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 #ifdef CONFIG_SB1_PASS_1_WORKAROUNDS
85 	/* Destructive read, clears register and interrupt */
86 	status = csr_in32(IOADDR(A_SCD_BUS_ERR_STATUS));
87 #elif defined(CONFIG_SIBYTE_BCM112X) || defined(CONFIG_SIBYTE_SB1250)
88 	/* Use non-destructive register */
89 	status = csr_in32(IOADDR(A_SCD_BUS_ERR_STATUS_DEBUG));
90 #elif defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
91 	/* Use non-destructive register */
92 	/* Same as 1250 except BUS_ERR_STATUS_DEBUG is in a different place. */
93 	status = csr_in32(IOADDR(A_BCM1480_BUS_ERR_STATUS_DEBUG));
94 #else
95 #error bus watcher being built for unknown Sibyte SOC!
96 #endif
97 	if (!(status & 0x7fffffff)) {
98 		printk("Using last values reaped by bus watcher driver\n");
99 		status = bw_stats.status;
100 		l2_err = bw_stats.l2_err;
101 		memio_err = bw_stats.memio_err;
102 	} else {
103 		l2_err = csr_in32(IOADDR(A_BUS_L2_ERRORS));
104 		memio_err = csr_in32(IOADDR(A_BUS_MEM_IO_ERRORS));
105 	}
106 	if (status & ~(1UL << 31))
107 		print_summary(status, l2_err, memio_err);
108 	else
109 		printk("Bus watcher indicates no error\n");
110 }
111 
112 #ifdef CONFIG_PROC_FS
113 
114 /* For simplicity, I want to assume a single read is required each
115    time */
116 static int bw_proc_show(struct seq_file *m, void *v)
117 {
118 	struct bw_stats_struct *stats = m->private;
119 
120 	seq_puts(m, "SiByte Bus Watcher statistics\n");
121 	seq_puts(m, "-----------------------------\n");
122 	seq_printf(m, "L2-d-cor %8ld\nL2-d-bad %8ld\n",
123 		   stats->l2_cor_d, stats->l2_bad_d);
124 	seq_printf(m, "L2-t-cor %8ld\nL2-t-bad %8ld\n",
125 		   stats->l2_cor_t, stats->l2_bad_t);
126 	seq_printf(m, "MC-d-cor %8ld\nMC-d-bad %8ld\n",
127 		   stats->mem_cor_d, stats->mem_bad_d);
128 	seq_printf(m, "IO-err   %8ld\n", stats->bus_error);
129 	seq_puts(m, "\nLast recorded signature:\n");
130 	seq_printf(m, "Request %02x from %d, answered by %d with Dcode %d\n",
131 		   (unsigned int)(G_SCD_BERR_TID(stats->status) & 0x3f),
132 		   (int)(G_SCD_BERR_TID(stats->status) >> 6),
133 		   (int)G_SCD_BERR_RID(stats->status),
134 		   (int)G_SCD_BERR_DCODE(stats->status));
135 	/* XXXKW indicate multiple errors between printings, or stats
136 	   collection (or both)? */
137 	if (stats->status & M_SCD_BERR_MULTERRS)
138 		seq_puts(m, "Multiple errors observed since last check.\n");
139 	if (stats->status_printed) {
140 		seq_puts(m, "(no change since last printing)\n");
141 	} else {
142 		stats->status_printed = 1;
143 	}
144 
145 	return 0;
146 }
147 
148 static int bw_proc_open(struct inode *inode, struct file *file)
149 {
150 	return single_open(file, bw_proc_show, PDE_DATA(inode));
151 }
152 
153 static const struct file_operations bw_proc_fops = {
154 	.open		= bw_proc_open,
155 	.read		= seq_read,
156 	.llseek		= seq_lseek,
157 	.release	= single_release,
158 };
159 
160 static void create_proc_decoder(struct bw_stats_struct *stats)
161 {
162 	struct proc_dir_entry *ent;
163 
164 	ent = proc_create_data("bus_watcher", S_IWUSR | S_IRUGO, NULL,
165 			       &bw_proc_fops, stats);
166 	if (!ent) {
167 		printk(KERN_INFO "Unable to initialize bus_watcher /proc entry\n");
168 		return;
169 	}
170 }
171 
172 #endif /* CONFIG_PROC_FS */
173 
174 /*
175  * sibyte_bw_int - handle bus watcher interrupts and accumulate counts
176  *
177  * notes: possible re-entry due to multiple sources
178  *	  should check/indicate saturation
179  */
180 static irqreturn_t sibyte_bw_int(int irq, void *data)
181 {
182 	struct bw_stats_struct *stats = data;
183 	unsigned long cntr;
184 #ifdef CONFIG_SIBYTE_BW_TRACE
185 	int i;
186 #endif
187 
188 #ifdef CONFIG_SIBYTE_BW_TRACE
189 	csr_out32(M_SCD_TRACE_CFG_FREEZE, IOADDR(A_SCD_TRACE_CFG));
190 	csr_out32(M_SCD_TRACE_CFG_START_READ, IOADDR(A_SCD_TRACE_CFG));
191 
192 	for (i=0; i<256*6; i++)
193 		printk("%016llx\n",
194 		       (long long)__raw_readq(IOADDR(A_SCD_TRACE_READ)));
195 
196 	csr_out32(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
197 	csr_out32(M_SCD_TRACE_CFG_START, IOADDR(A_SCD_TRACE_CFG));
198 #endif
199 
200 	/* Destructive read, clears register and interrupt */
201 	stats->status = csr_in32(IOADDR(A_SCD_BUS_ERR_STATUS));
202 	stats->status_printed = 0;
203 
204 	stats->l2_err = cntr = csr_in32(IOADDR(A_BUS_L2_ERRORS));
205 	stats->l2_cor_d += G_SCD_L2ECC_CORR_D(cntr);
206 	stats->l2_bad_d += G_SCD_L2ECC_BAD_D(cntr);
207 	stats->l2_cor_t += G_SCD_L2ECC_CORR_T(cntr);
208 	stats->l2_bad_t += G_SCD_L2ECC_BAD_T(cntr);
209 	csr_out32(0, IOADDR(A_BUS_L2_ERRORS));
210 
211 	stats->memio_err = cntr = csr_in32(IOADDR(A_BUS_MEM_IO_ERRORS));
212 	stats->mem_cor_d += G_SCD_MEM_ECC_CORR(cntr);
213 	stats->mem_bad_d += G_SCD_MEM_ECC_BAD(cntr);
214 	stats->bus_error += G_SCD_MEM_BUSERR(cntr);
215 	csr_out32(0, IOADDR(A_BUS_MEM_IO_ERRORS));
216 
217 	return IRQ_HANDLED;
218 }
219 
220 int __init sibyte_bus_watcher(void)
221 {
222 	memset(&bw_stats, 0, sizeof(struct bw_stats_struct));
223 	bw_stats.status_printed = 1;
224 
225 	if (request_irq(K_INT_BAD_ECC, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
226 		printk("Failed to register bus watcher BAD_ECC irq\n");
227 		return -1;
228 	}
229 	if (request_irq(K_INT_COR_ECC, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
230 		free_irq(K_INT_BAD_ECC, &bw_stats);
231 		printk("Failed to register bus watcher COR_ECC irq\n");
232 		return -1;
233 	}
234 	if (request_irq(K_INT_IO_BUS, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
235 		free_irq(K_INT_BAD_ECC, &bw_stats);
236 		free_irq(K_INT_COR_ECC, &bw_stats);
237 		printk("Failed to register bus watcher IO_BUS irq\n");
238 		return -1;
239 	}
240 
241 #ifdef CONFIG_PROC_FS
242 	create_proc_decoder(&bw_stats);
243 #endif
244 
245 #ifdef CONFIG_SIBYTE_BW_TRACE
246 	csr_out32((M_SCD_TRSEQ_ASAMPLE | M_SCD_TRSEQ_DSAMPLE |
247 		   K_SCD_TRSEQ_TRIGGER_ALL),
248 		  IOADDR(A_SCD_TRACE_SEQUENCE_0));
249 	csr_out32(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
250 	csr_out32(M_SCD_TRACE_CFG_START, IOADDR(A_SCD_TRACE_CFG));
251 #endif
252 
253 	return 0;
254 }
255 
256 __initcall(sibyte_bus_watcher);
257