xref: /linux/arch/s390/kernel/processor.c (revision e8d235d4d8fb8957bae5f6ed4521115203a00d8b)
1 /*
2  *  Copyright IBM Corp. 2008
3  *  Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
4  */
5 
6 #define KMSG_COMPONENT "cpu"
7 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
8 
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/seq_file.h>
12 #include <linux/delay.h>
13 #include <linux/cpu.h>
14 #include <asm/elf.h>
15 #include <asm/lowcore.h>
16 #include <asm/param.h>
17 #include <asm/smp.h>
18 
19 static DEFINE_PER_CPU(struct cpuid, cpu_id);
20 
21 void notrace cpu_relax(void)
22 {
23 	if (!smp_cpu_mtid && MACHINE_HAS_DIAG44)
24 		asm volatile("diag 0,0,0x44");
25 	barrier();
26 }
27 EXPORT_SYMBOL(cpu_relax);
28 
29 /*
30  * cpu_init - initializes state that is per-CPU.
31  */
32 void cpu_init(void)
33 {
34 	struct cpuid *id = this_cpu_ptr(&cpu_id);
35 
36 	get_cpu_id(id);
37 	atomic_inc(&init_mm.mm_count);
38 	current->active_mm = &init_mm;
39 	BUG_ON(current->mm);
40 	enter_lazy_tlb(&init_mm, current);
41 }
42 
43 /*
44  * show_cpuinfo - Get information on one CPU for use by procfs.
45  */
46 static int show_cpuinfo(struct seq_file *m, void *v)
47 {
48 	static const char *hwcap_str[] = {
49 		"esan3", "zarch", "stfle", "msa", "ldisp", "eimm", "dfp",
50 		"edat", "etf3eh", "highgprs", "te", "vx"
51 	};
52 	unsigned long n = (unsigned long) v - 1;
53 	int i;
54 
55 	if (!n) {
56 		s390_adjust_jiffies();
57 		seq_printf(m, "vendor_id       : IBM/S390\n"
58 			   "# processors    : %i\n"
59 			   "bogomips per cpu: %lu.%02lu\n",
60 			   num_online_cpus(), loops_per_jiffy/(500000/HZ),
61 			   (loops_per_jiffy/(5000/HZ))%100);
62 		seq_puts(m, "features\t: ");
63 		for (i = 0; i < ARRAY_SIZE(hwcap_str); i++)
64 			if (hwcap_str[i] && (elf_hwcap & (1UL << i)))
65 				seq_printf(m, "%s ", hwcap_str[i]);
66 		seq_puts(m, "\n");
67 		show_cacheinfo(m);
68 	}
69 	get_online_cpus();
70 	if (cpu_online(n)) {
71 		struct cpuid *id = &per_cpu(cpu_id, n);
72 		seq_printf(m, "processor %li: "
73 			   "version = %02X,  "
74 			   "identification = %06X,  "
75 			   "machine = %04X\n",
76 			   n, id->version, id->ident, id->machine);
77 	}
78 	put_online_cpus();
79 	return 0;
80 }
81 
82 static void *c_start(struct seq_file *m, loff_t *pos)
83 {
84 	return *pos < nr_cpu_ids ? (void *)((unsigned long) *pos + 1) : NULL;
85 }
86 
87 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
88 {
89 	++*pos;
90 	return c_start(m, pos);
91 }
92 
93 static void c_stop(struct seq_file *m, void *v)
94 {
95 }
96 
97 const struct seq_operations cpuinfo_op = {
98 	.start	= c_start,
99 	.next	= c_next,
100 	.stop	= c_stop,
101 	.show	= show_cpuinfo,
102 };
103 
104