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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 <asm/io.h>
34
35#include <asm/sibyte/sb1250.h>
36#include <asm/sibyte/sb1250_regs.h>
37#include <asm/sibyte/sb1250_int.h>
38#include <asm/sibyte/sb1250_scd.h>
39
40
41struct bw_stats_struct {
42 uint64_t status;
43 uint32_t l2_err;
44 uint32_t memio_err;
45 int status_printed;
46 unsigned long l2_cor_d;
47 unsigned long l2_bad_d;
48 unsigned long l2_cor_t;
49 unsigned long l2_bad_t;
50 unsigned long mem_cor_d;
51 unsigned long mem_bad_d;
52 unsigned long bus_error;
53} bw_stats;
54
55
56static void print_summary(uint32_t status, uint32_t l2_err,
57 uint32_t memio_err)
58{
59 printk("Bus watcher error counters: %08x %08x\n", l2_err, memio_err);
60 printk("\nLast recorded signature:\n");
61 printk("Request %02x from %d, answered by %d with Dcode %d\n",
62 (unsigned int)(G_SCD_BERR_TID(status) & 0x3f),
63 (int)(G_SCD_BERR_TID(status) >> 6),
64 (int)G_SCD_BERR_RID(status),
65 (int)G_SCD_BERR_DCODE(status));
66}
67
68/*
69 * check_bus_watcher is exported for use in situations where we want
70 * to see the most recent status of the bus watcher, which might have
71 * already been destructively read out of the registers.
72 *
73 * notes: this is currently used by the cache error handler
74 * should provide locking against the interrupt handler
75 */
76void check_bus_watcher(void)
77{
78 u32 status, l2_err, memio_err;
79
80#ifdef CONFIG_SB1_PASS_1_WORKAROUNDS
81 /* Destructive read, clears register and interrupt */
82 status = csr_in32(IOADDR(A_SCD_BUS_ERR_STATUS));
83#else
84 /* Use non-destructive register */
85 status = csr_in32(IOADDR(A_SCD_BUS_ERR_STATUS_DEBUG));
86#endif
87 if (!(status & 0x7fffffff)) {
88 printk("Using last values reaped by bus watcher driver\n");
89 status = bw_stats.status;
90 l2_err = bw_stats.l2_err;
91 memio_err = bw_stats.memio_err;
92 } else {
93 l2_err = csr_in32(IOADDR(A_BUS_L2_ERRORS));
94 memio_err = csr_in32(IOADDR(A_BUS_MEM_IO_ERRORS));
95 }
96 if (status & ~(1UL << 31))
97 print_summary(status, l2_err, memio_err);
98 else
99 printk("Bus watcher indicates no error\n");
100}
101
102static int bw_print_buffer(char *page, struct bw_stats_struct *stats)
103{
104 int len;
105
106 len = sprintf(page, "SiByte Bus Watcher statistics\n");
107 len += sprintf(page+len, "-----------------------------\n");
108 len += sprintf(page+len, "L2-d-cor %8ld\nL2-d-bad %8ld\n",
109 stats->l2_cor_d, stats->l2_bad_d);
110 len += sprintf(page+len, "L2-t-cor %8ld\nL2-t-bad %8ld\n",
111 stats->l2_cor_t, stats->l2_bad_t);
112 len += sprintf(page+len, "MC-d-cor %8ld\nMC-d-bad %8ld\n",
113 stats->mem_cor_d, stats->mem_bad_d);
114 len += sprintf(page+len, "IO-err %8ld\n", stats->bus_error);
115 len += sprintf(page+len, "\nLast recorded signature:\n");
116 len += sprintf(page+len, "Request %02x from %d, answered by %d with Dcode %d\n",
117 (unsigned int)(G_SCD_BERR_TID(stats->status) & 0x3f),
118 (int)(G_SCD_BERR_TID(stats->status) >> 6),
119 (int)G_SCD_BERR_RID(stats->status),
120 (int)G_SCD_BERR_DCODE(stats->status));
121 /* XXXKW indicate multiple errors between printings, or stats
122 collection (or both)? */
123 if (stats->status & M_SCD_BERR_MULTERRS)
124 len += sprintf(page+len, "Multiple errors observed since last check.\n");
125 if (stats->status_printed) {
126 len += sprintf(page+len, "(no change since last printing)\n");
127 } else {
128 stats->status_printed = 1;
129 }
130
131 return len;
132}
133
134#ifdef CONFIG_PROC_FS
135
136/* For simplicity, I want to assume a single read is required each
137 time */
138static int bw_read_proc(char *page, char **start, off_t off,
139 int count, int *eof, void *data)
140{
141 int len;
142
143 if (off == 0) {
144 len = bw_print_buffer(page, data);
145 *start = page;
146 } else {
147 len = 0;
148 *eof = 1;
149 }
150 return len;
151}
152
153static void create_proc_decoder(struct bw_stats_struct *stats)
154{
155 struct proc_dir_entry *ent;
156
157 ent = create_proc_read_entry("bus_watcher", S_IWUSR | S_IRUGO, NULL,
158 bw_read_proc, stats);
159 if (!ent) {
160 printk(KERN_INFO "Unable to initialize bus_watcher /proc entry\n");
161 return;
162 }
163}
164
165#endif /* CONFIG_PROC_FS */
166
167/*
168 * sibyte_bw_int - handle bus watcher interrupts and accumulate counts
169 *
170 * notes: possible re-entry due to multiple sources
171 * should check/indicate saturation
172 */
173static irqreturn_t sibyte_bw_int(int irq, void *data)
174{
175 struct bw_stats_struct *stats = data;
176 unsigned long cntr;
177#ifdef CONFIG_SIBYTE_BW_TRACE
178 int i;
179#endif
180#ifndef CONFIG_PROC_FS
181 char bw_buf[1024];
182#endif
183
184#ifdef CONFIG_SIBYTE_BW_TRACE
185 csr_out32(M_SCD_TRACE_CFG_FREEZE, IOADDR(A_SCD_TRACE_CFG));
186 csr_out32(M_SCD_TRACE_CFG_START_READ, IOADDR(A_SCD_TRACE_CFG));
187
188 for (i=0; i<256*6; i++)
189 printk("%016llx\n",
190 (long long)__raw_readq(IOADDR(A_SCD_TRACE_READ)));
191
192 csr_out32(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
193 csr_out32(M_SCD_TRACE_CFG_START, IOADDR(A_SCD_TRACE_CFG));
194#endif
195
196 /* Destructive read, clears register and interrupt */
197 stats->status = csr_in32(IOADDR(A_SCD_BUS_ERR_STATUS));
198 stats->status_printed = 0;
199
200 stats->l2_err = cntr = csr_in32(IOADDR(A_BUS_L2_ERRORS));
201 stats->l2_cor_d += G_SCD_L2ECC_CORR_D(cntr);
202 stats->l2_bad_d += G_SCD_L2ECC_BAD_D(cntr);
203 stats->l2_cor_t += G_SCD_L2ECC_CORR_T(cntr);
204 stats->l2_bad_t += G_SCD_L2ECC_BAD_T(cntr);
205 csr_out32(0, IOADDR(A_BUS_L2_ERRORS));
206
207 stats->memio_err = cntr = csr_in32(IOADDR(A_BUS_MEM_IO_ERRORS));
208 stats->mem_cor_d += G_SCD_MEM_ECC_CORR(cntr);
209 stats->mem_bad_d += G_SCD_MEM_ECC_BAD(cntr);
210 stats->bus_error += G_SCD_MEM_BUSERR(cntr);
211 csr_out32(0, IOADDR(A_BUS_MEM_IO_ERRORS));
212
213#ifndef CONFIG_PROC_FS
214 bw_print_buffer(bw_buf, stats);
215 printk(bw_buf);
216#endif
217
218 return IRQ_HANDLED;
219}
220
221int __init sibyte_bus_watcher(void)
222{
223 memset(&bw_stats, 0, sizeof(struct bw_stats_struct));
224 bw_stats.status_printed = 1;
225
226 if (request_irq(K_INT_BAD_ECC, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
227 printk("Failed to register bus watcher BAD_ECC irq\n");
228 return -1;
229 }
230 if (request_irq(K_INT_COR_ECC, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
231 free_irq(K_INT_BAD_ECC, &bw_stats);
232 printk("Failed to register bus watcher COR_ECC irq\n");
233 return -1;
234 }
235 if (request_irq(K_INT_IO_BUS, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
236 free_irq(K_INT_BAD_ECC, &bw_stats);
237 free_irq(K_INT_COR_ECC, &bw_stats);
238 printk("Failed to register bus watcher IO_BUS irq\n");
239 return -1;
240 }
241
242#ifdef CONFIG_PROC_FS
243 create_proc_decoder(&bw_stats);
244#endif
245
246#ifdef CONFIG_SIBYTE_BW_TRACE
247 csr_out32((M_SCD_TRSEQ_ASAMPLE | M_SCD_TRSEQ_DSAMPLE |
248 K_SCD_TRSEQ_TRIGGER_ALL),
249 IOADDR(A_SCD_TRACE_SEQUENCE_0));
250 csr_out32(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
251 csr_out32(M_SCD_TRACE_CFG_START, IOADDR(A_SCD_TRACE_CFG));
252#endif
253
254 return 0;
255}
256
257__initcall(sibyte_bus_watcher);