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