1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2002,2003 Broadcom Corporation
4 */
5
6 /*
7 * The Bus Watcher monitors internal bus transactions and maintains
8 * counts of transactions with error status, logging details and
9 * causing one of several interrupts. This driver provides a handler
10 * for those interrupts which aggregates the counts (to avoid
11 * saturating the 8-bit counters) and provides a presence in
12 * /proc/bus_watcher if PROC_FS is on.
13 */
14
15 #include <linux/init.h>
16 #include <linux/kernel.h>
17 #include <linux/interrupt.h>
18 #include <linux/sched.h>
19 #include <linux/proc_fs.h>
20 #include <linux/seq_file.h>
21 #include <asm/io.h>
22
23 #include <asm/sibyte/sb1250.h>
24 #include <asm/sibyte/sb1250_regs.h>
25 #include <asm/sibyte/sb1250_int.h>
26 #include <asm/sibyte/sb1250_scd.h>
27 #ifdef CONFIG_SIBYTE_BCM1x80
28 #include <asm/sibyte/bcm1480_regs.h>
29 #endif
30
31
32 struct bw_stats_struct {
33 uint64_t status;
34 uint32_t l2_err;
35 uint32_t memio_err;
36 int status_printed;
37 unsigned long l2_cor_d;
38 unsigned long l2_bad_d;
39 unsigned long l2_cor_t;
40 unsigned long l2_bad_t;
41 unsigned long mem_cor_d;
42 unsigned long mem_bad_d;
43 unsigned long bus_error;
44 } bw_stats;
45
46
print_summary(uint32_t status,uint32_t l2_err,uint32_t memio_err)47 static void print_summary(uint32_t status, uint32_t l2_err,
48 uint32_t memio_err)
49 {
50 printk("Bus watcher error counters: %08x %08x\n", l2_err, memio_err);
51 printk("\nLast recorded signature:\n");
52 printk("Request %02x from %d, answered by %d with Dcode %d\n",
53 (unsigned int)(G_SCD_BERR_TID(status) & 0x3f),
54 (int)(G_SCD_BERR_TID(status) >> 6),
55 (int)G_SCD_BERR_RID(status),
56 (int)G_SCD_BERR_DCODE(status));
57 }
58
59 /*
60 * check_bus_watcher is exported for use in situations where we want
61 * to see the most recent status of the bus watcher, which might have
62 * already been destructively read out of the registers.
63 *
64 * notes: this is currently used by the cache error handler
65 * should provide locking against the interrupt handler
66 */
check_bus_watcher(void)67 void check_bus_watcher(void)
68 {
69 u32 status, l2_err, memio_err;
70
71 #if defined(CONFIG_SIBYTE_BCM112X) || defined(CONFIG_SIBYTE_SB1250)
72 /* Use non-destructive register */
73 status = csr_in32(IOADDR(A_SCD_BUS_ERR_STATUS_DEBUG));
74 #elif defined(CONFIG_SIBYTE_BCM1x80)
75 /* Use non-destructive register */
76 /* Same as 1250 except BUS_ERR_STATUS_DEBUG is in a different place. */
77 status = csr_in32(IOADDR(A_BCM1480_BUS_ERR_STATUS_DEBUG));
78 #else
79 #error bus watcher being built for unknown Sibyte SOC!
80 #endif
81 if (!(status & 0x7fffffff)) {
82 printk("Using last values reaped by bus watcher driver\n");
83 status = bw_stats.status;
84 l2_err = bw_stats.l2_err;
85 memio_err = bw_stats.memio_err;
86 } else {
87 l2_err = csr_in32(IOADDR(A_BUS_L2_ERRORS));
88 memio_err = csr_in32(IOADDR(A_BUS_MEM_IO_ERRORS));
89 }
90 if (status & ~(1UL << 31))
91 print_summary(status, l2_err, memio_err);
92 else
93 printk("Bus watcher indicates no error\n");
94 }
95
96 #ifdef CONFIG_PROC_FS
97
98 /* For simplicity, I want to assume a single read is required each
99 time */
bw_proc_show(struct seq_file * m,void * v)100 static int bw_proc_show(struct seq_file *m, void *v)
101 {
102 struct bw_stats_struct *stats = m->private;
103
104 seq_puts(m, "SiByte Bus Watcher statistics\n");
105 seq_puts(m, "-----------------------------\n");
106 seq_printf(m, "L2-d-cor %8ld\nL2-d-bad %8ld\n",
107 stats->l2_cor_d, stats->l2_bad_d);
108 seq_printf(m, "L2-t-cor %8ld\nL2-t-bad %8ld\n",
109 stats->l2_cor_t, stats->l2_bad_t);
110 seq_printf(m, "MC-d-cor %8ld\nMC-d-bad %8ld\n",
111 stats->mem_cor_d, stats->mem_bad_d);
112 seq_printf(m, "IO-err %8ld\n", stats->bus_error);
113 seq_puts(m, "\nLast recorded signature:\n");
114 seq_printf(m, "Request %02x from %d, answered by %d with Dcode %d\n",
115 (unsigned int)(G_SCD_BERR_TID(stats->status) & 0x3f),
116 (int)(G_SCD_BERR_TID(stats->status) >> 6),
117 (int)G_SCD_BERR_RID(stats->status),
118 (int)G_SCD_BERR_DCODE(stats->status));
119 /* XXXKW indicate multiple errors between printings, or stats
120 collection (or both)? */
121 if (stats->status & M_SCD_BERR_MULTERRS)
122 seq_puts(m, "Multiple errors observed since last check.\n");
123 if (stats->status_printed) {
124 seq_puts(m, "(no change since last printing)\n");
125 } else {
126 stats->status_printed = 1;
127 }
128
129 return 0;
130 }
131
create_proc_decoder(struct bw_stats_struct * stats)132 static void create_proc_decoder(struct bw_stats_struct *stats)
133 {
134 struct proc_dir_entry *ent;
135
136 ent = proc_create_single_data("bus_watcher", S_IWUSR | S_IRUGO, NULL,
137 bw_proc_show, stats);
138 if (!ent) {
139 printk(KERN_INFO "Unable to initialize bus_watcher /proc entry\n");
140 return;
141 }
142 }
143
144 #endif /* CONFIG_PROC_FS */
145
146 /*
147 * sibyte_bw_int - handle bus watcher interrupts and accumulate counts
148 *
149 * notes: possible re-entry due to multiple sources
150 * should check/indicate saturation
151 */
sibyte_bw_int(int irq,void * data)152 static irqreturn_t sibyte_bw_int(int irq, void *data)
153 {
154 struct bw_stats_struct *stats = data;
155 unsigned long cntr;
156 #ifdef CONFIG_SIBYTE_BW_TRACE
157 int i;
158 #endif
159
160 #ifdef CONFIG_SIBYTE_BW_TRACE
161 csr_out32(M_SCD_TRACE_CFG_FREEZE, IOADDR(A_SCD_TRACE_CFG));
162 csr_out32(M_SCD_TRACE_CFG_START_READ, IOADDR(A_SCD_TRACE_CFG));
163
164 for (i=0; i<256*6; i++)
165 printk("%016llx\n",
166 (long long)__raw_readq(IOADDR(A_SCD_TRACE_READ)));
167
168 csr_out32(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
169 csr_out32(M_SCD_TRACE_CFG_START, IOADDR(A_SCD_TRACE_CFG));
170 #endif
171
172 /* Destructive read, clears register and interrupt */
173 stats->status = csr_in32(IOADDR(A_SCD_BUS_ERR_STATUS));
174 stats->status_printed = 0;
175
176 stats->l2_err = cntr = csr_in32(IOADDR(A_BUS_L2_ERRORS));
177 stats->l2_cor_d += G_SCD_L2ECC_CORR_D(cntr);
178 stats->l2_bad_d += G_SCD_L2ECC_BAD_D(cntr);
179 stats->l2_cor_t += G_SCD_L2ECC_CORR_T(cntr);
180 stats->l2_bad_t += G_SCD_L2ECC_BAD_T(cntr);
181 csr_out32(0, IOADDR(A_BUS_L2_ERRORS));
182
183 stats->memio_err = cntr = csr_in32(IOADDR(A_BUS_MEM_IO_ERRORS));
184 stats->mem_cor_d += G_SCD_MEM_ECC_CORR(cntr);
185 stats->mem_bad_d += G_SCD_MEM_ECC_BAD(cntr);
186 stats->bus_error += G_SCD_MEM_BUSERR(cntr);
187 csr_out32(0, IOADDR(A_BUS_MEM_IO_ERRORS));
188
189 return IRQ_HANDLED;
190 }
191
sibyte_bus_watcher(void)192 int __init sibyte_bus_watcher(void)
193 {
194 memset(&bw_stats, 0, sizeof(struct bw_stats_struct));
195 bw_stats.status_printed = 1;
196
197 if (request_irq(K_INT_BAD_ECC, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
198 printk("Failed to register bus watcher BAD_ECC irq\n");
199 return -1;
200 }
201 if (request_irq(K_INT_COR_ECC, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
202 free_irq(K_INT_BAD_ECC, &bw_stats);
203 printk("Failed to register bus watcher COR_ECC irq\n");
204 return -1;
205 }
206 if (request_irq(K_INT_IO_BUS, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
207 free_irq(K_INT_BAD_ECC, &bw_stats);
208 free_irq(K_INT_COR_ECC, &bw_stats);
209 printk("Failed to register bus watcher IO_BUS irq\n");
210 return -1;
211 }
212
213 #ifdef CONFIG_PROC_FS
214 create_proc_decoder(&bw_stats);
215 #endif
216
217 #ifdef CONFIG_SIBYTE_BW_TRACE
218 csr_out32((M_SCD_TRSEQ_ASAMPLE | M_SCD_TRSEQ_DSAMPLE |
219 K_SCD_TRSEQ_TRIGGER_ALL),
220 IOADDR(A_SCD_TRACE_SEQUENCE_0));
221 csr_out32(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
222 csr_out32(M_SCD_TRACE_CFG_START, IOADDR(A_SCD_TRACE_CFG));
223 #endif
224
225 return 0;
226 }
227
228 device_initcall(sibyte_bus_watcher);
229