arch/mips/sibyte/common/bus_watcher.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2002,2003 Broadcom Corporation
   4  */
   5
   6 /*
   7  * The Bus Watcher monitors internal bus transactions and maintains
   8  * counts of transactions with error status, logging details and
   9  * causing one of several interrupts.  This driver provides a handler
  10  * for those interrupts which aggregates the counts (to avoid
  11  * saturating the 8-bit counters) and provides a presence in
  12  * /proc/bus_watcher if PROC_FS is on.
  13  */
  14
  15 #include <linux/init.h>
  16 #include <linux/kernel.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/sched.h>
  19 #include <linux/proc_fs.h>
  20 #include <linux/seq_file.h>
  21 #include <asm/io.h>
  22
  23 #include <asm/sibyte/sb1250.h>
  24 #include <asm/sibyte/sb1250_regs.h>
  25 #include <asm/sibyte/sb1250_int.h>
  26 #include <asm/sibyte/sb1250_scd.h>
  27 #if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
  28 #include <asm/sibyte/bcm1480_regs.h>
  29 #endif
  30
  31
  32 struct bw_stats_struct {
  33         uint64_t status;
  34         uint32_t l2_err;
  35         uint32_t memio_err;
  36         int status_printed;
  37         unsigned long l2_cor_d;
  38         unsigned long l2_bad_d;
  39         unsigned long l2_cor_t;
  40         unsigned long l2_bad_t;
  41         unsigned long mem_cor_d;
  42         unsigned long mem_bad_d;
  43         unsigned long bus_error;
  44 } bw_stats;
  45
  46
  47 static void print_summary(uint32_t status, uint32_t l2_err,
  48                           uint32_t memio_err)
  49 {
  50         printk("Bus watcher error counters: %08x %08x\n", l2_err, memio_err);
  51         printk("\nLast recorded signature:\n");
  52         printk("Request %02x from %d, answered by %d with Dcode %d\n",
  53                (unsigned int)(G_SCD_BERR_TID(status) & 0x3f),
  54                (int)(G_SCD_BERR_TID(status) >> 6),
  55                (int)G_SCD_BERR_RID(status),
  56                (int)G_SCD_BERR_DCODE(status));
  57 }
  58
  59 /*
  60  * check_bus_watcher is exported for use in situations where we want
  61  * to see the most recent status of the bus watcher, which might have
  62  * already been destructively read out of the registers.
  63  *
  64  * notes: this is currently used by the cache error handler
  65  *        should provide locking against the interrupt handler
  66  */
  67 void check_bus_watcher(void)
  68 {
  69         u32 status, l2_err, memio_err;
  70
  71 #if defined(CONFIG_SIBYTE_BCM112X) || defined(CONFIG_SIBYTE_SB1250)
  72         /* Use non-destructive register */
  73         status = csr_in32(IOADDR(A_SCD_BUS_ERR_STATUS_DEBUG));
  74 #elif defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
  75         /* Use non-destructive register */
  76         /* Same as 1250 except BUS_ERR_STATUS_DEBUG is in a different place. */
  77         status = csr_in32(IOADDR(A_BCM1480_BUS_ERR_STATUS_DEBUG));
  78 #else
  79 #error bus watcher being built for unknown Sibyte SOC!
  80 #endif
  81         if (!(status & 0x7fffffff)) {
  82                 printk("Using last values reaped by bus watcher driver\n");
  83                 status = bw_stats.status;
  84                 l2_err = bw_stats.l2_err;
  85                 memio_err = bw_stats.memio_err;
  86         } else {
  87                 l2_err = csr_in32(IOADDR(A_BUS_L2_ERRORS));
  88                 memio_err = csr_in32(IOADDR(A_BUS_MEM_IO_ERRORS));
  89         }
  90         if (status & ~(1UL << 31))
  91                 print_summary(status, l2_err, memio_err);
  92         else
  93                 printk("Bus watcher indicates no error\n");
  94 }
  95
  96 #ifdef CONFIG_PROC_FS
  97
  98 /* For simplicity, I want to assume a single read is required each
  99    time */
 100 static int bw_proc_show(struct seq_file *m, void *v)
 101 {
 102         struct bw_stats_struct *stats = m->private;
 103
 104         seq_puts(m, "SiByte Bus Watcher statistics\n");
 105         seq_puts(m, "-----------------------------\n");
 106         seq_printf(m, "L2-d-cor %8ld\nL2-d-bad %8ld\n",
 107                    stats->l2_cor_d, stats->l2_bad_d);
 108         seq_printf(m, "L2-t-cor %8ld\nL2-t-bad %8ld\n",
 109                    stats->l2_cor_t, stats->l2_bad_t);
 110         seq_printf(m, "MC-d-cor %8ld\nMC-d-bad %8ld\n",
 111                    stats->mem_cor_d, stats->mem_bad_d);
 112         seq_printf(m, "IO-err   %8ld\n", stats->bus_error);
 113         seq_puts(m, "\nLast recorded signature:\n");
 114         seq_printf(m, "Request %02x from %d, answered by %d with Dcode %d\n",
 115                    (unsigned int)(G_SCD_BERR_TID(stats->status) & 0x3f),
 116                    (int)(G_SCD_BERR_TID(stats->status) >> 6),
 117                    (int)G_SCD_BERR_RID(stats->status),
 118                    (int)G_SCD_BERR_DCODE(stats->status));
 119         /* XXXKW indicate multiple errors between printings, or stats
 120            collection (or both)? */
 121         if (stats->status & M_SCD_BERR_MULTERRS)
 122                 seq_puts(m, "Multiple errors observed since last check.\n");
 123         if (stats->status_printed) {
 124                 seq_puts(m, "(no change since last printing)\n");
 125         } else {
 126                 stats->status_printed = 1;
 127         }
 128
 129         return 0;
 130 }
 131
 132 static void create_proc_decoder(struct bw_stats_struct *stats)
 133 {
 134         struct proc_dir_entry *ent;
 135
 136         ent = proc_create_single_data("bus_watcher", S_IWUSR | S_IRUGO, NULL,
 137                         bw_proc_show, stats);
 138         if (!ent) {
 139                 printk(KERN_INFO "Unable to initialize bus_watcher /proc entry\n");
 140                 return;
 141         }
 142 }
 143
 144 #endif /* CONFIG_PROC_FS */
 145
 146 /*
 147  * sibyte_bw_int - handle bus watcher interrupts and accumulate counts
 148  *
 149  * notes: possible re-entry due to multiple sources
 150  *        should check/indicate saturation
 151  */
 152 static irqreturn_t sibyte_bw_int(int irq, void *data)
 153 {
 154         struct bw_stats_struct *stats = data;
 155         unsigned long cntr;
 156 #ifdef CONFIG_SIBYTE_BW_TRACE
 157         int i;
 158 #endif
 159
 160 #ifdef CONFIG_SIBYTE_BW_TRACE
 161         csr_out32(M_SCD_TRACE_CFG_FREEZE, IOADDR(A_SCD_TRACE_CFG));
 162         csr_out32(M_SCD_TRACE_CFG_START_READ, IOADDR(A_SCD_TRACE_CFG));
 163
 164         for (i=0; i<256*6; i++)
 165                 printk("%016llx\n",
 166                        (long long)__raw_readq(IOADDR(A_SCD_TRACE_READ)));
 167
 168         csr_out32(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
 169         csr_out32(M_SCD_TRACE_CFG_START, IOADDR(A_SCD_TRACE_CFG));
 170 #endif
 171
 172         /* Destructive read, clears register and interrupt */
 173         stats->status = csr_in32(IOADDR(A_SCD_BUS_ERR_STATUS));
 174         stats->status_printed = 0;
 175
 176         stats->l2_err = cntr = csr_in32(IOADDR(A_BUS_L2_ERRORS));
 177         stats->l2_cor_d += G_SCD_L2ECC_CORR_D(cntr);
 178         stats->l2_bad_d += G_SCD_L2ECC_BAD_D(cntr);
 179         stats->l2_cor_t += G_SCD_L2ECC_CORR_T(cntr);
 180         stats->l2_bad_t += G_SCD_L2ECC_BAD_T(cntr);
 181         csr_out32(0, IOADDR(A_BUS_L2_ERRORS));
 182
 183         stats->memio_err = cntr = csr_in32(IOADDR(A_BUS_MEM_IO_ERRORS));
 184         stats->mem_cor_d += G_SCD_MEM_ECC_CORR(cntr);
 185         stats->mem_bad_d += G_SCD_MEM_ECC_BAD(cntr);
 186         stats->bus_error += G_SCD_MEM_BUSERR(cntr);
 187         csr_out32(0, IOADDR(A_BUS_MEM_IO_ERRORS));
 188
 189         return IRQ_HANDLED;
 190 }
 191
 192 int __init sibyte_bus_watcher(void)
 193 {
 194         memset(&bw_stats, 0, sizeof(struct bw_stats_struct));
 195         bw_stats.status_printed = 1;
 196
 197         if (request_irq(K_INT_BAD_ECC, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
 198                 printk("Failed to register bus watcher BAD_ECC irq\n");
 199                 return -1;
 200         }
 201         if (request_irq(K_INT_COR_ECC, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
 202                 free_irq(K_INT_BAD_ECC, &bw_stats);
 203                 printk("Failed to register bus watcher COR_ECC irq\n");
 204                 return -1;
 205         }
 206         if (request_irq(K_INT_IO_BUS, sibyte_bw_int, 0, "Bus watcher", &bw_stats)) {
 207                 free_irq(K_INT_BAD_ECC, &bw_stats);
 208                 free_irq(K_INT_COR_ECC, &bw_stats);
 209                 printk("Failed to register bus watcher IO_BUS irq\n");
 210                 return -1;
 211         }
 212
 213 #ifdef CONFIG_PROC_FS
 214         create_proc_decoder(&bw_stats);
 215 #endif
 216
 217 #ifdef CONFIG_SIBYTE_BW_TRACE
 218         csr_out32((M_SCD_TRSEQ_ASAMPLE | M_SCD_TRSEQ_DSAMPLE |
 219                    K_SCD_TRSEQ_TRIGGER_ALL),
 220                   IOADDR(A_SCD_TRACE_SEQUENCE_0));
 221         csr_out32(M_SCD_TRACE_CFG_RESET, IOADDR(A_SCD_TRACE_CFG));
 222         csr_out32(M_SCD_TRACE_CFG_START, IOADDR(A_SCD_TRACE_CFG));
 223 #endif
 224
 225         return 0;
 226 }
 227
 228 device_initcall(sibyte_bus_watcher);