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
10 #define pr_fmt(fmt) "mobility: " fmt
11
12 #include <linux/cpu.h>
13 #include <linux/kernel.h>
14 #include <linux/kobject.h>
15 #include <linux/sched.h>
16 #include <linux/smp.h>
17 #include <linux/stat.h>
18 #include <linux/completion.h>
19 #include <linux/device.h>
20 #include <linux/delay.h>
21 #include <linux/slab.h>
22 #include <linux/stringify.h>
23
24 #include <asm/machdep.h>
25 #include <asm/rtas.h>
26 #include "pseries.h"
27 #include "../../kernel/cacheinfo.h"
28
29 static struct kobject *mobility_kobj;
30
31 struct update_props_workarea {
32 __be32 phandle;
33 __be32 state;
34 __be64 reserved;
35 __be32 nprops;
36 } __packed;
37
38 #define NODE_ACTION_MASK 0xff000000
39 #define NODE_COUNT_MASK 0x00ffffff
40
41 #define DELETE_DT_NODE 0x01000000
42 #define UPDATE_DT_NODE 0x02000000
43 #define ADD_DT_NODE 0x03000000
44
45 #define MIGRATION_SCOPE (1)
46 #define PRRN_SCOPE -2
47
mobility_rtas_call(int token,char * buf,s32 scope)48 static int mobility_rtas_call(int token, char *buf, s32 scope)
49 {
50 int rc;
51
52 spin_lock(&rtas_data_buf_lock);
53
54 memcpy(rtas_data_buf, buf, RTAS_DATA_BUF_SIZE);
55 rc = rtas_call(token, 2, 1, NULL, rtas_data_buf, scope);
56 memcpy(buf, rtas_data_buf, RTAS_DATA_BUF_SIZE);
57
58 spin_unlock(&rtas_data_buf_lock);
59 return rc;
60 }
61
delete_dt_node(__be32 phandle)62 static int delete_dt_node(__be32 phandle)
63 {
64 struct device_node *dn;
65
66 dn = of_find_node_by_phandle(be32_to_cpu(phandle));
67 if (!dn)
68 return -ENOENT;
69
70 pr_debug("removing node %pOFfp\n", dn);
71
72 dlpar_detach_node(dn);
73 of_node_put(dn);
74 return 0;
75 }
76
update_dt_property(struct device_node * dn,struct property ** prop,const char * name,u32 vd,char * value)77 static int update_dt_property(struct device_node *dn, struct property **prop,
78 const char *name, u32 vd, char *value)
79 {
80 struct property *new_prop = *prop;
81 int more = 0;
82
83 /* A negative 'vd' value indicates that only part of the new property
84 * value is contained in the buffer and we need to call
85 * ibm,update-properties again to get the rest of the value.
86 *
87 * A negative value is also the two's compliment of the actual value.
88 */
89 if (vd & 0x80000000) {
90 vd = ~vd + 1;
91 more = 1;
92 }
93
94 if (new_prop) {
95 /* partial property fixup */
96 char *new_data = kzalloc(new_prop->length + vd, GFP_KERNEL);
97 if (!new_data)
98 return -ENOMEM;
99
100 memcpy(new_data, new_prop->value, new_prop->length);
101 memcpy(new_data + new_prop->length, value, vd);
102
103 kfree(new_prop->value);
104 new_prop->value = new_data;
105 new_prop->length += vd;
106 } else {
107 new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
108 if (!new_prop)
109 return -ENOMEM;
110
111 new_prop->name = kstrdup(name, GFP_KERNEL);
112 if (!new_prop->name) {
113 kfree(new_prop);
114 return -ENOMEM;
115 }
116
117 new_prop->length = vd;
118 new_prop->value = kzalloc(new_prop->length, GFP_KERNEL);
119 if (!new_prop->value) {
120 kfree(new_prop->name);
121 kfree(new_prop);
122 return -ENOMEM;
123 }
124
125 memcpy(new_prop->value, value, vd);
126 *prop = new_prop;
127 }
128
129 if (!more) {
130 pr_debug("updating node %pOF property %s\n", dn, name);
131 of_update_property(dn, new_prop);
132 *prop = NULL;
133 }
134
135 return 0;
136 }
137
update_dt_node(__be32 phandle,s32 scope)138 static int update_dt_node(__be32 phandle, s32 scope)
139 {
140 struct update_props_workarea *upwa;
141 struct device_node *dn;
142 struct property *prop = NULL;
143 int i, rc, rtas_rc;
144 char *prop_data;
145 char *rtas_buf;
146 int update_properties_token;
147 u32 nprops;
148 u32 vd;
149
150 update_properties_token = rtas_token("ibm,update-properties");
151 if (update_properties_token == RTAS_UNKNOWN_SERVICE)
152 return -EINVAL;
153
154 rtas_buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
155 if (!rtas_buf)
156 return -ENOMEM;
157
158 dn = of_find_node_by_phandle(be32_to_cpu(phandle));
159 if (!dn) {
160 kfree(rtas_buf);
161 return -ENOENT;
162 }
163
164 upwa = (struct update_props_workarea *)&rtas_buf[0];
165 upwa->phandle = phandle;
166
167 do {
168 rtas_rc = mobility_rtas_call(update_properties_token, rtas_buf,
169 scope);
170 if (rtas_rc < 0)
171 break;
172
173 prop_data = rtas_buf + sizeof(*upwa);
174 nprops = be32_to_cpu(upwa->nprops);
175
176 /* On the first call to ibm,update-properties for a node the
177 * the first property value descriptor contains an empty
178 * property name, the property value length encoded as u32,
179 * and the property value is the node path being updated.
180 */
181 if (*prop_data == 0) {
182 prop_data++;
183 vd = be32_to_cpu(*(__be32 *)prop_data);
184 prop_data += vd + sizeof(vd);
185 nprops--;
186 }
187
188 for (i = 0; i < nprops; i++) {
189 char *prop_name;
190
191 prop_name = prop_data;
192 prop_data += strlen(prop_name) + 1;
193 vd = be32_to_cpu(*(__be32 *)prop_data);
194 prop_data += sizeof(vd);
195
196 switch (vd) {
197 case 0x00000000:
198 /* name only property, nothing to do */
199 break;
200
201 case 0x80000000:
202 of_remove_property(dn, of_find_property(dn,
203 prop_name, NULL));
204 prop = NULL;
205 break;
206
207 default:
208 rc = update_dt_property(dn, &prop, prop_name,
209 vd, prop_data);
210 if (rc) {
211 printk(KERN_ERR "Could not update %s"
212 " property\n", prop_name);
213 }
214
215 prop_data += vd;
216 }
217
218 cond_resched();
219 }
220
221 cond_resched();
222 } while (rtas_rc == 1);
223
224 of_node_put(dn);
225 kfree(rtas_buf);
226 return 0;
227 }
228
add_dt_node(__be32 parent_phandle,__be32 drc_index)229 static int add_dt_node(__be32 parent_phandle, __be32 drc_index)
230 {
231 struct device_node *dn;
232 struct device_node *parent_dn;
233 int rc;
234
235 parent_dn = of_find_node_by_phandle(be32_to_cpu(parent_phandle));
236 if (!parent_dn)
237 return -ENOENT;
238
239 dn = dlpar_configure_connector(drc_index, parent_dn);
240 if (!dn) {
241 of_node_put(parent_dn);
242 return -ENOENT;
243 }
244
245 rc = dlpar_attach_node(dn, parent_dn);
246 if (rc)
247 dlpar_free_cc_nodes(dn);
248
249 pr_debug("added node %pOFfp\n", dn);
250
251 of_node_put(parent_dn);
252 return rc;
253 }
254
pseries_devicetree_update(s32 scope)255 int pseries_devicetree_update(s32 scope)
256 {
257 char *rtas_buf;
258 __be32 *data;
259 int update_nodes_token;
260 int rc;
261
262 update_nodes_token = rtas_token("ibm,update-nodes");
263 if (update_nodes_token == RTAS_UNKNOWN_SERVICE)
264 return -EINVAL;
265
266 rtas_buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
267 if (!rtas_buf)
268 return -ENOMEM;
269
270 do {
271 rc = mobility_rtas_call(update_nodes_token, rtas_buf, scope);
272 if (rc && rc != 1)
273 break;
274
275 data = (__be32 *)rtas_buf + 4;
276 while (be32_to_cpu(*data) & NODE_ACTION_MASK) {
277 int i;
278 u32 action = be32_to_cpu(*data) & NODE_ACTION_MASK;
279 u32 node_count = be32_to_cpu(*data) & NODE_COUNT_MASK;
280
281 data++;
282
283 for (i = 0; i < node_count; i++) {
284 __be32 phandle = *data++;
285 __be32 drc_index;
286
287 switch (action) {
288 case DELETE_DT_NODE:
289 delete_dt_node(phandle);
290 break;
291 case UPDATE_DT_NODE:
292 update_dt_node(phandle, scope);
293 break;
294 case ADD_DT_NODE:
295 drc_index = *data++;
296 add_dt_node(phandle, drc_index);
297 break;
298 }
299
300 cond_resched();
301 }
302 }
303
304 cond_resched();
305 } while (rc == 1);
306
307 kfree(rtas_buf);
308 return rc;
309 }
310
post_mobility_fixup(void)311 void post_mobility_fixup(void)
312 {
313 int rc;
314 int activate_fw_token;
315
316 activate_fw_token = rtas_token("ibm,activate-firmware");
317 if (activate_fw_token == RTAS_UNKNOWN_SERVICE) {
318 printk(KERN_ERR "Could not make post-mobility "
319 "activate-fw call.\n");
320 return;
321 }
322
323 do {
324 rc = rtas_call(activate_fw_token, 0, 1, NULL);
325 } while (rtas_busy_delay(rc));
326
327 if (rc)
328 printk(KERN_ERR "Post-mobility activate-fw failed: %d\n", rc);
329
330 /*
331 * We don't want CPUs to go online/offline while the device
332 * tree is being updated.
333 */
334 cpus_read_lock();
335
336 /*
337 * It's common for the destination firmware to replace cache
338 * nodes. Release all of the cacheinfo hierarchy's references
339 * before updating the device tree.
340 */
341 cacheinfo_teardown();
342
343 rc = pseries_devicetree_update(MIGRATION_SCOPE);
344 if (rc)
345 printk(KERN_ERR "Post-mobility device tree update "
346 "failed: %d\n", rc);
347
348 cacheinfo_rebuild();
349
350 cpus_read_unlock();
351
352 /* Possibly switch to a new L1 flush type */
353 pseries_setup_security_mitigations();
354
355 /* Reinitialise system information for hv-24x7 */
356 read_24x7_sys_info();
357
358 return;
359 }
360
migration_store(struct class * class,struct class_attribute * attr,const char * buf,size_t count)361 static ssize_t migration_store(struct class *class,
362 struct class_attribute *attr, const char *buf,
363 size_t count)
364 {
365 u64 streamid;
366 int rc;
367
368 rc = kstrtou64(buf, 0, &streamid);
369 if (rc)
370 return rc;
371
372 do {
373 rc = rtas_ibm_suspend_me(streamid);
374 if (rc == -EAGAIN)
375 ssleep(1);
376 } while (rc == -EAGAIN);
377
378 if (rc)
379 return rc;
380
381 post_mobility_fixup();
382
383 return count;
384 }
385
386 /*
387 * Used by drmgr to determine the kernel behavior of the migration interface.
388 *
389 * Version 1: Performs all PAPR requirements for migration including
390 * firmware activation and device tree update.
391 */
392 #define MIGRATION_API_VERSION 1
393
394 static CLASS_ATTR_WO(migration);
395 static CLASS_ATTR_STRING(api_version, 0444, __stringify(MIGRATION_API_VERSION));
396
mobility_sysfs_init(void)397 static int __init mobility_sysfs_init(void)
398 {
399 int rc;
400
401 mobility_kobj = kobject_create_and_add("mobility", kernel_kobj);
402 if (!mobility_kobj)
403 return -ENOMEM;
404
405 rc = sysfs_create_file(mobility_kobj, &class_attr_migration.attr);
406 if (rc)
407 pr_err("unable to create migration sysfs file (%d)\n", rc);
408
409 rc = sysfs_create_file(mobility_kobj, &class_attr_api_version.attr.attr);
410 if (rc)
411 pr_err("unable to create api_version sysfs file (%d)\n", rc);
412
413 return 0;
414 }
415 machine_device_initcall(pseries, mobility_sysfs_init);
416