summaryrefslogtreecommitdiffstats
path: root/drivers/xen/mcelog.c
blob: 72e87d2f1929724f89659cd5b922fa7fe51158ed (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
/******************************************************************************
 * mcelog.c
 * Driver for receiving and transferring machine check error infomation
 *
 * Copyright (c) 2012 Intel Corporation
 * Author: Liu, Jinsong <jinsong.liu@intel.com>
 * Author: Jiang, Yunhong <yunhong.jiang@intel.com>
 * Author: Ke, Liping <liping.ke@intel.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation; or, when distributed
 * separately from the Linux kernel or incorporated into other
 * software packages, subject to the following license:
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this source file (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy, modify,
 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#include <linux/init.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/miscdevice.h>
#include <linux/uaccess.h>
#include <linux/capability.h>

#include <xen/interface/xen.h>
#include <xen/events.h>
#include <xen/interface/vcpu.h>
#include <xen/xen.h>
#include <asm/xen/hypercall.h>
#include <asm/xen/hypervisor.h>

#define XEN_MCELOG "xen_mcelog: "

static struct mc_info g_mi;
static struct mcinfo_logical_cpu *g_physinfo;
static uint32_t ncpus;

static DEFINE_SPINLOCK(mcelog_lock);

static struct xen_mce_log xen_mcelog = {
	.signature	= XEN_MCE_LOG_SIGNATURE,
	.len		= XEN_MCE_LOG_LEN,
	.recordlen	= sizeof(struct xen_mce),
};

static DEFINE_SPINLOCK(xen_mce_chrdev_state_lock);
static int xen_mce_chrdev_open_count;	/* #times opened */
static int xen_mce_chrdev_open_exclu;	/* already open exclusive? */

static int xen_mce_chrdev_open(struct inode *inode, struct file *file)
{
	spin_lock(&xen_mce_chrdev_state_lock);

	if (xen_mce_chrdev_open_exclu ||
	    (xen_mce_chrdev_open_count && (file->f_flags & O_EXCL))) {
		spin_unlock(&xen_mce_chrdev_state_lock);

		return -EBUSY;
	}

	if (file->f_flags & O_EXCL)
		xen_mce_chrdev_open_exclu = 1;
	xen_mce_chrdev_open_count++;

	spin_unlock(&xen_mce_chrdev_state_lock);

	return nonseekable_open(inode, file);
}

static int xen_mce_chrdev_release(struct inode *inode, struct file *file)
{
	spin_lock(&xen_mce_chrdev_state_lock);

	xen_mce_chrdev_open_count--;
	xen_mce_chrdev_open_exclu = 0;

	spin_unlock(&xen_mce_chrdev_state_lock);

	return 0;
}

static ssize_t xen_mce_chrdev_read(struct file *filp, char __user *ubuf,
				size_t usize, loff_t *off)
{
	char __user *buf = ubuf;
	unsigned num;
	int i, err;

	spin_lock(&mcelog_lock);

	num = xen_mcelog.next;

	/* Only supports full reads right now */
	err = -EINVAL;
	if (*off != 0 || usize < XEN_MCE_LOG_LEN*sizeof(struct xen_mce))
		goto out;

	err = 0;
	for (i = 0; i < num; i++) {
		struct xen_mce *m = &xen_mcelog.entry[i];

		err |= copy_to_user(buf, m, sizeof(*m));
		buf += sizeof(*m);
	}

	memset(xen_mcelog.entry, 0, num * sizeof(struct xen_mce));
	xen_mcelog.next = 0;

	if (err)
		err = -EFAULT;

out:
	spin_unlock(&mcelog_lock);

	return err ? err : buf - ubuf;
}

static long xen_mce_chrdev_ioctl(struct file *f, unsigned int cmd,
				unsigned long arg)
{
	int __user *p = (int __user *)arg;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	switch (cmd) {
	case MCE_GET_RECORD_LEN:
		return put_user(sizeof(struct xen_mce), p);
	case MCE_GET_LOG_LEN:
		return put_user(XEN_MCE_LOG_LEN, p);
	case MCE_GETCLEAR_FLAGS: {
		unsigned flags;

		do {
			flags = xen_mcelog.flags;
		} while (cmpxchg(&xen_mcelog.flags, flags, 0) != flags);

		return put_user(flags, p);
	}
	default:
		return -ENOTTY;
	}
}

static const struct file_operations xen_mce_chrdev_ops = {
	.open			= xen_mce_chrdev_open,
	.release		= xen_mce_chrdev_release,
	.read			= xen_mce_chrdev_read,
	.unlocked_ioctl		= xen_mce_chrdev_ioctl,
	.llseek			= no_llseek,
};

static struct miscdevice xen_mce_chrdev_device = {
	MISC_MCELOG_MINOR,
	"mcelog",
	&xen_mce_chrdev_ops,
};

/*
 * Caller should hold the mcelog_lock
 */
static void xen_mce_log(struct xen_mce *mce)
{
	unsigned entry;

	entry = xen_mcelog.next;

	/*
	 * When the buffer fills up discard new entries.
	 * Assume that the earlier errors are the more
	 * interesting ones:
	 */
	if (entry >= XEN_MCE_LOG_LEN) {
		set_bit(XEN_MCE_OVERFLOW,
			(unsigned long *)&xen_mcelog.flags);
		return;
	}

	memcpy(xen_mcelog.entry + entry, mce, sizeof(struct xen_mce));

	xen_mcelog.next++;
}

static int convert_log(struct mc_info *mi)
{
	struct mcinfo_common *mic;
	struct mcinfo_global *mc_global;
	struct mcinfo_bank *mc_bank;
	struct xen_mce m;
	uint32_t i;

	mic = NULL;
	x86_mcinfo_lookup(&mic, mi, MC_TYPE_GLOBAL);
	if (unlikely(!mic)) {
		pr_warning(XEN_MCELOG "Failed to find global error info\n");
		return -ENODEV;
	}

	memset(&m, 0, sizeof(struct xen_mce));

	mc_global = (struct mcinfo_global *)mic;
	m.mcgstatus = mc_global->mc_gstatus;
	m.apicid = mc_global->mc_apicid;

	for (i = 0; i < ncpus; i++)
		if (g_physinfo[i].mc_apicid == m.apicid)
			break;
	if (unlikely(i == ncpus)) {
		pr_warning(XEN_MCELOG "Failed to match cpu with apicid %d\n",
			   m.apicid);
		return -ENODEV;
	}

	m.socketid = g_physinfo[i].mc_chipid;
	m.cpu = m.extcpu = g_physinfo[i].mc_cpunr;
	m.cpuvendor = (__u8)g_physinfo[i].mc_vendor;
	m.mcgcap = g_physinfo[i].mc_msrvalues[__MC_MSR_MCGCAP].value;

	mic = NULL;
	x86_mcinfo_lookup(&mic, mi, MC_TYPE_BANK);
	if (unlikely(!mic)) {
		pr_warning(XEN_MCELOG "Fail to find bank error info\n");
		return -ENODEV;
	}

	do {
		if ((!mic) || (mic->size == 0) ||
		    (mic->type != MC_TYPE_GLOBAL   &&
		     mic->type != MC_TYPE_BANK     &&
		     mic->type != MC_TYPE_EXTENDED &&
		     mic->type != MC_TYPE_RECOVERY))
			break;

		if (mic->type == MC_TYPE_BANK) {
			mc_bank = (struct mcinfo_bank *)mic;
			m.misc = mc_bank->mc_misc;
			m.status = mc_bank->mc_status;
			m.addr = mc_bank->mc_addr;
			m.tsc = mc_bank->mc_tsc;
			m.bank = mc_bank->mc_bank;
			m.finished = 1;
			/*log this record*/
			xen_mce_log(&m);
		}
		mic = x86_mcinfo_next(mic);
	} while (1);

	return 0;
}

static int mc_queue_handle(uint32_t flags)
{
	struct xen_mc mc_op;
	int ret = 0;

	mc_op.cmd = XEN_MC_fetch;
	mc_op.interface_version = XEN_MCA_INTERFACE_VERSION;
	set_xen_guest_handle(mc_op.u.mc_fetch.data, &g_mi);
	do {
		mc_op.u.mc_fetch.flags = flags;
		ret = HYPERVISOR_mca(&mc_op);
		if (ret) {
			pr_err(XEN_MCELOG "Failed to fetch %s error log\n",
			       (flags == XEN_MC_URGENT) ?
			       "urgnet" : "nonurgent");
			break;
		}

		if (mc_op.u.mc_fetch.flags & XEN_MC_NODATA ||
		    mc_op.u.mc_fetch.flags & XEN_MC_FETCHFAILED)
			break;
		else {
			ret = convert_log(&g_mi);
			if (ret)
				pr_warning(XEN_MCELOG
					   "Failed to convert this error log, "
					   "continue acking it anyway\n");

			mc_op.u.mc_fetch.flags = flags | XEN_MC_ACK;
			ret = HYPERVISOR_mca(&mc_op);
			if (ret) {
				pr_err(XEN_MCELOG
				       "Failed to ack previous error log\n");
				break;
			}
		}
	} while (1);

	return ret;
}

/* virq handler for machine check error info*/
static irqreturn_t xen_mce_interrupt(int irq, void *dev_id)
{
	int err;
	unsigned long tmp;

	spin_lock_irqsave(&mcelog_lock, tmp);

	/* urgent mc_info */
	err = mc_queue_handle(XEN_MC_URGENT);
	if (err)
		pr_err(XEN_MCELOG
		       "Failed to handle urgent mc_info queue, "
		       "continue handling nonurgent mc_info queue anyway.\n");

	/* nonurgent mc_info */
	err = mc_queue_handle(XEN_MC_NONURGENT);
	if (err)
		pr_err(XEN_MCELOG
		       "Failed to handle nonurgent mc_info queue.\n");

	spin_unlock_irqrestore(&mcelog_lock, tmp);

	return IRQ_HANDLED;
}

static int bind_virq_for_mce(void)
{
	int ret;
	struct xen_mc mc_op;

	memset(&mc_op, 0, sizeof(struct xen_mc));

	/* Fetch physical CPU Numbers */
	mc_op.cmd = XEN_MC_physcpuinfo;
	mc_op.interface_version = XEN_MCA_INTERFACE_VERSION;
	set_xen_guest_handle(mc_op.u.mc_physcpuinfo.info, g_physinfo);
	ret = HYPERVISOR_mca(&mc_op);
	if (ret) {
		pr_err(XEN_MCELOG "Failed to get CPU numbers\n");
		return ret;
	}

	/* Fetch each CPU Physical Info for later reference*/
	ncpus = mc_op.u.mc_physcpuinfo.ncpus;
	g_physinfo = kcalloc(ncpus, sizeof(struct mcinfo_logical_cpu),
			     GFP_KERNEL);
	if (!g_physinfo)
		return -ENOMEM;
	set_xen_guest_handle(mc_op.u.mc_physcpuinfo.info, g_physinfo);
	ret = HYPERVISOR_mca(&mc_op);
	if (ret) {
		pr_err(XEN_MCELOG "Failed to get CPU info\n");
		kfree(g_physinfo);
		return ret;
	}

	ret  = bind_virq_to_irqhandler(VIRQ_MCA, 0,
				       xen_mce_interrupt, 0, "mce", NULL);
	if (ret < 0) {
		pr_err(XEN_MCELOG "Failed to bind virq\n");
		kfree(g_physinfo);
		return ret;
	}

	return 0;
}

static int __init xen_late_init_mcelog(void)
{
	/* Only DOM0 is responsible for MCE logging */
	if (xen_initial_domain()) {
		/* register character device /dev/mcelog for xen mcelog */
		if (misc_register(&xen_mce_chrdev_device))
			return -ENODEV;
		return bind_virq_for_mce();
	}

	return -ENODEV;
}
device_initcall(xen_late_init_mcelog);
OpenPOWER on IntegriCloud