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
 45struct 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
 60static 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 */
 80void 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 */
113static 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
145static int bw_proc_open(struct inode *inode, struct file *file)
146{
147	return single_open(file, bw_proc_show, PDE_DATA(inode));
148}
149
150static const struct file_operations bw_proc_fops = {
151	.open		= bw_proc_open,
152	.read		= seq_read,
153	.llseek		= seq_lseek,
154	.release	= single_release,
155};
156
157static void create_proc_decoder(struct bw_stats_struct *stats)
158{
159	struct proc_dir_entry *ent;
160
161	ent = proc_create_data("bus_watcher", S_IWUSR | S_IRUGO, NULL,
162			       &bw_proc_fops, stats);
163	if (!ent) {
164		printk(KERN_INFO "Unable to initialize bus_watcher /proc entry\n");
165		return;
166	}
167}
168
169#endif /* CONFIG_PROC_FS */
170
171/*
172 * sibyte_bw_int - handle bus watcher interrupts and accumulate counts
173 *
174 * notes: possible re-entry due to multiple sources
175 *	  should check/indicate saturation
176 */
177static irqreturn_t sibyte_bw_int(int irq, void *data)
178{
179	struct bw_stats_struct *stats = data;
180	unsigned long cntr;
181#ifdef CONFIG_SIBYTE_BW_TRACE
182	int i;
183#endif
184
185#ifdef CONFIG_SIBYTE_BW_TRACE
186	csr_out32(M_SCD_TRACE_CFG_FREEZE, IOADDR(A_SCD_TRACE_CFG));
187	csr_out32(M_SCD_TRACE_CFG_START_READ, IOADDR(A_SCD_TRACE_CFG));
188
189	for (i=0; i<256*6; i++)
190		printk("%016llx\n",
191		       (long long)__raw_readq(IOADDR(A_SCD_TRACE_READ)));
192
193	csr_out32(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
194	csr_out32(M_SCD_TRACE_CFG_START, IOADDR(A_SCD_TRACE_CFG));
195#endif
196
197	/* Destructive read, clears register and interrupt */
198	stats->status = csr_in32(IOADDR(A_SCD_BUS_ERR_STATUS));
199	stats->status_printed = 0;
200
201	stats->l2_err = cntr = csr_in32(IOADDR(A_BUS_L2_ERRORS));
202	stats->l2_cor_d += G_SCD_L2ECC_CORR_D(cntr);
203	stats->l2_bad_d += G_SCD_L2ECC_BAD_D(cntr);
204	stats->l2_cor_t += G_SCD_L2ECC_CORR_T(cntr);
205	stats->l2_bad_t += G_SCD_L2ECC_BAD_T(cntr);
206	csr_out32(0, IOADDR(A_BUS_L2_ERRORS));
207
208	stats->memio_err = cntr = csr_in32(IOADDR(A_BUS_MEM_IO_ERRORS));
209	stats->mem_cor_d += G_SCD_MEM_ECC_CORR(cntr);
210	stats->mem_bad_d += G_SCD_MEM_ECC_BAD(cntr);
211	stats->bus_error += G_SCD_MEM_BUSERR(cntr);
212	csr_out32(0, IOADDR(A_BUS_MEM_IO_ERRORS));
213
214	return IRQ_HANDLED;
215}
216
217int __init sibyte_bus_watcher(void)
218{
219	memset(&bw_stats, 0, sizeof(struct bw_stats_struct));
220	bw_stats.status_printed = 1;
221
222	if (request_irq(K_INT_BAD_ECC, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
223		printk("Failed to register bus watcher BAD_ECC irq\n");
224		return -1;
225	}
226	if (request_irq(K_INT_COR_ECC, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
227		free_irq(K_INT_BAD_ECC, &bw_stats);
228		printk("Failed to register bus watcher COR_ECC irq\n");
229		return -1;
230	}
231	if (request_irq(K_INT_IO_BUS, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
232		free_irq(K_INT_BAD_ECC, &bw_stats);
233		free_irq(K_INT_COR_ECC, &bw_stats);
234		printk("Failed to register bus watcher IO_BUS irq\n");
235		return -1;
236	}
237
238#ifdef CONFIG_PROC_FS
239	create_proc_decoder(&bw_stats);
240#endif
241
242#ifdef CONFIG_SIBYTE_BW_TRACE
243	csr_out32((M_SCD_TRSEQ_ASAMPLE | M_SCD_TRSEQ_DSAMPLE |
244		   K_SCD_TRSEQ_TRIGGER_ALL),
245		  IOADDR(A_SCD_TRACE_SEQUENCE_0));
246	csr_out32(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
247	csr_out32(M_SCD_TRACE_CFG_START, IOADDR(A_SCD_TRACE_CFG));
248#endif
249
250	return 0;
251}
252
253device_initcall(sibyte_bus_watcher);