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