arch/csky/kernel/cpu-probe.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
   3
   4 #include <linux/of.h>
   5 #include <linux/init.h>
   6 #include <linux/seq_file.h>
   7 #include <linux/memblock.h>
   8
   9 #include <abi/reg_ops.h>
  10
  11 static void percpu_print(void *arg)
  12 {
  13         struct seq_file *m = (struct seq_file *)arg;
  14         unsigned int cur, next, i;
  15
  16         seq_printf(m, "processor       : %d\n", smp_processor_id());
  17         seq_printf(m, "C-SKY CPU model : %s\n", CSKYCPU_DEF_NAME);
  18
  19         /* read processor id, max is 100 */
  20         cur  = mfcr("cr13");
  21         for (i = 0; i < 100; i++) {
  22                 seq_printf(m, "product info[%d] : 0x%08x\n", i, cur);
  23
  24                 next = mfcr("cr13");
  25
  26                 /* some CPU only has one id reg */
  27                 if (cur == next)
  28                         break;
  29
  30                 cur = next;
  31
  32                 /* cpid index is 31-28, reset */
  33                 if (!(next >> 28)) {
  34                         while ((mfcr("cr13") >> 28) != i);
  35                         break;
  36                 }
  37         }
  38
  39         /* CPU feature regs, setup by bootloader or gdbinit */
  40         seq_printf(m, "hint (CPU funcs): 0x%08x\n", mfcr_hint());
  41         seq_printf(m, "ccr  (L1C & MMU): 0x%08x\n", mfcr("cr18"));
  42         seq_printf(m, "ccr2 (L2C)      : 0x%08x\n", mfcr_ccr2());
  43         seq_printf(m, "\n");
  44 }
  45
  46 static int c_show(struct seq_file *m, void *v)
  47 {
  48         int cpu;
  49
  50         for_each_online_cpu(cpu)
  51                 smp_call_function_single(cpu, percpu_print, m, true);
  52
  53 #ifdef CSKY_ARCH_VERSION
  54         seq_printf(m, "arch-version : %s\n", CSKY_ARCH_VERSION);
  55         seq_printf(m, "\n");
  56 #endif
  57
  58         return 0;
  59 }
  60
  61 static void *c_start(struct seq_file *m, loff_t *pos)
  62 {
  63         return *pos < 1 ? (void *)1 : NULL;
  64 }
  65
  66 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
  67 {
  68         ++*pos;
  69         return NULL;
  70 }
  71
  72 static void c_stop(struct seq_file *m, void *v) {}
  73
  74 const struct seq_operations cpuinfo_op = {
  75         .start  = c_start,
  76         .next   = c_next,
  77         .stop   = c_stop,
  78         .show   = c_show,
  79 };