xref: /illumos-gate/usr/src/uts/common/os/dacf_clnt.c (revision ddb365bfc9e868ad24ccdcb0dc91af18b10df082)
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 /*
27  * DACF (Device Autoconfiguration Framework) client code.
28  *
29  * DACF has two clients. the first is dacf modules which implement
30  * configuration operations; the second is the set of hooks in the kernel
31  * which do rule matching and invoke configuration operations.
32  *
33  * This file implements the second part, the kernel hooks.
34  *
35  * Currently implemented are post-attach and pre-detach handlers, and the hook
36  * for ddi_create_minor_common() which sets up post-attach and pre-detach
37  * reservations.
38  *
39  * This code depends on the core dacf code (in dacf.c) but the converse should
40  * never be true.
41  *
42  * This file also implements '__kernel', the kernel-supplied dacf module.
43  * For now, this is pretty much empty, except under DEBUG, in which case it
44  * contains some debugging code.
45  */
46 
47 #include <sys/param.h>
48 #include <sys/modctl.h>
49 #include <sys/sysmacros.h>
50 #include <sys/kmem.h>
51 #include <sys/cmn_err.h>
52 #include <sys/pathname.h>
53 #include <sys/ddi_impldefs.h>
54 #include <sys/sunddi.h>
55 #include <sys/autoconf.h>
56 #include <sys/modhash.h>
57 #include <sys/dacf_impl.h>
58 #include <sys/systm.h>
59 #include <sys/debug.h>
60 
61 /*
62  * dacfc_match_create_minor()
63  * 	Check to see if this minor node creation sequence matches a dacf
64  * 	(device autoconfiguration framework) rule.  If so make a reservation
65  * 	for the operation to be invoked at post-attach and/or pre-detach time.
66  */
67 void
68 dacfc_match_create_minor(const char *name, const char *node_type,
69     dev_info_t *dip, struct ddi_minor_data *dmdp, int flag)
70 {
71 	dacf_rule_t *r;
72 	char *dev_path, *dev_pathp, *drv_mname = NULL;
73 	dacf_rsrvlist_t *pa_rsrv, *pd_rsrv;
74 
75 	/*
76 	 * Check the dacf rule for non-clone devices or for network devices.
77 	 */
78 	if ((flag & CLONE_DEV) && (strcmp(node_type, DDI_NT_NET) != 0)) {
79 		return;
80 	}
81 
82 	/*
83 	 * Because dacf currently only implements post-attach and pre-detach
84 	 * processing, we only care about minor nodes created during attach.
85 	 * However, there is no restriction on drivers about when to create
86 	 * minor nodes.
87 	 */
88 	if (!DEVI_IS_ATTACHING(dmdp->dip)) {
89 		return;
90 	}
91 
92 	dev_path = kmem_alloc(MAXPATHLEN, KM_SLEEP);
93 	dev_pathp = ddi_pathname(dip, dev_path);
94 	pa_rsrv = kmem_alloc(sizeof (dacf_rsrvlist_t), KM_SLEEP);
95 	pd_rsrv = kmem_alloc(sizeof (dacf_rsrvlist_t), KM_SLEEP);
96 
97 	if (name) {
98 		const char *drv_name = ddi_driver_name(dip);
99 		if (drv_name == NULL)
100 			drv_name = "???";
101 		drv_mname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
102 		(void) snprintf(drv_mname, MAXPATHLEN, "%s:%s", drv_name, name);
103 	}
104 
105 	mutex_enter(&dacf_lock);
106 
107 	/*
108 	 * Ensure that we don't wind up in a 'matching loop' against a devinfo
109 	 * node, which could cause deadlock.  This could happen as follows:
110 	 *
111 	 * 	We match (just below)
112 	 * 	We invoke a task (later, at the end of devi_attach)
113 	 *	   this means we have taken the per-devinfo lock
114 	 * 	The task invoke winds up causing the same driver (that has
115 	 *	   just finished attaching) to create another minor node.
116 	 * 	We try to re-acquire the per-devinfo list lock again in the
117 	 *	   process of making another reservation
118 	 */
119 	mutex_enter(&(DEVI(dip)->devi_lock));
120 	if (DEVI_IS_INVOKING_DACF(dip)) {
121 		mutex_exit(&(DEVI(dip)->devi_lock));
122 		cmn_err(CE_WARN,
123 		    "!dacf detected deadlock, aborting matching procedure\n");
124 		mutex_exit(&dacf_lock);
125 		kmem_free(pa_rsrv, sizeof (dacf_rsrvlist_t));
126 		kmem_free(pd_rsrv, sizeof (dacf_rsrvlist_t));
127 		kmem_free(dev_path, MAXPATHLEN);
128 		if (drv_mname) {
129 			kmem_free(drv_mname, MAXPATHLEN);
130 		}
131 		return;
132 	}
133 	mutex_exit(&(DEVI(dip)->devi_lock));
134 
135 	/*
136 	 * Do rule matching.  It's possible to construct two rules that would
137 	 * match against the same minor node, so we match from most to least
138 	 * specific:
139 	 * 	device path
140 	 * 	minor node name (concatenation of drv_name:name
141 	 * 	node type
142 	 *
143 	 * Future additions to the set of device-specifiers should be
144 	 * sensitive to this ordering.
145 	 */
146 
147 	/*
148 	 * post-attach matching
149 	 */
150 	r = NULL;
151 	if (dev_pathp) {
152 		r = dacf_match(DACF_OPID_POSTATTACH, DACF_DS_DEV_PATH,
153 		    dev_pathp);
154 	}
155 	if (!r && drv_mname) {
156 		r = dacf_match(DACF_OPID_POSTATTACH, DACF_DS_DRV_MNAME,
157 		    drv_mname);
158 	}
159 	if (!r && node_type) {
160 		r = dacf_match(DACF_OPID_POSTATTACH, DACF_DS_MIN_NT, node_type);
161 	}
162 	if (r) {
163 		dacf_rsrv_make(pa_rsrv, r, dmdp, &(DEVI(dip)->devi_dacf_tasks));
164 
165 		if (dacfdebug & DACF_DBG_MSGS)
166 			printf("dacf: made 'post-attach' reservation for "
167 			    "%s, %s, %s\n", name, node_type, dev_pathp);
168 	} else {
169 		kmem_free(pa_rsrv, sizeof (dacf_rsrvlist_t));
170 	}
171 
172 	/*
173 	 * pre-detach matching
174 	 */
175 	r = NULL;
176 	if (dev_pathp) {
177 		r = dacf_match(DACF_OPID_PREDETACH, DACF_DS_DEV_PATH,
178 		    dev_pathp);
179 	}
180 	if (!r && drv_mname) {
181 		r = dacf_match(DACF_OPID_PREDETACH, DACF_DS_DRV_MNAME,
182 		    drv_mname);
183 	}
184 	if (!r && node_type) {
185 		r = dacf_match(DACF_OPID_PREDETACH, DACF_DS_MIN_NT, node_type);
186 	}
187 	if (r) {
188 		dacf_rsrv_make(pd_rsrv, r, dmdp, &(DEVI(dip)->devi_dacf_tasks));
189 
190 		if (dacfdebug & DACF_DBG_MSGS) {
191 			printf("dacf: made 'pre-detach' reservation for "
192 			    "%s, %s, %s\n", name, node_type, dev_pathp);
193 		}
194 	} else {
195 		kmem_free(pd_rsrv, sizeof (dacf_rsrvlist_t));
196 	}
197 
198 	mutex_exit(&dacf_lock);
199 	kmem_free(dev_path, MAXPATHLEN);
200 	if (drv_mname) {
201 		kmem_free(drv_mname, MAXPATHLEN);
202 	}
203 }
204 
205 /*
206  * dacfc_postattach()
207  * 	autoconfiguration for post-attach events.
208  *
209  * 	strategy: try to configure.  If some of the configuration operations
210  * 	fail, emit a warning.
211  */
212 int
213 dacfc_postattach(dev_info_t *devi)
214 {
215 	int err = DACF_SUCCESS;
216 	char *path, *pathp;
217 	dacf_rsrvlist_t **opsp, *op;
218 	ASSERT(MUTEX_HELD(&dacf_lock));
219 
220 	/*
221 	 * Instruct dacf_process_rsrvs() to invoke each POSTATTACH op.
222 	 */
223 	opsp = &DEVI(devi)->devi_dacf_tasks;
224 	dacf_process_rsrvs(opsp, DACF_OPID_POSTATTACH, DACF_PROC_INVOKE);
225 
226 	/*
227 	 * Check to see that all POSTATTACH's succeeded.
228 	 */
229 	for (op = *opsp; op != NULL; op = op->rsrv_next) {
230 		if (op->rsrv_rule->r_opid != DACF_OPID_POSTATTACH)
231 			continue;
232 		if (op->rsrv_result == DACF_SUCCESS)
233 			continue;
234 		if (dacfdebug & DACF_DBG_DEVI) {
235 			cmn_err(CE_WARN, "op failed, err = %d\n",
236 			    op->rsrv_result);
237 		}
238 		err = DACF_FAILURE;
239 		break;
240 	}
241 
242 	/*
243 	 * If one or more postattach's failed, give up.
244 	 */
245 	if ((err == DACF_FAILURE) && (dacfdebug & DACF_DBG_DEVI)) {
246 		path = kmem_alloc(MAXPATHLEN, KM_SLEEP);
247 		if ((pathp = ddi_pathname(devi, path)) == NULL)
248 			pathp = "<unknown>";
249 		cmn_err(CE_WARN, "%s attached, but failed to auto-configure",
250 		    pathp);
251 		kmem_free(path, MAXPATHLEN);
252 	}
253 
254 	return (err);
255 }
256 
257 /*
258  * dacfc_predetach()
259  * 	auto-unconfiguration for pre-detach events.
260  *
261  * 	strategy: call the pre-detach operation for all matching reservations.
262  * 	If any of these fail, make (one) attempt to reconfigure things back
263  * 	into a sane state.  if that fails, our state is uncertain.
264  */
265 int
266 dacfc_predetach(dev_info_t *devi)
267 {
268 	int err = DDI_SUCCESS;
269 	char *path, *pathp;
270 	dacf_rsrvlist_t **opsp, *op;
271 	ASSERT(MUTEX_HELD(&dacf_lock));
272 
273 	/*
274 	 * Instruct dacf_process_rsrvs() to invoke each PREDETACH op.
275 	 */
276 	opsp = &DEVI(devi)->devi_dacf_tasks;
277 	dacf_process_rsrvs(opsp, DACF_OPID_PREDETACH, DACF_PROC_INVOKE);
278 
279 	/*
280 	 * Check to see that all PREDETACH's succeeded.
281 	 */
282 	for (op = *opsp; op != NULL; op = op->rsrv_next) {
283 		if (op->rsrv_rule->r_opid != DACF_OPID_PREDETACH)
284 			continue;
285 		if (op->rsrv_result == 0)
286 			continue;
287 		err = DDI_FAILURE;
288 		break;
289 	}
290 
291 	/*
292 	 * If one or more predetach's failed, make one attempt to fix things
293 	 * by re-running all of the POST-ATTACH operations.  If any of those
294 	 * fail, give up.
295 	 */
296 	if (err == DDI_FAILURE) {
297 		int pa_err;
298 
299 		if (dacfdebug & DACF_DBG_DEVI) {
300 			path = kmem_alloc(MAXPATHLEN, KM_SLEEP);
301 			if ((pathp = ddi_pathname(devi, path)) == NULL)
302 				pathp = "<unknown>";
303 			cmn_err(CE_WARN, "%s failed to auto-unconfigure, "
304 			    "attempting to reconfigure...", pathp);
305 			kmem_free(path, MAXPATHLEN);
306 		}
307 
308 		pa_err = dacfc_postattach(devi);
309 
310 		if (dacfdebug & DACF_DBG_DEVI) {
311 			path = kmem_alloc(MAXPATHLEN, KM_SLEEP);
312 			if ((pathp = ddi_pathname(devi, path)) == NULL)
313 				pathp = "<unknown>";
314 
315 			if (pa_err == DDI_FAILURE) {
316 				cmn_err(CE_WARN, "%s failed to "
317 				    "auto-unconfigure, and could not be "
318 				    "re-autoconfigured.", pathp);
319 			} else {
320 				cmn_err(CE_WARN, "%s failed to "
321 				    "auto-unconfigure, but was successfully "
322 				    "re-autoconfigured.", pathp);
323 			}
324 			kmem_free(path, MAXPATHLEN);
325 		}
326 	}
327 
328 	return (err);
329 }
330 
331 /*
332  * kmod_dacfsw:
333  * 	This is the declaration for the kernel-supplied '__kernel' dacf module.
334  * 	DACF supplies a framework based around loadable modules.  However, it
335  * 	may be convenient (in the future) to have a module provided by the
336  * 	kernel.  This is useful in cases when a module can't be loaded (early in
337  * 	boot), or for code that would never get unloaded anyway.
338  */
339 #ifdef DEBUG
340 /*ARGSUSED*/
341 static int
342 kmod_test_postattach(dacf_infohdl_t info_hdl, dacf_arghdl_t arg_hdl, int flags)
343 {
344 	const char *verbose = dacf_get_arg(arg_hdl, "verbose");
345 	if (verbose && (strcmp(verbose, "true") == 0)) {
346 		cmn_err(CE_WARN, "got kmod_test_postattach\n");
347 	}
348 	return (0);
349 }
350 #endif
351 
352 static dacf_op_t kmod_op_test[] = {
353 #ifdef DEBUG
354 	{ DACF_OPID_POSTATTACH, kmod_test_postattach },
355 #endif
356 	{ DACF_OPID_END,	NULL },
357 };
358 
359 static dacf_opset_t kmod_opsets[] = {
360 #ifdef DEBUG
361 	{ "kmod_test",		kmod_op_test },
362 #endif
363 	{ NULL,			NULL },
364 };
365 
366 struct dacfsw kmod_dacfsw = {
367 	DACF_MODREV_1, kmod_opsets
368 };
369