summaryrefslogtreecommitdiffstats
path: root/drivers/xen/xen-acpi-memhotplug.c
blob: 2c3759ac10f07bd6ffe804f64b1bb2a84b047db5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
/*
 * Copyright (C) 2012 Intel Corporation
 *    Author: Liu Jinsong <jinsong.liu@intel.com>
 *    Author: Jiang Yunhong <yunhong.jiang@intel.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 * NON INFRINGEMENT.  See the GNU General Public License for more
 * details.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/acpi.h>
#include <acpi/acpi_drivers.h>
#include <xen/acpi.h>
#include <xen/interface/platform.h>
#include <asm/xen/hypercall.h>

#define PREFIX "ACPI:xen_memory_hotplug:"

struct acpi_memory_info {
	struct list_head list;
	u64 start_addr;		/* Memory Range start physical addr */
	u64 length;		/* Memory Range length */
	unsigned short caching;	/* memory cache attribute */
	unsigned short write_protect;	/* memory read/write attribute */
				/* copied from buffer getting from _CRS */
	unsigned int enabled:1;
};

struct acpi_memory_device {
	struct acpi_device *device;
	struct list_head res_list;
};

static bool acpi_hotmem_initialized __read_mostly;

static int xen_hotadd_memory(int pxm, struct acpi_memory_info *info)
{
	int rc;
	struct xen_platform_op op;

	op.cmd = XENPF_mem_hotadd;
	op.u.mem_add.spfn = info->start_addr >> PAGE_SHIFT;
	op.u.mem_add.epfn = (info->start_addr + info->length) >> PAGE_SHIFT;
	op.u.mem_add.pxm = pxm;

	rc = HYPERVISOR_dom0_op(&op);
	if (rc)
		pr_err(PREFIX "Xen Hotplug Memory Add failed on "
			"0x%lx -> 0x%lx, _PXM: %d, error: %d\n",
			(unsigned long)info->start_addr,
			(unsigned long)(info->start_addr + info->length),
			pxm, rc);

	return rc;
}

static int xen_acpi_get_pxm(acpi_handle h)
{
	unsigned long long pxm;
	acpi_status status;
	acpi_handle handle;
	acpi_handle phandle = h;

	do {
		handle = phandle;
		status = acpi_evaluate_integer(handle, "_PXM", NULL, &pxm);
		if (ACPI_SUCCESS(status))
			return pxm;
		status = acpi_get_parent(handle, &phandle);
	} while (ACPI_SUCCESS(status));

	return -ENXIO;
}

static int xen_acpi_memory_enable_device(struct acpi_memory_device *mem_device)
{
	int pxm, result;
	int num_enabled = 0;
	struct acpi_memory_info *info;

	if (!mem_device)
		return -EINVAL;

	pxm = xen_acpi_get_pxm(mem_device->device->handle);
	if (pxm < 0)
		return pxm;

	list_for_each_entry(info, &mem_device->res_list, list) {
		if (info->enabled) { /* just sanity check...*/
			num_enabled++;
			continue;
		}

		if (!info->length)
			continue;

		result = xen_hotadd_memory(pxm, info);
		if (result)
			continue;
		info->enabled = 1;
		num_enabled++;
	}

	if (!num_enabled)
		return -ENODEV;

	return 0;
}

static acpi_status
acpi_memory_get_resource(struct acpi_resource *resource, void *context)
{
	struct acpi_memory_device *mem_device = context;
	struct acpi_resource_address64 address64;
	struct acpi_memory_info *info, *new;
	acpi_status status;

	status = acpi_resource_to_address64(resource, &address64);
	if (ACPI_FAILURE(status) ||
	    (address64.resource_type != ACPI_MEMORY_RANGE))
		return AE_OK;

	list_for_each_entry(info, &mem_device->res_list, list) {
		if ((info->caching == address64.info.mem.caching) &&
		    (info->write_protect == address64.info.mem.write_protect) &&
		    (info->start_addr + info->length == address64.minimum)) {
			info->length += address64.address_length;
			return AE_OK;
		}
	}

	new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
	if (!new)
		return AE_ERROR;

	INIT_LIST_HEAD(&new->list);
	new->caching = address64.info.mem.caching;
	new->write_protect = address64.info.mem.write_protect;
	new->start_addr = address64.minimum;
	new->length = address64.address_length;
	list_add_tail(&new->list, &mem_device->res_list);

	return AE_OK;
}

static int
acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
{
	acpi_status status;
	struct acpi_memory_info *info, *n;

	if (!list_empty(&mem_device->res_list))
		return 0;

	status = acpi_walk_resources(mem_device->device->handle,
		METHOD_NAME__CRS, acpi_memory_get_resource, mem_device);

	if (ACPI_FAILURE(status)) {
		list_for_each_entry_safe(info, n, &mem_device->res_list, list)
			kfree(info);
		INIT_LIST_HEAD(&mem_device->res_list);
		return -EINVAL;
	}

	return 0;
}

static int
acpi_memory_get_device(acpi_handle handle,
		       struct acpi_memory_device **mem_device)
{
	acpi_status status;
	acpi_handle phandle;
	struct acpi_device *device = NULL;
	struct acpi_device *pdevice = NULL;
	int result;

	if (!acpi_bus_get_device(handle, &device) && device)
		goto end;

	status = acpi_get_parent(handle, &phandle);
	if (ACPI_FAILURE(status)) {
		pr_warn(PREFIX "Cannot find acpi parent\n");
		return -EINVAL;
	}

	/* Get the parent device */
	result = acpi_bus_get_device(phandle, &pdevice);
	if (result) {
		pr_warn(PREFIX "Cannot get acpi bus device\n");
		return -EINVAL;
	}

	/*
	 * Now add the notified device.  This creates the acpi_device
	 * and invokes .add function
	 */
	result = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
	if (result) {
		pr_warn(PREFIX "Cannot add acpi bus\n");
		return -EINVAL;
	}

end:
	*mem_device = acpi_driver_data(device);
	if (!(*mem_device)) {
		pr_err(PREFIX "Driver data not found\n");
		return -ENODEV;
	}

	return 0;
}

static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
{
	unsigned long long current_status;

	/* Get device present/absent information from the _STA */
	if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle,
				"_STA", NULL, &current_status)))
		return -ENODEV;
	/*
	 * Check for device status. Device should be
	 * present/enabled/functioning.
	 */
	if (!((current_status & ACPI_STA_DEVICE_PRESENT)
	      && (current_status & ACPI_STA_DEVICE_ENABLED)
	      && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
		return -ENODEV;

	return 0;
}

static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
{
	pr_debug(PREFIX "Xen does not support memory hotremove\n");

	return -ENOSYS;
}

static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
{
	struct acpi_memory_device *mem_device;
	struct acpi_device *device;
	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */

	switch (event) {
	case ACPI_NOTIFY_BUS_CHECK:
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
			"\nReceived BUS CHECK notification for device\n"));
		/* Fall Through */
	case ACPI_NOTIFY_DEVICE_CHECK:
		if (event == ACPI_NOTIFY_DEVICE_CHECK)
			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
			"\nReceived DEVICE CHECK notification for device\n"));

		if (acpi_memory_get_device(handle, &mem_device)) {
			pr_err(PREFIX "Cannot find driver data\n");
			break;
		}

		ost_code = ACPI_OST_SC_SUCCESS;
		break;

	case ACPI_NOTIFY_EJECT_REQUEST:
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
			"\nReceived EJECT REQUEST notification for device\n"));

		if (acpi_bus_get_device(handle, &device)) {
			pr_err(PREFIX "Device doesn't exist\n");
			break;
		}
		mem_device = acpi_driver_data(device);
		if (!mem_device) {
			pr_err(PREFIX "Driver Data is NULL\n");
			break;
		}

		/*
		 * TBD: implement acpi_memory_disable_device and invoke
		 * acpi_bus_remove if Xen support hotremove in the future
		 */
		acpi_memory_disable_device(mem_device);
		break;

	default:
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
				  "Unsupported event [0x%x]\n", event));
		/* non-hotplug event; possibly handled by other handler */
		return;
	}

	(void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
	return;
}

static int xen_acpi_memory_device_add(struct acpi_device *device)
{
	int result;
	struct acpi_memory_device *mem_device = NULL;


	if (!device)
		return -EINVAL;

	mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
	if (!mem_device)
		return -ENOMEM;

	INIT_LIST_HEAD(&mem_device->res_list);
	mem_device->device = device;
	sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
	sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
	device->driver_data = mem_device;

	/* Get the range from the _CRS */
	result = acpi_memory_get_device_resources(mem_device);
	if (result) {
		kfree(mem_device);
		return result;
	}

	/*
	 * For booting existed memory devices, early boot code has recognized
	 * memory area by EFI/E820. If DSDT shows these memory devices on boot,
	 * hotplug is not necessary for them.
	 * For hot-added memory devices during runtime, it need hypercall to
	 * Xen hypervisor to add memory.
	 */
	if (!acpi_hotmem_initialized)
		return 0;

	if (!acpi_memory_check_device(mem_device))
		result = xen_acpi_memory_enable_device(mem_device);

	return result;
}

static int xen_acpi_memory_device_remove(struct acpi_device *device, int type)
{
	struct acpi_memory_device *mem_device = NULL;

	if (!device || !acpi_driver_data(device))
		return -EINVAL;

	mem_device = acpi_driver_data(device);
	kfree(mem_device);

	return 0;
}

/*
 * Helper function to check for memory device
 */
static acpi_status is_memory_device(acpi_handle handle)
{
	char *hardware_id;
	acpi_status status;
	struct acpi_device_info *info;

	status = acpi_get_object_info(handle, &info);
	if (ACPI_FAILURE(status))
		return status;

	if (!(info->valid & ACPI_VALID_HID)) {
		kfree(info);
		return AE_ERROR;
	}

	hardware_id = info->hardware_id.string;
	if ((hardware_id == NULL) ||
	    (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
		status = AE_ERROR;

	kfree(info);
	return status;
}

static acpi_status
acpi_memory_register_notify_handler(acpi_handle handle,
				    u32 level, void *ctxt, void **retv)
{
	acpi_status status;

	status = is_memory_device(handle);
	if (ACPI_FAILURE(status))
		return AE_OK;	/* continue */

	status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
					     acpi_memory_device_notify, NULL);
	/* continue */
	return AE_OK;
}

static acpi_status
acpi_memory_deregister_notify_handler(acpi_handle handle,
				      u32 level, void *ctxt, void **retv)
{
	acpi_status status;

	status = is_memory_device(handle);
	if (ACPI_FAILURE(status))
		return AE_OK;	/* continue */

	status = acpi_remove_notify_handler(handle,
					    ACPI_SYSTEM_NOTIFY,
					    acpi_memory_device_notify);

	return AE_OK;	/* continue */
}

static const struct acpi_device_id memory_device_ids[] = {
	{ACPI_MEMORY_DEVICE_HID, 0},
	{"", 0},
};
MODULE_DEVICE_TABLE(acpi, memory_device_ids);

static struct acpi_driver xen_acpi_memory_device_driver = {
	.name = "acpi_memhotplug",
	.class = ACPI_MEMORY_DEVICE_CLASS,
	.ids = memory_device_ids,
	.ops = {
		.add = xen_acpi_memory_device_add,
		.remove = xen_acpi_memory_device_remove,
		},
};

static int __init xen_acpi_memory_device_init(void)
{
	int result;
	acpi_status status;

	if (!xen_initial_domain())
		return -ENODEV;

	/* unregister the stub which only used to reserve driver space */
	xen_stub_memory_device_exit();

	result = acpi_bus_register_driver(&xen_acpi_memory_device_driver);
	if (result < 0) {
		xen_stub_memory_device_init();
		return -ENODEV;
	}

	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
				     ACPI_UINT32_MAX,
				     acpi_memory_register_notify_handler,
				     NULL, NULL, NULL);

	if (ACPI_FAILURE(status)) {
		pr_warn(PREFIX "walk_namespace failed\n");
		acpi_bus_unregister_driver(&xen_acpi_memory_device_driver);
		xen_stub_memory_device_init();
		return -ENODEV;
	}

	acpi_hotmem_initialized = true;
	return 0;
}

static void __exit xen_acpi_memory_device_exit(void)
{
	acpi_status status;

	if (!xen_initial_domain())
		return;

	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
				     ACPI_UINT32_MAX,
				     acpi_memory_deregister_notify_handler,
				     NULL, NULL, NULL);
	if (ACPI_FAILURE(status))
		pr_warn(PREFIX "walk_namespace failed\n");

	acpi_bus_unregister_driver(&xen_acpi_memory_device_driver);

	/*
	 * stub reserve space again to prevent any chance of native
	 * driver loading.
	 */
	xen_stub_memory_device_init();
	return;
}

module_init(xen_acpi_memory_device_init);
module_exit(xen_acpi_memory_device_exit);
ACPI_MODULE_NAME("xen-acpi-memhotplug");
MODULE_AUTHOR("Liu Jinsong <jinsong.liu@intel.com>");
MODULE_DESCRIPTION("Xen Hotplug Mem Driver");
MODULE_LICENSE("GPL");