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 
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  */
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 */
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 
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  */
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 
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