xref: /linux/arch/mips/sibyte/common/bus_watcher.c (revision 856e7c4b619af622d56b3b454f7bec32a170ac99)
1 /*
2  * Copyright (C) 2002,2003 Broadcom Corporation
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version 2
7  * of the License, or (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
17  */
18 
19 /*
20  * The Bus Watcher monitors internal bus transactions and maintains
21  * counts of transactions with error status, logging details and
22  * causing one of several interrupts.  This driver provides a handler
23  * for those interrupts which aggregates the counts (to avoid
24  * saturating the 8-bit counters) and provides a presence in
25  * /proc/bus_watcher if PROC_FS is on.
26  */
27 
28 #include <linux/init.h>
29 #include <linux/kernel.h>
30 #include <linux/interrupt.h>
31 #include <linux/sched.h>
32 #include <linux/proc_fs.h>
33 #include <linux/seq_file.h>
34 #include <asm/io.h>
35 
36 #include <asm/sibyte/sb1250.h>
37 #include <asm/sibyte/sb1250_regs.h>
38 #include <asm/sibyte/sb1250_int.h>
39 #include <asm/sibyte/sb1250_scd.h>
40 #if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
41 #include <asm/sibyte/bcm1480_regs.h>
42 #endif
43 
44 
45 struct bw_stats_struct {
46 	uint64_t status;
47 	uint32_t l2_err;
48 	uint32_t memio_err;
49 	int status_printed;
50 	unsigned long l2_cor_d;
51 	unsigned long l2_bad_d;
52 	unsigned long l2_cor_t;
53 	unsigned long l2_bad_t;
54 	unsigned long mem_cor_d;
55 	unsigned long mem_bad_d;
56 	unsigned long bus_error;
57 } bw_stats;
58 
59 
60 static void print_summary(uint32_t status, uint32_t l2_err,
61 			  uint32_t memio_err)
62 {
63 	printk("Bus watcher error counters: %08x %08x\n", l2_err, memio_err);
64 	printk("\nLast recorded signature:\n");
65 	printk("Request %02x from %d, answered by %d with Dcode %d\n",
66 	       (unsigned int)(G_SCD_BERR_TID(status) & 0x3f),
67 	       (int)(G_SCD_BERR_TID(status) >> 6),
68 	       (int)G_SCD_BERR_RID(status),
69 	       (int)G_SCD_BERR_DCODE(status));
70 }
71 
72 /*
73  * check_bus_watcher is exported for use in situations where we want
74  * to see the most recent status of the bus watcher, which might have
75  * already been destructively read out of the registers.
76  *
77  * notes: this is currently used by the cache error handler
78  *	  should provide locking against the interrupt handler
79  */
80 void check_bus_watcher(void)
81 {
82 	u32 status, l2_err, memio_err;
83 
84 #if defined(CONFIG_SIBYTE_BCM112X) || defined(CONFIG_SIBYTE_SB1250)
85 	/* Use non-destructive register */
86 	status = csr_in32(IOADDR(A_SCD_BUS_ERR_STATUS_DEBUG));
87 #elif defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
88 	/* Use non-destructive register */
89 	/* Same as 1250 except BUS_ERR_STATUS_DEBUG is in a different place. */
90 	status = csr_in32(IOADDR(A_BCM1480_BUS_ERR_STATUS_DEBUG));
91 #else
92 #error bus watcher being built for unknown Sibyte SOC!
93 #endif
94 	if (!(status & 0x7fffffff)) {
95 		printk("Using last values reaped by bus watcher driver\n");
96 		status = bw_stats.status;
97 		l2_err = bw_stats.l2_err;
98 		memio_err = bw_stats.memio_err;
99 	} else {
100 		l2_err = csr_in32(IOADDR(A_BUS_L2_ERRORS));
101 		memio_err = csr_in32(IOADDR(A_BUS_MEM_IO_ERRORS));
102 	}
103 	if (status & ~(1UL << 31))
104 		print_summary(status, l2_err, memio_err);
105 	else
106 		printk("Bus watcher indicates no error\n");
107 }
108 
109 #ifdef CONFIG_PROC_FS
110 
111 /* For simplicity, I want to assume a single read is required each
112    time */
113 static int bw_proc_show(struct seq_file *m, void *v)
114 {
115 	struct bw_stats_struct *stats = m->private;
116 
117 	seq_puts(m, "SiByte Bus Watcher statistics\n");
118 	seq_puts(m, "-----------------------------\n");
119 	seq_printf(m, "L2-d-cor %8ld\nL2-d-bad %8ld\n",
120 		   stats->l2_cor_d, stats->l2_bad_d);
121 	seq_printf(m, "L2-t-cor %8ld\nL2-t-bad %8ld\n",
122 		   stats->l2_cor_t, stats->l2_bad_t);
123 	seq_printf(m, "MC-d-cor %8ld\nMC-d-bad %8ld\n",
124 		   stats->mem_cor_d, stats->mem_bad_d);
125 	seq_printf(m, "IO-err   %8ld\n", stats->bus_error);
126 	seq_puts(m, "\nLast recorded signature:\n");
127 	seq_printf(m, "Request %02x from %d, answered by %d with Dcode %d\n",
128 		   (unsigned int)(G_SCD_BERR_TID(stats->status) & 0x3f),
129 		   (int)(G_SCD_BERR_TID(stats->status) >> 6),
130 		   (int)G_SCD_BERR_RID(stats->status),
131 		   (int)G_SCD_BERR_DCODE(stats->status));
132 	/* XXXKW indicate multiple errors between printings, or stats
133 	   collection (or both)? */
134 	if (stats->status & M_SCD_BERR_MULTERRS)
135 		seq_puts(m, "Multiple errors observed since last check.\n");
136 	if (stats->status_printed) {
137 		seq_puts(m, "(no change since last printing)\n");
138 	} else {
139 		stats->status_printed = 1;
140 	}
141 
142 	return 0;
143 }
144 
145 static void create_proc_decoder(struct bw_stats_struct *stats)
146 {
147 	struct proc_dir_entry *ent;
148 
149 	ent = proc_create_single_data("bus_watcher", S_IWUSR | S_IRUGO, NULL,
150 			bw_proc_show, stats);
151 	if (!ent) {
152 		printk(KERN_INFO "Unable to initialize bus_watcher /proc entry\n");
153 		return;
154 	}
155 }
156 
157 #endif /* CONFIG_PROC_FS */
158 
159 /*
160  * sibyte_bw_int - handle bus watcher interrupts and accumulate counts
161  *
162  * notes: possible re-entry due to multiple sources
163  *	  should check/indicate saturation
164  */
165 static irqreturn_t sibyte_bw_int(int irq, void *data)
166 {
167 	struct bw_stats_struct *stats = data;
168 	unsigned long cntr;
169 #ifdef CONFIG_SIBYTE_BW_TRACE
170 	int i;
171 #endif
172 
173 #ifdef CONFIG_SIBYTE_BW_TRACE
174 	csr_out32(M_SCD_TRACE_CFG_FREEZE, IOADDR(A_SCD_TRACE_CFG));
175 	csr_out32(M_SCD_TRACE_CFG_START_READ, IOADDR(A_SCD_TRACE_CFG));
176 
177 	for (i=0; i<256*6; i++)
178 		printk("%016llx\n",
179 		       (long long)__raw_readq(IOADDR(A_SCD_TRACE_READ)));
180 
181 	csr_out32(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
182 	csr_out32(M_SCD_TRACE_CFG_START, IOADDR(A_SCD_TRACE_CFG));
183 #endif
184 
185 	/* Destructive read, clears register and interrupt */
186 	stats->status = csr_in32(IOADDR(A_SCD_BUS_ERR_STATUS));
187 	stats->status_printed = 0;
188 
189 	stats->l2_err = cntr = csr_in32(IOADDR(A_BUS_L2_ERRORS));
190 	stats->l2_cor_d += G_SCD_L2ECC_CORR_D(cntr);
191 	stats->l2_bad_d += G_SCD_L2ECC_BAD_D(cntr);
192 	stats->l2_cor_t += G_SCD_L2ECC_CORR_T(cntr);
193 	stats->l2_bad_t += G_SCD_L2ECC_BAD_T(cntr);
194 	csr_out32(0, IOADDR(A_BUS_L2_ERRORS));
195 
196 	stats->memio_err = cntr = csr_in32(IOADDR(A_BUS_MEM_IO_ERRORS));
197 	stats->mem_cor_d += G_SCD_MEM_ECC_CORR(cntr);
198 	stats->mem_bad_d += G_SCD_MEM_ECC_BAD(cntr);
199 	stats->bus_error += G_SCD_MEM_BUSERR(cntr);
200 	csr_out32(0, IOADDR(A_BUS_MEM_IO_ERRORS));
201 
202 	return IRQ_HANDLED;
203 }
204 
205 int __init sibyte_bus_watcher(void)
206 {
207 	memset(&bw_stats, 0, sizeof(struct bw_stats_struct));
208 	bw_stats.status_printed = 1;
209 
210 	if (request_irq(K_INT_BAD_ECC, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
211 		printk("Failed to register bus watcher BAD_ECC irq\n");
212 		return -1;
213 	}
214 	if (request_irq(K_INT_COR_ECC, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
215 		free_irq(K_INT_BAD_ECC, &bw_stats);
216 		printk("Failed to register bus watcher COR_ECC irq\n");
217 		return -1;
218 	}
219 	if (request_irq(K_INT_IO_BUS, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
220 		free_irq(K_INT_BAD_ECC, &bw_stats);
221 		free_irq(K_INT_COR_ECC, &bw_stats);
222 		printk("Failed to register bus watcher IO_BUS irq\n");
223 		return -1;
224 	}
225 
226 #ifdef CONFIG_PROC_FS
227 	create_proc_decoder(&bw_stats);
228 #endif
229 
230 #ifdef CONFIG_SIBYTE_BW_TRACE
231 	csr_out32((M_SCD_TRSEQ_ASAMPLE | M_SCD_TRSEQ_DSAMPLE |
232 		   K_SCD_TRSEQ_TRIGGER_ALL),
233 		  IOADDR(A_SCD_TRACE_SEQUENCE_0));
234 	csr_out32(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
235 	csr_out32(M_SCD_TRACE_CFG_START, IOADDR(A_SCD_TRACE_CFG));
236 #endif
237 
238 	return 0;
239 }
240 
241 device_initcall(sibyte_bus_watcher);
242