drivers/acpi/acpi_memhotplug.c

   1 /*
   2  * Copyright (C) 2004, 2013 Intel Corporation
   3  * Author: Naveen B S <naveen.b.s@intel.com>
   4  * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
   5  *
   6  * All rights reserved.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or (at
  11  * your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  16  * NON INFRINGEMENT.  See the GNU General Public License for more
  17  * details.
  18  *
  19  * ACPI based HotPlug driver that supports Memory Hotplug
  20  * This driver fields notifications from firmware for memory add
  21  * and remove operations and alerts the VM of the affected memory
  22  * ranges.
  23  */
  24
  25 #include <linux/acpi.h>
  26 #include <linux/memory.h>
  27 #include <linux/memory_hotplug.h>
  28
  29 #include "internal.h"
  30
  31 #define ACPI_MEMORY_DEVICE_CLASS                "memory"
  32 #define ACPI_MEMORY_DEVICE_HID                  "PNP0C80"
  33 #define ACPI_MEMORY_DEVICE_NAME                 "Hotplug Mem Device"
  34
  35 #define _COMPONENT              ACPI_MEMORY_DEVICE_COMPONENT
  36
  37 #undef PREFIX
  38 #define         PREFIX          "ACPI:memory_hp:"
  39
  40 ACPI_MODULE_NAME("acpi_memhotplug");
  41
  42 static const struct acpi_device_id memory_device_ids[] = {
  43         {ACPI_MEMORY_DEVICE_HID, 0},
  44         {"", 0},
  45 };
  46
  47 #ifdef CONFIG_ACPI_HOTPLUG_MEMORY
  48
  49 /* Memory Device States */
  50 #define MEMORY_INVALID_STATE    0
  51 #define MEMORY_POWER_ON_STATE   1
  52 #define MEMORY_POWER_OFF_STATE  2
  53
  54 static int acpi_memory_device_add(struct acpi_device *device,
  55                                   const struct acpi_device_id *not_used);
  56 static void acpi_memory_device_remove(struct acpi_device *device);
  57
  58 static struct acpi_scan_handler memory_device_handler = {
  59         .ids = memory_device_ids,
  60         .attach = acpi_memory_device_add,
  61         .detach = acpi_memory_device_remove,
  62         .hotplug = {
  63                 .enabled = true,
  64         },
  65 };
  66
  67 struct acpi_memory_info {
  68         struct list_head list;
  69         u64 start_addr;         /* Memory Range start physical addr */
  70         u64 length;             /* Memory Range length */
  71         unsigned short caching; /* memory cache attribute */
  72         unsigned short write_protect;   /* memory read/write attribute */
  73         unsigned int enabled:1;
  74 };
  75
  76 struct acpi_memory_device {
  77         struct acpi_device * device;
  78         unsigned int state;     /* State of the memory device */
  79         struct list_head res_list;
  80 };
  81
  82 static acpi_status
  83 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
  84 {
  85         struct acpi_memory_device *mem_device = context;
  86         struct acpi_resource_address64 address64;
  87         struct acpi_memory_info *info, *new;
  88         acpi_status status;
  89
  90         status = acpi_resource_to_address64(resource, &address64);
  91         if (ACPI_FAILURE(status) ||
  92             (address64.resource_type != ACPI_MEMORY_RANGE))
  93                 return AE_OK;
  94
  95         list_for_each_entry(info, &mem_device->res_list, list) {
  96                 /* Can we combine the resource range information? */
  97                 if ((info->caching == address64.info.mem.caching) &&
  98                     (info->write_protect == address64.info.mem.write_protect) &&
  99                     (info->start_addr + info->length == address64.address.minimum)) {
 100                         info->length += address64.address.address_length;
 101                         return AE_OK;
 102                 }
 103         }
 104
 105         new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
 106         if (!new)
 107                 return AE_ERROR;
 108
 109         INIT_LIST_HEAD(&new->list);
 110         new->caching = address64.info.mem.caching;
 111         new->write_protect = address64.info.mem.write_protect;
 112         new->start_addr = address64.address.minimum;
 113         new->length = address64.address.address_length;
 114         list_add_tail(&new->list, &mem_device->res_list);
 115
 116         return AE_OK;
 117 }
 118
 119 static void
 120 acpi_memory_free_device_resources(struct acpi_memory_device *mem_device)
 121 {
 122         struct acpi_memory_info *info, *n;
 123
 124         list_for_each_entry_safe(info, n, &mem_device->res_list, list)
 125                 kfree(info);
 126         INIT_LIST_HEAD(&mem_device->res_list);
 127 }
 128
 129 static int
 130 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
 131 {
 132         acpi_status status;
 133
 134         if (!list_empty(&mem_device->res_list))
 135                 return 0;
 136
 137         status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
 138                                      acpi_memory_get_resource, mem_device);
 139         if (ACPI_FAILURE(status)) {
 140                 acpi_memory_free_device_resources(mem_device);
 141                 return -EINVAL;
 142         }
 143
 144         return 0;
 145 }
 146
 147 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
 148 {
 149         unsigned long long current_status;
 150
 151         /* Get device present/absent information from the _STA */
 152         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle,
 153                                                METHOD_NAME__STA, NULL,
 154                                                &current_status)))
 155                 return -ENODEV;
 156         /*
 157          * Check for device status. Device should be
 158          * present/enabled/functioning.
 159          */
 160         if (!((current_status & ACPI_STA_DEVICE_PRESENT)
 161               && (current_status & ACPI_STA_DEVICE_ENABLED)
 162               && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
 163                 return -ENODEV;
 164
 165         return 0;
 166 }
 167
 168 static unsigned long acpi_meminfo_start_pfn(struct acpi_memory_info *info)
 169 {
 170         return PFN_DOWN(info->start_addr);
 171 }
 172
 173 static unsigned long acpi_meminfo_end_pfn(struct acpi_memory_info *info)
 174 {
 175         return PFN_UP(info->start_addr + info->length-1);
 176 }
 177
 178 static int acpi_bind_memblk(struct memory_block *mem, void *arg)
 179 {
 180         return acpi_bind_one(&mem->dev, arg);
 181 }
 182
 183 static int acpi_bind_memory_blocks(struct acpi_memory_info *info,
 184                                    struct acpi_device *adev)
 185 {
 186         return walk_memory_range(acpi_meminfo_start_pfn(info),
 187                                  acpi_meminfo_end_pfn(info), adev,
 188                                  acpi_bind_memblk);
 189 }
 190
 191 static int acpi_unbind_memblk(struct memory_block *mem, void *arg)
 192 {
 193         acpi_unbind_one(&mem->dev);
 194         return 0;
 195 }
 196
 197 static void acpi_unbind_memory_blocks(struct acpi_memory_info *info)
 198 {
 199         walk_memory_range(acpi_meminfo_start_pfn(info),
 200                           acpi_meminfo_end_pfn(info), NULL, acpi_unbind_memblk);
 201 }
 202
 203 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 204 {
 205         acpi_handle handle = mem_device->device->handle;
 206         int result, num_enabled = 0;
 207         struct acpi_memory_info *info;
 208         int node;
 209
 210         node = acpi_get_node(handle);
 211         /*
 212          * Tell the VM there is more memory here...
 213          * Note: Assume that this function returns zero on success
 214          * We don't have memory-hot-add rollback function,now.
 215          * (i.e. memory-hot-remove function)
 216          */
 217         list_for_each_entry(info, &mem_device->res_list, list) {
 218                 if (info->enabled) { /* just sanity check...*/
 219                         num_enabled++;
 220                         continue;
 221                 }
 222                 /*
 223                  * If the memory block size is zero, please ignore it.
 224                  * Don't try to do the following memory hotplug flowchart.
 225                  */
 226                 if (!info->length)
 227                         continue;
 228                 if (node < 0)
 229                         node = memory_add_physaddr_to_nid(info->start_addr);
 230
 231                 result = add_memory(node, info->start_addr, info->length);
 232
 233                 /*
 234                  * If the memory block has been used by the kernel, add_memory()
 235                  * returns -EEXIST. If add_memory() returns the other error, it
 236                  * means that this memory block is not used by the kernel.
 237                  */
 238                 if (result && result != -EEXIST)
 239                         continue;
 240
 241                 result = acpi_bind_memory_blocks(info, mem_device->device);
 242                 if (result) {
 243                         acpi_unbind_memory_blocks(info);
 244                         return -ENODEV;
 245                 }
 246
 247                 info->enabled = 1;
 248
 249                 /*
 250                  * Add num_enable even if add_memory() returns -EEXIST, so the
 251                  * device is bound to this driver.
 252                  */
 253                 num_enabled++;
 254         }
 255         if (!num_enabled) {
 256                 dev_err(&mem_device->device->dev, "add_memory failed\n");
 257                 mem_device->state = MEMORY_INVALID_STATE;
 258                 return -EINVAL;
 259         }
 260         /*
 261          * Sometimes the memory device will contain several memory blocks.
 262          * When one memory block is hot-added to the system memory, it will
 263          * be regarded as a success.
 264          * Otherwise if the last memory block can't be hot-added to the system
 265          * memory, it will be failure and the memory device can't be bound with
 266          * driver.
 267          */
 268         return 0;
 269 }
 270
 271 static void acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
 272 {
 273         acpi_handle handle = mem_device->device->handle;
 274         struct acpi_memory_info *info, *n;
 275         int nid = acpi_get_node(handle);
 276
 277         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 278                 if (!info->enabled)
 279                         continue;
 280
 281                 if (nid == NUMA_NO_NODE)
 282                         nid = memory_add_physaddr_to_nid(info->start_addr);
 283
 284                 acpi_unbind_memory_blocks(info);
 285                 remove_memory(nid, info->start_addr, info->length);
 286                 list_del(&info->list);
 287                 kfree(info);
 288         }
 289 }
 290
 291 static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
 292 {
 293         if (!mem_device)
 294                 return;
 295
 296         acpi_memory_free_device_resources(mem_device);
 297         mem_device->device->driver_data = NULL;
 298         kfree(mem_device);
 299 }
 300
 301 static int acpi_memory_device_add(struct acpi_device *device,
 302                                   const struct acpi_device_id *not_used)
 303 {
 304         struct acpi_memory_device *mem_device;
 305         int result;
 306
 307         if (!device)
 308                 return -EINVAL;
 309
 310         mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 311         if (!mem_device)
 312                 return -ENOMEM;
 313
 314         INIT_LIST_HEAD(&mem_device->res_list);
 315         mem_device->device = device;
 316         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 317         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 318         device->driver_data = mem_device;
 319
 320         /* Get the range from the _CRS */
 321         result = acpi_memory_get_device_resources(mem_device);
 322         if (result) {
 323                 device->driver_data = NULL;
 324                 kfree(mem_device);
 325                 return result;
 326         }
 327
 328         /* Set the device state */
 329         mem_device->state = MEMORY_POWER_ON_STATE;
 330
 331         result = acpi_memory_check_device(mem_device);
 332         if (result) {
 333                 acpi_memory_device_free(mem_device);
 334                 return 0;
 335         }
 336
 337         result = acpi_memory_enable_device(mem_device);
 338         if (result) {
 339                 dev_err(&device->dev, "acpi_memory_enable_device() error\n");
 340                 acpi_memory_device_free(mem_device);
 341                 return result;
 342         }
 343
 344         dev_dbg(&device->dev, "Memory device configured by ACPI\n");
 345         return 1;
 346 }
 347
 348 static void acpi_memory_device_remove(struct acpi_device *device)
 349 {
 350         struct acpi_memory_device *mem_device;
 351
 352         if (!device || !acpi_driver_data(device))
 353                 return;
 354
 355         mem_device = acpi_driver_data(device);
 356         acpi_memory_remove_memory(mem_device);
 357         acpi_memory_device_free(mem_device);
 358 }
 359
 360 static bool __initdata acpi_no_memhotplug;
 361
 362 void __init acpi_memory_hotplug_init(void)
 363 {
 364         if (acpi_no_memhotplug) {
 365                 memory_device_handler.attach = NULL;
 366                 acpi_scan_add_handler(&memory_device_handler);
 367                 return;
 368         }
 369         acpi_scan_add_handler_with_hotplug(&memory_device_handler, "memory");
 370 }
 371
 372 static int __init disable_acpi_memory_hotplug(char *str)
 373 {
 374         acpi_no_memhotplug = true;
 375         return 1;
 376 }
 377 __setup("acpi_no_memhotplug", disable_acpi_memory_hotplug);
 378
 379 #else
 380
 381 static struct acpi_scan_handler memory_device_handler = {
 382         .ids = memory_device_ids,
 383 };
 384
 385 void __init acpi_memory_hotplug_init(void)
 386 {
 387         acpi_scan_add_handler(&memory_device_handler);
 388 }
 389
 390 #endif /* CONFIG_ACPI_HOTPLUG_MEMORY */