arch/powerpc/platforms/pseries/mobility.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Support for Partition Mobility/Migration
   4  *
   5  * Copyright (C) 2010 Nathan Fontenot
   6  * Copyright (C) 2010 IBM Corporation
   7  */
   8
   9
  10 #define pr_fmt(fmt) "mobility: " fmt
  11
  12 #include <linux/cpu.h>
  13 #include <linux/kernel.h>
  14 #include <linux/kobject.h>
  15 #include <linux/sched.h>
  16 #include <linux/smp.h>
  17 #include <linux/stat.h>
  18 #include <linux/completion.h>
  19 #include <linux/device.h>
  20 #include <linux/delay.h>
  21 #include <linux/slab.h>
  22 #include <linux/stringify.h>
  23
  24 #include <asm/machdep.h>
  25 #include <asm/rtas.h>
  26 #include "pseries.h"
  27 #include "../../kernel/cacheinfo.h"
  28
  29 static struct kobject *mobility_kobj;
  30
  31 struct update_props_workarea {
  32         __be32 phandle;
  33         __be32 state;
  34         __be64 reserved;
  35         __be32 nprops;
  36 } __packed;
  37
  38 #define NODE_ACTION_MASK        0xff000000
  39 #define NODE_COUNT_MASK         0x00ffffff
  40
  41 #define DELETE_DT_NODE  0x01000000
  42 #define UPDATE_DT_NODE  0x02000000
  43 #define ADD_DT_NODE     0x03000000
  44
  45 #define MIGRATION_SCOPE (1)
  46 #define PRRN_SCOPE -2
  47
  48 static int mobility_rtas_call(int token, char *buf, s32 scope)
  49 {
  50         int rc;
  51
  52         spin_lock(&rtas_data_buf_lock);
  53
  54         memcpy(rtas_data_buf, buf, RTAS_DATA_BUF_SIZE);
  55         rc = rtas_call(token, 2, 1, NULL, rtas_data_buf, scope);
  56         memcpy(buf, rtas_data_buf, RTAS_DATA_BUF_SIZE);
  57
  58         spin_unlock(&rtas_data_buf_lock);
  59         return rc;
  60 }
  61
  62 static int delete_dt_node(struct device_node *dn)
  63 {
  64         struct device_node *pdn;
  65         bool is_platfac;
  66
  67         pdn = of_get_parent(dn);
  68         is_platfac = of_node_is_type(dn, "ibm,platform-facilities") ||
  69                      of_node_is_type(pdn, "ibm,platform-facilities");
  70         of_node_put(pdn);
  71
  72         /*
  73          * The drivers that bind to nodes in the platform-facilities
  74          * hierarchy don't support node removal, and the removal directive
  75          * from firmware is always followed by an add of an equivalent
  76          * node. The capability (e.g. RNG, encryption, compression)
  77          * represented by the node is never interrupted by the migration.
  78          * So ignore changes to this part of the tree.
  79          */
  80         if (is_platfac) {
  81                 pr_notice("ignoring remove operation for %pOFfp\n", dn);
  82                 return 0;
  83         }
  84
  85         pr_debug("removing node %pOFfp\n", dn);
  86         dlpar_detach_node(dn);
  87         return 0;
  88 }
  89
  90 static int update_dt_property(struct device_node *dn, struct property **prop,
  91                               const char *name, u32 vd, char *value)
  92 {
  93         struct property *new_prop = *prop;
  94         int more = 0;
  95
  96         /* A negative 'vd' value indicates that only part of the new property
  97          * value is contained in the buffer and we need to call
  98          * ibm,update-properties again to get the rest of the value.
  99          *
 100          * A negative value is also the two's compliment of the actual value.
 101          */
 102         if (vd & 0x80000000) {
 103                 vd = ~vd + 1;
 104                 more = 1;
 105         }
 106
 107         if (new_prop) {
 108                 /* partial property fixup */
 109                 char *new_data = kzalloc(new_prop->length + vd, GFP_KERNEL);
 110                 if (!new_data)
 111                         return -ENOMEM;
 112
 113                 memcpy(new_data, new_prop->value, new_prop->length);
 114                 memcpy(new_data + new_prop->length, value, vd);
 115
 116                 kfree(new_prop->value);
 117                 new_prop->value = new_data;
 118                 new_prop->length += vd;
 119         } else {
 120                 new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
 121                 if (!new_prop)
 122                         return -ENOMEM;
 123
 124                 new_prop->name = kstrdup(name, GFP_KERNEL);
 125                 if (!new_prop->name) {
 126                         kfree(new_prop);
 127                         return -ENOMEM;
 128                 }
 129
 130                 new_prop->length = vd;
 131                 new_prop->value = kzalloc(new_prop->length, GFP_KERNEL);
 132                 if (!new_prop->value) {
 133                         kfree(new_prop->name);
 134                         kfree(new_prop);
 135                         return -ENOMEM;
 136                 }
 137
 138                 memcpy(new_prop->value, value, vd);
 139                 *prop = new_prop;
 140         }
 141
 142         if (!more) {
 143                 pr_debug("updating node %pOF property %s\n", dn, name);
 144                 of_update_property(dn, new_prop);
 145                 *prop = NULL;
 146         }
 147
 148         return 0;
 149 }
 150
 151 static int update_dt_node(struct device_node *dn, s32 scope)
 152 {
 153         struct update_props_workarea *upwa;
 154         struct property *prop = NULL;
 155         int i, rc, rtas_rc;
 156         char *prop_data;
 157         char *rtas_buf;
 158         int update_properties_token;
 159         u32 nprops;
 160         u32 vd;
 161
 162         update_properties_token = rtas_token("ibm,update-properties");
 163         if (update_properties_token == RTAS_UNKNOWN_SERVICE)
 164                 return -EINVAL;
 165
 166         rtas_buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
 167         if (!rtas_buf)
 168                 return -ENOMEM;
 169
 170         upwa = (struct update_props_workarea *)&rtas_buf[0];
 171         upwa->phandle = cpu_to_be32(dn->phandle);
 172
 173         do {
 174                 rtas_rc = mobility_rtas_call(update_properties_token, rtas_buf,
 175                                         scope);
 176                 if (rtas_rc < 0)
 177                         break;
 178
 179                 prop_data = rtas_buf + sizeof(*upwa);
 180                 nprops = be32_to_cpu(upwa->nprops);
 181
 182                 /* On the first call to ibm,update-properties for a node the
 183                  * the first property value descriptor contains an empty
 184                  * property name, the property value length encoded as u32,
 185                  * and the property value is the node path being updated.
 186                  */
 187                 if (*prop_data == 0) {
 188                         prop_data++;
 189                         vd = be32_to_cpu(*(__be32 *)prop_data);
 190                         prop_data += vd + sizeof(vd);
 191                         nprops--;
 192                 }
 193
 194                 for (i = 0; i < nprops; i++) {
 195                         char *prop_name;
 196
 197                         prop_name = prop_data;
 198                         prop_data += strlen(prop_name) + 1;
 199                         vd = be32_to_cpu(*(__be32 *)prop_data);
 200                         prop_data += sizeof(vd);
 201
 202                         switch (vd) {
 203                         case 0x00000000:
 204                                 /* name only property, nothing to do */
 205                                 break;
 206
 207                         case 0x80000000:
 208                                 of_remove_property(dn, of_find_property(dn,
 209                                                         prop_name, NULL));
 210                                 prop = NULL;
 211                                 break;
 212
 213                         default:
 214                                 rc = update_dt_property(dn, &prop, prop_name,
 215                                                         vd, prop_data);
 216                                 if (rc) {
 217                                         printk(KERN_ERR "Could not update %s"
 218                                                " property\n", prop_name);
 219                                 }
 220
 221                                 prop_data += vd;
 222                         }
 223
 224                         cond_resched();
 225                 }
 226
 227                 cond_resched();
 228         } while (rtas_rc == 1);
 229
 230         kfree(rtas_buf);
 231         return 0;
 232 }
 233
 234 static int add_dt_node(struct device_node *parent_dn, __be32 drc_index)
 235 {
 236         struct device_node *dn;
 237         int rc;
 238
 239         dn = dlpar_configure_connector(drc_index, parent_dn);
 240         if (!dn)
 241                 return -ENOENT;
 242
 243         /*
 244          * Since delete_dt_node() ignores this node type, this is the
 245          * necessary counterpart. We also know that a platform-facilities
 246          * node returned from dlpar_configure_connector() has children
 247          * attached, and dlpar_attach_node() only adds the parent, leaking
 248          * the children. So ignore these on the add side for now.
 249          */
 250         if (of_node_is_type(dn, "ibm,platform-facilities")) {
 251                 pr_notice("ignoring add operation for %pOF\n", dn);
 252                 dlpar_free_cc_nodes(dn);
 253                 return 0;
 254         }
 255
 256         rc = dlpar_attach_node(dn, parent_dn);
 257         if (rc)
 258                 dlpar_free_cc_nodes(dn);
 259
 260         pr_debug("added node %pOFfp\n", dn);
 261
 262         return rc;
 263 }
 264
 265 int pseries_devicetree_update(s32 scope)
 266 {
 267         char *rtas_buf;
 268         __be32 *data;
 269         int update_nodes_token;
 270         int rc;
 271
 272         update_nodes_token = rtas_token("ibm,update-nodes");
 273         if (update_nodes_token == RTAS_UNKNOWN_SERVICE)
 274                 return -EINVAL;
 275
 276         rtas_buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
 277         if (!rtas_buf)
 278                 return -ENOMEM;
 279
 280         do {
 281                 rc = mobility_rtas_call(update_nodes_token, rtas_buf, scope);
 282                 if (rc && rc != 1)
 283                         break;
 284
 285                 data = (__be32 *)rtas_buf + 4;
 286                 while (be32_to_cpu(*data) & NODE_ACTION_MASK) {
 287                         int i;
 288                         u32 action = be32_to_cpu(*data) & NODE_ACTION_MASK;
 289                         u32 node_count = be32_to_cpu(*data) & NODE_COUNT_MASK;
 290
 291                         data++;
 292
 293                         for (i = 0; i < node_count; i++) {
 294                                 struct device_node *np;
 295                                 __be32 phandle = *data++;
 296                                 __be32 drc_index;
 297
 298                                 np = of_find_node_by_phandle(be32_to_cpu(phandle));
 299                                 if (!np) {
 300                                         pr_warn("Failed lookup: phandle 0x%x for action 0x%x\n",
 301                                                 be32_to_cpu(phandle), action);
 302                                         continue;
 303                                 }
 304
 305                                 switch (action) {
 306                                 case DELETE_DT_NODE:
 307                                         delete_dt_node(np);
 308                                         break;
 309                                 case UPDATE_DT_NODE:
 310                                         update_dt_node(np, scope);
 311                                         break;
 312                                 case ADD_DT_NODE:
 313                                         drc_index = *data++;
 314                                         add_dt_node(np, drc_index);
 315                                         break;
 316                                 }
 317
 318                                 of_node_put(np);
 319                                 cond_resched();
 320                         }
 321                 }
 322
 323                 cond_resched();
 324         } while (rc == 1);
 325
 326         kfree(rtas_buf);
 327         return rc;
 328 }
 329
 330 void post_mobility_fixup(void)
 331 {
 332         int rc;
 333         int activate_fw_token;
 334
 335         activate_fw_token = rtas_token("ibm,activate-firmware");
 336         if (activate_fw_token == RTAS_UNKNOWN_SERVICE) {
 337                 printk(KERN_ERR "Could not make post-mobility "
 338                        "activate-fw call.\n");
 339                 return;
 340         }
 341
 342         do {
 343                 rc = rtas_call(activate_fw_token, 0, 1, NULL);
 344         } while (rtas_busy_delay(rc));
 345
 346         if (rc)
 347                 printk(KERN_ERR "Post-mobility activate-fw failed: %d\n", rc);
 348
 349         /*
 350          * We don't want CPUs to go online/offline while the device
 351          * tree is being updated.
 352          */
 353         cpus_read_lock();
 354
 355         /*
 356          * It's common for the destination firmware to replace cache
 357          * nodes.  Release all of the cacheinfo hierarchy's references
 358          * before updating the device tree.
 359          */
 360         cacheinfo_teardown();
 361
 362         rc = pseries_devicetree_update(MIGRATION_SCOPE);
 363         if (rc)
 364                 printk(KERN_ERR "Post-mobility device tree update "
 365                         "failed: %d\n", rc);
 366
 367         cacheinfo_rebuild();
 368
 369         cpus_read_unlock();
 370
 371         /* Possibly switch to a new L1 flush type */
 372         pseries_setup_security_mitigations();
 373
 374         /* Reinitialise system information for hv-24x7 */
 375         read_24x7_sys_info();
 376
 377         return;
 378 }
 379
 380 static ssize_t migration_store(struct class *class,
 381                                struct class_attribute *attr, const char *buf,
 382                                size_t count)
 383 {
 384         u64 streamid;
 385         int rc;
 386
 387         rc = kstrtou64(buf, 0, &streamid);
 388         if (rc)
 389                 return rc;
 390
 391         do {
 392                 rc = rtas_ibm_suspend_me(streamid);
 393                 if (rc == -EAGAIN)
 394                         ssleep(1);
 395         } while (rc == -EAGAIN);
 396
 397         if (rc)
 398                 return rc;
 399
 400         post_mobility_fixup();
 401
 402         return count;
 403 }
 404
 405 /*
 406  * Used by drmgr to determine the kernel behavior of the migration interface.
 407  *
 408  * Version 1: Performs all PAPR requirements for migration including
 409  *      firmware activation and device tree update.
 410  */
 411 #define MIGRATION_API_VERSION   1
 412
 413 static CLASS_ATTR_WO(migration);
 414 static CLASS_ATTR_STRING(api_version, 0444, __stringify(MIGRATION_API_VERSION));
 415
 416 static int __init mobility_sysfs_init(void)
 417 {
 418         int rc;
 419
 420         mobility_kobj = kobject_create_and_add("mobility", kernel_kobj);
 421         if (!mobility_kobj)
 422                 return -ENOMEM;
 423
 424         rc = sysfs_create_file(mobility_kobj, &class_attr_migration.attr);
 425         if (rc)
 426                 pr_err("unable to create migration sysfs file (%d)\n", rc);
 427
 428         rc = sysfs_create_file(mobility_kobj, &class_attr_api_version.attr.attr);
 429         if (rc)
 430                 pr_err("unable to create api_version sysfs file (%d)\n", rc);
 431
 432         return 0;
 433 }
 434 machine_device_initcall(pseries, mobility_sysfs_init);