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