Pileus Git - ~andy/linux/blob - drivers/xen/xen-acpi-memhotplug.c

   1 /*
   2  * Copyright (C) 2012 Intel Corporation
   3  *    Author: Liu Jinsong <jinsong.liu@intel.com>
   4  *    Author: Jiang Yunhong <yunhong.jiang@intel.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or (at
   9  * your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  14  * NON INFRINGEMENT.  See the GNU General Public License for more
  15  * details.
  16  */
  17
  18 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  19
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/init.h>
  23 #include <linux/types.h>
  24 #include <linux/acpi.h>
  25 #include <acpi/acpi_drivers.h>
  26 #include <xen/acpi.h>
  27 #include <xen/interface/platform.h>
  28 #include <asm/xen/hypercall.h>
  29
  30 #define PREFIX "ACPI:xen_memory_hotplug:"
  31
  32 struct acpi_memory_info {
  33         struct list_head list;
  34         u64 start_addr;         /* Memory Range start physical addr */
  35         u64 length;             /* Memory Range length */
  36         unsigned short caching; /* memory cache attribute */
  37         unsigned short write_protect;   /* memory read/write attribute */
  38                                 /* copied from buffer getting from _CRS */
  39         unsigned int enabled:1;
  40 };
  41
  42 struct acpi_memory_device {
  43         struct acpi_device *device;
  44         struct list_head res_list;
  45 };
  46
  47 static bool acpi_hotmem_initialized __read_mostly;
  48
  49 static int xen_hotadd_memory(int pxm, struct acpi_memory_info *info)
  50 {
  51         int rc;
  52         struct xen_platform_op op;
  53
  54         op.cmd = XENPF_mem_hotadd;
  55         op.u.mem_add.spfn = info->start_addr >> PAGE_SHIFT;
  56         op.u.mem_add.epfn = (info->start_addr + info->length) >> PAGE_SHIFT;
  57         op.u.mem_add.pxm = pxm;
  58
  59         rc = HYPERVISOR_dom0_op(&op);
  60         if (rc)
  61                 pr_err(PREFIX "Xen Hotplug Memory Add failed on "
  62                         "0x%lx -> 0x%lx, _PXM: %d, error: %d\n",
  63                         (unsigned long)info->start_addr,
  64                         (unsigned long)(info->start_addr + info->length),
  65                         pxm, rc);
  66
  67         return rc;
  68 }
  69
  70 static int xen_acpi_memory_enable_device(struct acpi_memory_device *mem_device)
  71 {
  72         int pxm, result;
  73         int num_enabled = 0;
  74         struct acpi_memory_info *info;
  75
  76         if (!mem_device)
  77                 return -EINVAL;
  78
  79         pxm = xen_acpi_get_pxm(mem_device->device->handle);
  80         if (pxm < 0)
  81                 return pxm;
  82
  83         list_for_each_entry(info, &mem_device->res_list, list) {
  84                 if (info->enabled) { /* just sanity check...*/
  85                         num_enabled++;
  86                         continue;
  87                 }
  88
  89                 if (!info->length)
  90                         continue;
  91
  92                 result = xen_hotadd_memory(pxm, info);
  93                 if (result)
  94                         continue;
  95                 info->enabled = 1;
  96                 num_enabled++;
  97         }
  98
  99         if (!num_enabled)
 100                 return -ENODEV;
 101
 102         return 0;
 103 }
 104
 105 static acpi_status
 106 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
 107 {
 108         struct acpi_memory_device *mem_device = context;
 109         struct acpi_resource_address64 address64;
 110         struct acpi_memory_info *info, *new;
 111         acpi_status status;
 112
 113         status = acpi_resource_to_address64(resource, &address64);
 114         if (ACPI_FAILURE(status) ||
 115             (address64.resource_type != ACPI_MEMORY_RANGE))
 116                 return AE_OK;
 117
 118         list_for_each_entry(info, &mem_device->res_list, list) {
 119                 if ((info->caching == address64.info.mem.caching) &&
 120                     (info->write_protect == address64.info.mem.write_protect) &&
 121                     (info->start_addr + info->length == address64.minimum)) {
 122                         info->length += address64.address_length;
 123                         return AE_OK;
 124                 }
 125         }
 126
 127         new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
 128         if (!new)
 129                 return AE_ERROR;
 130
 131         INIT_LIST_HEAD(&new->list);
 132         new->caching = address64.info.mem.caching;
 133         new->write_protect = address64.info.mem.write_protect;
 134         new->start_addr = address64.minimum;
 135         new->length = address64.address_length;
 136         list_add_tail(&new->list, &mem_device->res_list);
 137
 138         return AE_OK;
 139 }
 140
 141 static int
 142 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
 143 {
 144         acpi_status status;
 145         struct acpi_memory_info *info, *n;
 146
 147         if (!list_empty(&mem_device->res_list))
 148                 return 0;
 149
 150         status = acpi_walk_resources(mem_device->device->handle,
 151                 METHOD_NAME__CRS, acpi_memory_get_resource, mem_device);
 152
 153         if (ACPI_FAILURE(status)) {
 154                 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
 155                         kfree(info);
 156                 INIT_LIST_HEAD(&mem_device->res_list);
 157                 return -EINVAL;
 158         }
 159
 160         return 0;
 161 }
 162
 163 static int acpi_memory_get_device(acpi_handle handle,
 164                                   struct acpi_memory_device **mem_device)
 165 {
 166         struct acpi_device *device = NULL;
 167         int result = 0;
 168
 169         acpi_scan_lock_acquire();
 170
 171         acpi_bus_get_device(handle, &device);
 172         if (acpi_device_enumerated(device))
 173                 goto end;
 174
 175         /*
 176          * Now add the notified device.  This creates the acpi_device
 177          * and invokes .add function
 178          */
 179         result = acpi_bus_scan(handle);
 180         if (result) {
 181                 pr_warn(PREFIX "ACPI namespace scan failed\n");
 182                 result = -EINVAL;
 183                 goto out;
 184         }
 185         device = NULL;
 186         acpi_bus_get_device(handle, &device);
 187         if (!acpi_device_enumerated(device)) {
 188                 pr_warn(PREFIX "Missing device object\n");
 189                 result = -EINVAL;
 190                 goto out;
 191         }
 192
 193 end:
 194         *mem_device = acpi_driver_data(device);
 195         if (!(*mem_device)) {
 196                 pr_err(PREFIX "driver data not found\n");
 197                 result = -ENODEV;
 198                 goto out;
 199         }
 200
 201 out:
 202         acpi_scan_lock_release();
 203         return result;
 204 }
 205
 206 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
 207 {
 208         unsigned long long current_status;
 209
 210         /* Get device present/absent information from the _STA */
 211         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle,
 212                                 "_STA", NULL, &current_status)))
 213                 return -ENODEV;
 214         /*
 215          * Check for device status. Device should be
 216          * present/enabled/functioning.
 217          */
 218         if (!((current_status & ACPI_STA_DEVICE_PRESENT)
 219               && (current_status & ACPI_STA_DEVICE_ENABLED)
 220               && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
 221                 return -ENODEV;
 222
 223         return 0;
 224 }
 225
 226 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
 227 {
 228         pr_debug(PREFIX "Xen does not support memory hotremove\n");
 229
 230         return -ENOSYS;
 231 }
 232
 233 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
 234 {
 235         struct acpi_memory_device *mem_device;
 236         struct acpi_device *device;
 237         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
 238
 239         switch (event) {
 240         case ACPI_NOTIFY_BUS_CHECK:
 241                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 242                         "\nReceived BUS CHECK notification for device\n"));
 243                 /* Fall Through */
 244         case ACPI_NOTIFY_DEVICE_CHECK:
 245                 if (event == ACPI_NOTIFY_DEVICE_CHECK)
 246                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 247                         "\nReceived DEVICE CHECK notification for device\n"));
 248
 249                 if (acpi_memory_get_device(handle, &mem_device)) {
 250                         pr_err(PREFIX "Cannot find driver data\n");
 251                         break;
 252                 }
 253
 254                 ost_code = ACPI_OST_SC_SUCCESS;
 255                 break;
 256
 257         case ACPI_NOTIFY_EJECT_REQUEST:
 258                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 259                         "\nReceived EJECT REQUEST notification for device\n"));
 260
 261                 acpi_scan_lock_acquire();
 262                 if (acpi_bus_get_device(handle, &device)) {
 263                         acpi_scan_lock_release();
 264                         pr_err(PREFIX "Device doesn't exist\n");
 265                         break;
 266                 }
 267                 mem_device = acpi_driver_data(device);
 268                 if (!mem_device) {
 269                         acpi_scan_lock_release();
 270                         pr_err(PREFIX "Driver Data is NULL\n");
 271                         break;
 272                 }
 273
 274                 /*
 275                  * TBD: implement acpi_memory_disable_device and invoke
 276                  * acpi_bus_remove if Xen support hotremove in the future
 277                  */
 278                 acpi_memory_disable_device(mem_device);
 279                 acpi_scan_lock_release();
 280                 break;
 281
 282         default:
 283                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 284                                   "Unsupported event [0x%x]\n", event));
 285                 /* non-hotplug event; possibly handled by other handler */
 286                 return;
 287         }
 288
 289         (void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
 290         return;
 291 }
 292
 293 static int xen_acpi_memory_device_add(struct acpi_device *device)
 294 {
 295         int result;
 296         struct acpi_memory_device *mem_device = NULL;
 297
 298
 299         if (!device)
 300                 return -EINVAL;
 301
 302         mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 303         if (!mem_device)
 304                 return -ENOMEM;
 305
 306         INIT_LIST_HEAD(&mem_device->res_list);
 307         mem_device->device = device;
 308         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 309         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 310         device->driver_data = mem_device;
 311
 312         /* Get the range from the _CRS */
 313         result = acpi_memory_get_device_resources(mem_device);
 314         if (result) {
 315                 kfree(mem_device);
 316                 return result;
 317         }
 318
 319         /*
 320          * For booting existed memory devices, early boot code has recognized
 321          * memory area by EFI/E820. If DSDT shows these memory devices on boot,
 322          * hotplug is not necessary for them.
 323          * For hot-added memory devices during runtime, it need hypercall to
 324          * Xen hypervisor to add memory.
 325          */
 326         if (!acpi_hotmem_initialized)
 327                 return 0;
 328
 329         if (!acpi_memory_check_device(mem_device))
 330                 result = xen_acpi_memory_enable_device(mem_device);
 331
 332         return result;
 333 }
 334
 335 static int xen_acpi_memory_device_remove(struct acpi_device *device)
 336 {
 337         struct acpi_memory_device *mem_device = NULL;
 338
 339         if (!device || !acpi_driver_data(device))
 340                 return -EINVAL;
 341
 342         mem_device = acpi_driver_data(device);
 343         kfree(mem_device);
 344
 345         return 0;
 346 }
 347
 348 /*
 349  * Helper function to check for memory device
 350  */
 351 static acpi_status is_memory_device(acpi_handle handle)
 352 {
 353         char *hardware_id;
 354         acpi_status status;
 355         struct acpi_device_info *info;
 356
 357         status = acpi_get_object_info(handle, &info);
 358         if (ACPI_FAILURE(status))
 359                 return status;
 360
 361         if (!(info->valid & ACPI_VALID_HID)) {
 362                 kfree(info);
 363                 return AE_ERROR;
 364         }
 365
 366         hardware_id = info->hardware_id.string;
 367         if ((hardware_id == NULL) ||
 368             (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
 369                 status = AE_ERROR;
 370
 371         kfree(info);
 372         return status;
 373 }
 374
 375 static acpi_status
 376 acpi_memory_register_notify_handler(acpi_handle handle,
 377                                     u32 level, void *ctxt, void **retv)
 378 {
 379         acpi_status status;
 380
 381         status = is_memory_device(handle);
 382         if (ACPI_FAILURE(status))
 383                 return AE_OK;   /* continue */
 384
 385         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 386                                              acpi_memory_device_notify, NULL);
 387         /* continue */
 388         return AE_OK;
 389 }
 390
 391 static acpi_status
 392 acpi_memory_deregister_notify_handler(acpi_handle handle,
 393                                       u32 level, void *ctxt, void **retv)
 394 {
 395         acpi_status status;
 396
 397         status = is_memory_device(handle);
 398         if (ACPI_FAILURE(status))
 399                 return AE_OK;   /* continue */
 400
 401         status = acpi_remove_notify_handler(handle,
 402                                             ACPI_SYSTEM_NOTIFY,
 403                                             acpi_memory_device_notify);
 404
 405         return AE_OK;   /* continue */
 406 }
 407
 408 static const struct acpi_device_id memory_device_ids[] = {
 409         {ACPI_MEMORY_DEVICE_HID, 0},
 410         {"", 0},
 411 };
 412 MODULE_DEVICE_TABLE(acpi, memory_device_ids);
 413
 414 static struct acpi_driver xen_acpi_memory_device_driver = {
 415         .name = "acpi_memhotplug",
 416         .class = ACPI_MEMORY_DEVICE_CLASS,
 417         .ids = memory_device_ids,
 418         .ops = {
 419                 .add = xen_acpi_memory_device_add,
 420                 .remove = xen_acpi_memory_device_remove,
 421                 },
 422 };
 423
 424 static int __init xen_acpi_memory_device_init(void)
 425 {
 426         int result;
 427         acpi_status status;
 428
 429         if (!xen_initial_domain())
 430                 return -ENODEV;
 431
 432         /* unregister the stub which only used to reserve driver space */
 433         xen_stub_memory_device_exit();
 434
 435         result = acpi_bus_register_driver(&xen_acpi_memory_device_driver);
 436         if (result < 0) {
 437                 xen_stub_memory_device_init();
 438                 return -ENODEV;
 439         }
 440
 441         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 442                                      ACPI_UINT32_MAX,
 443                                      acpi_memory_register_notify_handler,
 444                                      NULL, NULL, NULL);
 445
 446         if (ACPI_FAILURE(status)) {
 447                 pr_warn(PREFIX "walk_namespace failed\n");
 448                 acpi_bus_unregister_driver(&xen_acpi_memory_device_driver);
 449                 xen_stub_memory_device_init();
 450                 return -ENODEV;
 451         }
 452
 453         acpi_hotmem_initialized = true;
 454         return 0;
 455 }
 456
 457 static void __exit xen_acpi_memory_device_exit(void)
 458 {
 459         acpi_status status;
 460
 461         if (!xen_initial_domain())
 462                 return;
 463
 464         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 465                                      ACPI_UINT32_MAX,
 466                                      acpi_memory_deregister_notify_handler,
 467                                      NULL, NULL, NULL);
 468         if (ACPI_FAILURE(status))
 469                 pr_warn(PREFIX "walk_namespace failed\n");
 470
 471         acpi_bus_unregister_driver(&xen_acpi_memory_device_driver);
 472
 473         /*
 474          * stub reserve space again to prevent any chance of native
 475          * driver loading.
 476          */
 477         xen_stub_memory_device_init();
 478         return;
 479 }
 480
 481 module_init(xen_acpi_memory_device_init);
 482 module_exit(xen_acpi_memory_device_exit);
 483 ACPI_MODULE_NAME("xen-acpi-memhotplug");
 484 MODULE_AUTHOR("Liu Jinsong <jinsong.liu@intel.com>");
 485 MODULE_DESCRIPTION("Xen Hotplug Mem Driver");
 486 MODULE_LICENSE("GPL");