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  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22  *
  23  *
  24  * ACPI based HotPlug driver that supports Memory Hotplug
  25  * This driver fields notifications from firmware for memory add
  26  * and remove operations and alerts the VM of the affected memory
  27  * ranges.
  28  */
  29
  30 #include <linux/acpi.h>
  31 #include <linux/memory.h>
  32 #include <linux/memory_hotplug.h>
  33
  34 #include "internal.h"
  35
  36 #define ACPI_MEMORY_DEVICE_CLASS                "memory"
  37 #define ACPI_MEMORY_DEVICE_HID                  "PNP0C80"
  38 #define ACPI_MEMORY_DEVICE_NAME                 "Hotplug Mem Device"
  39
  40 #define _COMPONENT              ACPI_MEMORY_DEVICE_COMPONENT
  41
  42 #undef PREFIX
  43 #define         PREFIX          "ACPI:memory_hp:"
  44
  45 ACPI_MODULE_NAME("acpi_memhotplug");
  46
  47 static const struct acpi_device_id memory_device_ids[] = {
  48         {ACPI_MEMORY_DEVICE_HID, 0},
  49         {"", 0},
  50 };
  51
  52 #ifdef CONFIG_ACPI_HOTPLUG_MEMORY
  53
  54 /* Memory Device States */
  55 #define MEMORY_INVALID_STATE    0
  56 #define MEMORY_POWER_ON_STATE   1
  57 #define MEMORY_POWER_OFF_STATE  2
  58
  59 static int acpi_memory_device_add(struct acpi_device *device,
  60                                   const struct acpi_device_id *not_used);
  61 static void acpi_memory_device_remove(struct acpi_device *device);
  62
  63 static struct acpi_scan_handler memory_device_handler = {
  64         .ids = memory_device_ids,
  65         .attach = acpi_memory_device_add,
  66         .detach = acpi_memory_device_remove,
  67         .hotplug = {
  68                 .enabled = true,
  69         },
  70 };
  71
  72 struct acpi_memory_info {
  73         struct list_head list;
  74         u64 start_addr;         /* Memory Range start physical addr */
  75         u64 length;             /* Memory Range length */
  76         unsigned short caching; /* memory cache attribute */
  77         unsigned short write_protect;   /* memory read/write attribute */
  78         unsigned int enabled:1;
  79 };
  80
  81 struct acpi_memory_device {
  82         struct acpi_device * device;
  83         unsigned int state;     /* State of the memory device */
  84         struct list_head res_list;
  85 };
  86
  87 static acpi_status
  88 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
  89 {
  90         struct acpi_memory_device *mem_device = context;
  91         struct acpi_resource_address64 address64;
  92         struct acpi_memory_info *info, *new;
  93         acpi_status status;
  94
  95         status = acpi_resource_to_address64(resource, &address64);
  96         if (ACPI_FAILURE(status) ||
  97             (address64.resource_type != ACPI_MEMORY_RANGE))
  98                 return AE_OK;
  99
 100         list_for_each_entry(info, &mem_device->res_list, list) {
 101                 /* Can we combine the resource range information? */
 102                 if ((info->caching == address64.info.mem.caching) &&
 103                     (info->write_protect == address64.info.mem.write_protect) &&
 104                     (info->start_addr + info->length == address64.minimum)) {
 105                         info->length += address64.address_length;
 106                         return AE_OK;
 107                 }
 108         }
 109
 110         new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
 111         if (!new)
 112                 return AE_ERROR;
 113
 114         INIT_LIST_HEAD(&new->list);
 115         new->caching = address64.info.mem.caching;
 116         new->write_protect = address64.info.mem.write_protect;
 117         new->start_addr = address64.minimum;
 118         new->length = address64.address_length;
 119         list_add_tail(&new->list, &mem_device->res_list);
 120
 121         return AE_OK;
 122 }
 123
 124 static void
 125 acpi_memory_free_device_resources(struct acpi_memory_device *mem_device)
 126 {
 127         struct acpi_memory_info *info, *n;
 128
 129         list_for_each_entry_safe(info, n, &mem_device->res_list, list)
 130                 kfree(info);
 131         INIT_LIST_HEAD(&mem_device->res_list);
 132 }
 133
 134 static int
 135 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
 136 {
 137         acpi_status status;
 138
 139         if (!list_empty(&mem_device->res_list))
 140                 return 0;
 141
 142         status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
 143                                      acpi_memory_get_resource, mem_device);
 144         if (ACPI_FAILURE(status)) {
 145                 acpi_memory_free_device_resources(mem_device);
 146                 return -EINVAL;
 147         }
 148
 149         return 0;
 150 }
 151
 152 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
 153 {
 154         unsigned long long current_status;
 155
 156         /* Get device present/absent information from the _STA */
 157         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle,
 158                                                METHOD_NAME__STA, NULL,
 159                                                &current_status)))
 160                 return -ENODEV;
 161         /*
 162          * Check for device status. Device should be
 163          * present/enabled/functioning.
 164          */
 165         if (!((current_status & ACPI_STA_DEVICE_PRESENT)
 166               && (current_status & ACPI_STA_DEVICE_ENABLED)
 167               && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
 168                 return -ENODEV;
 169
 170         return 0;
 171 }
 172
 173 static unsigned long acpi_meminfo_start_pfn(struct acpi_memory_info *info)
 174 {
 175         return PFN_DOWN(info->start_addr);
 176 }
 177
 178 static unsigned long acpi_meminfo_end_pfn(struct acpi_memory_info *info)
 179 {
 180         return PFN_UP(info->start_addr + info->length-1);
 181 }
 182
 183 static int acpi_bind_memblk(struct memory_block *mem, void *arg)
 184 {
 185         return acpi_bind_one(&mem->dev, arg);
 186 }
 187
 188 static int acpi_bind_memory_blocks(struct acpi_memory_info *info,
 189                                    struct acpi_device *adev)
 190 {
 191         return walk_memory_range(acpi_meminfo_start_pfn(info),
 192                                  acpi_meminfo_end_pfn(info), adev,
 193                                  acpi_bind_memblk);
 194 }
 195
 196 static int acpi_unbind_memblk(struct memory_block *mem, void *arg)
 197 {
 198         acpi_unbind_one(&mem->dev);
 199         return 0;
 200 }
 201
 202 static void acpi_unbind_memory_blocks(struct acpi_memory_info *info)
 203 {
 204         walk_memory_range(acpi_meminfo_start_pfn(info),
 205                           acpi_meminfo_end_pfn(info), NULL, acpi_unbind_memblk);
 206 }
 207
 208 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 209 {
 210         acpi_handle handle = mem_device->device->handle;
 211         int result, num_enabled = 0;
 212         struct acpi_memory_info *info;
 213         int node;
 214
 215         node = acpi_get_node(handle);
 216         /*
 217          * Tell the VM there is more memory here...
 218          * Note: Assume that this function returns zero on success
 219          * We don't have memory-hot-add rollback function,now.
 220          * (i.e. memory-hot-remove function)
 221          */
 222         list_for_each_entry(info, &mem_device->res_list, list) {
 223                 if (info->enabled) { /* just sanity check...*/
 224                         num_enabled++;
 225                         continue;
 226                 }
 227                 /*
 228                  * If the memory block size is zero, please ignore it.
 229                  * Don't try to do the following memory hotplug flowchart.
 230                  */
 231                 if (!info->length)
 232                         continue;
 233                 if (node < 0)
 234                         node = memory_add_physaddr_to_nid(info->start_addr);
 235
 236                 result = add_memory(node, info->start_addr, info->length);
 237
 238                 /*
 239                  * If the memory block has been used by the kernel, add_memory()
 240                  * returns -EEXIST. If add_memory() returns the other error, it
 241                  * means that this memory block is not used by the kernel.
 242                  */
 243                 if (result && result != -EEXIST)
 244                         continue;
 245
 246                 result = acpi_bind_memory_blocks(info, mem_device->device);
 247                 if (result) {
 248                         acpi_unbind_memory_blocks(info);
 249                         return -ENODEV;
 250                 }
 251
 252                 info->enabled = 1;
 253
 254                 /*
 255                  * Add num_enable even if add_memory() returns -EEXIST, so the
 256                  * device is bound to this driver.
 257                  */
 258                 num_enabled++;
 259         }
 260         if (!num_enabled) {
 261                 dev_err(&mem_device->device->dev, "add_memory failed\n");
 262                 mem_device->state = MEMORY_INVALID_STATE;
 263                 return -EINVAL;
 264         }
 265         /*
 266          * Sometimes the memory device will contain several memory blocks.
 267          * When one memory block is hot-added to the system memory, it will
 268          * be regarded as a success.
 269          * Otherwise if the last memory block can't be hot-added to the system
 270          * memory, it will be failure and the memory device can't be bound with
 271          * driver.
 272          */
 273         return 0;
 274 }
 275
 276 static void acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
 277 {
 278         acpi_handle handle = mem_device->device->handle;
 279         struct acpi_memory_info *info, *n;
 280         int nid = acpi_get_node(handle);
 281
 282         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 283                 if (!info->enabled)
 284                         continue;
 285
 286                 if (nid == NUMA_NO_NODE)
 287                         nid = memory_add_physaddr_to_nid(info->start_addr);
 288
 289                 acpi_unbind_memory_blocks(info);
 290                 remove_memory(nid, info->start_addr, info->length);
 291                 list_del(&info->list);
 292                 kfree(info);
 293         }
 294 }
 295
 296 static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
 297 {
 298         if (!mem_device)
 299                 return;
 300
 301         acpi_memory_free_device_resources(mem_device);
 302         mem_device->device->driver_data = NULL;
 303         kfree(mem_device);
 304 }
 305
 306 static int acpi_memory_device_add(struct acpi_device *device,
 307                                   const struct acpi_device_id *not_used)
 308 {
 309         struct acpi_memory_device *mem_device;
 310         int result;
 311
 312         if (!device)
 313                 return -EINVAL;
 314
 315         mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 316         if (!mem_device)
 317                 return -ENOMEM;
 318
 319         INIT_LIST_HEAD(&mem_device->res_list);
 320         mem_device->device = device;
 321         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 322         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 323         device->driver_data = mem_device;
 324
 325         /* Get the range from the _CRS */
 326         result = acpi_memory_get_device_resources(mem_device);
 327         if (result) {
 328                 device->driver_data = NULL;
 329                 kfree(mem_device);
 330                 return result;
 331         }
 332
 333         /* Set the device state */
 334         mem_device->state = MEMORY_POWER_ON_STATE;
 335
 336         result = acpi_memory_check_device(mem_device);
 337         if (result) {
 338                 acpi_memory_device_free(mem_device);
 339                 return 0;
 340         }
 341
 342         result = acpi_memory_enable_device(mem_device);
 343         if (result) {
 344                 dev_err(&device->dev, "acpi_memory_enable_device() error\n");
 345                 acpi_memory_device_free(mem_device);
 346                 return result;
 347         }
 348
 349         dev_dbg(&device->dev, "Memory device configured by ACPI\n");
 350         return 1;
 351 }
 352
 353 static void acpi_memory_device_remove(struct acpi_device *device)
 354 {
 355         struct acpi_memory_device *mem_device;
 356
 357         if (!device || !acpi_driver_data(device))
 358                 return;
 359
 360         mem_device = acpi_driver_data(device);
 361         acpi_memory_remove_memory(mem_device);
 362         acpi_memory_device_free(mem_device);
 363 }
 364
 365 static bool __initdata acpi_no_memhotplug;
 366
 367 void __init acpi_memory_hotplug_init(void)
 368 {
 369         if (acpi_no_memhotplug) {
 370                 memory_device_handler.attach = NULL;
 371                 acpi_scan_add_handler(&memory_device_handler);
 372                 return;
 373         }
 374         acpi_scan_add_handler_with_hotplug(&memory_device_handler, "memory");
 375 }
 376
 377 static int __init disable_acpi_memory_hotplug(char *str)
 378 {
 379         acpi_no_memhotplug = true;
 380         return 1;
 381 }
 382 __setup("acpi_no_memhotplug", disable_acpi_memory_hotplug);
 383
 384 #else
 385
 386 static struct acpi_scan_handler memory_device_handler = {
 387         .ids = memory_device_ids,
 388 };
 389
 390 void __init acpi_memory_hotplug_init(void)
 391 {
 392         acpi_scan_add_handler(&memory_device_handler);
 393 }
 394
 395 #endif /* CONFIG_ACPI_HOTPLUG_MEMORY */