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>
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.
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
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.
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
30 #include <linux/acpi.h>
31 #include <linux/memory.h>
32 #include <linux/memory_hotplug.h>
36 #define ACPI_MEMORY_DEVICE_CLASS "memory"
37 #define ACPI_MEMORY_DEVICE_HID "PNP0C80"
38 #define ACPI_MEMORY_DEVICE_NAME "Hotplug Mem Device"
40 #define _COMPONENT ACPI_MEMORY_DEVICE_COMPONENT
43 #define PREFIX "ACPI:memory_hp:"
45 ACPI_MODULE_NAME("acpi_memhotplug");
47 static const struct acpi_device_id memory_device_ids[] = {
48 {ACPI_MEMORY_DEVICE_HID, 0},
52 #ifdef CONFIG_ACPI_HOTPLUG_MEMORY
54 /* Memory Device States */
55 #define MEMORY_INVALID_STATE 0
56 #define MEMORY_POWER_ON_STATE 1
57 #define MEMORY_POWER_OFF_STATE 2
59 static int acpi_memory_device_add(struct acpi_device *device,
60 const struct acpi_device_id *not_used);
61 static void acpi_memory_device_remove(struct acpi_device *device);
63 static struct acpi_scan_handler memory_device_handler = {
64 .ids = memory_device_ids,
65 .attach = acpi_memory_device_add,
66 .detach = acpi_memory_device_remove,
72 struct acpi_memory_info {
73 struct list_head list;
74 u64 start_addr; /* Memory Range start physical addr */
75 u64 length; /* Memory Range length */
76 unsigned short caching; /* memory cache attribute */
77 unsigned short write_protect; /* memory read/write attribute */
78 unsigned int enabled:1;
81 struct acpi_memory_device {
82 struct acpi_device * device;
83 unsigned int state; /* State of the memory device */
84 struct list_head res_list;
88 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
90 struct acpi_memory_device *mem_device = context;
91 struct acpi_resource_address64 address64;
92 struct acpi_memory_info *info, *new;
95 status = acpi_resource_to_address64(resource, &address64);
96 if (ACPI_FAILURE(status) ||
97 (address64.resource_type != ACPI_MEMORY_RANGE))
100 list_for_each_entry(info, &mem_device->res_list, list) {
101 /* Can we combine the resource range information? */
102 if ((info->caching == address64.info.mem.caching) &&
103 (info->write_protect == address64.info.mem.write_protect) &&
104 (info->start_addr + info->length == address64.address.minimum)) {
105 info->length += address64.address.address_length;
110 new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
114 INIT_LIST_HEAD(&new->list);
115 new->caching = address64.info.mem.caching;
116 new->write_protect = address64.info.mem.write_protect;
117 new->start_addr = address64.address.minimum;
118 new->length = address64.address.address_length;
119 list_add_tail(&new->list, &mem_device->res_list);
125 acpi_memory_free_device_resources(struct acpi_memory_device *mem_device)
127 struct acpi_memory_info *info, *n;
129 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
131 INIT_LIST_HEAD(&mem_device->res_list);
135 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
139 if (!list_empty(&mem_device->res_list))
142 status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
143 acpi_memory_get_resource, mem_device);
144 if (ACPI_FAILURE(status)) {
145 acpi_memory_free_device_resources(mem_device);
152 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
154 unsigned long long current_status;
156 /* Get device present/absent information from the _STA */
157 if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle,
158 METHOD_NAME__STA, NULL,
162 * Check for device status. Device should be
163 * present/enabled/functioning.
165 if (!((current_status & ACPI_STA_DEVICE_PRESENT)
166 && (current_status & ACPI_STA_DEVICE_ENABLED)
167 && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
173 static unsigned long acpi_meminfo_start_pfn(struct acpi_memory_info *info)
175 return PFN_DOWN(info->start_addr);
178 static unsigned long acpi_meminfo_end_pfn(struct acpi_memory_info *info)
180 return PFN_UP(info->start_addr + info->length-1);
183 static int acpi_bind_memblk(struct memory_block *mem, void *arg)
185 return acpi_bind_one(&mem->dev, arg);
188 static int acpi_bind_memory_blocks(struct acpi_memory_info *info,
189 struct acpi_device *adev)
191 return walk_memory_range(acpi_meminfo_start_pfn(info),
192 acpi_meminfo_end_pfn(info), adev,
196 static int acpi_unbind_memblk(struct memory_block *mem, void *arg)
198 acpi_unbind_one(&mem->dev);
202 static void acpi_unbind_memory_blocks(struct acpi_memory_info *info)
204 walk_memory_range(acpi_meminfo_start_pfn(info),
205 acpi_meminfo_end_pfn(info), NULL, acpi_unbind_memblk);
208 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
210 acpi_handle handle = mem_device->device->handle;
211 int result, num_enabled = 0;
212 struct acpi_memory_info *info;
215 node = acpi_get_node(handle);
217 * Tell the VM there is more memory here...
218 * Note: Assume that this function returns zero on success
219 * We don't have memory-hot-add rollback function,now.
220 * (i.e. memory-hot-remove function)
222 list_for_each_entry(info, &mem_device->res_list, list) {
223 if (info->enabled) { /* just sanity check...*/
228 * If the memory block size is zero, please ignore it.
229 * Don't try to do the following memory hotplug flowchart.
234 node = memory_add_physaddr_to_nid(info->start_addr);
236 result = add_memory(node, info->start_addr, info->length);
239 * If the memory block has been used by the kernel, add_memory()
240 * returns -EEXIST. If add_memory() returns the other error, it
241 * means that this memory block is not used by the kernel.
243 if (result && result != -EEXIST)
246 result = acpi_bind_memory_blocks(info, mem_device->device);
248 acpi_unbind_memory_blocks(info);
255 * Add num_enable even if add_memory() returns -EEXIST, so the
256 * device is bound to this driver.
261 dev_err(&mem_device->device->dev, "add_memory failed\n");
262 mem_device->state = MEMORY_INVALID_STATE;
266 * Sometimes the memory device will contain several memory blocks.
267 * When one memory block is hot-added to the system memory, it will
268 * be regarded as a success.
269 * Otherwise if the last memory block can't be hot-added to the system
270 * memory, it will be failure and the memory device can't be bound with
276 static void acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
278 acpi_handle handle = mem_device->device->handle;
279 struct acpi_memory_info *info, *n;
280 int nid = acpi_get_node(handle);
282 list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
286 if (nid == NUMA_NO_NODE)
287 nid = memory_add_physaddr_to_nid(info->start_addr);
289 acpi_unbind_memory_blocks(info);
290 remove_memory(nid, info->start_addr, info->length);
291 list_del(&info->list);
296 static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
301 acpi_memory_free_device_resources(mem_device);
302 mem_device->device->driver_data = NULL;
306 static int acpi_memory_device_add(struct acpi_device *device,
307 const struct acpi_device_id *not_used)
309 struct acpi_memory_device *mem_device;
315 mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
319 INIT_LIST_HEAD(&mem_device->res_list);
320 mem_device->device = device;
321 sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
322 sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
323 device->driver_data = mem_device;
325 /* Get the range from the _CRS */
326 result = acpi_memory_get_device_resources(mem_device);
328 device->driver_data = NULL;
333 /* Set the device state */
334 mem_device->state = MEMORY_POWER_ON_STATE;
336 result = acpi_memory_check_device(mem_device);
338 acpi_memory_device_free(mem_device);
342 result = acpi_memory_enable_device(mem_device);
344 dev_err(&device->dev, "acpi_memory_enable_device() error\n");
345 acpi_memory_device_free(mem_device);
349 dev_dbg(&device->dev, "Memory device configured by ACPI\n");
353 static void acpi_memory_device_remove(struct acpi_device *device)
355 struct acpi_memory_device *mem_device;
357 if (!device || !acpi_driver_data(device))
360 mem_device = acpi_driver_data(device);
361 acpi_memory_remove_memory(mem_device);
362 acpi_memory_device_free(mem_device);
365 static bool __initdata acpi_no_memhotplug;
367 void __init acpi_memory_hotplug_init(void)
369 if (acpi_no_memhotplug) {
370 memory_device_handler.attach = NULL;
371 acpi_scan_add_handler(&memory_device_handler);
374 acpi_scan_add_handler_with_hotplug(&memory_device_handler, "memory");
377 static int __init disable_acpi_memory_hotplug(char *str)
379 acpi_no_memhotplug = true;
382 __setup("acpi_no_memhotplug", disable_acpi_memory_hotplug);
386 static struct acpi_scan_handler memory_device_handler = {
387 .ids = memory_device_ids,
390 void __init acpi_memory_hotplug_init(void)
392 acpi_scan_add_handler(&memory_device_handler);
395 #endif /* CONFIG_ACPI_HOTPLUG_MEMORY */