arch/powerpc/platforms/pseries/mobility.c

   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);