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
25static struct kobject *mobility_kobj;
26
27struct 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
43static 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
57static 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
70static 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
130static 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				prop = of_find_property(dn, prop_name, NULL);
195				of_remove_property(dn, prop);
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
217static 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
239int 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
291void 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
318static 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
349static CLASS_ATTR(migration, S_IWUSR, NULL, migrate_store);
350static CLASS_ATTR_STRING(api_version, S_IRUGO, __stringify(MIGRATION_API_VERSION));
351
352static 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}
370machine_device_initcall(pseries, mobility_sysfs_init);
371