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 2007 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 * CPR driver support routines
30 */
31
32 #include <sys/types.h>
33 #include <sys/errno.h>
34 #include <sys/kmem.h>
35 #include <sys/systm.h>
36 #include <sys/sunddi.h>
37 #include <sys/ddi_impldefs.h>
38 #include <sys/epm.h>
39 #include <sys/cpr.h>
40
41 #define CPR_BUFSIZE 128
42
43 extern int devi_detach(dev_info_t *, int);
44 extern int devi_attach(dev_info_t *, int);
45
46 static char *devi_string(dev_info_t *, char *);
47 static int cpr_is_real_device(dev_info_t *);
48 /*
49 * Xen uses this code to suspend _all_ drivers quickly and easily.
50 * Suspend and Resume uses it for the same reason, but also has
51 * to contend with some platform specific code that Xen does not.
52 * it is also used as a test entry point for developers/testers to
53 * execute code without going through a complete suspend. So additions
54 * that have platform implications shall need #if[n]def's.
55 */
56 #ifndef __xpv
57 extern void i_cpr_save_configuration(dev_info_t *);
58 extern void i_cpr_restore_configuration(dev_info_t *);
59 #endif
60
61 /*
62 * Traverse the dev info tree:
63 * Call each device driver in the system via a special case
64 * of the detach() entry point to quiesce itself.
65 * Suspend children first.
66 *
67 * We only suspend/resume real devices.
68 */
69
70 int
cpr_suspend_devices(dev_info_t * dip)71 cpr_suspend_devices(dev_info_t *dip)
72 {
73 int error;
74 char buf[CPR_BUFSIZE];
75
76 for (; dip != NULL; dip = ddi_get_next_sibling(dip)) {
77 if (cpr_suspend_devices(ddi_get_child(dip)))
78 return (ENXIO);
79 if (!cpr_is_real_device(dip))
80 continue;
81 CPR_DEBUG(CPR_DEBUG2, "Suspending device %s\n",
82 devi_string(dip, buf));
83 ASSERT((DEVI(dip)->devi_cpr_flags & DCF_CPR_SUSPENDED) == 0);
84
85 #ifndef __xpv
86 i_cpr_save_configuration(dip);
87 #endif
88
89
90 if (!i_ddi_devi_attached(dip)) {
91 error = DDI_FAILURE;
92 } else {
93 #ifndef __xpv
94 if (cpr_test_point != DEVICE_SUSPEND_TO_RAM ||
95 (cpr_test_point == DEVICE_SUSPEND_TO_RAM &&
96 cpr_device == ddi_driver_major(dip))) {
97 #endif
98 error = devi_detach(dip, DDI_SUSPEND);
99 #ifndef __xpv
100 } else {
101 error = DDI_SUCCESS;
102 }
103 #endif
104 }
105
106 if (error == DDI_SUCCESS) {
107 DEVI(dip)->devi_cpr_flags |= DCF_CPR_SUSPENDED;
108 }
109
110 else {
111 CPR_DEBUG(CPR_DEBUG2,
112 "WARNING: Unable to suspend device %s\n",
113 devi_string(dip, buf));
114 cpr_err(CE_WARN, "Unable to suspend device %s.",
115 devi_string(dip, buf));
116 cpr_err(CE_WARN, "Device is busy or does not "
117 "support suspend/resume.");
118 #ifndef __xpv
119 /*
120 * the device has failed to suspend however,
121 * if cpr_test_point == FORCE_SUSPEND_TO_RAM
122 * after putting out the warning message above,
123 * we carry on as if suspending the device had
124 * been successful
125 */
126 if (cpr_test_point == FORCE_SUSPEND_TO_RAM)
127 DEVI(dip)->devi_cpr_flags |= DCF_CPR_SUSPENDED;
128 else
129 #endif
130 return (ENXIO);
131 }
132 }
133 return (0);
134 }
135
136 /*
137 * Traverse the dev info tree:
138 * Call each device driver in the system via a special case
139 * of the attach() entry point to restore itself.
140 * This is a little tricky because it has to reverse the traversal
141 * order of cpr_suspend_devices().
142 */
143 int
cpr_resume_devices(dev_info_t * start,int resume_failed)144 cpr_resume_devices(dev_info_t *start, int resume_failed)
145 {
146 dev_info_t *dip, *next, *last = NULL;
147 int did_suspend;
148 int error = resume_failed;
149 char buf[CPR_BUFSIZE];
150
151 while (last != start) {
152 dip = start;
153 next = ddi_get_next_sibling(dip);
154 while (next != last) {
155 dip = next;
156 next = ddi_get_next_sibling(dip);
157 }
158
159 /*
160 * cpr is the only one that uses this field and the device
161 * itself hasn't resumed yet, there is no need to use a
162 * lock, even though kernel threads are active by now.
163 */
164 did_suspend = DEVI(dip)->devi_cpr_flags & DCF_CPR_SUSPENDED;
165 if (did_suspend)
166 DEVI(dip)->devi_cpr_flags &= ~DCF_CPR_SUSPENDED;
167
168 /*
169 * Always attempt to restore device configuration before
170 * attempting resume
171 */
172 #ifndef __xpv
173 i_cpr_restore_configuration(dip);
174 #endif
175
176 /*
177 * There may be background attaches happening on devices
178 * that were not originally suspended by cpr, so resume
179 * only devices that were suspended by cpr. Also, stop
180 * resuming after the first resume failure, but traverse
181 * the entire tree to clear the suspend flag unless the
182 * FORCE_SUSPEND_TO_RAM test point is set.
183 */
184 #ifndef __xpv
185 if (did_suspend && (!error ||
186 cpr_test_point == FORCE_SUSPEND_TO_RAM)) {
187 #else
188 if (did_suspend && !error) {
189 #endif
190 CPR_DEBUG(CPR_DEBUG2, "Resuming device %s\n",
191 devi_string(dip, buf));
192 /*
193 * If a device suspended by cpr gets detached during
194 * the resume process (for example, due to hotplugging)
195 * before cpr gets around to issuing it a DDI_RESUME,
196 * we'll have problems.
197 */
198 if (!i_ddi_devi_attached(dip)) {
199 CPR_DEBUG(CPR_DEBUG2, "WARNING: Skipping "
200 "%s, device not ready for resume\n",
201 devi_string(dip, buf));
202 cpr_err(CE_WARN, "Skipping %s, device "
203 "not ready for resume",
204 devi_string(dip, buf));
205 #ifndef __xpv
206 } else if (cpr_test_point != DEVICE_SUSPEND_TO_RAM ||
207 (cpr_test_point == DEVICE_SUSPEND_TO_RAM &&
208 cpr_device == ddi_driver_major(dip))) {
209 #else
210 } else {
211 #endif
212 if (devi_attach(dip, DDI_RESUME) !=
213 DDI_SUCCESS) {
214 error = ENXIO;
215 }
216 }
217 }
218
219 if (error == ENXIO) {
220 CPR_DEBUG(CPR_DEBUG2,
221 "WARNING: Unable to resume device %s\n",
222 devi_string(dip, buf));
223 cpr_err(CE_WARN, "Unable to resume device %s",
224 devi_string(dip, buf));
225 }
226
227 error = cpr_resume_devices(ddi_get_child(dip), error);
228 last = dip;
229 }
230
231 return (error);
232 }
233
234 /*
235 * Returns a string which contains device name and address.
236 */
237 static char *
238 devi_string(dev_info_t *devi, char *buf)
239 {
240 char *name;
241 char *address;
242 int size;
243
244 name = ddi_node_name(devi);
245 address = ddi_get_name_addr(devi);
246 size = (name == NULL) ? strlen("<null name>") : strlen(name);
247 size += (address == NULL) ? strlen("<null>") : strlen(address);
248
249 /*
250 * Make sure that we don't over-run the buffer.
251 * There are 2 additional characters in the string.
252 */
253 ASSERT((size + 2) <= CPR_BUFSIZE);
254
255 if (name == NULL)
256 (void) strcpy(buf, "<null name>");
257 else
258 (void) strcpy(buf, name);
259
260 (void) strcat(buf, "@");
261 if (address == NULL)
262 (void) strcat(buf, "<null>");
263 else
264 (void) strcat(buf, address);
265
266 return (buf);
267 }
268
269 /*
270 * This function determines whether the given device is real (and should
271 * be suspended) or not (pseudo like). If the device has a "reg" property
272 * then it is presumed to have register state to save/restore.
273 */
274 static int
275 cpr_is_real_device(dev_info_t *dip)
276 {
277 struct regspec *regbuf;
278 int length;
279 int rc;
280
281 if (ddi_get_driver(dip) == NULL)
282 return (0);
283
284 /*
285 * First those devices for which special arrangements have been made
286 */
287 if (DEVI(dip)->devi_pm_flags & (PMC_NEEDS_SR|PMC_PARENTAL_SR))
288 return (1);
289 if (DEVI(dip)->devi_pm_flags & PMC_NO_SR)
290 return (0);
291
292 /*
293 * now the general case
294 */
295 rc = ddi_getlongprop(DDI_DEV_T_ANY, dip, DDI_PROP_DONTPASS, "reg",
296 (caddr_t)®buf, &length);
297 ASSERT(rc != DDI_PROP_NO_MEMORY);
298 if (rc != DDI_PROP_SUCCESS) {
299 return (0);
300 } else {
301 kmem_free((caddr_t)regbuf, length);
302 return (1);
303 }
304 }
305