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 /*
27 * CPR driver support routines
28 */
29
30 #include <sys/types.h>
31 #include <sys/errno.h>
32 #include <sys/kmem.h>
33 #include <sys/systm.h>
34 #include <sys/sunddi.h>
35 #include <sys/ddi_impldefs.h>
36 #include <sys/epm.h>
37 #include <sys/cpr.h>
38
39 #define CPR_BUFSIZE 128
40
41 extern int devi_detach(dev_info_t *, int);
42 extern int devi_attach(dev_info_t *, int);
43
44 static char *devi_string(dev_info_t *, char *);
45 static int cpr_is_real_device(dev_info_t *);
46 /*
47 * Xen uses this code to suspend _all_ drivers quickly and easily.
48 * Suspend and Resume uses it for the same reason, but also has
49 * to contend with some platform specific code that Xen does not.
50 * it is also used as a test entry point for developers/testers to
51 * execute code without going through a complete suspend. So additions
52 * that have platform implications shall need #if[n]def's.
53 */
54 #ifndef __xpv
55 extern void i_cpr_save_configuration(dev_info_t *);
56 extern void i_cpr_restore_configuration(dev_info_t *);
57 #endif
58
59 /*
60 * Traverse the dev info tree:
61 * Call each device driver in the system via a special case
62 * of the detach() entry point to quiesce itself.
63 * Suspend children first.
64 *
65 * We only suspend/resume real devices.
66 */
67
68 int
cpr_suspend_devices(dev_info_t * dip)69 cpr_suspend_devices(dev_info_t *dip)
70 {
71 int error;
72 char buf[CPR_BUFSIZE];
73
74 for (; dip != NULL; dip = ddi_get_next_sibling(dip)) {
75 if (cpr_suspend_devices(ddi_get_child(dip)))
76 return (ENXIO);
77 if (!cpr_is_real_device(dip))
78 continue;
79 CPR_DEBUG(CPR_DEBUG2, "Suspending device %s\n",
80 devi_string(dip, buf));
81 ASSERT((DEVI(dip)->devi_cpr_flags & DCF_CPR_SUSPENDED) == 0);
82
83 #ifndef __xpv
84 i_cpr_save_configuration(dip);
85 #endif
86
87
88 if (!i_ddi_devi_attached(dip)) {
89 error = DDI_FAILURE;
90 } else {
91 #ifndef __xpv
92 if (cpr_test_point != DEVICE_SUSPEND_TO_RAM ||
93 (cpr_test_point == DEVICE_SUSPEND_TO_RAM &&
94 cpr_device == ddi_driver_major(dip))) {
95 #endif
96 error = devi_detach(dip, DDI_SUSPEND);
97 #ifndef __xpv
98 } else {
99 error = DDI_SUCCESS;
100 }
101 #endif
102 }
103
104 if (error == DDI_SUCCESS) {
105 DEVI(dip)->devi_cpr_flags |= DCF_CPR_SUSPENDED;
106 }
107
108 else {
109 CPR_DEBUG(CPR_DEBUG2,
110 "WARNING: Unable to suspend device %s\n",
111 devi_string(dip, buf));
112 cpr_err(CE_WARN, "Unable to suspend device %s.",
113 devi_string(dip, buf));
114 cpr_err(CE_WARN, "Device is busy or does not "
115 "support suspend/resume.");
116 #ifndef __xpv
117 /*
118 * the device has failed to suspend however,
119 * if cpr_test_point == FORCE_SUSPEND_TO_RAM
120 * after putting out the warning message above,
121 * we carry on as if suspending the device had
122 * been successful
123 */
124 if (cpr_test_point == FORCE_SUSPEND_TO_RAM)
125 DEVI(dip)->devi_cpr_flags |= DCF_CPR_SUSPENDED;
126 else
127 #endif
128 return (ENXIO);
129 }
130 }
131 return (0);
132 }
133
134 /*
135 * Traverse the dev info tree:
136 * Call each device driver in the system via a special case
137 * of the attach() entry point to restore itself.
138 * This is a little tricky because it has to reverse the traversal
139 * order of cpr_suspend_devices().
140 */
141 int
cpr_resume_devices(dev_info_t * start,int resume_failed)142 cpr_resume_devices(dev_info_t *start, int resume_failed)
143 {
144 dev_info_t *dip, *next, *last = NULL;
145 int did_suspend;
146 int error = resume_failed;
147 char buf[CPR_BUFSIZE];
148
149 while (last != start) {
150 dip = start;
151 next = ddi_get_next_sibling(dip);
152 while (next != last) {
153 dip = next;
154 next = ddi_get_next_sibling(dip);
155 }
156
157 /*
158 * cpr is the only one that uses this field and the device
159 * itself hasn't resumed yet, there is no need to use a
160 * lock, even though kernel threads are active by now.
161 */
162 did_suspend = DEVI(dip)->devi_cpr_flags & DCF_CPR_SUSPENDED;
163 if (did_suspend)
164 DEVI(dip)->devi_cpr_flags &= ~DCF_CPR_SUSPENDED;
165
166 /*
167 * Always attempt to restore device configuration before
168 * attempting resume
169 */
170 #ifndef __xpv
171 i_cpr_restore_configuration(dip);
172 #endif
173
174 /*
175 * There may be background attaches happening on devices
176 * that were not originally suspended by cpr, so resume
177 * only devices that were suspended by cpr. Also, stop
178 * resuming after the first resume failure, but traverse
179 * the entire tree to clear the suspend flag unless the
180 * FORCE_SUSPEND_TO_RAM test point is set.
181 */
182 #ifndef __xpv
183 if (did_suspend && (!error ||
184 cpr_test_point == FORCE_SUSPEND_TO_RAM)) {
185 #else
186 if (did_suspend && !error) {
187 #endif
188 CPR_DEBUG(CPR_DEBUG2, "Resuming device %s\n",
189 devi_string(dip, buf));
190 /*
191 * If a device suspended by cpr gets detached during
192 * the resume process (for example, due to hotplugging)
193 * before cpr gets around to issuing it a DDI_RESUME,
194 * we'll have problems.
195 */
196 if (!i_ddi_devi_attached(dip)) {
197 CPR_DEBUG(CPR_DEBUG2, "WARNING: Skipping "
198 "%s, device not ready for resume\n",
199 devi_string(dip, buf));
200 cpr_err(CE_WARN, "Skipping %s, device "
201 "not ready for resume",
202 devi_string(dip, buf));
203 #ifndef __xpv
204 } else if (cpr_test_point != DEVICE_SUSPEND_TO_RAM ||
205 (cpr_test_point == DEVICE_SUSPEND_TO_RAM &&
206 cpr_device == ddi_driver_major(dip))) {
207 #else
208 } else {
209 #endif
210 if (devi_attach(dip, DDI_RESUME) !=
211 DDI_SUCCESS) {
212 error = ENXIO;
213 }
214 }
215 }
216
217 if (error == ENXIO) {
218 CPR_DEBUG(CPR_DEBUG2,
219 "WARNING: Unable to resume device %s\n",
220 devi_string(dip, buf));
221 cpr_err(CE_WARN, "Unable to resume device %s",
222 devi_string(dip, buf));
223 }
224
225 error = cpr_resume_devices(ddi_get_child(dip), error);
226 last = dip;
227 }
228
229 return (error);
230 }
231
232 /*
233 * Returns a string which contains device name and address.
234 */
235 static char *
236 devi_string(dev_info_t *devi, char *buf)
237 {
238 char *name;
239 char *address;
240 int size;
241
242 name = ddi_node_name(devi);
243 address = ddi_get_name_addr(devi);
244 size = (name == NULL) ? strlen("<null name>") : strlen(name);
245 size += (address == NULL) ? strlen("<null>") : strlen(address);
246
247 /*
248 * Make sure that we don't over-run the buffer.
249 * There are 2 additional characters in the string.
250 */
251 ASSERT((size + 2) <= CPR_BUFSIZE);
252
253 if (name == NULL)
254 (void) strcpy(buf, "<null name>");
255 else
256 (void) strcpy(buf, name);
257
258 (void) strcat(buf, "@");
259 if (address == NULL)
260 (void) strcat(buf, "<null>");
261 else
262 (void) strcat(buf, address);
263
264 return (buf);
265 }
266
267 /*
268 * This function determines whether the given device is real (and should
269 * be suspended) or not (pseudo like). If the device has a "reg" property
270 * then it is presumed to have register state to save/restore.
271 */
272 static int
273 cpr_is_real_device(dev_info_t *dip)
274 {
275 struct regspec *regbuf;
276 int length;
277 int rc;
278
279 if (ddi_get_driver(dip) == NULL)
280 return (0);
281
282 /*
283 * First those devices for which special arrangements have been made
284 */
285 if (DEVI(dip)->devi_pm_flags & (PMC_NEEDS_SR|PMC_PARENTAL_SR))
286 return (1);
287 if (DEVI(dip)->devi_pm_flags & PMC_NO_SR)
288 return (0);
289
290 /*
291 * now the general case
292 */
293 rc = ddi_getlongprop(DDI_DEV_T_ANY, dip, DDI_PROP_DONTPASS, "reg",
294 (caddr_t)®buf, &length);
295 ASSERT(rc != DDI_PROP_NO_MEMORY);
296 if (rc != DDI_PROP_SUCCESS) {
297 return (0);
298 } else {
299 kmem_free((caddr_t)regbuf, length);
300 return (1);
301 }
302 }
303