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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/sched.h>
15 #include <linux/smp.h>
16 #include <linux/stat.h>
17 #include <linux/completion.h>
18 #include <linux/device.h>
19 #include <linux/delay.h>
20 #include <linux/slab.h>
21 
22 #include <asm/machdep.h>
23 #include <asm/rtas.h>
24 #include "pseries.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 
mobility_rtas_call(int token,char * buf,s32 scope)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 
delete_dt_node(__be32 phandle)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 
update_dt_property(struct device_node * dn,struct property ** prop,const char * name,u32 vd,char * value)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 
update_dt_node(__be32 phandle,s32 scope)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 				prop = of_find_property(dn, prop_name, NULL);
196 				of_remove_property(dn, prop);
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 			cond_resched();
212 		}
213 
214 		cond_resched();
215 	} while (rtas_rc == 1);
216 
217 	of_node_put(dn);
218 	kfree(rtas_buf);
219 	return 0;
220 }
221 
add_dt_node(__be32 parent_phandle,__be32 drc_index)222 static int add_dt_node(__be32 parent_phandle, __be32 drc_index)
223 {
224 	struct device_node *dn;
225 	struct device_node *parent_dn;
226 	int rc;
227 
228 	parent_dn = of_find_node_by_phandle(be32_to_cpu(parent_phandle));
229 	if (!parent_dn)
230 		return -ENOENT;
231 
232 	dn = dlpar_configure_connector(drc_index, parent_dn);
233 	if (!dn) {
234 		of_node_put(parent_dn);
235 		return -ENOENT;
236 	}
237 
238 	rc = dlpar_attach_node(dn);
239 	if (rc)
240 		dlpar_free_cc_nodes(dn);
241 
242 	of_node_put(parent_dn);
243 	return rc;
244 }
245 
pseries_devicetree_update(s32 scope)246 int pseries_devicetree_update(s32 scope)
247 {
248 	char *rtas_buf;
249 	__be32 *data;
250 	int update_nodes_token;
251 	int rc;
252 
253 	update_nodes_token = rtas_token("ibm,update-nodes");
254 	if (update_nodes_token == RTAS_UNKNOWN_SERVICE)
255 		return -EINVAL;
256 
257 	rtas_buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
258 	if (!rtas_buf)
259 		return -ENOMEM;
260 
261 	do {
262 		rc = mobility_rtas_call(update_nodes_token, rtas_buf, scope);
263 		if (rc && rc != 1)
264 			break;
265 
266 		data = (__be32 *)rtas_buf + 4;
267 		while (be32_to_cpu(*data) & NODE_ACTION_MASK) {
268 			int i;
269 			u32 action = be32_to_cpu(*data) & NODE_ACTION_MASK;
270 			u32 node_count = be32_to_cpu(*data) & NODE_COUNT_MASK;
271 
272 			data++;
273 
274 			for (i = 0; i < node_count; i++) {
275 				__be32 phandle = *data++;
276 				__be32 drc_index;
277 
278 				switch (action) {
279 				case DELETE_DT_NODE:
280 					delete_dt_node(phandle);
281 					break;
282 				case UPDATE_DT_NODE:
283 					update_dt_node(phandle, scope);
284 					break;
285 				case ADD_DT_NODE:
286 					drc_index = *data++;
287 					add_dt_node(phandle, drc_index);
288 					break;
289 				}
290 
291 				cond_resched();
292 			}
293 		}
294 
295 		cond_resched();
296 	} while (rc == 1);
297 
298 	kfree(rtas_buf);
299 	return rc;
300 }
301 
post_mobility_fixup(void)302 void post_mobility_fixup(void)
303 {
304 	int rc;
305 	int activate_fw_token;
306 
307 	activate_fw_token = rtas_token("ibm,activate-firmware");
308 	if (activate_fw_token == RTAS_UNKNOWN_SERVICE) {
309 		printk(KERN_ERR "Could not make post-mobility "
310 		       "activate-fw call.\n");
311 		return;
312 	}
313 
314 	do {
315 		rc = rtas_call(activate_fw_token, 0, 1, NULL);
316 	} while (rtas_busy_delay(rc));
317 
318 	if (rc)
319 		printk(KERN_ERR "Post-mobility activate-fw failed: %d\n", rc);
320 
321 	rc = pseries_devicetree_update(MIGRATION_SCOPE);
322 	if (rc)
323 		printk(KERN_ERR "Post-mobility device tree update "
324 			"failed: %d\n", rc);
325 
326 	/* Possibly switch to a new RFI flush type */
327 	pseries_setup_rfi_flush();
328 
329 	return;
330 }
331 
migrate_store(struct class * class,struct class_attribute * attr,const char * buf,size_t count)332 static ssize_t migrate_store(struct class *class, struct class_attribute *attr,
333 			     const char *buf, size_t count)
334 {
335 	u64 streamid;
336 	int rc;
337 
338 	rc = kstrtou64(buf, 0, &streamid);
339 	if (rc)
340 		return rc;
341 
342 	do {
343 		rc = rtas_ibm_suspend_me(streamid);
344 		if (rc == -EAGAIN)
345 			ssleep(1);
346 	} while (rc == -EAGAIN);
347 
348 	if (rc)
349 		return rc;
350 
351 	post_mobility_fixup();
352 	return count;
353 }
354 
355 /*
356  * Used by drmgr to determine the kernel behavior of the migration interface.
357  *
358  * Version 1: Performs all PAPR requirements for migration including
359  *	firmware activation and device tree update.
360  */
361 #define MIGRATION_API_VERSION	1
362 
363 static CLASS_ATTR(migration, S_IWUSR, NULL, migrate_store);
364 static CLASS_ATTR_STRING(api_version, S_IRUGO, __stringify(MIGRATION_API_VERSION));
365 
mobility_sysfs_init(void)366 static int __init mobility_sysfs_init(void)
367 {
368 	int rc;
369 
370 	mobility_kobj = kobject_create_and_add("mobility", kernel_kobj);
371 	if (!mobility_kobj)
372 		return -ENOMEM;
373 
374 	rc = sysfs_create_file(mobility_kobj, &class_attr_migration.attr);
375 	if (rc)
376 		pr_err("mobility: unable to create migration sysfs file (%d)\n", rc);
377 
378 	rc = sysfs_create_file(mobility_kobj, &class_attr_api_version.attr.attr);
379 	if (rc)
380 		pr_err("mobility: unable to create api_version sysfs file (%d)\n", rc);
381 
382 	return 0;
383 }
384 machine_device_initcall(pseries, mobility_sysfs_init);
385