aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/s390/s390mach.c
blob: ffa996c8a9082eb1b1e49ed1fd427283e17f255c (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
/*
 *  drivers/s390/s390mach.c
 *   S/390 machine check handler
 *
 *  S390 version
 *    Copyright (C) 2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
 *    Author(s): Ingo Adlung (adlung@de.ibm.com)
 *		 Martin Schwidefsky (schwidefsky@de.ibm.com)
 */

#include <linux/config.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/workqueue.h>

#include <asm/lowcore.h>

#include "s390mach.h"

#define DBG printk
// #define DBG(args,...) do {} while (0);

static struct semaphore m_sem;

extern int css_process_crw(int);
extern int chsc_process_crw(void);
extern int chp_process_crw(int, int);
extern void css_reiterate_subchannels(void);

extern struct workqueue_struct *slow_path_wq;
extern struct work_struct slow_path_work;

static void
s390_handle_damage(char *msg)
{
	printk(KERN_EMERG "%s\n", msg);
#ifdef CONFIG_SMP
	smp_send_stop();
#endif
	disabled_wait((unsigned long) __builtin_return_address(0));
}

/*
 * Retrieve CRWs and call function to handle event.
 *
 * Note : we currently process CRWs for io and chsc subchannels only
 */
static int
s390_collect_crw_info(void *param)
{
	struct crw crw;
	int ccode, ret, slow;
	struct semaphore *sem;

	sem = (struct semaphore *)param;
	/* Set a nice name. */
	daemonize("kmcheck");
repeat:
	down_interruptible(sem);
	slow = 0;
	while (1) {
		ccode = stcrw(&crw);
		if (ccode != 0)
			break;
		DBG(KERN_DEBUG "crw_info : CRW reports slct=%d, oflw=%d, "
		    "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
		    crw.slct, crw.oflw, crw.chn, crw.rsc, crw.anc,
		    crw.erc, crw.rsid);
		/* Check for overflows. */
		if (crw.oflw) {
			pr_debug("%s: crw overflow detected!\n", __FUNCTION__);
			css_reiterate_subchannels();
			slow = 1;
			continue;
		}
		switch (crw.rsc) {
		case CRW_RSC_SCH:
			pr_debug("source is subchannel %04X\n", crw.rsid);
			ret = css_process_crw (crw.rsid);
			if (ret == -EAGAIN)
				slow = 1;
			break;
		case CRW_RSC_MONITOR:
			pr_debug("source is monitoring facility\n");
			break;
		case CRW_RSC_CPATH:
			pr_debug("source is channel path %02X\n", crw.rsid);
			switch (crw.erc) {
			case CRW_ERC_IPARM: /* Path has come. */
				ret = chp_process_crw(crw.rsid, 1);
				break;
			case CRW_ERC_PERRI: /* Path has gone. */
			case CRW_ERC_PERRN:
				ret = chp_process_crw(crw.rsid, 0);
				break;
			default:
				pr_debug("Don't know how to handle erc=%x\n",
					 crw.erc);
				ret = 0;
			}
			if (ret == -EAGAIN)
				slow = 1;
			break;
		case CRW_RSC_CONFIG:
			pr_debug("source is configuration-alert facility\n");
			break;
		case CRW_RSC_CSS:
			pr_debug("source is channel subsystem\n");
			ret = chsc_process_crw();
			if (ret == -EAGAIN)
				slow = 1;
			break;
		default:
			pr_debug("unknown source\n");
			break;
		}
	}
	if (slow)
		queue_work(slow_path_wq, &slow_path_work);
	goto repeat;
	return 0;
}

/*
 * machine check handler.
 */
void
s390_do_machine_check(void)
{
	struct mci *mci;

	mci = (struct mci *) &S390_lowcore.mcck_interruption_code;

	if (mci->sd)		/* system damage */
		s390_handle_damage("received system damage machine check\n");

	if (mci->pd)		/* instruction processing damage */
		s390_handle_damage("received instruction processing "
				   "damage machine check\n");

	if (mci->se)		/* storage error uncorrected */
		s390_handle_damage("received storage error uncorrected "
				   "machine check\n");

	if (mci->sc)		/* storage error corrected */
		printk(KERN_WARNING
		       "received storage error corrected machine check\n");

	if (mci->ke)		/* storage key-error uncorrected */
		s390_handle_damage("received storage key-error uncorrected "
				   "machine check\n");

	if (mci->ds && mci->fa)	/* storage degradation */
		s390_handle_damage("received storage degradation machine "
				   "check\n");

	if (mci->cp)		/* channel report word pending */
		up(&m_sem);

#ifdef CONFIG_MACHCHK_WARNING
/*
 * The warning may remain for a prolonged period on the bare iron.
 * (actually till the machine is powered off, or until the problem is gone)
 * So we just stop listening for the WARNING MCH and prevent continuously
 * being interrupted.  One caveat is however, that we must do this per
 * processor and cannot use the smp version of ctl_clear_bit().
 * On VM we only get one interrupt per virtally presented machinecheck.
 * Though one suffices, we may get one interrupt per (virtual) processor.
 */
	if (mci->w) {	/* WARNING pending ? */
		static int mchchk_wng_posted = 0;
		/*
		 * Use single machine clear, as we cannot handle smp right now
		 */
		__ctl_clear_bit(14, 24);	/* Disable WARNING MCH */
		if (xchg(&mchchk_wng_posted, 1) == 0)
			kill_proc(1, SIGPWR, 1);
	}
#endif
}

/*
 * s390_init_machine_check
 *
 * initialize machine check handling
 */
static int
machine_check_init(void)
{
	init_MUTEX_LOCKED(&m_sem);
	ctl_clear_bit(14, 25);	/* disable damage MCH */
	ctl_set_bit(14, 26);	/* enable degradation MCH */
	ctl_set_bit(14, 27);	/* enable system recovery MCH */
#ifdef CONFIG_MACHCHK_WARNING
	ctl_set_bit(14, 24);	/* enable warning MCH */
#endif
	return 0;
}

/*
 * Initialize the machine check handler really early to be able to
 * catch all machine checks that happen during boot
 */
arch_initcall(machine_check_init);

/*
 * Machine checks for the channel subsystem must be enabled
 * after the channel subsystem is initialized
 */
static int __init
machine_check_crw_init (void)
{
	kernel_thread(s390_collect_crw_info, &m_sem, CLONE_FS|CLONE_FILES);
	ctl_set_bit(14, 28);	/* enable channel report MCH */
	return 0;
}

device_initcall (machine_check_crw_init);