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/rtas.h>
22 #include "pseries.h"
23 
24 static struct kobject *mobility_kobj;
25 
26 struct update_props_workarea {
27 	u32 phandle;
28 	u32 state;
29 	u64 reserved;
30 	u32 nprops;
31 } __packed;
32 
33 #define NODE_ACTION_MASK	0xff000000
34 #define NODE_COUNT_MASK		0x00ffffff
35 
36 #define DELETE_DT_NODE	0x01000000
37 #define UPDATE_DT_NODE	0x02000000
38 #define ADD_DT_NODE	0x03000000
39 
40 #define MIGRATION_SCOPE	(1)
41 
42 static int mobility_rtas_call(int token, char *buf, s32 scope)
43 {
44 	int rc;
45 
46 	spin_lock(&rtas_data_buf_lock);
47 
48 	memcpy(rtas_data_buf, buf, RTAS_DATA_BUF_SIZE);
49 	rc = rtas_call(token, 2, 1, NULL, rtas_data_buf, scope);
50 	memcpy(buf, rtas_data_buf, RTAS_DATA_BUF_SIZE);
51 
52 	spin_unlock(&rtas_data_buf_lock);
53 	return rc;
54 }
55 
56 static int delete_dt_node(u32 phandle)
57 {
58 	struct device_node *dn;
59 
60 	dn = of_find_node_by_phandle(phandle);
61 	if (!dn)
62 		return -ENOENT;
63 
64 	dlpar_detach_node(dn);
65 	of_node_put(dn);
66 	return 0;
67 }
68 
69 static int update_dt_property(struct device_node *dn, struct property **prop,
70 			      const char *name, u32 vd, char *value)
71 {
72 	struct property *new_prop = *prop;
73 	int more = 0;
74 
75 	/* A negative 'vd' value indicates that only part of the new property
76 	 * value is contained in the buffer and we need to call
77 	 * ibm,update-properties again to get the rest of the value.
78 	 *
79 	 * A negative value is also the two's compliment of the actual value.
80 	 */
81 	if (vd & 0x80000000) {
82 		vd = ~vd + 1;
83 		more = 1;
84 	}
85 
86 	if (new_prop) {
87 		/* partial property fixup */
88 		char *new_data = kzalloc(new_prop->length + vd, GFP_KERNEL);
89 		if (!new_data)
90 			return -ENOMEM;
91 
92 		memcpy(new_data, new_prop->value, new_prop->length);
93 		memcpy(new_data + new_prop->length, value, vd);
94 
95 		kfree(new_prop->value);
96 		new_prop->value = new_data;
97 		new_prop->length += vd;
98 	} else {
99 		new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
100 		if (!new_prop)
101 			return -ENOMEM;
102 
103 		new_prop->name = kstrdup(name, GFP_KERNEL);
104 		if (!new_prop->name) {
105 			kfree(new_prop);
106 			return -ENOMEM;
107 		}
108 
109 		new_prop->length = vd;
110 		new_prop->value = kzalloc(new_prop->length, GFP_KERNEL);
111 		if (!new_prop->value) {
112 			kfree(new_prop->name);
113 			kfree(new_prop);
114 			return -ENOMEM;
115 		}
116 
117 		memcpy(new_prop->value, value, vd);
118 		*prop = new_prop;
119 	}
120 
121 	if (!more) {
122 		of_update_property(dn, new_prop);
123 		*prop = NULL;
124 	}
125 
126 	return 0;
127 }
128 
129 static int update_dt_node(u32 phandle, s32 scope)
130 {
131 	struct update_props_workarea *upwa;
132 	struct device_node *dn;
133 	struct property *prop = NULL;
134 	int i, rc, rtas_rc;
135 	char *prop_data;
136 	char *rtas_buf;
137 	int update_properties_token;
138 	u32 vd;
139 
140 	update_properties_token = rtas_token("ibm,update-properties");
141 	if (update_properties_token == RTAS_UNKNOWN_SERVICE)
142 		return -EINVAL;
143 
144 	rtas_buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
145 	if (!rtas_buf)
146 		return -ENOMEM;
147 
148 	dn = of_find_node_by_phandle(phandle);
149 	if (!dn) {
150 		kfree(rtas_buf);
151 		return -ENOENT;
152 	}
153 
154 	upwa = (struct update_props_workarea *)&rtas_buf[0];
155 	upwa->phandle = phandle;
156 
157 	do {
158 		rtas_rc = mobility_rtas_call(update_properties_token, rtas_buf,
159 					scope);
160 		if (rtas_rc < 0)
161 			break;
162 
163 		prop_data = rtas_buf + sizeof(*upwa);
164 
165 		/* On the first call to ibm,update-properties for a node the
166 		 * the first property value descriptor contains an empty
167 		 * property name, the property value length encoded as u32,
168 		 * and the property value is the node path being updated.
169 		 */
170 		if (*prop_data == 0) {
171 			prop_data++;
172 			vd = *(u32 *)prop_data;
173 			prop_data += vd + sizeof(vd);
174 			upwa->nprops--;
175 		}
176 
177 		for (i = 0; i < upwa->nprops; i++) {
178 			char *prop_name;
179 
180 			prop_name = prop_data;
181 			prop_data += strlen(prop_name) + 1;
182 			vd = *(u32 *)prop_data;
183 			prop_data += sizeof(vd);
184 
185 			switch (vd) {
186 			case 0x00000000:
187 				/* name only property, nothing to do */
188 				break;
189 
190 			case 0x80000000:
191 				prop = of_find_property(dn, prop_name, NULL);
192 				of_remove_property(dn, prop);
193 				prop = NULL;
194 				break;
195 
196 			default:
197 				rc = update_dt_property(dn, &prop, prop_name,
198 							vd, prop_data);
199 				if (rc) {
200 					printk(KERN_ERR "Could not update %s"
201 					       " property\n", prop_name);
202 				}
203 
204 				prop_data += vd;
205 			}
206 		}
207 	} while (rtas_rc == 1);
208 
209 	of_node_put(dn);
210 	kfree(rtas_buf);
211 	return 0;
212 }
213 
214 static int add_dt_node(u32 parent_phandle, u32 drc_index)
215 {
216 	struct device_node *dn;
217 	struct device_node *parent_dn;
218 	int rc;
219 
220 	parent_dn = of_find_node_by_phandle(parent_phandle);
221 	if (!parent_dn)
222 		return -ENOENT;
223 
224 	dn = dlpar_configure_connector(drc_index, parent_dn);
225 	if (!dn)
226 		return -ENOENT;
227 
228 	rc = dlpar_attach_node(dn);
229 	if (rc)
230 		dlpar_free_cc_nodes(dn);
231 
232 	of_node_put(parent_dn);
233 	return rc;
234 }
235 
236 int pseries_devicetree_update(s32 scope)
237 {
238 	char *rtas_buf;
239 	u32 *data;
240 	int update_nodes_token;
241 	int rc;
242 
243 	update_nodes_token = rtas_token("ibm,update-nodes");
244 	if (update_nodes_token == RTAS_UNKNOWN_SERVICE)
245 		return -EINVAL;
246 
247 	rtas_buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
248 	if (!rtas_buf)
249 		return -ENOMEM;
250 
251 	do {
252 		rc = mobility_rtas_call(update_nodes_token, rtas_buf, scope);
253 		if (rc && rc != 1)
254 			break;
255 
256 		data = (u32 *)rtas_buf + 4;
257 		while (*data & NODE_ACTION_MASK) {
258 			int i;
259 			u32 action = *data & NODE_ACTION_MASK;
260 			int node_count = *data & NODE_COUNT_MASK;
261 
262 			data++;
263 
264 			for (i = 0; i < node_count; i++) {
265 				u32 phandle = *data++;
266 				u32 drc_index;
267 
268 				switch (action) {
269 				case DELETE_DT_NODE:
270 					delete_dt_node(phandle);
271 					break;
272 				case UPDATE_DT_NODE:
273 					update_dt_node(phandle, scope);
274 					break;
275 				case ADD_DT_NODE:
276 					drc_index = *data++;
277 					add_dt_node(phandle, drc_index);
278 					break;
279 				}
280 			}
281 		}
282 	} while (rc == 1);
283 
284 	kfree(rtas_buf);
285 	return rc;
286 }
287 
288 void post_mobility_fixup(void)
289 {
290 	int rc;
291 	int activate_fw_token;
292 
293 	activate_fw_token = rtas_token("ibm,activate-firmware");
294 	if (activate_fw_token == RTAS_UNKNOWN_SERVICE) {
295 		printk(KERN_ERR "Could not make post-mobility "
296 		       "activate-fw call.\n");
297 		return;
298 	}
299 
300 	do {
301 		rc = rtas_call(activate_fw_token, 0, 1, NULL);
302 	} while (rtas_busy_delay(rc));
303 
304 	if (rc)
305 		printk(KERN_ERR "Post-mobility activate-fw failed: %d\n", rc);
306 
307 	rc = pseries_devicetree_update(MIGRATION_SCOPE);
308 	if (rc)
309 		printk(KERN_ERR "Post-mobility device tree update "
310 			"failed: %d\n", rc);
311 
312 	return;
313 }
314 
315 static ssize_t migrate_store(struct class *class, struct class_attribute *attr,
316 			     const char *buf, size_t count)
317 {
318 	struct rtas_args args;
319 	u64 streamid;
320 	int rc;
321 
322 	rc = strict_strtoull(buf, 0, &streamid);
323 	if (rc)
324 		return rc;
325 
326 	memset(&args, 0, sizeof(args));
327 	args.token = rtas_token("ibm,suspend-me");
328 	args.nargs = 2;
329 	args.nret = 1;
330 
331 	args.args[0] = streamid >> 32 ;
332 	args.args[1] = streamid & 0xffffffff;
333 	args.rets = &args.args[args.nargs];
334 
335 	do {
336 		args.rets[0] = 0;
337 		rc = rtas_ibm_suspend_me(&args);
338 		if (!rc && args.rets[0] == RTAS_NOT_SUSPENDABLE)
339 			ssleep(1);
340 	} while (!rc && args.rets[0] == RTAS_NOT_SUSPENDABLE);
341 
342 	if (rc)
343 		return rc;
344 	else if (args.rets[0])
345 		return args.rets[0];
346 
347 	post_mobility_fixup();
348 	return count;
349 }
350 
351 static CLASS_ATTR(migration, S_IWUSR, NULL, migrate_store);
352 
353 static int __init mobility_sysfs_init(void)
354 {
355 	int rc;
356 
357 	mobility_kobj = kobject_create_and_add("mobility", kernel_kobj);
358 	if (!mobility_kobj)
359 		return -ENOMEM;
360 
361 	rc = sysfs_create_file(mobility_kobj, &class_attr_migration.attr);
362 
363 	return rc;
364 }
365 device_initcall(mobility_sysfs_init);
366