LXR linux/drivers/acpi/acpi

   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
  25static 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
  32static int acpi_memory_device_add(struct acpi_device *device,
  33                                  const struct acpi_device_id *not_used);
  34static void acpi_memory_device_remove(struct acpi_device *device);
  35
  36static 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
  45struct 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
  54struct acpi_memory_device {
  55        struct acpi_device *device;
  56        struct list_head res_list;
  57};
  58
  59static acpi_status
  60acpi_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
  96static void
  97acpi_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
 106static int
 107acpi_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
 124static 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
 145static int acpi_bind_memblk(struct memory_block *mem, void *arg)
 146{
 147        return acpi_bind_one(&mem->dev, arg);
 148}
 149
 150static 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
 157static int acpi_unbind_memblk(struct memory_block *mem, void *arg)
 158{
 159        acpi_unbind_one(&mem->dev);
 160        return 0;
 161}
 162
 163static 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
 169static 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        mhp_t mhp_flags = MHP_NONE;
 175        int node;
 176
 177        node = acpi_get_node(handle);
 178        /*
 179         * Tell the VM there is more memory here...
 180         * Note: Assume that this function returns zero on success
 181         * We don't have memory-hot-add rollback function,now.
 182         * (i.e. memory-hot-remove function)
 183         */
 184        list_for_each_entry(info, &mem_device->res_list, list) {
 185                if (info->enabled) { /* just sanity check...*/
 186                        num_enabled++;
 187                        continue;
 188                }
 189                /*
 190                 * If the memory block size is zero, please ignore it.
 191                 * Don't try to do the following memory hotplug flowchart.
 192                 */
 193                if (!info->length)
 194                        continue;
 195                if (node < 0)
 196                        node = memory_add_physaddr_to_nid(info->start_addr);
 197
 198                if (mhp_supports_memmap_on_memory(info->length))
 199                        mhp_flags |= MHP_MEMMAP_ON_MEMORY;
 200                result = __add_memory(node, info->start_addr, info->length,
 201                                      mhp_flags);
 202
 203                /*
 204                 * If the memory block has been used by the kernel, add_memory()
 205                 * returns -EEXIST. If add_memory() returns the other error, it
 206                 * means that this memory block is not used by the kernel.
 207                 */
 208                if (result && result != -EEXIST)
 209                        continue;
 210
 211                result = acpi_bind_memory_blocks(info, mem_device->device);
 212                if (result) {
 213                        acpi_unbind_memory_blocks(info);
 214                        return -ENODEV;
 215                }
 216
 217                info->enabled = 1;
 218
 219                /*
 220                 * Add num_enable even if add_memory() returns -EEXIST, so the
 221                 * device is bound to this driver.
 222                 */
 223                num_enabled++;
 224        }
 225        if (!num_enabled) {
 226                dev_err(&mem_device->device->dev, "add_memory failed\n");
 227                return -EINVAL;
 228        }
 229        /*
 230         * Sometimes the memory device will contain several memory blocks.
 231         * When one memory block is hot-added to the system memory, it will
 232         * be regarded as a success.
 233         * Otherwise if the last memory block can't be hot-added to the system
 234         * memory, it will be failure and the memory device can't be bound with
 235         * driver.
 236         */
 237        return 0;
 238}
 239
 240static void acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
 241{
 242        acpi_handle handle = mem_device->device->handle;
 243        struct acpi_memory_info *info, *n;
 244        int nid = acpi_get_node(handle);
 245
 246        list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
 247                if (!info->enabled)
 248                        continue;
 249
 250                if (nid == NUMA_NO_NODE)
 251                        nid = memory_add_physaddr_to_nid(info->start_addr);
 252
 253                acpi_unbind_memory_blocks(info);
 254                __remove_memory(nid, info->start_addr, info->length);
 255                list_del(&info->list);
 256                kfree(info);
 257        }
 258}
 259
 260static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
 261{
 262        if (!mem_device)
 263                return;
 264
 265        acpi_memory_free_device_resources(mem_device);
 266        mem_device->device->driver_data = NULL;
 267        kfree(mem_device);
 268}
 269
 270static int acpi_memory_device_add(struct acpi_device *device,
 271                                  const struct acpi_device_id *not_used)
 272{
 273        struct acpi_memory_device *mem_device;
 274        int result;
 275
 276        if (!device)
 277                return -EINVAL;
 278
 279        mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
 280        if (!mem_device)
 281                return -ENOMEM;
 282
 283        INIT_LIST_HEAD(&mem_device->res_list);
 284        mem_device->device = device;
 285        sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
 286        sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
 287        device->driver_data = mem_device;
 288
 289        /* Get the range from the _CRS */
 290        result = acpi_memory_get_device_resources(mem_device);
 291        if (result) {
 292                device->driver_data = NULL;
 293                kfree(mem_device);
 294                return result;
 295        }
 296
 297        result = acpi_memory_check_device(mem_device);
 298        if (result) {
 299                acpi_memory_device_free(mem_device);
 300                return 0;
 301        }
 302
 303        result = acpi_memory_enable_device(mem_device);
 304        if (result) {
 305                dev_err(&device->dev, "acpi_memory_enable_device() error\n");
 306                acpi_memory_device_free(mem_device);
 307                return result;
 308        }
 309
 310        dev_dbg(&device->dev, "Memory device configured by ACPI\n");
 311        return 1;
 312}
 313
 314static void acpi_memory_device_remove(struct acpi_device *device)
 315{
 316        struct acpi_memory_device *mem_device;
 317
 318        if (!device || !acpi_driver_data(device))
 319                return;
 320
 321        mem_device = acpi_driver_data(device);
 322        acpi_memory_remove_memory(mem_device);
 323        acpi_memory_device_free(mem_device);
 324}
 325
 326static bool __initdata acpi_no_memhotplug;
 327
 328void __init acpi_memory_hotplug_init(void)
 329{
 330        if (acpi_no_memhotplug) {
 331                memory_device_handler.attach = NULL;
 332                acpi_scan_add_handler(&memory_device_handler);
 333                return;
 334        }
 335        acpi_scan_add_handler_with_hotplug(&memory_device_handler, "memory");
 336}
 337
 338static int __init disable_acpi_memory_hotplug(char *str)
 339{
 340        acpi_no_memhotplug = true;
 341        return 1;
 342}
 343__setup("acpi_no_memhotplug", disable_acpi_memory_hotplug);
 344
 345#else
 346
 347static struct acpi_scan_handler memory_device_handler = {
 348        .ids = memory_device_ids,
 349};
 350
 351void __init acpi_memory_hotplug_init(void)
 352{
 353        acpi_scan_add_handler(&memory_device_handler);
 354}
 355
 356#endif /* CONFIG_ACPI_HOTPLUG_MEMORY */
 357