LXR linux/arch/mips/sibyte/sb1250/bus

   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/system.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
  41
  42struct bw_stats_struct {
  43        uint64_t status;
  44        uint32_t l2_err;
  45        uint32_t memio_err;
  46        int status_printed;
  47        unsigned long l2_cor_d;
  48        unsigned long l2_bad_d;
  49        unsigned long l2_cor_t;
  50        unsigned long l2_bad_t;
  51        unsigned long mem_cor_d;
  52        unsigned long mem_bad_d;
  53        unsigned long bus_error;
  54} bw_stats;
  55
  56
  57static void print_summary(uint32_t status, uint32_t l2_err,
  58                          uint32_t memio_err)
  59{
  60        printk("Bus watcher error counters: %08x %08x\n", l2_err, memio_err);
  61        printk("\nLast recorded signature:\n");
  62        printk("Request %02x from %d, answered by %d with Dcode %d\n",
  63               (unsigned int)(G_SCD_BERR_TID(status) & 0x3f),
  64               (int)(G_SCD_BERR_TID(status) >> 6),
  65               (int)G_SCD_BERR_RID(status),
  66               (int)G_SCD_BERR_DCODE(status));
  67}
  68
  69/*
  70 * check_bus_watcher is exported for use in situations where we want
  71 * to see the most recent status of the bus watcher, which might have
  72 * already been destructively read out of the registers.
  73 *
  74 * notes: this is currently used by the cache error handler
  75 *        should provide locking against the interrupt handler
  76 */
  77void check_bus_watcher(void)
  78{
  79        u32 status, l2_err, memio_err;
  80
  81#ifdef CONFIG_SB1_PASS_1_WORKAROUNDS
  82        /* Destructive read, clears register and interrupt */
  83        status = csr_in32(IOADDR(A_SCD_BUS_ERR_STATUS));
  84#else
  85        /* Use non-destructive register */
  86        status = csr_in32(IOADDR(A_SCD_BUS_ERR_STATUS_DEBUG));
  87#endif
  88        if (!(status & 0x7fffffff)) {
  89                printk("Using last values reaped by bus watcher driver\n");
  90                status = bw_stats.status;
  91                l2_err = bw_stats.l2_err;
  92                memio_err = bw_stats.memio_err;
  93        } else {
  94                l2_err = csr_in32(IOADDR(A_BUS_L2_ERRORS));
  95                memio_err = csr_in32(IOADDR(A_BUS_MEM_IO_ERRORS));
  96        }
  97        if (status & ~(1UL << 31))
  98                print_summary(status, l2_err, memio_err);
  99        else
 100                printk("Bus watcher indicates no error\n");
 101}
 102
 103static int bw_print_buffer(char *page, struct bw_stats_struct *stats)
 104{
 105        int len;
 106
 107        len = sprintf(page, "SiByte Bus Watcher statistics\n");
 108        len += sprintf(page+len, "-----------------------------\n");
 109        len += sprintf(page+len, "L2-d-cor %8ld\nL2-d-bad %8ld\n",
 110                       stats->l2_cor_d, stats->l2_bad_d);
 111        len += sprintf(page+len, "L2-t-cor %8ld\nL2-t-bad %8ld\n",
 112                       stats->l2_cor_t, stats->l2_bad_t);
 113        len += sprintf(page+len, "MC-d-cor %8ld\nMC-d-bad %8ld\n",
 114                       stats->mem_cor_d, stats->mem_bad_d);
 115        len += sprintf(page+len, "IO-err   %8ld\n", stats->bus_error);
 116        len += sprintf(page+len, "\nLast recorded signature:\n");
 117        len += sprintf(page+len, "Request %02x from %d, answered by %d with Dcode %d\n",
 118                       (unsigned int)(G_SCD_BERR_TID(stats->status) & 0x3f),
 119                       (int)(G_SCD_BERR_TID(stats->status) >> 6),
 120                       (int)G_SCD_BERR_RID(stats->status),
 121                       (int)G_SCD_BERR_DCODE(stats->status));
 122        /* XXXKW indicate multiple errors between printings, or stats
 123           collection (or both)? */
 124        if (stats->status & M_SCD_BERR_MULTERRS)
 125                len += sprintf(page+len, "Multiple errors observed since last check.\n");
 126        if (stats->status_printed) {
 127                len += sprintf(page+len, "(no change since last printing)\n");
 128        } else {
 129                stats->status_printed = 1;
 130        }
 131
 132        return len;
 133}
 134
 135#ifdef CONFIG_PROC_FS
 136
 137/* For simplicity, I want to assume a single read is required each
 138   time */
 139static int bw_read_proc(char *page, char **start, off_t off,
 140                        int count, int *eof, void *data)
 141{
 142        int len;
 143
 144        if (off == 0) {
 145                len = bw_print_buffer(page, data);
 146                *start = page;
 147        } else {
 148                len = 0;
 149                *eof = 1;
 150        }
 151        return len;
 152}
 153
 154static void create_proc_decoder(struct bw_stats_struct *stats)
 155{
 156        struct proc_dir_entry *ent;
 157
 158        ent = create_proc_read_entry("bus_watcher", S_IWUSR | S_IRUGO, NULL,
 159                                     bw_read_proc, stats);
 160        if (!ent) {
 161                printk(KERN_INFO "Unable to initialize bus_watcher /proc entry\n");
 162                return;
 163        }
 164}
 165
 166#endif /* CONFIG_PROC_FS */
 167
 168/*
 169 * sibyte_bw_int - handle bus watcher interrupts and accumulate counts
 170 *
 171 * notes: possible re-entry due to multiple sources
 172 *        should check/indicate saturation
 173 */
 174static irqreturn_t sibyte_bw_int(int irq, void *data)
 175{
 176        struct bw_stats_struct *stats = data;
 177        unsigned long cntr;
 178#ifdef CONFIG_SIBYTE_BW_TRACE
 179        int i;
 180#endif
 181#ifndef CONFIG_PROC_FS
 182        char bw_buf[1024];
 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#ifndef CONFIG_PROC_FS
 215        bw_print_buffer(bw_buf, stats);
 216        printk(bw_buf);
 217#endif
 218
 219        return IRQ_HANDLED;
 220}
 221
 222int __init sibyte_bus_watcher(void)
 223{
 224        memset(&bw_stats, 0, sizeof(struct bw_stats_struct));
 225        bw_stats.status_printed = 1;
 226
 227        if (request_irq(K_INT_BAD_ECC, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
 228                printk("Failed to register bus watcher BAD_ECC irq\n");
 229                return -1;
 230        }
 231        if (request_irq(K_INT_COR_ECC, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
 232                free_irq(K_INT_BAD_ECC, &bw_stats);
 233                printk("Failed to register bus watcher COR_ECC irq\n");
 234                return -1;
 235        }
 236        if (request_irq(K_INT_IO_BUS, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
 237                free_irq(K_INT_BAD_ECC, &bw_stats);
 238                free_irq(K_INT_COR_ECC, &bw_stats);
 239                printk("Failed to register bus watcher IO_BUS irq\n");
 240                return -1;
 241        }
 242
 243#ifdef CONFIG_PROC_FS
 244        create_proc_decoder(&bw_stats);
 245#endif
 246
 247#ifdef CONFIG_SIBYTE_BW_TRACE
 248        csr_out32((M_SCD_TRSEQ_ASAMPLE | M_SCD_TRSEQ_DSAMPLE |
 249                   K_SCD_TRSEQ_TRIGGER_ALL),
 250                  IOADDR(A_SCD_TRACE_SEQUENCE_0));
 251        csr_out32(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
 252        csr_out32(M_SCD_TRACE_CFG_START, IOADDR(A_SCD_TRACE_CFG));
 253#endif
 254
 255        return 0;
 256}
 257
 258__initcall(sibyte_bus_watcher);
 259