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/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
  42 struct 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
  57 static 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  */
  77 void 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
 103 static 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 */
 139 static 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
 154 static 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  */
 174 static 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
 222 int __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);