drivers/acpi/acpi_memhotplug.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2004, 2013 Intel Corporation
   4  * Author: Naveen B S <naveen.b.s@intel.com>
   5  * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
   6  *
   7  * All rights reserved.
   8  *
   9  * ACPI based HotPlug driver that supports Memory Hotplug
  10  * This driver fields notifications from firmware for memory add
  11  * and remove operations and alerts the VM of the affected memory
  12  * ranges.
  13  */
  14
  15 #include <linux/acpi.h>
  16 #include <linux/memory.h>
  17 #include <linux/memory_hotplug.h>
  18
  19 #include "internal.h"
  20
  21 #define ACPI_MEMORY_DEVICE_CLASS                "memory"
  22 #define ACPI_MEMORY_DEVICE_HID                  "PNP0C80"
  23 #define ACPI_MEMORY_DEVICE_NAME                 "Hotplug Mem Device"
  24
  25 static const struct acpi_device_id memory_device_ids[] = {
  26         {ACPI_MEMORY_DEVICE_HID, 0},
  27         {"", 0},
  28 };
  29
  30 #ifdef CONFIG_ACPI_HOTPLUG_MEMORY
  31
  32 static int acpi_memory_device_add(struct acpi_device *device,
  33                                   const struct acpi_device_id *not_used);
  34 static void acpi_memory_device_remove(struct acpi_device *device);
  35
  36 static struct acpi_scan_handler memory_device_handler = {
  37         .ids = memory_device_ids,
  38         .attach = acpi_memory_device_add,
  39         .detach = acpi_memory_device_remove,
  40         .hotplug = {
  41                 .enabled = true,
  42         },
  43 };
  44
  45 struct acpi_memory_info {
  46         struct list_head list;
  47         u64 start_addr;         /* Memory Range start physical addr */
  48         u64 length;             /* Memory Range length */
  49         unsigned short caching; /* memory cache attribute */
  50         unsigned short write_protect;   /* memory read/write attribute */
  51         unsigned int enabled:1;
  52 };
  53
  54 struct acpi_memory_device {
  55         struct acpi_device *device;
  56         struct list_head res_list;
  57         int mgid;
  58 };
  59
  60 static acpi_status
  61 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
  62 {
  63         struct acpi_memory_device *mem_device = context;
  64         struct acpi_resource_address64 address64;
  65         struct acpi_memory_info *info, *new;
  66         acpi_status status;
  67
  68         status = acpi_resource_to_address64(resource, &address64);
  69         if (ACPI_FAILURE(status) ||
  70             (address64.resource_type != ACPI_MEMORY_RANGE))
  71                 return AE_OK;
  72
  73         list_for_each_entry(info, &mem_device->res_list, list) {
  74                 /* Can we combine the resource range information? */
  75                 if ((info->caching == address64.info.mem.caching) &&
  76                     (info->write_protect == address64.info.mem.write_protect) &&
  77                     (info->start_addr + info->length == address64.address.minimum)) {
  78                         info->length += address64.address.address_length;
  79                         return AE_OK;
  80                 }
  81         }
  82
  83         new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
  84         if (!new)
  85                 return AE_ERROR;
  86
  87         INIT_LIST_HEAD(&new->list);
  88         new->caching = address64.info.mem.caching;
  89         new->write_protect = address64.info.mem.write_protect;
  90         new->start_addr = address64.address.minimum;
  91         new->length = address64.address.address_length;
  92         list_add_tail(&new->list, &mem_device->res_list);
  93
  94         return AE_OK;
  95 }
  96
  97 static void
  98 acpi_memory_free_device_resources(struct acpi_memory_device *mem_device)
  99 {
 100         struct acpi_memory_info *info, *n;
 101
 102         list_for_each_entry_safe(info, n, &mem_device->res_list, list)
 103                 kfree(info);
 104         INIT_LIST_HEAD(&mem_device->res_list);
 105 }
 106
 107 static int
 108 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
 109 {
 110         acpi_status status;
 111
 112         if (!list_empty(&mem_device->res_list))
 113                 return 0;
 114
 115         status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
 116                                      acpi_memory_get_resource, mem_device);
 117         if (ACPI_FAILURE(status)) {
 118                 acpi_memory_free_device_resources(mem_device);
 119                 return -EINVAL;
 120         }
 121
 122         return 0;
 123 }
 124
 125 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
 126 {
 127         unsigned long long current_status;
 128
 129         /* Get device present/absent information from the _STA */
 130         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle,
 131                                                METHOD_NAME__STA, NULL,
 132                                                &current_status)))
 133                 return -ENODEV;
 134         /*
 135          * Check for device status. Device should be
 136          * present/enabled/functioning.
 137          */
 138         if (!((current_status & ACPI_STA_DEVICE_PRESENT)
 139               && (current_status & ACPI_STA_DEVICE_ENABLED)
 140               && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
 141                 return -ENODEV;
 142
 143         return 0;
 144 }
 145
 146 static int acpi_bind_memblk(struct memory_block *mem, void *arg)
 147 {
 148         return acpi_bind_one(&mem->dev, arg);
 149 }
 150
 151 static int acpi_bind_memory_blocks(struct acpi_memory_info *info,
 152                                    struct acpi_device *adev)
 153 {
 154         return walk_memory_blocks(info->start_addr, info->length, adev,
 155                                   acpi_bind_memblk);
 156 }
 157
 158 static int acpi_unbind_memblk(struct memory_block *mem, void *arg)
 159 {
 160         acpi_unbind_one(&mem->dev);
 161         return 0;
 162 }
 163
 164 static void acpi_unbind_memory_blocks(struct acpi_memory_info *info)
 165 {
 166         walk_memory_blocks(info->start_addr, info->length, NULL,
 167                            acpi_unbind_memblk);
 168 }
 169
 170 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 171 {
 172         acpi_handle handle = mem_device->device->handle;
 173         mhp_t mhp_flags = MHP_NID_IS_MGID;
 174         int result, num_enabled = 0;
 175         struct acpi_memory_info *info;
 176         u64 total_length = 0;
 177         int node, mgid;
 178
 179         node = acpi_get_node(handle);
 180
 181         list_for_each_entry(info, &mem_device->res_list, list) {
 182                 if (!info->length)
 183                         continue;
 184                 /* We want a single node for the whole memory group */
 185                 if (node < 0)
 186                         node = memory_add_physaddr_to_nid(info->start_addr);
 187                 total_length += info->length;
 188         }
 189
 190         if (!total_length) {
 191                 dev_err(&mem_device->device->dev, "device is empty\n");
 192                 return -EINVAL;
 193         }
 194
 195         mgid = memory_group_register_static(node, PFN_UP(total_length));
 196         if (mgid < 0)
 197                 return mgid;
 198         mem_device->mgid = mgid;
 199
 200         /*
 201          * Tell the VM there is more memory here...
 202          * Note: Assume that this function returns zero on success
 203          * We don't have memory-hot-add rollback function,now.
 204          * (i.e. memory-hot-remove function)
 205          */
 206         list_for_each_entry(info, &mem_device->res_list, list) {
 207                 /*
 208                  * If the memory block size is zero, please ignore it.
 209                  * Don't try to do the following memory hotplug flowchart.
 210                  */
 211                 if (!info->length)
 212                         continue;
 213
 214                 mhp_flags |= MHP_MEMMAP_ON_MEMORY;
 215                 result = __add_memory(mgid, info->start_addr, info->length,
 216                                       mhp_flags);
 217
 218                 /*
 219                  * If the memory block has been used by the kernel, add_memory()
 220                  * returns -EEXIST. If add_memory() returns the other error, it
 221                  * means that this memory block is not used by the kernel.
 222                  */
 223                 if (result && result != -EEXIST)
 224                         continue;
 225
 226                 result = acpi_bind_memory_blocks(info, mem_device->device);
 227                 if (result) {
 228                         acpi_unbind_memory_blocks(info);
 229                         return -ENODEV;
 230                 }
 231
 232                 info->enabled = 1;
 233
 234                 /*
 235                  * Add num_enable even if add_memory() returns -EEXIST, so the
 236                  * device is bound to this driver.
 237                  */
 238                 num_enabled++;
 239         }
 240         if (!num_enabled) {
 241                 dev_err(&mem_device->device->dev, "add_memory failed\n");
 242                 return -EINVAL;
 243         }
 244         /*
 245          * Sometimes the memory device will contain several memory blocks.
 246          * When one memory block is hot-added to the system memory, it will
 247          * be regarded as a success.
 248          * Otherwise if the last memory block can't be hot-added to the system
 249          * memory, it will be failure and the memory device can't be bound with
 250          * driver.
 251          */
 252         return 0;
 253 }
 254
 255 static void acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
 256 {
 257         struct acpi_memory_info *info, *n;
 258
 259         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 260                 if (!info->enabled)
 261                         continue;
 262
 263                 acpi_unbind_memory_blocks(info);
 264                 __remove_memory(info->start_addr, info->length);
 265                 list_del(&info->list);
 266                 kfree(info);
 267         }
 268 }
 269
 270 static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
 271 {
 272         if (!mem_device)
 273                 return;
 274
 275         /* In case we succeeded adding *some* memory, unregistering fails. */
 276         if (mem_device->mgid >= 0)
 277                 memory_group_unregister(mem_device->mgid);
 278
 279         acpi_memory_free_device_resources(mem_device);
 280         mem_device->device->driver_data = NULL;
 281         kfree(mem_device);
 282 }
 283
 284 static int acpi_memory_device_add(struct acpi_device *device,
 285                                   const struct acpi_device_id *not_used)
 286 {
 287         struct acpi_memory_device *mem_device;
 288         int result;
 289
 290         if (!device)
 291                 return -EINVAL;
 292
 293         mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 294         if (!mem_device)
 295                 return -ENOMEM;
 296
 297         INIT_LIST_HEAD(&mem_device->res_list);
 298         mem_device->device = device;
 299         mem_device->mgid = -1;
 300         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 301         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 302         device->driver_data = mem_device;
 303
 304         /* Get the range from the _CRS */
 305         result = acpi_memory_get_device_resources(mem_device);
 306         if (result) {
 307                 device->driver_data = NULL;
 308                 kfree(mem_device);
 309                 return result;
 310         }
 311
 312         result = acpi_memory_check_device(mem_device);
 313         if (result) {
 314                 acpi_memory_device_free(mem_device);
 315                 return 0;
 316         }
 317
 318         result = acpi_memory_enable_device(mem_device);
 319         if (result) {
 320                 dev_err(&device->dev, "acpi_memory_enable_device() error\n");
 321                 acpi_memory_device_free(mem_device);
 322                 return result;
 323         }
 324
 325         dev_dbg(&device->dev, "Memory device configured by ACPI\n");
 326         return 1;
 327 }
 328
 329 static void acpi_memory_device_remove(struct acpi_device *device)
 330 {
 331         struct acpi_memory_device *mem_device;
 332
 333         if (!device || !acpi_driver_data(device))
 334                 return;
 335
 336         mem_device = acpi_driver_data(device);
 337         acpi_memory_remove_memory(mem_device);
 338         acpi_memory_device_free(mem_device);
 339 }
 340
 341 static bool __initdata acpi_no_memhotplug;
 342
 343 void __init acpi_memory_hotplug_init(void)
 344 {
 345         if (acpi_no_memhotplug) {
 346                 memory_device_handler.attach = NULL;
 347                 acpi_scan_add_handler(&memory_device_handler);
 348                 return;
 349         }
 350         acpi_scan_add_handler_with_hotplug(&memory_device_handler, "memory");
 351 }
 352
 353 static int __init disable_acpi_memory_hotplug(char *str)
 354 {
 355         acpi_no_memhotplug = true;
 356         return 1;
 357 }
 358 __setup("acpi_no_memhotplug", disable_acpi_memory_hotplug);
 359
 360 #else
 361
 362 static struct acpi_scan_handler memory_device_handler = {
 363         .ids = memory_device_ids,
 364 };
 365
 366 void __init acpi_memory_hotplug_init(void)
 367 {
 368         acpi_scan_add_handler(&memory_device_handler);
 369 }
 370
 371 #endif /* CONFIG_ACPI_HOTPLUG_MEMORY */