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_hotplug.h>
  32
  33 #include "internal.h"
  34
  35 #define ACPI_MEMORY_DEVICE_CLASS                "memory"
  36 #define ACPI_MEMORY_DEVICE_HID                  "PNP0C80"
  37 #define ACPI_MEMORY_DEVICE_NAME                 "Hotplug Mem Device"
  38
  39 #define _COMPONENT              ACPI_MEMORY_DEVICE_COMPONENT
  40
  41 #undef PREFIX
  42 #define         PREFIX          "ACPI:memory_hp:"
  43
  44 ACPI_MODULE_NAME("acpi_memhotplug");
  45
  46 /* Memory Device States */
  47 #define MEMORY_INVALID_STATE    0
  48 #define MEMORY_POWER_ON_STATE   1
  49 #define MEMORY_POWER_OFF_STATE  2
  50
  51 static int acpi_memory_device_add(struct acpi_device *device,
  52                                   const struct acpi_device_id *not_used);
  53 static void acpi_memory_device_remove(struct acpi_device *device);
  54
  55 static const struct acpi_device_id memory_device_ids[] = {
  56         {ACPI_MEMORY_DEVICE_HID, 0},
  57         {"", 0},
  58 };
  59
  60 static struct acpi_scan_handler memory_device_handler = {
  61         .ids = memory_device_ids,
  62         .attach = acpi_memory_device_add,
  63         .detach = acpi_memory_device_remove,
  64         .hotplug = {
  65                 .enabled = true,
  66         },
  67 };
  68
  69 struct acpi_memory_info {
  70         struct list_head list;
  71         u64 start_addr;         /* Memory Range start physical addr */
  72         u64 length;             /* Memory Range length */
  73         unsigned short caching; /* memory cache attribute */
  74         unsigned short write_protect;   /* memory read/write attribute */
  75         unsigned int enabled:1;
  76 };
  77
  78 struct acpi_memory_device {
  79         struct acpi_device * device;
  80         unsigned int state;     /* State of the memory device */
  81         struct list_head res_list;
  82 };
  83
  84 static acpi_status
  85 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
  86 {
  87         struct acpi_memory_device *mem_device = context;
  88         struct acpi_resource_address64 address64;
  89         struct acpi_memory_info *info, *new;
  90         acpi_status status;
  91
  92         status = acpi_resource_to_address64(resource, &address64);
  93         if (ACPI_FAILURE(status) ||
  94             (address64.resource_type != ACPI_MEMORY_RANGE))
  95                 return AE_OK;
  96
  97         list_for_each_entry(info, &mem_device->res_list, list) {
  98                 /* Can we combine the resource range information? */
  99                 if ((info->caching == address64.info.mem.caching) &&
 100                     (info->write_protect == address64.info.mem.write_protect) &&
 101                     (info->start_addr + info->length == address64.minimum)) {
 102                         info->length += address64.address_length;
 103                         return AE_OK;
 104                 }
 105         }
 106
 107         new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
 108         if (!new)
 109                 return AE_ERROR;
 110
 111         INIT_LIST_HEAD(&new->list);
 112         new->caching = address64.info.mem.caching;
 113         new->write_protect = address64.info.mem.write_protect;
 114         new->start_addr = address64.minimum;
 115         new->length = address64.address_length;
 116         list_add_tail(&new->list, &mem_device->res_list);
 117
 118         return AE_OK;
 119 }
 120
 121 static void
 122 acpi_memory_free_device_resources(struct acpi_memory_device *mem_device)
 123 {
 124         struct acpi_memory_info *info, *n;
 125
 126         list_for_each_entry_safe(info, n, &mem_device->res_list, list)
 127                 kfree(info);
 128         INIT_LIST_HEAD(&mem_device->res_list);
 129 }
 130
 131 static int
 132 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
 133 {
 134         acpi_status status;
 135
 136         if (!list_empty(&mem_device->res_list))
 137                 return 0;
 138
 139         status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
 140                                      acpi_memory_get_resource, mem_device);
 141         if (ACPI_FAILURE(status)) {
 142                 acpi_memory_free_device_resources(mem_device);
 143                 return -EINVAL;
 144         }
 145
 146         return 0;
 147 }
 148
 149 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
 150 {
 151         unsigned long long current_status;
 152
 153         /* Get device present/absent information from the _STA */
 154         if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
 155                                                NULL, &current_status)))
 156                 return -ENODEV;
 157         /*
 158          * Check for device status. Device should be
 159          * present/enabled/functioning.
 160          */
 161         if (!((current_status & ACPI_STA_DEVICE_PRESENT)
 162               && (current_status & ACPI_STA_DEVICE_ENABLED)
 163               && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
 164                 return -ENODEV;
 165
 166         return 0;
 167 }
 168
 169 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 170 {
 171         int result, num_enabled = 0;
 172         struct acpi_memory_info *info;
 173         int node;
 174
 175         node = acpi_get_node(mem_device->device->handle);
 176         /*
 177          * Tell the VM there is more memory here...
 178          * Note: Assume that this function returns zero on success
 179          * We don't have memory-hot-add rollback function,now.
 180          * (i.e. memory-hot-remove function)
 181          */
 182         list_for_each_entry(info, &mem_device->res_list, list) {
 183                 if (info->enabled) { /* just sanity check...*/
 184                         num_enabled++;
 185                         continue;
 186                 }
 187                 /*
 188                  * If the memory block size is zero, please ignore it.
 189                  * Don't try to do the following memory hotplug flowchart.
 190                  */
 191                 if (!info->length)
 192                         continue;
 193                 if (node < 0)
 194                         node = memory_add_physaddr_to_nid(info->start_addr);
 195
 196                 result = add_memory(node, info->start_addr, info->length);
 197
 198                 /*
 199                  * If the memory block has been used by the kernel, add_memory()
 200                  * returns -EEXIST. If add_memory() returns the other error, it
 201                  * means that this memory block is not used by the kernel.
 202                  */
 203                 if (result && result != -EEXIST)
 204                         continue;
 205
 206                 info->enabled = 1;
 207
 208                 /*
 209                  * Add num_enable even if add_memory() returns -EEXIST, so the
 210                  * device is bound to this driver.
 211                  */
 212                 num_enabled++;
 213         }
 214         if (!num_enabled) {
 215                 dev_err(&mem_device->device->dev, "add_memory failed\n");
 216                 mem_device->state = MEMORY_INVALID_STATE;
 217                 return -EINVAL;
 218         }
 219         /*
 220          * Sometimes the memory device will contain several memory blocks.
 221          * When one memory block is hot-added to the system memory, it will
 222          * be regarded as a success.
 223          * Otherwise if the last memory block can't be hot-added to the system
 224          * memory, it will be failure and the memory device can't be bound with
 225          * driver.
 226          */
 227         return 0;
 228 }
 229
 230 static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
 231 {
 232         int result = 0, nid;
 233         struct acpi_memory_info *info, *n;
 234
 235         nid = acpi_get_node(mem_device->device->handle);
 236
 237         list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 238                 if (!info->enabled)
 239                         continue;
 240
 241                 if (nid < 0)
 242                         nid = memory_add_physaddr_to_nid(info->start_addr);
 243                 result = remove_memory(nid, info->start_addr, info->length);
 244                 if (result)
 245                         return result;
 246
 247                 list_del(&info->list);
 248                 kfree(info);
 249         }
 250
 251         return result;
 252 }
 253
 254 static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
 255 {
 256         if (!mem_device)
 257                 return;
 258
 259         acpi_memory_free_device_resources(mem_device);
 260         mem_device->device->driver_data = NULL;
 261         kfree(mem_device);
 262 }
 263
 264 static int acpi_memory_device_add(struct acpi_device *device,
 265                                   const struct acpi_device_id *not_used)
 266 {
 267         struct acpi_memory_device *mem_device;
 268         int result;
 269
 270         if (!device)
 271                 return -EINVAL;
 272
 273         mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 274         if (!mem_device)
 275                 return -ENOMEM;
 276
 277         INIT_LIST_HEAD(&mem_device->res_list);
 278         mem_device->device = device;
 279         sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 280         sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 281         device->driver_data = mem_device;
 282
 283         /* Get the range from the _CRS */
 284         result = acpi_memory_get_device_resources(mem_device);
 285         if (result) {
 286                 device->driver_data = NULL;
 287                 kfree(mem_device);
 288                 return result;
 289         }
 290
 291         /* Set the device state */
 292         mem_device->state = MEMORY_POWER_ON_STATE;
 293
 294         result = acpi_memory_check_device(mem_device);
 295         if (result) {
 296                 acpi_memory_device_free(mem_device);
 297                 return 0;
 298         }
 299
 300         result = acpi_memory_enable_device(mem_device);
 301         if (result) {
 302                 dev_err(&device->dev, "acpi_memory_enable_device() error\n");
 303                 acpi_memory_device_free(mem_device);
 304                 return -ENODEV;
 305         }
 306
 307         dev_dbg(&device->dev, "Memory device configured by ACPI\n");
 308         return 1;
 309 }
 310
 311 static void acpi_memory_device_remove(struct acpi_device *device)
 312 {
 313         struct acpi_memory_device *mem_device;
 314
 315         if (!device || !acpi_driver_data(device))
 316                 return;
 317
 318         mem_device = acpi_driver_data(device);
 319         acpi_memory_remove_memory(mem_device);
 320         acpi_memory_device_free(mem_device);
 321 }
 322
 323 void __init acpi_memory_hotplug_init(void)
 324 {
 325         acpi_scan_add_handler_with_hotplug(&memory_device_handler, "memory");
 326 }