 			if ((pathp = ddi_pathname(devi, path)) == NULL)
315 				pathp = "<unknown>";
316 
317 			if (pa_err == DDI_FAILURE) {
318 				cmn_err(CE_WARN, "%s failed to "
319 				    "auto-unconfigure, and could not be "
320 				    "re-autoconfigured.", pathp);
321 			} else {
322 				cmn_err(CE_WARN, "%s failed to "
323 				    "auto-unconfigure, but was successfully "
324 				    "re-autoconfigured.", pathp);
325 			}
326 			kmem_free(path, MAXPATHLEN);
327 		}
328 	}
329 
330 	return (err);
331 }
332 
333 /*
334  * kmod_dacfsw:
335  * 	This is the declaration for the kernel-supplied '__kernel' dacf module.
336  * 	DACF supplies a framework based around loadable modules.  However, it
337  * 	may be convenient (in the future) to have a module provided by the
338  * 	kernel.  This is useful in cases when a module can't be loaded (early in
339  * 	boot), or for code that would never get unloaded anyway.
340  */
341 #ifdef DEBUG
342 /*ARGSUSED*/
343 static int
344 kmod_test_postattach(dacf_infohdl_t info_hdl, dacf_arghdl_t arg_hdl, int flags)
345 {
346 	const char *verbose = dacf_get_arg(arg_hdl, "verbose");
347 	if (verbose && (strcmp(verbose, "true") == 0)) {
348 		cmn_err(CE_WARN, "got kmod_test_postattach\n");
349 	}
350 	return (0);
351 }
352 #endif
353 
354 static dacf_op_t kmod_op_test[] = {
355 #ifdef DEBUG
356 	{ DACF_OPID_POSTATTACH, kmod_test_postattach },
357 #endif
358 	{ DACF_OPID_END,	NULL },
359 };
360 
361 static dacf_opset_t kmod_opsets[] = {
362 #ifdef DEBUG
363 	{ "kmod_test",		kmod_op_test },
364 #endif
365 	{ NULL,			NULL },
366 };
367 
368 struct dacfsw kmod_dacfsw = {
369 	DACF_MODREV_1, kmod_opsets
370 };
371