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
11static 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, fmt: "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, fmt: "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, fmt: "hint (CPU funcs): 0x%08x\n", mfcr_hint());
41 seq_printf(m, fmt: "ccr (L1C & MMU): 0x%08x\n", mfcr("cr18"));
42 seq_printf(m, fmt: "ccr2 (L2C) : 0x%08x\n", mfcr_ccr2());
43 seq_printf(m, fmt: "\n");
44}
45
46static 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(cpuid: cpu, func: percpu_print, info: m, wait: 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
61static void *c_start(struct seq_file *m, loff_t *pos)
62{
63 return *pos < 1 ? (void *)1 : NULL;
64}
65
66static void *c_next(struct seq_file *m, void *v, loff_t *pos)
67{
68 ++*pos;
69 return NULL;
70}
71
72static void c_stop(struct seq_file *m, void *v) {}
73
74const struct seq_operations cpuinfo_op = {
75 .start = c_start,
76 .next = c_next,
77 .stop = c_stop,
78 .show = c_show,
79};
80

source code of linux/arch/csky/kernel/cpu-probe.c