aboutsummaryrefslogtreecommitdiffstats
path: root/arch/mips/sibyte/sb1250/bus_watcher.c
blob: 45274bd3cd8b8958643cfd7fb1750db0620ad55a (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
/*
 * Copyright (C) 2002,2003 Broadcom Corporation
 *
 * 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.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

/*
 * The Bus Watcher monitors internal bus transactions and maintains
 * counts of transactions with error status, logging details and
 * causing one of several interrupts.  This driver provides a handler
 * for those interrupts which aggregates the counts (to avoid
 * saturating the 8-bit counters) and provides a presence in
 * /proc/bus_watcher if PROC_FS is on.
 */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/proc_fs.h>
#include <asm/system.h>
#include <asm/io.h>

#include <asm/sibyte/sb1250.h>
#include <asm/sibyte/sb1250_regs.h>
#include <asm/sibyte/sb1250_int.h>
#include <asm/sibyte/sb1250_scd.h>


struct bw_stats_struct {
	uint64_t status;
	uint32_t l2_err;
	uint32_t memio_err;
	int status_printed;
	unsigned long l2_cor_d;
	unsigned long l2_bad_d;
	unsigned long l2_cor_t;
	unsigned long l2_bad_t;
	unsigned long mem_cor_d;
	unsigned long mem_bad_d;
	unsigned long bus_error;
} bw_stats;


static void print_summary(uint32_t status, uint32_t l2_err,
			  uint32_t memio_err)
{
	printk("Bus watcher error counters: %08x %08x\n", l2_err, memio_err);
	printk("\nLast recorded signature:\n");
	printk("Request %02x from %d, answered by %d with Dcode %d\n",
	       (unsigned int)(G_SCD_BERR_TID(status) & 0x3f),
	       (int)(G_SCD_BERR_TID(status) >> 6),
	       (int)G_SCD_BERR_RID(status),
	       (int)G_SCD_BERR_DCODE(status));
}

/*
 * check_bus_watcher is exported for use in situations where we want
 * to see the most recent status of the bus watcher, which might have
 * already been destructively read out of the registers.
 *
 * notes: this is currently used by the cache error handler
 *        should provide locking against the interrupt handler
 */
void check_bus_watcher(void)
{
	u32 status, l2_err, memio_err;

#ifdef CONFIG_SB1_PASS_1_WORKAROUNDS
	/* Destructive read, clears register and interrupt */
	status = csr_in32(IOADDR(A_SCD_BUS_ERR_STATUS));
#else
	/* Use non-destructive register */
	status = csr_in32(IOADDR(A_SCD_BUS_ERR_STATUS_DEBUG));
#endif
	if (!(status & 0x7fffffff)) {
		printk("Using last values reaped by bus watcher driver\n");
		status = bw_stats.status;
		l2_err = bw_stats.l2_err;
		memio_err = bw_stats.memio_err;
	} else {
		l2_err = csr_in32(IOADDR(A_BUS_L2_ERRORS));
		memio_err = csr_in32(IOADDR(A_BUS_MEM_IO_ERRORS));
	}
	if (status & ~(1UL << 31))
		print_summary(status, l2_err, memio_err);
	else
		printk("Bus watcher indicates no error\n");
}

static int bw_print_buffer(char *page, struct bw_stats_struct *stats)
{
	int len;

	len = sprintf(page, "SiByte Bus Watcher statistics\n");
	len += sprintf(page+len, "-----------------------------\n");
	len += sprintf(page+len, "L2-d-cor %8ld\nL2-d-bad %8ld\n",
		       stats->l2_cor_d, stats->l2_bad_d);
	len += sprintf(page+len, "L2-t-cor %8ld\nL2-t-bad %8ld\n",
		       stats->l2_cor_t, stats->l2_bad_t);
	len += sprintf(page+len, "MC-d-cor %8ld\nMC-d-bad %8ld\n",
		       stats->mem_cor_d, stats->mem_bad_d);
	len += sprintf(page+len, "IO-err   %8ld\n", stats->bus_error);
	len += sprintf(page+len, "\nLast recorded signature:\n");
	len += sprintf(page+len, "Request %02x from %d, answered by %d with Dcode %d\n",
		       (unsigned int)(G_SCD_BERR_TID(stats->status) & 0x3f),
		       (int)(G_SCD_BERR_TID(stats->status) >> 6),
		       (int)G_SCD_BERR_RID(stats->status),
		       (int)G_SCD_BERR_DCODE(stats->status));
	/* XXXKW indicate multiple errors between printings, or stats
           collection (or both)? */
	if (stats->status & M_SCD_BERR_MULTERRS)
		len += sprintf(page+len, "Multiple errors observed since last check.\n");
	if (stats->status_printed) {
		len += sprintf(page+len, "(no change since last printing)\n");
	} else {
		stats->status_printed = 1;
	}

	return len;
}

#ifdef CONFIG_PROC_FS

/* For simplicity, I want to assume a single read is required each
   time */
static int bw_read_proc(char *page, char **start, off_t off,
			int count, int *eof, void *data)
{
	int len;

	if (off == 0) {
		len = bw_print_buffer(page, data);
		*start = page;
	} else {
		len = 0;
		*eof = 1;
	}
	return len;
}

static void create_proc_decoder(struct bw_stats_struct *stats)
{
	struct proc_dir_entry *ent;

	ent = create_proc_read_entry("bus_watcher", S_IWUSR | S_IRUGO, NULL,
				     bw_read_proc, stats);
	if (!ent) {
		printk(KERN_INFO "Unable to initialize bus_watcher /proc entry\n");
		return;
	}
}

#endif /* CONFIG_PROC_FS */

/*
 * sibyte_bw_int - handle bus watcher interrupts and accumulate counts
 *
 * notes: possible re-entry due to multiple sources
 *        should check/indicate saturation
 */
static irqreturn_t sibyte_bw_int(int irq, void *data)
{
	struct bw_stats_struct *stats = data;
	unsigned long cntr;
#ifdef CONFIG_SIBYTE_BW_TRACE
	int i;
#endif
#ifndef CONFIG_PROC_FS
	char bw_buf[1024];
#endif

#ifdef CONFIG_SIBYTE_BW_TRACE
	csr_out32(M_SCD_TRACE_CFG_FREEZE, IOADDR(A_SCD_TRACE_CFG));
	csr_out32(M_SCD_TRACE_CFG_START_READ, IOADDR(A_SCD_TRACE_CFG));

	for (i=0; i<256*6; i++)
		printk("%016llx\n",
		       (long long)__raw_readq(IOADDR(A_SCD_TRACE_READ)));

	csr_out32(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
	csr_out32(M_SCD_TRACE_CFG_START, IOADDR(A_SCD_TRACE_CFG));
#endif

	/* Destructive read, clears register and interrupt */
	stats->status = csr_in32(IOADDR(A_SCD_BUS_ERR_STATUS));
	stats->status_printed = 0;

	stats->l2_err = cntr = csr_in32(IOADDR(A_BUS_L2_ERRORS));
	stats->l2_cor_d += G_SCD_L2ECC_CORR_D(cntr);
	stats->l2_bad_d += G_SCD_L2ECC_BAD_D(cntr);
	stats->l2_cor_t += G_SCD_L2ECC_CORR_T(cntr);
	stats->l2_bad_t += G_SCD_L2ECC_BAD_T(cntr);
	csr_out32(0, IOADDR(A_BUS_L2_ERRORS));

	stats->memio_err = cntr = csr_in32(IOADDR(A_BUS_MEM_IO_ERRORS));
	stats->mem_cor_d += G_SCD_MEM_ECC_CORR(cntr);
	stats->mem_bad_d += G_SCD_MEM_ECC_BAD(cntr);
	stats->bus_error += G_SCD_MEM_BUSERR(cntr);
	csr_out32(0, IOADDR(A_BUS_MEM_IO_ERRORS));

#ifndef CONFIG_PROC_FS
	bw_print_buffer(bw_buf, stats);
	printk(bw_buf);
#endif

	return IRQ_HANDLED;
}

int __init sibyte_bus_watcher(void)
{
	memset(&bw_stats, 0, sizeof(struct bw_stats_struct));
	bw_stats.status_printed = 1;

	if (request_irq(K_INT_BAD_ECC, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
		printk("Failed to register bus watcher BAD_ECC irq\n");
		return -1;
	}
	if (request_irq(K_INT_COR_ECC, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
		free_irq(K_INT_BAD_ECC, &bw_stats);
		printk("Failed to register bus watcher COR_ECC irq\n");
		return -1;
	}
	if (request_irq(K_INT_IO_BUS, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
		free_irq(K_INT_BAD_ECC, &bw_stats);
		free_irq(K_INT_COR_ECC, &bw_stats);
		printk("Failed to register bus watcher IO_BUS irq\n");
		return -1;
	}

#ifdef CONFIG_PROC_FS
	create_proc_decoder(&bw_stats);
#endif

#ifdef CONFIG_SIBYTE_BW_TRACE
	csr_out32((M_SCD_TRSEQ_ASAMPLE | M_SCD_TRSEQ_DSAMPLE |
		   K_SCD_TRSEQ_TRIGGER_ALL),
		  IOADDR(A_SCD_TRACE_SEQUENCE_0));
	csr_out32(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
	csr_out32(M_SCD_TRACE_CFG_START, IOADDR(A_SCD_TRACE_CFG));
#endif

	return 0;
}

__initcall(sibyte_bus_watcher);