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 | static 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 | |
32 | static int acpi_memory_device_add(struct acpi_device *device, |
33 | const struct acpi_device_id *not_used); |
34 | static void acpi_memory_device_remove(struct acpi_device *device); |
35 | |
36 | static 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 | |
45 | struct 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 | |
54 | struct acpi_memory_device { |
55 | struct acpi_device *device; |
56 | struct list_head res_list; |
57 | int mgid; |
58 | }; |
59 | |
60 | static acpi_status |
61 | acpi_memory_get_resource(struct acpi_resource *resource, void *context) |
62 | { |
63 | struct acpi_memory_device *mem_device = context; |
64 | struct acpi_resource_address64 address64; |
65 | struct acpi_memory_info *info, *new; |
66 | acpi_status status; |
67 | |
68 | status = acpi_resource_to_address64(resource, out: &address64); |
69 | if (ACPI_FAILURE(status) || |
70 | (address64.resource_type != ACPI_MEMORY_RANGE)) |
71 | return AE_OK; |
72 | |
73 | list_for_each_entry(info, &mem_device->res_list, list) { |
74 | /* Can we combine the resource range information? */ |
75 | if ((info->caching == address64.info.mem.caching) && |
76 | (info->write_protect == address64.info.mem.write_protect) && |
77 | (info->start_addr + info->length == address64.address.minimum)) { |
78 | info->length += address64.address.address_length; |
79 | return AE_OK; |
80 | } |
81 | } |
82 | |
83 | new = kzalloc(size: sizeof(struct acpi_memory_info), GFP_KERNEL); |
84 | if (!new) |
85 | return AE_ERROR; |
86 | |
87 | INIT_LIST_HEAD(list: &new->list); |
88 | new->caching = address64.info.mem.caching; |
89 | new->write_protect = address64.info.mem.write_protect; |
90 | new->start_addr = address64.address.minimum; |
91 | new->length = address64.address.address_length; |
92 | list_add_tail(new: &new->list, head: &mem_device->res_list); |
93 | |
94 | return AE_OK; |
95 | } |
96 | |
97 | static void |
98 | acpi_memory_free_device_resources(struct acpi_memory_device *mem_device) |
99 | { |
100 | struct acpi_memory_info *info, *n; |
101 | |
102 | list_for_each_entry_safe(info, n, &mem_device->res_list, list) |
103 | kfree(objp: info); |
104 | INIT_LIST_HEAD(list: &mem_device->res_list); |
105 | } |
106 | |
107 | static int |
108 | acpi_memory_get_device_resources(struct acpi_memory_device *mem_device) |
109 | { |
110 | acpi_status status; |
111 | |
112 | if (!list_empty(head: &mem_device->res_list)) |
113 | return 0; |
114 | |
115 | status = acpi_walk_resources(device: mem_device->device->handle, METHOD_NAME__CRS, |
116 | user_function: acpi_memory_get_resource, context: mem_device); |
117 | if (ACPI_FAILURE(status)) { |
118 | acpi_memory_free_device_resources(mem_device); |
119 | return -EINVAL; |
120 | } |
121 | |
122 | return 0; |
123 | } |
124 | |
125 | static int acpi_memory_check_device(struct acpi_memory_device *mem_device) |
126 | { |
127 | unsigned long long current_status; |
128 | |
129 | /* Get device present/absent information from the _STA */ |
130 | if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, |
131 | METHOD_NAME__STA, NULL, |
132 | ¤t_status))) |
133 | return -ENODEV; |
134 | /* |
135 | * Check for device status. Device should be |
136 | * present/enabled/functioning. |
137 | */ |
138 | if (!((current_status & ACPI_STA_DEVICE_PRESENT) |
139 | && (current_status & ACPI_STA_DEVICE_ENABLED) |
140 | && (current_status & ACPI_STA_DEVICE_FUNCTIONING))) |
141 | return -ENODEV; |
142 | |
143 | return 0; |
144 | } |
145 | |
146 | static int acpi_bind_memblk(struct memory_block *mem, void *arg) |
147 | { |
148 | return acpi_bind_one(dev: &mem->dev, adev: arg); |
149 | } |
150 | |
151 | static int acpi_bind_memory_blocks(struct acpi_memory_info *info, |
152 | struct acpi_device *adev) |
153 | { |
154 | return walk_memory_blocks(start: info->start_addr, size: info->length, arg: adev, |
155 | func: acpi_bind_memblk); |
156 | } |
157 | |
158 | static int acpi_unbind_memblk(struct memory_block *mem, void *arg) |
159 | { |
160 | acpi_unbind_one(dev: &mem->dev); |
161 | return 0; |
162 | } |
163 | |
164 | static void acpi_unbind_memory_blocks(struct acpi_memory_info *info) |
165 | { |
166 | walk_memory_blocks(start: info->start_addr, size: info->length, NULL, |
167 | func: acpi_unbind_memblk); |
168 | } |
169 | |
170 | static int acpi_memory_enable_device(struct acpi_memory_device *mem_device) |
171 | { |
172 | acpi_handle handle = mem_device->device->handle; |
173 | mhp_t mhp_flags = MHP_NID_IS_MGID; |
174 | int result, num_enabled = 0; |
175 | struct acpi_memory_info *info; |
176 | u64 total_length = 0; |
177 | int node, mgid; |
178 | |
179 | node = acpi_get_node(handle); |
180 | |
181 | list_for_each_entry(info, &mem_device->res_list, list) { |
182 | if (!info->length) |
183 | continue; |
184 | /* We want a single node for the whole memory group */ |
185 | if (node < 0) |
186 | node = memory_add_physaddr_to_nid(start: info->start_addr); |
187 | total_length += info->length; |
188 | } |
189 | |
190 | if (!total_length) { |
191 | dev_err(&mem_device->device->dev, "device is empty\n" ); |
192 | return -EINVAL; |
193 | } |
194 | |
195 | mgid = memory_group_register_static(nid: node, PFN_UP(total_length)); |
196 | if (mgid < 0) |
197 | return mgid; |
198 | mem_device->mgid = mgid; |
199 | |
200 | /* |
201 | * Tell the VM there is more memory here... |
202 | * Note: Assume that this function returns zero on success |
203 | * We don't have memory-hot-add rollback function,now. |
204 | * (i.e. memory-hot-remove function) |
205 | */ |
206 | list_for_each_entry(info, &mem_device->res_list, list) { |
207 | /* |
208 | * If the memory block size is zero, please ignore it. |
209 | * Don't try to do the following memory hotplug flowchart. |
210 | */ |
211 | if (!info->length) |
212 | continue; |
213 | |
214 | mhp_flags |= MHP_MEMMAP_ON_MEMORY; |
215 | result = __add_memory(nid: mgid, start: info->start_addr, size: info->length, |
216 | mhp_flags); |
217 | |
218 | /* |
219 | * If the memory block has been used by the kernel, add_memory() |
220 | * returns -EEXIST. If add_memory() returns the other error, it |
221 | * means that this memory block is not used by the kernel. |
222 | */ |
223 | if (result && result != -EEXIST) |
224 | continue; |
225 | |
226 | result = acpi_bind_memory_blocks(info, adev: mem_device->device); |
227 | if (result) { |
228 | acpi_unbind_memory_blocks(info); |
229 | return -ENODEV; |
230 | } |
231 | |
232 | info->enabled = 1; |
233 | |
234 | /* |
235 | * Add num_enable even if add_memory() returns -EEXIST, so the |
236 | * device is bound to this driver. |
237 | */ |
238 | num_enabled++; |
239 | } |
240 | if (!num_enabled) { |
241 | dev_err(&mem_device->device->dev, "add_memory failed\n" ); |
242 | return -EINVAL; |
243 | } |
244 | /* |
245 | * Sometimes the memory device will contain several memory blocks. |
246 | * When one memory block is hot-added to the system memory, it will |
247 | * be regarded as a success. |
248 | * Otherwise if the last memory block can't be hot-added to the system |
249 | * memory, it will be failure and the memory device can't be bound with |
250 | * driver. |
251 | */ |
252 | return 0; |
253 | } |
254 | |
255 | static void acpi_memory_remove_memory(struct acpi_memory_device *mem_device) |
256 | { |
257 | struct acpi_memory_info *info, *n; |
258 | |
259 | list_for_each_entry_safe(info, n, &mem_device->res_list, list) { |
260 | if (!info->enabled) |
261 | continue; |
262 | |
263 | acpi_unbind_memory_blocks(info); |
264 | __remove_memory(start: info->start_addr, size: info->length); |
265 | list_del(entry: &info->list); |
266 | kfree(objp: 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 | /* In case we succeeded adding *some* memory, unregistering fails. */ |
276 | if (mem_device->mgid >= 0) |
277 | memory_group_unregister(mgid: mem_device->mgid); |
278 | |
279 | acpi_memory_free_device_resources(mem_device); |
280 | mem_device->device->driver_data = NULL; |
281 | kfree(objp: mem_device); |
282 | } |
283 | |
284 | static int acpi_memory_device_add(struct acpi_device *device, |
285 | const struct acpi_device_id *not_used) |
286 | { |
287 | struct acpi_memory_device *mem_device; |
288 | int result; |
289 | |
290 | if (!device) |
291 | return -EINVAL; |
292 | |
293 | mem_device = kzalloc(size: sizeof(struct acpi_memory_device), GFP_KERNEL); |
294 | if (!mem_device) |
295 | return -ENOMEM; |
296 | |
297 | INIT_LIST_HEAD(list: &mem_device->res_list); |
298 | mem_device->device = device; |
299 | mem_device->mgid = -1; |
300 | sprintf(acpi_device_name(device), fmt: "%s" , ACPI_MEMORY_DEVICE_NAME); |
301 | sprintf(acpi_device_class(device), fmt: "%s" , ACPI_MEMORY_DEVICE_CLASS); |
302 | device->driver_data = mem_device; |
303 | |
304 | /* Get the range from the _CRS */ |
305 | result = acpi_memory_get_device_resources(mem_device); |
306 | if (result) { |
307 | device->driver_data = NULL; |
308 | kfree(objp: mem_device); |
309 | return result; |
310 | } |
311 | |
312 | result = acpi_memory_check_device(mem_device); |
313 | if (result) { |
314 | acpi_memory_device_free(mem_device); |
315 | return 0; |
316 | } |
317 | |
318 | result = acpi_memory_enable_device(mem_device); |
319 | if (result) { |
320 | dev_err(&device->dev, "acpi_memory_enable_device() error\n" ); |
321 | acpi_memory_device_free(mem_device); |
322 | return result; |
323 | } |
324 | |
325 | dev_dbg(&device->dev, "Memory device configured by ACPI\n" ); |
326 | return 1; |
327 | } |
328 | |
329 | static void acpi_memory_device_remove(struct acpi_device *device) |
330 | { |
331 | struct acpi_memory_device *mem_device; |
332 | |
333 | if (!device || !acpi_driver_data(d: device)) |
334 | return; |
335 | |
336 | mem_device = acpi_driver_data(d: device); |
337 | acpi_memory_remove_memory(mem_device); |
338 | acpi_memory_device_free(mem_device); |
339 | } |
340 | |
341 | static bool __initdata acpi_no_memhotplug; |
342 | |
343 | void __init acpi_memory_hotplug_init(void) |
344 | { |
345 | if (acpi_no_memhotplug) { |
346 | memory_device_handler.attach = NULL; |
347 | acpi_scan_add_handler(handler: &memory_device_handler); |
348 | return; |
349 | } |
350 | acpi_scan_add_handler_with_hotplug(handler: &memory_device_handler, hotplug_profile_name: "memory" ); |
351 | } |
352 | |
353 | static int __init disable_acpi_memory_hotplug(char *str) |
354 | { |
355 | acpi_no_memhotplug = true; |
356 | return 1; |
357 | } |
358 | __setup("acpi_no_memhotplug" , disable_acpi_memory_hotplug); |
359 | |
360 | #else |
361 | |
362 | static struct acpi_scan_handler memory_device_handler = { |
363 | .ids = memory_device_ids, |
364 | }; |
365 | |
366 | void __init acpi_memory_hotplug_init(void) |
367 | { |
368 | acpi_scan_add_handler(&memory_device_handler); |
369 | } |
370 | |
371 | #endif /* CONFIG_ACPI_HOTPLUG_MEMORY */ |
372 | |