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1/*
2 * Copyright (C) 2012 Intel Corporation
3 * Author: Liu Jinsong <jinsong.liu@intel.com>
4 * Author: Jiang Yunhong <yunhong.jiang@intel.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or (at
9 * your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
14 * NON INFRINGEMENT. See the GNU General Public License for more
15 * details.
16 */
17
18#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
19
20#include <linux/kernel.h>
21#include <linux/module.h>
22#include <linux/init.h>
23#include <linux/types.h>
24#include <linux/acpi.h>
25#include <xen/acpi.h>
26#include <xen/interface/platform.h>
27#include <asm/xen/hypercall.h>
28
29#define PREFIX "ACPI:xen_memory_hotplug:"
30
31struct acpi_memory_info {
32 struct list_head list;
33 u64 start_addr; /* Memory Range start physical addr */
34 u64 length; /* Memory Range length */
35 unsigned short caching; /* memory cache attribute */
36 unsigned short write_protect; /* memory read/write attribute */
37 /* copied from buffer getting from _CRS */
38 unsigned int enabled:1;
39};
40
41struct acpi_memory_device {
42 struct acpi_device *device;
43 struct list_head res_list;
44};
45
46static bool acpi_hotmem_initialized __read_mostly;
47
48static int xen_hotadd_memory(int pxm, struct acpi_memory_info *info)
49{
50 int rc;
51 struct xen_platform_op op;
52
53 op.cmd = XENPF_mem_hotadd;
54 op.u.mem_add.spfn = info->start_addr >> PAGE_SHIFT;
55 op.u.mem_add.epfn = (info->start_addr + info->length) >> PAGE_SHIFT;
56 op.u.mem_add.pxm = pxm;
57
58 rc = HYPERVISOR_dom0_op(&op);
59 if (rc)
60 pr_err(PREFIX "Xen Hotplug Memory Add failed on "
61 "0x%lx -> 0x%lx, _PXM: %d, error: %d\n",
62 (unsigned long)info->start_addr,
63 (unsigned long)(info->start_addr + info->length),
64 pxm, rc);
65
66 return rc;
67}
68
69static int xen_acpi_memory_enable_device(struct acpi_memory_device *mem_device)
70{
71 int pxm, result;
72 int num_enabled = 0;
73 struct acpi_memory_info *info;
74
75 if (!mem_device)
76 return -EINVAL;
77
78 pxm = xen_acpi_get_pxm(mem_device->device->handle);
79 if (pxm < 0)
80 return pxm;
81
82 list_for_each_entry(info, &mem_device->res_list, list) {
83 if (info->enabled) { /* just sanity check...*/
84 num_enabled++;
85 continue;
86 }
87
88 if (!info->length)
89 continue;
90
91 result = xen_hotadd_memory(pxm, info);
92 if (result)
93 continue;
94 info->enabled = 1;
95 num_enabled++;
96 }
97
98 if (!num_enabled)
99 return -ENODEV;
100
101 return 0;
102}
103
104static acpi_status
105acpi_memory_get_resource(struct acpi_resource *resource, void *context)
106{
107 struct acpi_memory_device *mem_device = context;
108 struct acpi_resource_address64 address64;
109 struct acpi_memory_info *info, *new;
110 acpi_status status;
111
112 status = acpi_resource_to_address64(resource, &address64);
113 if (ACPI_FAILURE(status) ||
114 (address64.resource_type != ACPI_MEMORY_RANGE))
115 return AE_OK;
116
117 list_for_each_entry(info, &mem_device->res_list, list) {
118 if ((info->caching == address64.info.mem.caching) &&
119 (info->write_protect == address64.info.mem.write_protect) &&
120 (info->start_addr + info->length == address64.address.minimum)) {
121 info->length += address64.address.address_length;
122 return AE_OK;
123 }
124 }
125
126 new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
127 if (!new)
128 return AE_ERROR;
129
130 INIT_LIST_HEAD(&new->list);
131 new->caching = address64.info.mem.caching;
132 new->write_protect = address64.info.mem.write_protect;
133 new->start_addr = address64.address.minimum;
134 new->length = address64.address.address_length;
135 list_add_tail(&new->list, &mem_device->res_list);
136
137 return AE_OK;
138}
139
140static int
141acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
142{
143 acpi_status status;
144 struct acpi_memory_info *info, *n;
145
146 if (!list_empty(&mem_device->res_list))
147 return 0;
148
149 status = acpi_walk_resources(mem_device->device->handle,
150 METHOD_NAME__CRS, acpi_memory_get_resource, mem_device);
151
152 if (ACPI_FAILURE(status)) {
153 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
154 kfree(info);
155 INIT_LIST_HEAD(&mem_device->res_list);
156 return -EINVAL;
157 }
158
159 return 0;
160}
161
162static int acpi_memory_get_device(acpi_handle handle,
163 struct acpi_memory_device **mem_device)
164{
165 struct acpi_device *device = NULL;
166 int result = 0;
167
168 acpi_scan_lock_acquire();
169
170 acpi_bus_get_device(handle, &device);
171 if (acpi_device_enumerated(device))
172 goto end;
173
174 /*
175 * Now add the notified device. This creates the acpi_device
176 * and invokes .add function
177 */
178 result = acpi_bus_scan(handle);
179 if (result) {
180 pr_warn(PREFIX "ACPI namespace scan failed\n");
181 result = -EINVAL;
182 goto out;
183 }
184 device = NULL;
185 acpi_bus_get_device(handle, &device);
186 if (!acpi_device_enumerated(device)) {
187 pr_warn(PREFIX "Missing device object\n");
188 result = -EINVAL;
189 goto out;
190 }
191
192end:
193 *mem_device = acpi_driver_data(device);
194 if (!(*mem_device)) {
195 pr_err(PREFIX "driver data not found\n");
196 result = -ENODEV;
197 goto out;
198 }
199
200out:
201 acpi_scan_lock_release();
202 return result;
203}
204
205static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
206{
207 unsigned long long current_status;
208
209 /* Get device present/absent information from the _STA */
210 if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle,
211 "_STA", NULL, &current_status)))
212 return -ENODEV;
213 /*
214 * Check for device status. Device should be
215 * present/enabled/functioning.
216 */
217 if (!((current_status & ACPI_STA_DEVICE_PRESENT)
218 && (current_status & ACPI_STA_DEVICE_ENABLED)
219 && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
220 return -ENODEV;
221
222 return 0;
223}
224
225static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
226{
227 pr_debug(PREFIX "Xen does not support memory hotremove\n");
228
229 return -ENOSYS;
230}
231
232static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
233{
234 struct acpi_memory_device *mem_device;
235 struct acpi_device *device;
236 u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
237
238 switch (event) {
239 case ACPI_NOTIFY_BUS_CHECK:
240 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
241 "\nReceived BUS CHECK notification for device\n"));
242 /* Fall Through */
243 case ACPI_NOTIFY_DEVICE_CHECK:
244 if (event == ACPI_NOTIFY_DEVICE_CHECK)
245 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
246 "\nReceived DEVICE CHECK notification for device\n"));
247
248 if (acpi_memory_get_device(handle, &mem_device)) {
249 pr_err(PREFIX "Cannot find driver data\n");
250 break;
251 }
252
253 ost_code = ACPI_OST_SC_SUCCESS;
254 break;
255
256 case ACPI_NOTIFY_EJECT_REQUEST:
257 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
258 "\nReceived EJECT REQUEST notification for device\n"));
259
260 acpi_scan_lock_acquire();
261 if (acpi_bus_get_device(handle, &device)) {
262 acpi_scan_lock_release();
263 pr_err(PREFIX "Device doesn't exist\n");
264 break;
265 }
266 mem_device = acpi_driver_data(device);
267 if (!mem_device) {
268 acpi_scan_lock_release();
269 pr_err(PREFIX "Driver Data is NULL\n");
270 break;
271 }
272
273 /*
274 * TBD: implement acpi_memory_disable_device and invoke
275 * acpi_bus_remove if Xen support hotremove in the future
276 */
277 acpi_memory_disable_device(mem_device);
278 acpi_scan_lock_release();
279 break;
280
281 default:
282 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
283 "Unsupported event [0x%x]\n", event));
284 /* non-hotplug event; possibly handled by other handler */
285 return;
286 }
287
288 (void) acpi_evaluate_ost(handle, event, ost_code, NULL);
289 return;
290}
291
292static int xen_acpi_memory_device_add(struct acpi_device *device)
293{
294 int result;
295 struct acpi_memory_device *mem_device = NULL;
296
297
298 if (!device)
299 return -EINVAL;
300
301 mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
302 if (!mem_device)
303 return -ENOMEM;
304
305 INIT_LIST_HEAD(&mem_device->res_list);
306 mem_device->device = device;
307 sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
308 sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
309 device->driver_data = mem_device;
310
311 /* Get the range from the _CRS */
312 result = acpi_memory_get_device_resources(mem_device);
313 if (result) {
314 kfree(mem_device);
315 return result;
316 }
317
318 /*
319 * For booting existed memory devices, early boot code has recognized
320 * memory area by EFI/E820. If DSDT shows these memory devices on boot,
321 * hotplug is not necessary for them.
322 * For hot-added memory devices during runtime, it need hypercall to
323 * Xen hypervisor to add memory.
324 */
325 if (!acpi_hotmem_initialized)
326 return 0;
327
328 if (!acpi_memory_check_device(mem_device))
329 result = xen_acpi_memory_enable_device(mem_device);
330
331 return result;
332}
333
334static int xen_acpi_memory_device_remove(struct acpi_device *device)
335{
336 struct acpi_memory_device *mem_device = NULL;
337
338 if (!device || !acpi_driver_data(device))
339 return -EINVAL;
340
341 mem_device = acpi_driver_data(device);
342 kfree(mem_device);
343
344 return 0;
345}
346
347/*
348 * Helper function to check for memory device
349 */
350static acpi_status is_memory_device(acpi_handle handle)
351{
352 char *hardware_id;
353 acpi_status status;
354 struct acpi_device_info *info;
355
356 status = acpi_get_object_info(handle, &info);
357 if (ACPI_FAILURE(status))
358 return status;
359
360 if (!(info->valid & ACPI_VALID_HID)) {
361 kfree(info);
362 return AE_ERROR;
363 }
364
365 hardware_id = info->hardware_id.string;
366 if ((hardware_id == NULL) ||
367 (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
368 status = AE_ERROR;
369
370 kfree(info);
371 return status;
372}
373
374static acpi_status
375acpi_memory_register_notify_handler(acpi_handle handle,
376 u32 level, void *ctxt, void **retv)
377{
378 acpi_status status;
379
380 status = is_memory_device(handle);
381 if (ACPI_FAILURE(status))
382 return AE_OK; /* continue */
383
384 status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
385 acpi_memory_device_notify, NULL);
386 /* continue */
387 return AE_OK;
388}
389
390static acpi_status
391acpi_memory_deregister_notify_handler(acpi_handle handle,
392 u32 level, void *ctxt, void **retv)
393{
394 acpi_status status;
395
396 status = is_memory_device(handle);
397 if (ACPI_FAILURE(status))
398 return AE_OK; /* continue */
399
400 status = acpi_remove_notify_handler(handle,
401 ACPI_SYSTEM_NOTIFY,
402 acpi_memory_device_notify);
403
404 return AE_OK; /* continue */
405}
406
407static const struct acpi_device_id memory_device_ids[] = {
408 {ACPI_MEMORY_DEVICE_HID, 0},
409 {"", 0},
410};
411MODULE_DEVICE_TABLE(acpi, memory_device_ids);
412
413static struct acpi_driver xen_acpi_memory_device_driver = {
414 .name = "acpi_memhotplug",
415 .class = ACPI_MEMORY_DEVICE_CLASS,
416 .ids = memory_device_ids,
417 .ops = {
418 .add = xen_acpi_memory_device_add,
419 .remove = xen_acpi_memory_device_remove,
420 },
421};
422
423static int __init xen_acpi_memory_device_init(void)
424{
425 int result;
426 acpi_status status;
427
428 if (!xen_initial_domain())
429 return -ENODEV;
430
431 /* unregister the stub which only used to reserve driver space */
432 xen_stub_memory_device_exit();
433
434 result = acpi_bus_register_driver(&xen_acpi_memory_device_driver);
435 if (result < 0) {
436 xen_stub_memory_device_init();
437 return -ENODEV;
438 }
439
440 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
441 ACPI_UINT32_MAX,
442 acpi_memory_register_notify_handler,
443 NULL, NULL, NULL);
444
445 if (ACPI_FAILURE(status)) {
446 pr_warn(PREFIX "walk_namespace failed\n");
447 acpi_bus_unregister_driver(&xen_acpi_memory_device_driver);
448 xen_stub_memory_device_init();
449 return -ENODEV;
450 }
451
452 acpi_hotmem_initialized = true;
453 return 0;
454}
455
456static void __exit xen_acpi_memory_device_exit(void)
457{
458 acpi_status status;
459
460 if (!xen_initial_domain())
461 return;
462
463 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
464 ACPI_UINT32_MAX,
465 acpi_memory_deregister_notify_handler,
466 NULL, NULL, NULL);
467 if (ACPI_FAILURE(status))
468 pr_warn(PREFIX "walk_namespace failed\n");
469
470 acpi_bus_unregister_driver(&xen_acpi_memory_device_driver);
471
472 /*
473 * stub reserve space again to prevent any chance of native
474 * driver loading.
475 */
476 xen_stub_memory_device_init();
477 return;
478}
479
480module_init(xen_acpi_memory_device_init);
481module_exit(xen_acpi_memory_device_exit);
482ACPI_MODULE_NAME("xen-acpi-memhotplug");
483MODULE_AUTHOR("Liu Jinsong <jinsong.liu@intel.com>");
484MODULE_DESCRIPTION("Xen Hotplug Mem Driver");
485MODULE_LICENSE("GPL");
486

Warning: That file was not part of the compilation database. It may have many parsing errors.