blob: a493c7315e94007f2a621f037e83a34bce7e7a47 [file] [log] [blame]
Liu, Jinsongcef12ee2012-06-07 19:56:51 +08001/******************************************************************************
2 * mcelog.c
3 * Driver for receiving and transferring machine check error infomation
4 *
5 * Copyright (c) 2012 Intel Corporation
6 * Author: Liu, Jinsong <jinsong.liu@intel.com>
7 * Author: Jiang, Yunhong <yunhong.jiang@intel.com>
8 * Author: Ke, Liping <liping.ke@intel.com>
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License version 2
12 * as published by the Free Software Foundation; or, when distributed
13 * separately from the Linux kernel or incorporated into other
14 * software packages, subject to the following license:
15 *
16 * Permission is hereby granted, free of charge, to any person obtaining a copy
17 * of this source file (the "Software"), to deal in the Software without
18 * restriction, including without limitation the rights to use, copy, modify,
19 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
20 * and to permit persons to whom the Software is furnished to do so, subject to
21 * the following conditions:
22 *
23 * The above copyright notice and this permission notice shall be included in
24 * all copies or substantial portions of the Software.
25 *
26 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
27 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
28 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
29 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
30 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
31 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
32 * IN THE SOFTWARE.
33 */
34
Joe Perches283c0972013-06-28 03:21:41 -070035#define pr_fmt(fmt) "xen_mcelog: " fmt
36
Liu, Jinsongcef12ee2012-06-07 19:56:51 +080037#include <linux/init.h>
38#include <linux/types.h>
39#include <linux/kernel.h>
40#include <linux/slab.h>
41#include <linux/fs.h>
42#include <linux/device.h>
43#include <linux/miscdevice.h>
44#include <linux/uaccess.h>
45#include <linux/capability.h>
Liu, Jinsonga867e5d2012-06-15 09:03:39 +080046#include <linux/poll.h>
47#include <linux/sched.h>
Liu, Jinsongcef12ee2012-06-07 19:56:51 +080048
49#include <xen/interface/xen.h>
50#include <xen/events.h>
51#include <xen/interface/vcpu.h>
52#include <xen/xen.h>
53#include <asm/xen/hypercall.h>
54#include <asm/xen/hypervisor.h>
55
Liu, Jinsongcef12ee2012-06-07 19:56:51 +080056static struct mc_info g_mi;
57static struct mcinfo_logical_cpu *g_physinfo;
58static uint32_t ncpus;
59
Liu, Jinsong1b2a0552012-06-12 23:11:16 +080060static DEFINE_MUTEX(mcelog_lock);
Liu, Jinsongcef12ee2012-06-07 19:56:51 +080061
62static struct xen_mce_log xen_mcelog = {
63 .signature = XEN_MCE_LOG_SIGNATURE,
64 .len = XEN_MCE_LOG_LEN,
65 .recordlen = sizeof(struct xen_mce),
66};
67
68static DEFINE_SPINLOCK(xen_mce_chrdev_state_lock);
69static int xen_mce_chrdev_open_count; /* #times opened */
70static int xen_mce_chrdev_open_exclu; /* already open exclusive? */
71
Liu, Jinsonga867e5d2012-06-15 09:03:39 +080072static DECLARE_WAIT_QUEUE_HEAD(xen_mce_chrdev_wait);
73
Liu, Jinsongcef12ee2012-06-07 19:56:51 +080074static int xen_mce_chrdev_open(struct inode *inode, struct file *file)
75{
76 spin_lock(&xen_mce_chrdev_state_lock);
77
78 if (xen_mce_chrdev_open_exclu ||
79 (xen_mce_chrdev_open_count && (file->f_flags & O_EXCL))) {
80 spin_unlock(&xen_mce_chrdev_state_lock);
81
82 return -EBUSY;
83 }
84
85 if (file->f_flags & O_EXCL)
86 xen_mce_chrdev_open_exclu = 1;
87 xen_mce_chrdev_open_count++;
88
89 spin_unlock(&xen_mce_chrdev_state_lock);
90
91 return nonseekable_open(inode, file);
92}
93
94static int xen_mce_chrdev_release(struct inode *inode, struct file *file)
95{
96 spin_lock(&xen_mce_chrdev_state_lock);
97
98 xen_mce_chrdev_open_count--;
99 xen_mce_chrdev_open_exclu = 0;
100
101 spin_unlock(&xen_mce_chrdev_state_lock);
102
103 return 0;
104}
105
106static ssize_t xen_mce_chrdev_read(struct file *filp, char __user *ubuf,
107 size_t usize, loff_t *off)
108{
109 char __user *buf = ubuf;
110 unsigned num;
111 int i, err;
112
Liu, Jinsong1b2a0552012-06-12 23:11:16 +0800113 mutex_lock(&mcelog_lock);
Liu, Jinsongcef12ee2012-06-07 19:56:51 +0800114
115 num = xen_mcelog.next;
116
117 /* Only supports full reads right now */
118 err = -EINVAL;
119 if (*off != 0 || usize < XEN_MCE_LOG_LEN*sizeof(struct xen_mce))
120 goto out;
121
122 err = 0;
123 for (i = 0; i < num; i++) {
124 struct xen_mce *m = &xen_mcelog.entry[i];
125
126 err |= copy_to_user(buf, m, sizeof(*m));
127 buf += sizeof(*m);
128 }
129
130 memset(xen_mcelog.entry, 0, num * sizeof(struct xen_mce));
131 xen_mcelog.next = 0;
132
133 if (err)
134 err = -EFAULT;
135
136out:
Liu, Jinsong1b2a0552012-06-12 23:11:16 +0800137 mutex_unlock(&mcelog_lock);
Liu, Jinsongcef12ee2012-06-07 19:56:51 +0800138
139 return err ? err : buf - ubuf;
140}
141
Liu, Jinsonga867e5d2012-06-15 09:03:39 +0800142static unsigned int xen_mce_chrdev_poll(struct file *file, poll_table *wait)
143{
144 poll_wait(file, &xen_mce_chrdev_wait, wait);
145
146 if (xen_mcelog.next)
147 return POLLIN | POLLRDNORM;
148
149 return 0;
150}
151
Liu, Jinsongcef12ee2012-06-07 19:56:51 +0800152static long xen_mce_chrdev_ioctl(struct file *f, unsigned int cmd,
153 unsigned long arg)
154{
155 int __user *p = (int __user *)arg;
156
157 if (!capable(CAP_SYS_ADMIN))
158 return -EPERM;
159
160 switch (cmd) {
161 case MCE_GET_RECORD_LEN:
162 return put_user(sizeof(struct xen_mce), p);
163 case MCE_GET_LOG_LEN:
164 return put_user(XEN_MCE_LOG_LEN, p);
165 case MCE_GETCLEAR_FLAGS: {
166 unsigned flags;
167
168 do {
169 flags = xen_mcelog.flags;
170 } while (cmpxchg(&xen_mcelog.flags, flags, 0) != flags);
171
172 return put_user(flags, p);
173 }
174 default:
175 return -ENOTTY;
176 }
177}
178
179static const struct file_operations xen_mce_chrdev_ops = {
180 .open = xen_mce_chrdev_open,
181 .release = xen_mce_chrdev_release,
182 .read = xen_mce_chrdev_read,
Liu, Jinsonga867e5d2012-06-15 09:03:39 +0800183 .poll = xen_mce_chrdev_poll,
Liu, Jinsongcef12ee2012-06-07 19:56:51 +0800184 .unlocked_ioctl = xen_mce_chrdev_ioctl,
185 .llseek = no_llseek,
186};
187
188static struct miscdevice xen_mce_chrdev_device = {
189 MISC_MCELOG_MINOR,
190 "mcelog",
191 &xen_mce_chrdev_ops,
192};
193
194/*
195 * Caller should hold the mcelog_lock
196 */
197static void xen_mce_log(struct xen_mce *mce)
198{
199 unsigned entry;
200
201 entry = xen_mcelog.next;
202
203 /*
204 * When the buffer fills up discard new entries.
205 * Assume that the earlier errors are the more
206 * interesting ones:
207 */
208 if (entry >= XEN_MCE_LOG_LEN) {
209 set_bit(XEN_MCE_OVERFLOW,
210 (unsigned long *)&xen_mcelog.flags);
211 return;
212 }
213
214 memcpy(xen_mcelog.entry + entry, mce, sizeof(struct xen_mce));
215
216 xen_mcelog.next++;
217}
218
219static int convert_log(struct mc_info *mi)
220{
221 struct mcinfo_common *mic;
222 struct mcinfo_global *mc_global;
223 struct mcinfo_bank *mc_bank;
224 struct xen_mce m;
225 uint32_t i;
226
227 mic = NULL;
228 x86_mcinfo_lookup(&mic, mi, MC_TYPE_GLOBAL);
229 if (unlikely(!mic)) {
Joe Perches283c0972013-06-28 03:21:41 -0700230 pr_warn("Failed to find global error info\n");
Liu, Jinsongcef12ee2012-06-07 19:56:51 +0800231 return -ENODEV;
232 }
233
234 memset(&m, 0, sizeof(struct xen_mce));
235
236 mc_global = (struct mcinfo_global *)mic;
237 m.mcgstatus = mc_global->mc_gstatus;
238 m.apicid = mc_global->mc_apicid;
239
240 for (i = 0; i < ncpus; i++)
241 if (g_physinfo[i].mc_apicid == m.apicid)
242 break;
243 if (unlikely(i == ncpus)) {
Joe Perches283c0972013-06-28 03:21:41 -0700244 pr_warn("Failed to match cpu with apicid %d\n", m.apicid);
Liu, Jinsongcef12ee2012-06-07 19:56:51 +0800245 return -ENODEV;
246 }
247
248 m.socketid = g_physinfo[i].mc_chipid;
249 m.cpu = m.extcpu = g_physinfo[i].mc_cpunr;
250 m.cpuvendor = (__u8)g_physinfo[i].mc_vendor;
251 m.mcgcap = g_physinfo[i].mc_msrvalues[__MC_MSR_MCGCAP].value;
252
253 mic = NULL;
254 x86_mcinfo_lookup(&mic, mi, MC_TYPE_BANK);
255 if (unlikely(!mic)) {
Joe Perches283c0972013-06-28 03:21:41 -0700256 pr_warn("Fail to find bank error info\n");
Liu, Jinsongcef12ee2012-06-07 19:56:51 +0800257 return -ENODEV;
258 }
259
260 do {
261 if ((!mic) || (mic->size == 0) ||
262 (mic->type != MC_TYPE_GLOBAL &&
263 mic->type != MC_TYPE_BANK &&
264 mic->type != MC_TYPE_EXTENDED &&
265 mic->type != MC_TYPE_RECOVERY))
266 break;
267
268 if (mic->type == MC_TYPE_BANK) {
269 mc_bank = (struct mcinfo_bank *)mic;
270 m.misc = mc_bank->mc_misc;
271 m.status = mc_bank->mc_status;
272 m.addr = mc_bank->mc_addr;
273 m.tsc = mc_bank->mc_tsc;
274 m.bank = mc_bank->mc_bank;
275 m.finished = 1;
276 /*log this record*/
277 xen_mce_log(&m);
278 }
279 mic = x86_mcinfo_next(mic);
280 } while (1);
281
282 return 0;
283}
284
285static int mc_queue_handle(uint32_t flags)
286{
287 struct xen_mc mc_op;
288 int ret = 0;
289
290 mc_op.cmd = XEN_MC_fetch;
291 mc_op.interface_version = XEN_MCA_INTERFACE_VERSION;
292 set_xen_guest_handle(mc_op.u.mc_fetch.data, &g_mi);
293 do {
294 mc_op.u.mc_fetch.flags = flags;
295 ret = HYPERVISOR_mca(&mc_op);
296 if (ret) {
Joe Perches283c0972013-06-28 03:21:41 -0700297 pr_err("Failed to fetch %surgent error log\n",
298 flags == XEN_MC_URGENT ? "" : "non");
Liu, Jinsongcef12ee2012-06-07 19:56:51 +0800299 break;
300 }
301
302 if (mc_op.u.mc_fetch.flags & XEN_MC_NODATA ||
303 mc_op.u.mc_fetch.flags & XEN_MC_FETCHFAILED)
304 break;
305 else {
306 ret = convert_log(&g_mi);
307 if (ret)
Joe Perches283c0972013-06-28 03:21:41 -0700308 pr_warn("Failed to convert this error log, continue acking it anyway\n");
Liu, Jinsongcef12ee2012-06-07 19:56:51 +0800309
310 mc_op.u.mc_fetch.flags = flags | XEN_MC_ACK;
311 ret = HYPERVISOR_mca(&mc_op);
312 if (ret) {
Joe Perches283c0972013-06-28 03:21:41 -0700313 pr_err("Failed to ack previous error log\n");
Liu, Jinsongcef12ee2012-06-07 19:56:51 +0800314 break;
315 }
316 }
317 } while (1);
318
319 return ret;
320}
321
322/* virq handler for machine check error info*/
Liu, Jinsong1b2a0552012-06-12 23:11:16 +0800323static void xen_mce_work_fn(struct work_struct *work)
Liu, Jinsongcef12ee2012-06-07 19:56:51 +0800324{
325 int err;
Liu, Jinsongcef12ee2012-06-07 19:56:51 +0800326
Liu, Jinsong1b2a0552012-06-12 23:11:16 +0800327 mutex_lock(&mcelog_lock);
Liu, Jinsongcef12ee2012-06-07 19:56:51 +0800328
329 /* urgent mc_info */
330 err = mc_queue_handle(XEN_MC_URGENT);
331 if (err)
Joe Perches283c0972013-06-28 03:21:41 -0700332 pr_err("Failed to handle urgent mc_info queue, continue handling nonurgent mc_info queue anyway\n");
Liu, Jinsongcef12ee2012-06-07 19:56:51 +0800333
334 /* nonurgent mc_info */
335 err = mc_queue_handle(XEN_MC_NONURGENT);
336 if (err)
Joe Perches283c0972013-06-28 03:21:41 -0700337 pr_err("Failed to handle nonurgent mc_info queue\n");
Liu, Jinsongcef12ee2012-06-07 19:56:51 +0800338
Liu, Jinsonga867e5d2012-06-15 09:03:39 +0800339 /* wake processes polling /dev/mcelog */
340 wake_up_interruptible(&xen_mce_chrdev_wait);
341
Liu, Jinsong1b2a0552012-06-12 23:11:16 +0800342 mutex_unlock(&mcelog_lock);
343}
344static DECLARE_WORK(xen_mce_work, xen_mce_work_fn);
Liu, Jinsongcef12ee2012-06-07 19:56:51 +0800345
Liu, Jinsong1b2a0552012-06-12 23:11:16 +0800346static irqreturn_t xen_mce_interrupt(int irq, void *dev_id)
347{
348 schedule_work(&xen_mce_work);
Liu, Jinsongcef12ee2012-06-07 19:56:51 +0800349 return IRQ_HANDLED;
350}
351
352static int bind_virq_for_mce(void)
353{
354 int ret;
355 struct xen_mc mc_op;
356
357 memset(&mc_op, 0, sizeof(struct xen_mc));
358
359 /* Fetch physical CPU Numbers */
360 mc_op.cmd = XEN_MC_physcpuinfo;
361 mc_op.interface_version = XEN_MCA_INTERFACE_VERSION;
362 set_xen_guest_handle(mc_op.u.mc_physcpuinfo.info, g_physinfo);
363 ret = HYPERVISOR_mca(&mc_op);
364 if (ret) {
Joe Perches283c0972013-06-28 03:21:41 -0700365 pr_err("Failed to get CPU numbers\n");
Liu, Jinsongcef12ee2012-06-07 19:56:51 +0800366 return ret;
367 }
368
369 /* Fetch each CPU Physical Info for later reference*/
370 ncpus = mc_op.u.mc_physcpuinfo.ncpus;
371 g_physinfo = kcalloc(ncpus, sizeof(struct mcinfo_logical_cpu),
372 GFP_KERNEL);
373 if (!g_physinfo)
374 return -ENOMEM;
375 set_xen_guest_handle(mc_op.u.mc_physcpuinfo.info, g_physinfo);
376 ret = HYPERVISOR_mca(&mc_op);
377 if (ret) {
Joe Perches283c0972013-06-28 03:21:41 -0700378 pr_err("Failed to get CPU info\n");
Liu, Jinsongcef12ee2012-06-07 19:56:51 +0800379 kfree(g_physinfo);
380 return ret;
381 }
382
383 ret = bind_virq_to_irqhandler(VIRQ_MCA, 0,
384 xen_mce_interrupt, 0, "mce", NULL);
385 if (ret < 0) {
Joe Perches283c0972013-06-28 03:21:41 -0700386 pr_err("Failed to bind virq\n");
Liu, Jinsongcef12ee2012-06-07 19:56:51 +0800387 kfree(g_physinfo);
388 return ret;
389 }
390
391 return 0;
392}
393
394static int __init xen_late_init_mcelog(void)
395{
Dan Carpenterebfe79a2015-03-05 14:24:17 +0300396 int ret;
Liu, Jinsongcef12ee2012-06-07 19:56:51 +0800397
Dan Carpenterebfe79a2015-03-05 14:24:17 +0300398 /* Only DOM0 is responsible for MCE logging */
399 if (!xen_initial_domain())
400 return -ENODEV;
401
402 /* register character device /dev/mcelog for xen mcelog */
403 ret = misc_register(&xen_mce_chrdev_device);
404 if (ret)
405 return ret;
406
407 ret = bind_virq_for_mce();
408 if (ret)
409 goto deregister;
410
411 return 0;
412
413deregister:
414 misc_deregister(&xen_mce_chrdev_device);
415 return ret;
Liu, Jinsongcef12ee2012-06-07 19:56:51 +0800416}
417device_initcall(xen_late_init_mcelog);