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