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