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, "_STA",
 156                                                NULL, &current_status)))
 157                 return -ENODEV;
 158         /*
 159          * Check for device status. Device should be
 160          * present/enabled/functioning.
 161          */
 162         if (!((current_status & ACPI_STA_DEVICE_PRESENT)
 163               && (current_status & ACPI_STA_DEVICE_ENABLED)
 164               && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
 165                 return -ENODEV;
 166
 167         return 0;
 168 }
 169
 170 static unsigned long acpi_meminfo_start_pfn(struct acpi_memory_info *info)
 171 {
 172         return PFN_DOWN(info->start_addr);
 173 }
 174
 175 static unsigned long acpi_meminfo_end_pfn(struct acpi_memory_info *info)
 176 {
 177         return PFN_UP(info->start_addr + info->length-1);
 178 }
 179
 180 static int acpi_bind_memblk(struct memory_block *mem, void *arg)
 181 {
 182         return acpi_bind_one(&mem->dev, (acpi_handle)arg);
 183 }
 184
 185 static int acpi_bind_memory_blocks(struct acpi_memory_info *info,
 186                                    acpi_handle handle)
 187 {
 188         return walk_memory_range(acpi_meminfo_start_pfn(info),
 189                                  acpi_meminfo_end_pfn(info), (void *)handle,
 190                                  acpi_bind_memblk);
 191 }
 192
 193 static int acpi_unbind_memblk(struct memory_block *mem, void *arg)
 194 {
 195         acpi_unbind_one(&mem->dev);
 196         return 0;
 197 }
 198
 199 static void acpi_unbind_memory_blocks(struct acpi_memory_info *info,
 200                                       acpi_handle handle)
 201 {
 202         walk_memory_range(acpi_meminfo_start_pfn(info),
 203                           acpi_meminfo_end_pfn(info), NULL, acpi_unbind_memblk);
 204 }
 205
 206 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 207 {
 208         acpi_handle handle = mem_device->device->handle;
 209         int result, num_enabled = 0;
 210         struct acpi_memory_info *info;
 211         int node;
 212
 213         node = acpi_get_node(handle);
 214         /*
 215          * Tell the VM there is more memory here...
 216          * Note: Assume that this function returns zero on success
 217          * We don't have memory-hot-add rollback function,now.
 218          * (i.e. memory-hot-remove function)
 219          */
 220         list_for_each_entry(info, &mem_device->res_list, list) {
 221                 if (info->enabled) { /* just sanity check...*/
 222                         num_enabled++;
 223                         continue;
 224                 }
 225                 /*
 226                  * If the memory block size is zero, please ignore it.
 227                  * Don't try to do the following memory hotplug flowchart.
 228                  */
 229                 if (!info->length)
 230                         continue;
 231                 if (node < 0)
 232                         node = memory_add_physaddr_to_nid(info->start_addr);
 233
 234                 result = add_memory(node, info->start_addr, info->length);
 235
 236                 /*
 237                  * If the memory block has been used by the kernel, add_memory()
 238                  * returns -EEXIST. If add_memory() returns the other error, it
 239                  * means that this memory block is not used by the kernel.
 240                  */
 241                 if (result && result != -EEXIST)
 242                         continue;
 243
 244                 result = acpi_bind_memory_blocks(info, handle);
 245                 if (result) {
 246                         acpi_unbind_memory_blocks(info, handle);
 247                         return -ENODEV;
 248                 }
 249
 250                 info->enabled = 1;
 251
 252                 /*
 253                  * Add num_enable even if add_memory() returns -EEXIST, so the
 254                  * device is bound to this driver.
 255                  */
 256                 num_enabled++;
 257         }
 258         if (!num_enabled) {
 259                 dev_err(&mem_device->device->dev, "add_memory failed\n");
 260                 mem_device->state = MEMORY_INVALID_STATE;
 261                 return -EINVAL;
 262         }
 263         /*
 264          * Sometimes the memory device will contain several memory blocks.
 265          * When one memory block is hot-added to the system memory, it will
 266          * be regarded as a success.
 267          * Otherwise if the last memory block can't be hot-added to the system
 268          * memory, it will be failure and the memory device can't be bound with
 269          * driver.
 270          */
 271         return 0;
 272 }
 273
 274 static void acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
 275 {
 276         acpi_handle handle = mem_device->device->handle;
 277         struct acpi_memory_info *info, *n;
 278         int nid = acpi_get_node(handle);
 279
 280         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 281                 if (!info->enabled)
 282                         continue;
 283
 284                 if (nid < 0)
 285                         nid = memory_add_physaddr_to_nid(info->start_addr);
 286
 287                 acpi_unbind_memory_blocks(info, handle);
 288                 remove_memory(nid, info->start_addr, info->length);
 289                 list_del(&info->list);
 290                 kfree(info);
 291         }
 292 }
 293
 294 static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
 295 {
 296         if (!mem_device)
 297                 return;
 298
 299         acpi_memory_free_device_resources(mem_device);
 300         mem_device->device->driver_data = NULL;
 301         kfree(mem_device);
 302 }
 303
 304 static int acpi_memory_device_add(struct acpi_device *device,
 305                                   const struct acpi_device_id *not_used)
 306 {
 307         struct acpi_memory_device *mem_device;
 308         int result;
 309
 310         if (!device)
 311                 return -EINVAL;
 312
 313         mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 314         if (!mem_device)
 315                 return -ENOMEM;
 316
 317         INIT_LIST_HEAD(&mem_device->res_list);
 318         mem_device->device = device;
 319         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 320         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 321         device->driver_data = mem_device;
 322
 323         /* Get the range from the _CRS */
 324         result = acpi_memory_get_device_resources(mem_device);
 325         if (result) {
 326                 device->driver_data = NULL;
 327                 kfree(mem_device);
 328                 return result;
 329         }
 330
 331         /* Set the device state */
 332         mem_device->state = MEMORY_POWER_ON_STATE;
 333
 334         result = acpi_memory_check_device(mem_device);
 335         if (result) {
 336                 acpi_memory_device_free(mem_device);
 337                 return 0;
 338         }
 339
 340         result = acpi_memory_enable_device(mem_device);
 341         if (result) {
 342                 dev_err(&device->dev, "acpi_memory_enable_device() error\n");
 343                 acpi_memory_device_free(mem_device);
 344                 return result;
 345         }
 346
 347         dev_dbg(&device->dev, "Memory device configured by ACPI\n");
 348         return 1;
 349 }
 350
 351 static void acpi_memory_device_remove(struct acpi_device *device)
 352 {
 353         struct acpi_memory_device *mem_device;
 354
 355         if (!device || !acpi_driver_data(device))
 356                 return;
 357
 358         mem_device = acpi_driver_data(device);
 359         acpi_memory_remove_memory(mem_device);
 360         acpi_memory_device_free(mem_device);
 361 }
 362
 363 void __init acpi_memory_hotplug_init(void)
 364 {
 365         acpi_scan_add_handler_with_hotplug(&memory_device_handler, "memory");
 366 }