arch/mips/sibyte/sb1250/bus_watcher.c

   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/config.h>
  29 #include <linux/init.h>
  30 #include <linux/kernel.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/sched.h>
  33 #include <linux/proc_fs.h>
  34 #include <asm/system.h>
  35 #include <asm/io.h>
  36
  37 #include <asm/sibyte/sb1250.h>
  38 #include <asm/sibyte/sb1250_regs.h>
  39 #include <asm/sibyte/sb1250_int.h>
  40 #include <asm/sibyte/sb1250_scd.h>
  41
  42
  43 struct bw_stats_struct {
  44         uint64_t status;
  45         uint32_t l2_err;
  46         uint32_t memio_err;
  47         int status_printed;
  48         unsigned long l2_cor_d;
  49         unsigned long l2_bad_d;
  50         unsigned long l2_cor_t;
  51         unsigned long l2_bad_t;
  52         unsigned long mem_cor_d;
  53         unsigned long mem_bad_d;
  54         unsigned long bus_error;
  55 } bw_stats;
  56
  57
  58 static void print_summary(uint32_t status, uint32_t l2_err,
  59                           uint32_t memio_err)
  60 {
  61         printk("Bus watcher error counters: %08x %08x\n", l2_err, memio_err);
  62         printk("\nLast recorded signature:\n");
  63         printk("Request %02x from %d, answered by %d with Dcode %d\n",
  64                (unsigned int)(G_SCD_BERR_TID(status) & 0x3f),
  65                (int)(G_SCD_BERR_TID(status) >> 6),
  66                (int)G_SCD_BERR_RID(status),
  67                (int)G_SCD_BERR_DCODE(status));
  68 }
  69
  70 /*
  71  * check_bus_watcher is exported for use in situations where we want
  72  * to see the most recent status of the bus watcher, which might have
  73  * already been destructively read out of the registers.
  74  *
  75  * notes: this is currently used by the cache error handler
  76  *        should provide locking against the interrupt handler
  77  */
  78 void check_bus_watcher(void)
  79 {
  80         u32 status, l2_err, memio_err;
  81
  82 #ifdef CONFIG_SB1_PASS_1_WORKAROUNDS
  83         /* Destructive read, clears register and interrupt */
  84         status = csr_in32(IOADDR(A_SCD_BUS_ERR_STATUS));
  85 #else
  86         /* Use non-destructive register */
  87         status = csr_in32(IOADDR(A_SCD_BUS_ERR_STATUS_DEBUG));
  88 #endif
  89         if (!(status & 0x7fffffff)) {
  90                 printk("Using last values reaped by bus watcher driver\n");
  91                 status = bw_stats.status;
  92                 l2_err = bw_stats.l2_err;
  93                 memio_err = bw_stats.memio_err;
  94         } else {
  95                 l2_err = csr_in32(IOADDR(A_BUS_L2_ERRORS));
  96                 memio_err = csr_in32(IOADDR(A_BUS_MEM_IO_ERRORS));
  97         }
  98         if (status & ~(1UL << 31))
  99                 print_summary(status, l2_err, memio_err);
 100         else
 101                 printk("Bus watcher indicates no error\n");
 102 }
 103
 104 static int bw_print_buffer(char *page, struct bw_stats_struct *stats)
 105 {
 106         int len;
 107
 108         len = sprintf(page, "SiByte Bus Watcher statistics\n");
 109         len += sprintf(page+len, "-----------------------------\n");
 110         len += sprintf(page+len, "L2-d-cor %8ld\nL2-d-bad %8ld\n",
 111                        stats->l2_cor_d, stats->l2_bad_d);
 112         len += sprintf(page+len, "L2-t-cor %8ld\nL2-t-bad %8ld\n",
 113                        stats->l2_cor_t, stats->l2_bad_t);
 114         len += sprintf(page+len, "MC-d-cor %8ld\nMC-d-bad %8ld\n",
 115                        stats->mem_cor_d, stats->mem_bad_d);
 116         len += sprintf(page+len, "IO-err   %8ld\n", stats->bus_error);
 117         len += sprintf(page+len, "\nLast recorded signature:\n");
 118         len += sprintf(page+len, "Request %02x from %d, answered by %d with Dcode %d\n",
 119                        (unsigned int)(G_SCD_BERR_TID(stats->status) & 0x3f),
 120                        (int)(G_SCD_BERR_TID(stats->status) >> 6),
 121                        (int)G_SCD_BERR_RID(stats->status),
 122                        (int)G_SCD_BERR_DCODE(stats->status));
 123         /* XXXKW indicate multiple errors between printings, or stats
 124            collection (or both)? */
 125         if (stats->status & M_SCD_BERR_MULTERRS)
 126                 len += sprintf(page+len, "Multiple errors observed since last check.\n");
 127         if (stats->status_printed) {
 128                 len += sprintf(page+len, "(no change since last printing)\n");
 129         } else {
 130                 stats->status_printed = 1;
 131         }
 132
 133         return len;
 134 }
 135
 136 #ifdef CONFIG_PROC_FS
 137
 138 /* For simplicity, I want to assume a single read is required each
 139    time */
 140 static int bw_read_proc(char *page, char **start, off_t off,
 141                         int count, int *eof, void *data)
 142 {
 143         int len;
 144
 145         if (off == 0) {
 146                 len = bw_print_buffer(page, data);
 147                 *start = page;
 148         } else {
 149                 len = 0;
 150                 *eof = 1;
 151         }
 152         return len;
 153 }
 154
 155 static void create_proc_decoder(struct bw_stats_struct *stats)
 156 {
 157         struct proc_dir_entry *ent;
 158
 159         ent = create_proc_read_entry("bus_watcher", S_IWUSR | S_IRUGO, NULL,
 160                                      bw_read_proc, stats);
 161         if (!ent) {
 162                 printk(KERN_INFO "Unable to initialize bus_watcher /proc entry\n");
 163                 return;
 164         }
 165 }
 166
 167 #endif /* CONFIG_PROC_FS */
 168
 169 /*
 170  * sibyte_bw_int - handle bus watcher interrupts and accumulate counts
 171  *
 172  * notes: possible re-entry due to multiple sources
 173  *        should check/indicate saturation
 174  */
 175 static irqreturn_t sibyte_bw_int(int irq, void *data, struct pt_regs *regs)
 176 {
 177         struct bw_stats_struct *stats = data;
 178         unsigned long cntr;
 179 #ifdef CONFIG_SIBYTE_BW_TRACE
 180         int i;
 181 #endif
 182 #ifndef CONFIG_PROC_FS
 183         char bw_buf[1024];
 184 #endif
 185
 186 #ifdef CONFIG_SIBYTE_BW_TRACE
 187         csr_out32(M_SCD_TRACE_CFG_FREEZE, IOADDR(A_SCD_TRACE_CFG));
 188         csr_out32(M_SCD_TRACE_CFG_START_READ, IOADDR(A_SCD_TRACE_CFG));
 189
 190         for (i=0; i<256*6; i++)
 191                 printk("%016llx\n",
 192                        (unsigned long long)bus_readq(IOADDR(A_SCD_TRACE_READ)));
 193
 194         csr_out32(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
 195         csr_out32(M_SCD_TRACE_CFG_START, IOADDR(A_SCD_TRACE_CFG));
 196 #endif
 197
 198         /* Destructive read, clears register and interrupt */
 199         stats->status = csr_in32(IOADDR(A_SCD_BUS_ERR_STATUS));
 200         stats->status_printed = 0;
 201
 202         stats->l2_err = cntr = csr_in32(IOADDR(A_BUS_L2_ERRORS));
 203         stats->l2_cor_d += G_SCD_L2ECC_CORR_D(cntr);
 204         stats->l2_bad_d += G_SCD_L2ECC_BAD_D(cntr);
 205         stats->l2_cor_t += G_SCD_L2ECC_CORR_T(cntr);
 206         stats->l2_bad_t += G_SCD_L2ECC_BAD_T(cntr);
 207         csr_out32(0, IOADDR(A_BUS_L2_ERRORS));
 208
 209         stats->memio_err = cntr = csr_in32(IOADDR(A_BUS_MEM_IO_ERRORS));
 210         stats->mem_cor_d += G_SCD_MEM_ECC_CORR(cntr);
 211         stats->mem_bad_d += G_SCD_MEM_ECC_BAD(cntr);
 212         stats->bus_error += G_SCD_MEM_BUSERR(cntr);
 213         csr_out32(0, IOADDR(A_BUS_MEM_IO_ERRORS));
 214
 215 #ifndef CONFIG_PROC_FS
 216         bw_print_buffer(bw_buf, stats);
 217         printk(bw_buf);
 218 #endif
 219
 220         return IRQ_HANDLED;
 221 }
 222
 223 int __init sibyte_bus_watcher(void)
 224 {
 225         memset(&bw_stats, 0, sizeof(struct bw_stats_struct));
 226         bw_stats.status_printed = 1;
 227
 228         if (request_irq(K_INT_BAD_ECC, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
 229                 printk("Failed to register bus watcher BAD_ECC irq\n");
 230                 return -1;
 231         }
 232         if (request_irq(K_INT_COR_ECC, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
 233                 free_irq(K_INT_BAD_ECC, &bw_stats);
 234                 printk("Failed to register bus watcher COR_ECC irq\n");
 235                 return -1;
 236         }
 237         if (request_irq(K_INT_IO_BUS, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
 238                 free_irq(K_INT_BAD_ECC, &bw_stats);
 239                 free_irq(K_INT_COR_ECC, &bw_stats);
 240                 printk("Failed to register bus watcher IO_BUS irq\n");
 241                 return -1;
 242         }
 243
 244 #ifdef CONFIG_PROC_FS
 245         create_proc_decoder(&bw_stats);
 246 #endif
 247
 248 #ifdef CONFIG_SIBYTE_BW_TRACE
 249         csr_out32((M_SCD_TRSEQ_ASAMPLE | M_SCD_TRSEQ_DSAMPLE |
 250                    K_SCD_TRSEQ_TRIGGER_ALL),
 251                   IOADDR(A_SCD_TRACE_SEQUENCE_0));
 252         csr_out32(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
 253         csr_out32(M_SCD_TRACE_CFG_START, IOADDR(A_SCD_TRACE_CFG));
 254 #endif
 255
 256         return 0;
 257 }
 258
 259 __initcall(sibyte_bus_watcher);