1 // SPDX-License-Identifier: GPL-2.0-or-later
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>
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
15 #include <linux/acpi.h>
16 #include <linux/memory.h>
17 #include <linux/memory_hotplug.h>
21 #define ACPI_MEMORY_DEVICE_CLASS "memory"
22 #define ACPI_MEMORY_DEVICE_HID "PNP0C80"
23 #define ACPI_MEMORY_DEVICE_NAME "Hotplug Mem Device"
25 #define _COMPONENT ACPI_MEMORY_DEVICE_COMPONENT
28 #define PREFIX "ACPI:memory_hp:"
30 ACPI_MODULE_NAME("acpi_memhotplug");
32 static const struct acpi_device_id memory_device_ids[] = {
33 {ACPI_MEMORY_DEVICE_HID, 0},
37 #ifdef CONFIG_ACPI_HOTPLUG_MEMORY
39 /* Memory Device States */
40 #define MEMORY_INVALID_STATE 0
41 #define MEMORY_POWER_ON_STATE 1
42 #define MEMORY_POWER_OFF_STATE 2
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);
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,
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;
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;
73 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
75 struct acpi_memory_device *mem_device = context;
76 struct acpi_resource_address64 address64;
77 struct acpi_memory_info *info, *new;
80 status = acpi_resource_to_address64(resource, &address64);
81 if (ACPI_FAILURE(status) ||
82 (address64.resource_type != ACPI_MEMORY_RANGE))
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;
95 new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
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);
110 acpi_memory_free_device_resources(struct acpi_memory_device *mem_device)
112 struct acpi_memory_info *info, *n;
114 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
116 INIT_LIST_HEAD(&mem_device->res_list);
120 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
124 if (!list_empty(&mem_device->res_list))
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);
137 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
139 unsigned long long current_status;
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,
147 * Check for device status. Device should be
148 * present/enabled/functioning.
150 if (!((current_status & ACPI_STA_DEVICE_PRESENT)
151 && (current_status & ACPI_STA_DEVICE_ENABLED)
152 && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
158 static unsigned long acpi_meminfo_start_pfn(struct acpi_memory_info *info)
160 return PFN_DOWN(info->start_addr);
163 static unsigned long acpi_meminfo_end_pfn(struct acpi_memory_info *info)
165 return PFN_UP(info->start_addr + info->length-1);
168 static int acpi_bind_memblk(struct memory_block *mem, void *arg)
170 return acpi_bind_one(&mem->dev, arg);
173 static int acpi_bind_memory_blocks(struct acpi_memory_info *info,
174 struct acpi_device *adev)
176 return walk_memory_range(acpi_meminfo_start_pfn(info),
177 acpi_meminfo_end_pfn(info), adev,
181 static int acpi_unbind_memblk(struct memory_block *mem, void *arg)
183 acpi_unbind_one(&mem->dev);
187 static void acpi_unbind_memory_blocks(struct acpi_memory_info *info)
189 walk_memory_range(acpi_meminfo_start_pfn(info),
190 acpi_meminfo_end_pfn(info), NULL, acpi_unbind_memblk);
193 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
195 acpi_handle handle = mem_device->device->handle;
196 int result, num_enabled = 0;
197 struct acpi_memory_info *info;
200 node = acpi_get_node(handle);
202 * Tell the VM there is more memory here...
203 * Note: Assume that this function returns zero on success
204 * We don't have memory-hot-add rollback function,now.
205 * (i.e. memory-hot-remove function)
207 list_for_each_entry(info, &mem_device->res_list, list) {
208 if (info->enabled) { /* just sanity check...*/
213 * If the memory block size is zero, please ignore it.
214 * Don't try to do the following memory hotplug flowchart.
219 node = memory_add_physaddr_to_nid(info->start_addr);
221 result = __add_memory(node, info->start_addr, info->length);
224 * If the memory block has been used by the kernel, add_memory()
225 * returns -EEXIST. If add_memory() returns the other error, it
226 * means that this memory block is not used by the kernel.
228 if (result && result != -EEXIST)
231 result = acpi_bind_memory_blocks(info, mem_device->device);
233 acpi_unbind_memory_blocks(info);
240 * Add num_enable even if add_memory() returns -EEXIST, so the
241 * device is bound to this driver.
246 dev_err(&mem_device->device->dev, "add_memory failed\n");
247 mem_device->state = MEMORY_INVALID_STATE;
251 * Sometimes the memory device will contain several memory blocks.
252 * When one memory block is hot-added to the system memory, it will
253 * be regarded as a success.
254 * Otherwise if the last memory block can't be hot-added to the system
255 * memory, it will be failure and the memory device can't be bound with
261 static void acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
263 acpi_handle handle = mem_device->device->handle;
264 struct acpi_memory_info *info, *n;
265 int nid = acpi_get_node(handle);
267 list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
271 if (nid == NUMA_NO_NODE)
272 nid = memory_add_physaddr_to_nid(info->start_addr);
274 acpi_unbind_memory_blocks(info);
275 __remove_memory(nid, info->start_addr, info->length);
276 list_del(&info->list);
281 static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
286 acpi_memory_free_device_resources(mem_device);
287 mem_device->device->driver_data = NULL;
291 static int acpi_memory_device_add(struct acpi_device *device,
292 const struct acpi_device_id *not_used)
294 struct acpi_memory_device *mem_device;
300 mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
304 INIT_LIST_HEAD(&mem_device->res_list);
305 mem_device->device = device;
306 sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
307 sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
308 device->driver_data = mem_device;
310 /* Get the range from the _CRS */
311 result = acpi_memory_get_device_resources(mem_device);
313 device->driver_data = NULL;
318 /* Set the device state */
319 mem_device->state = MEMORY_POWER_ON_STATE;
321 result = acpi_memory_check_device(mem_device);
323 acpi_memory_device_free(mem_device);
327 result = acpi_memory_enable_device(mem_device);
329 dev_err(&device->dev, "acpi_memory_enable_device() error\n");
330 acpi_memory_device_free(mem_device);
334 dev_dbg(&device->dev, "Memory device configured by ACPI\n");
338 static void acpi_memory_device_remove(struct acpi_device *device)
340 struct acpi_memory_device *mem_device;
342 if (!device || !acpi_driver_data(device))
345 mem_device = acpi_driver_data(device);
346 acpi_memory_remove_memory(mem_device);
347 acpi_memory_device_free(mem_device);
350 static bool __initdata acpi_no_memhotplug;
352 void __init acpi_memory_hotplug_init(void)
354 if (acpi_no_memhotplug) {
355 memory_device_handler.attach = NULL;
356 acpi_scan_add_handler(&memory_device_handler);
359 acpi_scan_add_handler_with_hotplug(&memory_device_handler, "memory");
362 static int __init disable_acpi_memory_hotplug(char *str)
364 acpi_no_memhotplug = true;
367 __setup("acpi_no_memhotplug", disable_acpi_memory_hotplug);
371 static struct acpi_scan_handler memory_device_handler = {
372 .ids = memory_device_ids,
375 void __init acpi_memory_hotplug_init(void)
377 acpi_scan_add_handler(&memory_device_handler);
380 #endif /* CONFIG_ACPI_HOTPLUG_MEMORY */