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4359375c | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
ef92e7ca LJ |
2 | /* |
3 | * Copyright (C) 2012 Intel Corporation | |
4 | * Author: Liu Jinsong <jinsong.liu@intel.com> | |
5 | * Author: Jiang Yunhong <yunhong.jiang@intel.com> | |
ef92e7ca LJ |
6 | */ |
7 | ||
283c0972 JP |
8 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
9 | ||
ef92e7ca LJ |
10 | #include <linux/kernel.h> |
11 | #include <linux/module.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/types.h> | |
14 | #include <linux/acpi.h> | |
ef92e7ca LJ |
15 | #include <xen/acpi.h> |
16 | #include <xen/interface/platform.h> | |
17 | #include <asm/xen/hypercall.h> | |
18 | ||
19 | #define PREFIX "ACPI:xen_memory_hotplug:" | |
20 | ||
21 | struct acpi_memory_info { | |
22 | struct list_head list; | |
23 | u64 start_addr; /* Memory Range start physical addr */ | |
24 | u64 length; /* Memory Range length */ | |
25 | unsigned short caching; /* memory cache attribute */ | |
26 | unsigned short write_protect; /* memory read/write attribute */ | |
27 | /* copied from buffer getting from _CRS */ | |
28 | unsigned int enabled:1; | |
29 | }; | |
30 | ||
31 | struct acpi_memory_device { | |
32 | struct acpi_device *device; | |
33 | struct list_head res_list; | |
34 | }; | |
35 | ||
36 | static bool acpi_hotmem_initialized __read_mostly; | |
37 | ||
38 | static int xen_hotadd_memory(int pxm, struct acpi_memory_info *info) | |
39 | { | |
40 | int rc; | |
41 | struct xen_platform_op op; | |
42 | ||
43 | op.cmd = XENPF_mem_hotadd; | |
44 | op.u.mem_add.spfn = info->start_addr >> PAGE_SHIFT; | |
45 | op.u.mem_add.epfn = (info->start_addr + info->length) >> PAGE_SHIFT; | |
46 | op.u.mem_add.pxm = pxm; | |
47 | ||
48 | rc = HYPERVISOR_dom0_op(&op); | |
49 | if (rc) | |
50 | pr_err(PREFIX "Xen Hotplug Memory Add failed on " | |
51 | "0x%lx -> 0x%lx, _PXM: %d, error: %d\n", | |
52 | (unsigned long)info->start_addr, | |
53 | (unsigned long)(info->start_addr + info->length), | |
54 | pxm, rc); | |
55 | ||
56 | return rc; | |
57 | } | |
58 | ||
ef92e7ca LJ |
59 | static int xen_acpi_memory_enable_device(struct acpi_memory_device *mem_device) |
60 | { | |
61 | int pxm, result; | |
62 | int num_enabled = 0; | |
63 | struct acpi_memory_info *info; | |
64 | ||
65 | if (!mem_device) | |
66 | return -EINVAL; | |
67 | ||
68 | pxm = xen_acpi_get_pxm(mem_device->device->handle); | |
69 | if (pxm < 0) | |
70 | return pxm; | |
71 | ||
72 | list_for_each_entry(info, &mem_device->res_list, list) { | |
73 | if (info->enabled) { /* just sanity check...*/ | |
74 | num_enabled++; | |
75 | continue; | |
76 | } | |
77 | ||
78 | if (!info->length) | |
79 | continue; | |
80 | ||
81 | result = xen_hotadd_memory(pxm, info); | |
82 | if (result) | |
83 | continue; | |
84 | info->enabled = 1; | |
85 | num_enabled++; | |
86 | } | |
87 | ||
88 | if (!num_enabled) | |
89 | return -ENODEV; | |
90 | ||
91 | return 0; | |
92 | } | |
93 | ||
94 | static acpi_status | |
95 | acpi_memory_get_resource(struct acpi_resource *resource, void *context) | |
96 | { | |
97 | struct acpi_memory_device *mem_device = context; | |
98 | struct acpi_resource_address64 address64; | |
99 | struct acpi_memory_info *info, *new; | |
100 | acpi_status status; | |
101 | ||
102 | status = acpi_resource_to_address64(resource, &address64); | |
103 | if (ACPI_FAILURE(status) || | |
104 | (address64.resource_type != ACPI_MEMORY_RANGE)) | |
105 | return AE_OK; | |
106 | ||
107 | list_for_each_entry(info, &mem_device->res_list, list) { | |
108 | if ((info->caching == address64.info.mem.caching) && | |
109 | (info->write_protect == address64.info.mem.write_protect) && | |
a45de93e LZ |
110 | (info->start_addr + info->length == address64.address.minimum)) { |
111 | info->length += address64.address.address_length; | |
ef92e7ca LJ |
112 | return AE_OK; |
113 | } | |
114 | } | |
115 | ||
116 | new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL); | |
117 | if (!new) | |
118 | return AE_ERROR; | |
119 | ||
120 | INIT_LIST_HEAD(&new->list); | |
121 | new->caching = address64.info.mem.caching; | |
122 | new->write_protect = address64.info.mem.write_protect; | |
a45de93e LZ |
123 | new->start_addr = address64.address.minimum; |
124 | new->length = address64.address.address_length; | |
ef92e7ca LJ |
125 | list_add_tail(&new->list, &mem_device->res_list); |
126 | ||
127 | return AE_OK; | |
128 | } | |
129 | ||
130 | static int | |
131 | acpi_memory_get_device_resources(struct acpi_memory_device *mem_device) | |
132 | { | |
133 | acpi_status status; | |
134 | struct acpi_memory_info *info, *n; | |
135 | ||
136 | if (!list_empty(&mem_device->res_list)) | |
137 | return 0; | |
138 | ||
139 | status = acpi_walk_resources(mem_device->device->handle, | |
140 | METHOD_NAME__CRS, acpi_memory_get_resource, mem_device); | |
141 | ||
142 | if (ACPI_FAILURE(status)) { | |
143 | list_for_each_entry_safe(info, n, &mem_device->res_list, list) | |
144 | kfree(info); | |
145 | INIT_LIST_HEAD(&mem_device->res_list); | |
146 | return -EINVAL; | |
147 | } | |
148 | ||
149 | return 0; | |
150 | } | |
151 | ||
484400ff LJ |
152 | static int acpi_memory_get_device(acpi_handle handle, |
153 | struct acpi_memory_device **mem_device) | |
ef92e7ca | 154 | { |
ef92e7ca | 155 | struct acpi_device *device = NULL; |
484400ff | 156 | int result = 0; |
ef92e7ca | 157 | |
484400ff | 158 | acpi_scan_lock_acquire(); |
ef92e7ca | 159 | |
484400ff | 160 | acpi_bus_get_device(handle, &device); |
202317a5 | 161 | if (acpi_device_enumerated(device)) |
484400ff | 162 | goto end; |
ef92e7ca LJ |
163 | |
164 | /* | |
165 | * Now add the notified device. This creates the acpi_device | |
166 | * and invokes .add function | |
167 | */ | |
77be36de | 168 | result = acpi_bus_scan(handle); |
ef92e7ca | 169 | if (result) { |
484400ff LJ |
170 | pr_warn(PREFIX "ACPI namespace scan failed\n"); |
171 | result = -EINVAL; | |
172 | goto out; | |
173 | } | |
202317a5 RW |
174 | device = NULL; |
175 | acpi_bus_get_device(handle, &device); | |
176 | if (!acpi_device_enumerated(device)) { | |
484400ff LJ |
177 | pr_warn(PREFIX "Missing device object\n"); |
178 | result = -EINVAL; | |
179 | goto out; | |
ef92e7ca LJ |
180 | } |
181 | ||
182 | end: | |
183 | *mem_device = acpi_driver_data(device); | |
184 | if (!(*mem_device)) { | |
484400ff LJ |
185 | pr_err(PREFIX "driver data not found\n"); |
186 | result = -ENODEV; | |
187 | goto out; | |
ef92e7ca LJ |
188 | } |
189 | ||
484400ff LJ |
190 | out: |
191 | acpi_scan_lock_release(); | |
192 | return result; | |
ef92e7ca LJ |
193 | } |
194 | ||
195 | static int acpi_memory_check_device(struct acpi_memory_device *mem_device) | |
196 | { | |
197 | unsigned long long current_status; | |
198 | ||
199 | /* Get device present/absent information from the _STA */ | |
200 | if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, | |
201 | "_STA", NULL, ¤t_status))) | |
202 | return -ENODEV; | |
203 | /* | |
204 | * Check for device status. Device should be | |
205 | * present/enabled/functioning. | |
206 | */ | |
207 | if (!((current_status & ACPI_STA_DEVICE_PRESENT) | |
208 | && (current_status & ACPI_STA_DEVICE_ENABLED) | |
209 | && (current_status & ACPI_STA_DEVICE_FUNCTIONING))) | |
210 | return -ENODEV; | |
211 | ||
212 | return 0; | |
213 | } | |
214 | ||
215 | static int acpi_memory_disable_device(struct acpi_memory_device *mem_device) | |
216 | { | |
217 | pr_debug(PREFIX "Xen does not support memory hotremove\n"); | |
218 | ||
219 | return -ENOSYS; | |
220 | } | |
221 | ||
222 | static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data) | |
223 | { | |
224 | struct acpi_memory_device *mem_device; | |
225 | struct acpi_device *device; | |
226 | u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */ | |
227 | ||
228 | switch (event) { | |
229 | case ACPI_NOTIFY_BUS_CHECK: | |
230 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, | |
231 | "\nReceived BUS CHECK notification for device\n")); | |
df561f66 | 232 | fallthrough; |
ef92e7ca LJ |
233 | case ACPI_NOTIFY_DEVICE_CHECK: |
234 | if (event == ACPI_NOTIFY_DEVICE_CHECK) | |
235 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, | |
236 | "\nReceived DEVICE CHECK notification for device\n")); | |
237 | ||
238 | if (acpi_memory_get_device(handle, &mem_device)) { | |
239 | pr_err(PREFIX "Cannot find driver data\n"); | |
240 | break; | |
241 | } | |
242 | ||
243 | ost_code = ACPI_OST_SC_SUCCESS; | |
244 | break; | |
245 | ||
246 | case ACPI_NOTIFY_EJECT_REQUEST: | |
247 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, | |
248 | "\nReceived EJECT REQUEST notification for device\n")); | |
249 | ||
484400ff | 250 | acpi_scan_lock_acquire(); |
ef92e7ca | 251 | if (acpi_bus_get_device(handle, &device)) { |
484400ff | 252 | acpi_scan_lock_release(); |
ef92e7ca LJ |
253 | pr_err(PREFIX "Device doesn't exist\n"); |
254 | break; | |
255 | } | |
256 | mem_device = acpi_driver_data(device); | |
257 | if (!mem_device) { | |
484400ff | 258 | acpi_scan_lock_release(); |
ef92e7ca LJ |
259 | pr_err(PREFIX "Driver Data is NULL\n"); |
260 | break; | |
261 | } | |
262 | ||
263 | /* | |
264 | * TBD: implement acpi_memory_disable_device and invoke | |
265 | * acpi_bus_remove if Xen support hotremove in the future | |
266 | */ | |
267 | acpi_memory_disable_device(mem_device); | |
484400ff | 268 | acpi_scan_lock_release(); |
ef92e7ca LJ |
269 | break; |
270 | ||
271 | default: | |
272 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, | |
273 | "Unsupported event [0x%x]\n", event)); | |
274 | /* non-hotplug event; possibly handled by other handler */ | |
275 | return; | |
276 | } | |
277 | ||
700b8422 | 278 | (void) acpi_evaluate_ost(handle, event, ost_code, NULL); |
ef92e7ca LJ |
279 | return; |
280 | } | |
281 | ||
282 | static int xen_acpi_memory_device_add(struct acpi_device *device) | |
283 | { | |
284 | int result; | |
285 | struct acpi_memory_device *mem_device = NULL; | |
286 | ||
287 | ||
288 | if (!device) | |
289 | return -EINVAL; | |
290 | ||
291 | mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL); | |
292 | if (!mem_device) | |
293 | return -ENOMEM; | |
294 | ||
295 | INIT_LIST_HEAD(&mem_device->res_list); | |
296 | mem_device->device = device; | |
297 | sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME); | |
298 | sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS); | |
299 | device->driver_data = mem_device; | |
300 | ||
301 | /* Get the range from the _CRS */ | |
302 | result = acpi_memory_get_device_resources(mem_device); | |
303 | if (result) { | |
304 | kfree(mem_device); | |
305 | return result; | |
306 | } | |
307 | ||
308 | /* | |
309 | * For booting existed memory devices, early boot code has recognized | |
310 | * memory area by EFI/E820. If DSDT shows these memory devices on boot, | |
311 | * hotplug is not necessary for them. | |
312 | * For hot-added memory devices during runtime, it need hypercall to | |
313 | * Xen hypervisor to add memory. | |
314 | */ | |
315 | if (!acpi_hotmem_initialized) | |
316 | return 0; | |
317 | ||
318 | if (!acpi_memory_check_device(mem_device)) | |
319 | result = xen_acpi_memory_enable_device(mem_device); | |
320 | ||
321 | return result; | |
322 | } | |
323 | ||
77be36de | 324 | static int xen_acpi_memory_device_remove(struct acpi_device *device) |
ef92e7ca LJ |
325 | { |
326 | struct acpi_memory_device *mem_device = NULL; | |
327 | ||
328 | if (!device || !acpi_driver_data(device)) | |
329 | return -EINVAL; | |
330 | ||
331 | mem_device = acpi_driver_data(device); | |
332 | kfree(mem_device); | |
333 | ||
334 | return 0; | |
335 | } | |
336 | ||
337 | /* | |
338 | * Helper function to check for memory device | |
339 | */ | |
340 | static acpi_status is_memory_device(acpi_handle handle) | |
341 | { | |
342 | char *hardware_id; | |
343 | acpi_status status; | |
344 | struct acpi_device_info *info; | |
345 | ||
346 | status = acpi_get_object_info(handle, &info); | |
347 | if (ACPI_FAILURE(status)) | |
348 | return status; | |
349 | ||
350 | if (!(info->valid & ACPI_VALID_HID)) { | |
351 | kfree(info); | |
352 | return AE_ERROR; | |
353 | } | |
354 | ||
355 | hardware_id = info->hardware_id.string; | |
356 | if ((hardware_id == NULL) || | |
357 | (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID))) | |
358 | status = AE_ERROR; | |
359 | ||
360 | kfree(info); | |
361 | return status; | |
362 | } | |
363 | ||
364 | static acpi_status | |
365 | acpi_memory_register_notify_handler(acpi_handle handle, | |
366 | u32 level, void *ctxt, void **retv) | |
367 | { | |
368 | acpi_status status; | |
369 | ||
370 | status = is_memory_device(handle); | |
371 | if (ACPI_FAILURE(status)) | |
372 | return AE_OK; /* continue */ | |
373 | ||
374 | status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY, | |
375 | acpi_memory_device_notify, NULL); | |
376 | /* continue */ | |
377 | return AE_OK; | |
378 | } | |
379 | ||
380 | static acpi_status | |
381 | acpi_memory_deregister_notify_handler(acpi_handle handle, | |
382 | u32 level, void *ctxt, void **retv) | |
383 | { | |
384 | acpi_status status; | |
385 | ||
386 | status = is_memory_device(handle); | |
387 | if (ACPI_FAILURE(status)) | |
388 | return AE_OK; /* continue */ | |
389 | ||
390 | status = acpi_remove_notify_handler(handle, | |
391 | ACPI_SYSTEM_NOTIFY, | |
392 | acpi_memory_device_notify); | |
393 | ||
394 | return AE_OK; /* continue */ | |
395 | } | |
396 | ||
397 | static const struct acpi_device_id memory_device_ids[] = { | |
398 | {ACPI_MEMORY_DEVICE_HID, 0}, | |
399 | {"", 0}, | |
400 | }; | |
401 | MODULE_DEVICE_TABLE(acpi, memory_device_ids); | |
402 | ||
403 | static struct acpi_driver xen_acpi_memory_device_driver = { | |
404 | .name = "acpi_memhotplug", | |
405 | .class = ACPI_MEMORY_DEVICE_CLASS, | |
406 | .ids = memory_device_ids, | |
407 | .ops = { | |
408 | .add = xen_acpi_memory_device_add, | |
409 | .remove = xen_acpi_memory_device_remove, | |
410 | }, | |
411 | }; | |
412 | ||
413 | static int __init xen_acpi_memory_device_init(void) | |
414 | { | |
415 | int result; | |
416 | acpi_status status; | |
417 | ||
418 | if (!xen_initial_domain()) | |
419 | return -ENODEV; | |
420 | ||
421 | /* unregister the stub which only used to reserve driver space */ | |
422 | xen_stub_memory_device_exit(); | |
423 | ||
424 | result = acpi_bus_register_driver(&xen_acpi_memory_device_driver); | |
425 | if (result < 0) { | |
426 | xen_stub_memory_device_init(); | |
427 | return -ENODEV; | |
428 | } | |
429 | ||
430 | status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, | |
431 | ACPI_UINT32_MAX, | |
432 | acpi_memory_register_notify_handler, | |
433 | NULL, NULL, NULL); | |
434 | ||
435 | if (ACPI_FAILURE(status)) { | |
436 | pr_warn(PREFIX "walk_namespace failed\n"); | |
437 | acpi_bus_unregister_driver(&xen_acpi_memory_device_driver); | |
438 | xen_stub_memory_device_init(); | |
439 | return -ENODEV; | |
440 | } | |
441 | ||
442 | acpi_hotmem_initialized = true; | |
443 | return 0; | |
444 | } | |
445 | ||
446 | static void __exit xen_acpi_memory_device_exit(void) | |
447 | { | |
448 | acpi_status status; | |
449 | ||
450 | if (!xen_initial_domain()) | |
451 | return; | |
452 | ||
453 | status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, | |
454 | ACPI_UINT32_MAX, | |
455 | acpi_memory_deregister_notify_handler, | |
456 | NULL, NULL, NULL); | |
457 | if (ACPI_FAILURE(status)) | |
458 | pr_warn(PREFIX "walk_namespace failed\n"); | |
459 | ||
460 | acpi_bus_unregister_driver(&xen_acpi_memory_device_driver); | |
461 | ||
462 | /* | |
463 | * stub reserve space again to prevent any chance of native | |
464 | * driver loading. | |
465 | */ | |
466 | xen_stub_memory_device_init(); | |
467 | return; | |
468 | } | |
469 | ||
470 | module_init(xen_acpi_memory_device_init); | |
471 | module_exit(xen_acpi_memory_device_exit); | |
472 | ACPI_MODULE_NAME("xen-acpi-memhotplug"); | |
473 | MODULE_AUTHOR("Liu Jinsong <jinsong.liu@intel.com>"); | |
474 | MODULE_DESCRIPTION("Xen Hotplug Mem Driver"); | |
475 | MODULE_LICENSE("GPL"); |