1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Support for Partition Mobility/Migration
4 *
5 * Copyright (C) 2010 Nathan Fontenot
6 * Copyright (C) 2010 IBM Corporation
7 */
8
9 #include <linux/cpu.h>
10 #include <linux/kernel.h>
11 #include <linux/kobject.h>
12 #include <linux/sched.h>
13 #include <linux/smp.h>
14 #include <linux/stat.h>
15 #include <linux/completion.h>
16 #include <linux/device.h>
17 #include <linux/delay.h>
18 #include <linux/slab.h>
19 #include <linux/stringify.h>
20
21 #include <asm/machdep.h>
22 #include <asm/rtas.h>
23 #include "pseries.h"
24 #include "../../kernel/cacheinfo.h"
25
26 static struct kobject *mobility_kobj;
27
28 struct update_props_workarea {
29 __be32 phandle;
30 __be32 state;
31 __be64 reserved;
32 __be32 nprops;
33 } __packed;
34
35 #define NODE_ACTION_MASK 0xff000000
36 #define NODE_COUNT_MASK 0x00ffffff
37
38 #define DELETE_DT_NODE 0x01000000
39 #define UPDATE_DT_NODE 0x02000000
40 #define ADD_DT_NODE 0x03000000
41
42 #define MIGRATION_SCOPE (1)
43 #define PRRN_SCOPE -2
44
mobility_rtas_call(int token,char * buf,s32 scope)45 static int mobility_rtas_call(int token, char *buf, s32 scope)
46 {
47 int rc;
48
49 spin_lock(&rtas_data_buf_lock);
50
51 memcpy(rtas_data_buf, buf, RTAS_DATA_BUF_SIZE);
52 rc = rtas_call(token, 2, 1, NULL, rtas_data_buf, scope);
53 memcpy(buf, rtas_data_buf, RTAS_DATA_BUF_SIZE);
54
55 spin_unlock(&rtas_data_buf_lock);
56 return rc;
57 }
58
delete_dt_node(__be32 phandle)59 static int delete_dt_node(__be32 phandle)
60 {
61 struct device_node *dn;
62
63 dn = of_find_node_by_phandle(be32_to_cpu(phandle));
64 if (!dn)
65 return -ENOENT;
66
67 dlpar_detach_node(dn);
68 of_node_put(dn);
69 return 0;
70 }
71
update_dt_property(struct device_node * dn,struct property ** prop,const char * name,u32 vd,char * value)72 static int update_dt_property(struct device_node *dn, struct property **prop,
73 const char *name, u32 vd, char *value)
74 {
75 struct property *new_prop = *prop;
76 int more = 0;
77
78 /* A negative 'vd' value indicates that only part of the new property
79 * value is contained in the buffer and we need to call
80 * ibm,update-properties again to get the rest of the value.
81 *
82 * A negative value is also the two's compliment of the actual value.
83 */
84 if (vd & 0x80000000) {
85 vd = ~vd + 1;
86 more = 1;
87 }
88
89 if (new_prop) {
90 /* partial property fixup */
91 char *new_data = kzalloc(new_prop->length + vd, GFP_KERNEL);
92 if (!new_data)
93 return -ENOMEM;
94
95 memcpy(new_data, new_prop->value, new_prop->length);
96 memcpy(new_data + new_prop->length, value, vd);
97
98 kfree(new_prop->value);
99 new_prop->value = new_data;
100 new_prop->length += vd;
101 } else {
102 new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
103 if (!new_prop)
104 return -ENOMEM;
105
106 new_prop->name = kstrdup(name, GFP_KERNEL);
107 if (!new_prop->name) {
108 kfree(new_prop);
109 return -ENOMEM;
110 }
111
112 new_prop->length = vd;
113 new_prop->value = kzalloc(new_prop->length, GFP_KERNEL);
114 if (!new_prop->value) {
115 kfree(new_prop->name);
116 kfree(new_prop);
117 return -ENOMEM;
118 }
119
120 memcpy(new_prop->value, value, vd);
121 *prop = new_prop;
122 }
123
124 if (!more) {
125 of_update_property(dn, new_prop);
126 *prop = NULL;
127 }
128
129 return 0;
130 }
131
update_dt_node(__be32 phandle,s32 scope)132 static int update_dt_node(__be32 phandle, s32 scope)
133 {
134 struct update_props_workarea *upwa;
135 struct device_node *dn;
136 struct property *prop = NULL;
137 int i, rc, rtas_rc;
138 char *prop_data;
139 char *rtas_buf;
140 int update_properties_token;
141 u32 nprops;
142 u32 vd;
143
144 update_properties_token = rtas_token("ibm,update-properties");
145 if (update_properties_token == RTAS_UNKNOWN_SERVICE)
146 return -EINVAL;
147
148 rtas_buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
149 if (!rtas_buf)
150 return -ENOMEM;
151
152 dn = of_find_node_by_phandle(be32_to_cpu(phandle));
153 if (!dn) {
154 kfree(rtas_buf);
155 return -ENOENT;
156 }
157
158 upwa = (struct update_props_workarea *)&rtas_buf[0];
159 upwa->phandle = phandle;
160
161 do {
162 rtas_rc = mobility_rtas_call(update_properties_token, rtas_buf,
163 scope);
164 if (rtas_rc < 0)
165 break;
166
167 prop_data = rtas_buf + sizeof(*upwa);
168 nprops = be32_to_cpu(upwa->nprops);
169
170 /* On the first call to ibm,update-properties for a node the
171 * the first property value descriptor contains an empty
172 * property name, the property value length encoded as u32,
173 * and the property value is the node path being updated.
174 */
175 if (*prop_data == 0) {
176 prop_data++;
177 vd = be32_to_cpu(*(__be32 *)prop_data);
178 prop_data += vd + sizeof(vd);
179 nprops--;
180 }
181
182 for (i = 0; i < nprops; i++) {
183 char *prop_name;
184
185 prop_name = prop_data;
186 prop_data += strlen(prop_name) + 1;
187 vd = be32_to_cpu(*(__be32 *)prop_data);
188 prop_data += sizeof(vd);
189
190 switch (vd) {
191 case 0x00000000:
192 /* name only property, nothing to do */
193 break;
194
195 case 0x80000000:
196 of_remove_property(dn, of_find_property(dn,
197 prop_name, NULL));
198 prop = NULL;
199 break;
200
201 default:
202 rc = update_dt_property(dn, &prop, prop_name,
203 vd, prop_data);
204 if (rc) {
205 printk(KERN_ERR "Could not update %s"
206 " property\n", prop_name);
207 }
208
209 prop_data += vd;
210 }
211
212 cond_resched();
213 }
214
215 cond_resched();
216 } while (rtas_rc == 1);
217
218 of_node_put(dn);
219 kfree(rtas_buf);
220 return 0;
221 }
222
add_dt_node(__be32 parent_phandle,__be32 drc_index)223 static int add_dt_node(__be32 parent_phandle, __be32 drc_index)
224 {
225 struct device_node *dn;
226 struct device_node *parent_dn;
227 int rc;
228
229 parent_dn = of_find_node_by_phandle(be32_to_cpu(parent_phandle));
230 if (!parent_dn)
231 return -ENOENT;
232
233 dn = dlpar_configure_connector(drc_index, parent_dn);
234 if (!dn) {
235 of_node_put(parent_dn);
236 return -ENOENT;
237 }
238
239 rc = dlpar_attach_node(dn, parent_dn);
240 if (rc)
241 dlpar_free_cc_nodes(dn);
242
243 of_node_put(parent_dn);
244 return rc;
245 }
246
prrn_update_node(__be32 phandle)247 static void prrn_update_node(__be32 phandle)
248 {
249 struct pseries_hp_errorlog hp_elog;
250 struct device_node *dn;
251
252 /*
253 * If a node is found from a the given phandle, the phandle does not
254 * represent the drc index of an LMB and we can ignore.
255 */
256 dn = of_find_node_by_phandle(be32_to_cpu(phandle));
257 if (dn) {
258 of_node_put(dn);
259 return;
260 }
261
262 hp_elog.resource = PSERIES_HP_ELOG_RESOURCE_MEM;
263 hp_elog.action = PSERIES_HP_ELOG_ACTION_READD;
264 hp_elog.id_type = PSERIES_HP_ELOG_ID_DRC_INDEX;
265 hp_elog._drc_u.drc_index = phandle;
266
267 handle_dlpar_errorlog(&hp_elog);
268 }
269
pseries_devicetree_update(s32 scope)270 int pseries_devicetree_update(s32 scope)
271 {
272 char *rtas_buf;
273 __be32 *data;
274 int update_nodes_token;
275 int rc;
276
277 update_nodes_token = rtas_token("ibm,update-nodes");
278 if (update_nodes_token == RTAS_UNKNOWN_SERVICE)
279 return -EINVAL;
280
281 rtas_buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
282 if (!rtas_buf)
283 return -ENOMEM;
284
285 do {
286 rc = mobility_rtas_call(update_nodes_token, rtas_buf, scope);
287 if (rc && rc != 1)
288 break;
289
290 data = (__be32 *)rtas_buf + 4;
291 while (be32_to_cpu(*data) & NODE_ACTION_MASK) {
292 int i;
293 u32 action = be32_to_cpu(*data) & NODE_ACTION_MASK;
294 u32 node_count = be32_to_cpu(*data) & NODE_COUNT_MASK;
295
296 data++;
297
298 for (i = 0; i < node_count; i++) {
299 __be32 phandle = *data++;
300 __be32 drc_index;
301
302 switch (action) {
303 case DELETE_DT_NODE:
304 delete_dt_node(phandle);
305 break;
306 case UPDATE_DT_NODE:
307 update_dt_node(phandle, scope);
308
309 if (scope == PRRN_SCOPE)
310 prrn_update_node(phandle);
311
312 break;
313 case ADD_DT_NODE:
314 drc_index = *data++;
315 add_dt_node(phandle, drc_index);
316 break;
317 }
318
319 cond_resched();
320 }
321 }
322
323 cond_resched();
324 } while (rc == 1);
325
326 kfree(rtas_buf);
327 return rc;
328 }
329
post_mobility_fixup(void)330 void post_mobility_fixup(void)
331 {
332 int rc;
333 int activate_fw_token;
334
335 activate_fw_token = rtas_token("ibm,activate-firmware");
336 if (activate_fw_token == RTAS_UNKNOWN_SERVICE) {
337 printk(KERN_ERR "Could not make post-mobility "
338 "activate-fw call.\n");
339 return;
340 }
341
342 do {
343 rc = rtas_call(activate_fw_token, 0, 1, NULL);
344 } while (rtas_busy_delay(rc));
345
346 if (rc)
347 printk(KERN_ERR "Post-mobility activate-fw failed: %d\n", rc);
348
349 /*
350 * We don't want CPUs to go online/offline while the device
351 * tree is being updated.
352 */
353 cpus_read_lock();
354
355 /*
356 * It's common for the destination firmware to replace cache
357 * nodes. Release all of the cacheinfo hierarchy's references
358 * before updating the device tree.
359 */
360 cacheinfo_teardown();
361
362 rc = pseries_devicetree_update(MIGRATION_SCOPE);
363 if (rc)
364 printk(KERN_ERR "Post-mobility device tree update "
365 "failed: %d\n", rc);
366
367 cacheinfo_rebuild();
368
369 cpus_read_unlock();
370
371 /* Possibly switch to a new RFI flush type */
372 pseries_setup_rfi_flush();
373
374 return;
375 }
376
migration_store(struct class * class,struct class_attribute * attr,const char * buf,size_t count)377 static ssize_t migration_store(struct class *class,
378 struct class_attribute *attr, const char *buf,
379 size_t count)
380 {
381 u64 streamid;
382 int rc;
383
384 rc = kstrtou64(buf, 0, &streamid);
385 if (rc)
386 return rc;
387
388 stop_topology_update();
389
390 do {
391 rc = rtas_ibm_suspend_me(streamid);
392 if (rc == -EAGAIN)
393 ssleep(1);
394 } while (rc == -EAGAIN);
395
396 if (rc)
397 return rc;
398
399 post_mobility_fixup();
400
401 start_topology_update();
402
403 return count;
404 }
405
406 /*
407 * Used by drmgr to determine the kernel behavior of the migration interface.
408 *
409 * Version 1: Performs all PAPR requirements for migration including
410 * firmware activation and device tree update.
411 */
412 #define MIGRATION_API_VERSION 1
413
414 static CLASS_ATTR_WO(migration);
415 static CLASS_ATTR_STRING(api_version, 0444, __stringify(MIGRATION_API_VERSION));
416
mobility_sysfs_init(void)417 static int __init mobility_sysfs_init(void)
418 {
419 int rc;
420
421 mobility_kobj = kobject_create_and_add("mobility", kernel_kobj);
422 if (!mobility_kobj)
423 return -ENOMEM;
424
425 rc = sysfs_create_file(mobility_kobj, &class_attr_migration.attr);
426 if (rc)
427 pr_err("mobility: unable to create migration sysfs file (%d)\n", rc);
428
429 rc = sysfs_create_file(mobility_kobj, &class_attr_api_version.attr.attr);
430 if (rc)
431 pr_err("mobility: unable to create api_version sysfs file (%d)\n", rc);
432
433 return 0;
434 }
435 machine_device_initcall(pseries, mobility_sysfs_init);
436