xref: /openbmc/linux/arch/csky/kernel/cpu-probe.c (revision 6c33a6f4)
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 };
80