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                 if (mhp_supports_memmap_on_memory(info->length))
 215                         mhp_flags |= MHP_MEMMAP_ON_MEMORY;
 216                 result = __add_memory(mgid, info->start_addr, info->length,
 217                                       mhp_flags);
 218
 219                 /*
 220                  * If the memory block has been used by the kernel, add_memory()
 221                  * returns -EEXIST. If add_memory() returns the other error, it
 222                  * means that this memory block is not used by the kernel.
 223                  */
 224                 if (result && result != -EEXIST)
 225                         continue;
 226
 227                 result = acpi_bind_memory_blocks(info, mem_device->device);
 228                 if (result) {
 229                         acpi_unbind_memory_blocks(info);
 230                         return -ENODEV;
 231                 }
 232
 233                 info->enabled = 1;
 234
 235                 /*
 236                  * Add num_enable even if add_memory() returns -EEXIST, so the
 237                  * device is bound to this driver.
 238                  */
 239                 num_enabled++;
 240         }
 241         if (!num_enabled) {
 242                 dev_err(&mem_device->device->dev, "add_memory failed\n");
 243                 return -EINVAL;
 244         }
 245         /*
 246          * Sometimes the memory device will contain several memory blocks.
 247          * When one memory block is hot-added to the system memory, it will
 248          * be regarded as a success.
 249          * Otherwise if the last memory block can't be hot-added to the system
 250          * memory, it will be failure and the memory device can't be bound with
 251          * driver.
 252          */
 253         return 0;
 254 }
 255
 256 static void acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
 257 {
 258         struct acpi_memory_info *info, *n;
 259
 260         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 261                 if (!info->enabled)
 262                         continue;
 263
 264                 acpi_unbind_memory_blocks(info);
 265                 __remove_memory(info->start_addr, info->length);
 266                 list_del(&info->list);
 267                 kfree(info);
 268         }
 269 }
 270
 271 static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
 272 {
 273         if (!mem_device)
 274                 return;
 275
 276         /* In case we succeeded adding *some* memory, unregistering fails. */
 277         if (mem_device->mgid >= 0)
 278                 memory_group_unregister(mem_device->mgid);
 279
 280         acpi_memory_free_device_resources(mem_device);
 281         mem_device->device->driver_data = NULL;
 282         kfree(mem_device);
 283 }
 284
 285 static int acpi_memory_device_add(struct acpi_device *device,
 286                                   const struct acpi_device_id *not_used)
 287 {
 288         struct acpi_memory_device *mem_device;
 289         int result;
 290
 291         if (!device)
 292                 return -EINVAL;
 293
 294         mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 295         if (!mem_device)
 296                 return -ENOMEM;
 297
 298         INIT_LIST_HEAD(&mem_device->res_list);
 299         mem_device->device = device;
 300         mem_device->mgid = -1;
 301         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 302         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 303         device->driver_data = mem_device;
 304
 305         /* Get the range from the _CRS */
 306         result = acpi_memory_get_device_resources(mem_device);
 307         if (result) {
 308                 device->driver_data = NULL;
 309                 kfree(mem_device);
 310                 return result;
 311         }
 312
 313         result = acpi_memory_check_device(mem_device);
 314         if (result) {
 315                 acpi_memory_device_free(mem_device);
 316                 return 0;
 317         }
 318
 319         result = acpi_memory_enable_device(mem_device);
 320         if (result) {
 321                 dev_err(&device->dev, "acpi_memory_enable_device() error\n");
 322                 acpi_memory_device_free(mem_device);
 323                 return result;
 324         }
 325
 326         dev_dbg(&device->dev, "Memory device configured by ACPI\n");
 327         return 1;
 328 }
 329
 330 static void acpi_memory_device_remove(struct acpi_device *device)
 331 {
 332         struct acpi_memory_device *mem_device;
 333
 334         if (!device || !acpi_driver_data(device))
 335                 return;
 336
 337         mem_device = acpi_driver_data(device);
 338         acpi_memory_remove_memory(mem_device);
 339         acpi_memory_device_free(mem_device);
 340 }
 341
 342 static bool __initdata acpi_no_memhotplug;
 343
 344 void __init acpi_memory_hotplug_init(void)
 345 {
 346         if (acpi_no_memhotplug) {
 347                 memory_device_handler.attach = NULL;
 348                 acpi_scan_add_handler(&memory_device_handler);
 349                 return;
 350         }
 351         acpi_scan_add_handler_with_hotplug(&memory_device_handler, "memory");
 352 }
 353
 354 static int __init disable_acpi_memory_hotplug(char *str)
 355 {
 356         acpi_no_memhotplug = true;
 357         return 1;
 358 }
 359 __setup("acpi_no_memhotplug", disable_acpi_memory_hotplug);
 360
 361 #else
 362
 363 static struct acpi_scan_handler memory_device_handler = {
 364         .ids = memory_device_ids,
 365 };
 366
 367 void __init acpi_memory_hotplug_init(void)
 368 {
 369         acpi_scan_add_handler(&memory_device_handler);
 370 }
 371
 372 #endif /* CONFIG_ACPI_HOTPLUG_MEMORY */