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 
43 static int mobility_rtas_call(int token, char *buf, s32 scope)
44 {
45 	int rc;
46 
47 	spin_lock(&rtas_data_buf_lock);
48 
49 	memcpy(rtas_data_buf, buf, RTAS_DATA_BUF_SIZE);
50 	rc = rtas_call(token, 2, 1, NULL, rtas_data_buf, scope);
51 	memcpy(buf, rtas_data_buf, RTAS_DATA_BUF_SIZE);
52 
53 	spin_unlock(&rtas_data_buf_lock);
54 	return rc;
55 }
56 
57 static int delete_dt_node(__be32 phandle)
58 {
59 	struct device_node *dn;
60 
61 	dn = of_find_node_by_phandle(be32_to_cpu(phandle));
62 	if (!dn)
63 		return -ENOENT;
64 
65 	dlpar_detach_node(dn);
66 	of_node_put(dn);
67 	return 0;
68 }
69 
70 static int update_dt_property(struct device_node *dn, struct property **prop,
71 			      const char *name, u32 vd, char *value)
72 {
73 	struct property *new_prop = *prop;
74 	int more = 0;
75 
76 	/* A negative 'vd' value indicates that only part of the new property
77 	 * value is contained in the buffer and we need to call
78 	 * ibm,update-properties again to get the rest of the value.
79 	 *
80 	 * A negative value is also the two's compliment of the actual value.
81 	 */
82 	if (vd & 0x80000000) {
83 		vd = ~vd + 1;
84 		more = 1;
85 	}
86 
87 	if (new_prop) {
88 		/* partial property fixup */
89 		char *new_data = kzalloc(new_prop->length + vd, GFP_KERNEL);
90 		if (!new_data)
91 			return -ENOMEM;
92 
93 		memcpy(new_data, new_prop->value, new_prop->length);
94 		memcpy(new_data + new_prop->length, value, vd);
95 
96 		kfree(new_prop->value);
97 		new_prop->value = new_data;
98 		new_prop->length += vd;
99 	} else {
100 		new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
101 		if (!new_prop)
102 			return -ENOMEM;
103 
104 		new_prop->name = kstrdup(name, GFP_KERNEL);
105 		if (!new_prop->name) {
106 			kfree(new_prop);
107 			return -ENOMEM;
108 		}
109 
110 		new_prop->length = vd;
111 		new_prop->value = kzalloc(new_prop->length, GFP_KERNEL);
112 		if (!new_prop->value) {
113 			kfree(new_prop->name);
114 			kfree(new_prop);
115 			return -ENOMEM;
116 		}
117 
118 		memcpy(new_prop->value, value, vd);
119 		*prop = new_prop;
120 	}
121 
122 	if (!more) {
123 		of_update_property(dn, new_prop);
124 		*prop = NULL;
125 	}
126 
127 	return 0;
128 }
129 
130 static int update_dt_node(__be32 phandle, s32 scope)
131 {
132 	struct update_props_workarea *upwa;
133 	struct device_node *dn;
134 	struct property *prop = NULL;
135 	int i, rc, rtas_rc;
136 	char *prop_data;
137 	char *rtas_buf;
138 	int update_properties_token;
139 	u32 nprops;
140 	u32 vd;
141 
142 	update_properties_token = rtas_token("ibm,update-properties");
143 	if (update_properties_token == RTAS_UNKNOWN_SERVICE)
144 		return -EINVAL;
145 
146 	rtas_buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
147 	if (!rtas_buf)
148 		return -ENOMEM;
149 
150 	dn = of_find_node_by_phandle(be32_to_cpu(phandle));
151 	if (!dn) {
152 		kfree(rtas_buf);
153 		return -ENOENT;
154 	}
155 
156 	upwa = (struct update_props_workarea *)&rtas_buf[0];
157 	upwa->phandle = phandle;
158 
159 	do {
160 		rtas_rc = mobility_rtas_call(update_properties_token, rtas_buf,
161 					scope);
162 		if (rtas_rc < 0)
163 			break;
164 
165 		prop_data = rtas_buf + sizeof(*upwa);
166 		nprops = be32_to_cpu(upwa->nprops);
167 
168 		/* On the first call to ibm,update-properties for a node the
169 		 * the first property value descriptor contains an empty
170 		 * property name, the property value length encoded as u32,
171 		 * and the property value is the node path being updated.
172 		 */
173 		if (*prop_data == 0) {
174 			prop_data++;
175 			vd = be32_to_cpu(*(__be32 *)prop_data);
176 			prop_data += vd + sizeof(vd);
177 			nprops--;
178 		}
179 
180 		for (i = 0; i < nprops; i++) {
181 			char *prop_name;
182 
183 			prop_name = prop_data;
184 			prop_data += strlen(prop_name) + 1;
185 			vd = be32_to_cpu(*(__be32 *)prop_data);
186 			prop_data += sizeof(vd);
187 
188 			switch (vd) {
189 			case 0x00000000:
190 				/* name only property, nothing to do */
191 				break;
192 
193 			case 0x80000000:
194 				of_remove_property(dn, of_find_property(dn,
195 							prop_name, NULL));
196 				prop = NULL;
197 				break;
198 
199 			default:
200 				rc = update_dt_property(dn, &prop, prop_name,
201 							vd, prop_data);
202 				if (rc) {
203 					printk(KERN_ERR "Could not update %s"
204 					       " property\n", prop_name);
205 				}
206 
207 				prop_data += vd;
208 			}
209 		}
210 	} while (rtas_rc == 1);
211 
212 	of_node_put(dn);
213 	kfree(rtas_buf);
214 	return 0;
215 }
216 
217 static int add_dt_node(__be32 parent_phandle, __be32 drc_index)
218 {
219 	struct device_node *dn;
220 	struct device_node *parent_dn;
221 	int rc;
222 
223 	parent_dn = of_find_node_by_phandle(be32_to_cpu(parent_phandle));
224 	if (!parent_dn)
225 		return -ENOENT;
226 
227 	dn = dlpar_configure_connector(drc_index, parent_dn);
228 	if (!dn)
229 		return -ENOENT;
230 
231 	rc = dlpar_attach_node(dn);
232 	if (rc)
233 		dlpar_free_cc_nodes(dn);
234 
235 	of_node_put(parent_dn);
236 	return rc;
237 }
238 
239 int pseries_devicetree_update(s32 scope)
240 {
241 	char *rtas_buf;
242 	__be32 *data;
243 	int update_nodes_token;
244 	int rc;
245 
246 	update_nodes_token = rtas_token("ibm,update-nodes");
247 	if (update_nodes_token == RTAS_UNKNOWN_SERVICE)
248 		return -EINVAL;
249 
250 	rtas_buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
251 	if (!rtas_buf)
252 		return -ENOMEM;
253 
254 	do {
255 		rc = mobility_rtas_call(update_nodes_token, rtas_buf, scope);
256 		if (rc && rc != 1)
257 			break;
258 
259 		data = (__be32 *)rtas_buf + 4;
260 		while (be32_to_cpu(*data) & NODE_ACTION_MASK) {
261 			int i;
262 			u32 action = be32_to_cpu(*data) & NODE_ACTION_MASK;
263 			u32 node_count = be32_to_cpu(*data) & NODE_COUNT_MASK;
264 
265 			data++;
266 
267 			for (i = 0; i < node_count; i++) {
268 				__be32 phandle = *data++;
269 				__be32 drc_index;
270 
271 				switch (action) {
272 				case DELETE_DT_NODE:
273 					delete_dt_node(phandle);
274 					break;
275 				case UPDATE_DT_NODE:
276 					update_dt_node(phandle, scope);
277 					break;
278 				case ADD_DT_NODE:
279 					drc_index = *data++;
280 					add_dt_node(phandle, drc_index);
281 					break;
282 				}
283 			}
284 		}
285 	} while (rc == 1);
286 
287 	kfree(rtas_buf);
288 	return rc;
289 }
290 
291 void post_mobility_fixup(void)
292 {
293 	int rc;
294 	int activate_fw_token;
295 
296 	activate_fw_token = rtas_token("ibm,activate-firmware");
297 	if (activate_fw_token == RTAS_UNKNOWN_SERVICE) {
298 		printk(KERN_ERR "Could not make post-mobility "
299 		       "activate-fw call.\n");
300 		return;
301 	}
302 
303 	do {
304 		rc = rtas_call(activate_fw_token, 0, 1, NULL);
305 	} while (rtas_busy_delay(rc));
306 
307 	if (rc)
308 		printk(KERN_ERR "Post-mobility activate-fw failed: %d\n", rc);
309 
310 	rc = pseries_devicetree_update(MIGRATION_SCOPE);
311 	if (rc)
312 		printk(KERN_ERR "Post-mobility device tree update "
313 			"failed: %d\n", rc);
314 
315 	return;
316 }
317 
318 static ssize_t migrate_store(struct class *class, struct class_attribute *attr,
319 			     const char *buf, size_t count)
320 {
321 	u64 streamid;
322 	int rc;
323 
324 	rc = kstrtou64(buf, 0, &streamid);
325 	if (rc)
326 		return rc;
327 
328 	do {
329 		rc = rtas_ibm_suspend_me(streamid);
330 		if (rc == -EAGAIN)
331 			ssleep(1);
332 	} while (rc == -EAGAIN);
333 
334 	if (rc)
335 		return rc;
336 
337 	post_mobility_fixup();
338 	return count;
339 }
340 
341 /*
342  * Used by drmgr to determine the kernel behavior of the migration interface.
343  *
344  * Version 1: Performs all PAPR requirements for migration including
345  *	firmware activation and device tree update.
346  */
347 #define MIGRATION_API_VERSION	1
348 
349 static CLASS_ATTR(migration, S_IWUSR, NULL, migrate_store);
350 static CLASS_ATTR_STRING(api_version, S_IRUGO, __stringify(MIGRATION_API_VERSION));
351 
352 static int __init mobility_sysfs_init(void)
353 {
354 	int rc;
355 
356 	mobility_kobj = kobject_create_and_add("mobility", kernel_kobj);
357 	if (!mobility_kobj)
358 		return -ENOMEM;
359 
360 	rc = sysfs_create_file(mobility_kobj, &class_attr_migration.attr);
361 	if (rc)
362 		pr_err("mobility: unable to create migration sysfs file (%d)\n", rc);
363 
364 	rc = sysfs_create_file(mobility_kobj, &class_attr_api_version.attr.attr);
365 	if (rc)
366 		pr_err("mobility: unable to create api_version sysfs file (%d)\n", rc);
367 
368 	return 0;
369 }
370 machine_device_initcall(pseries, mobility_sysfs_init);
371