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