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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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