xref: /linux/arch/s390/kernel/processor.c (revision b85d45947951d23cb22d90caecf4c1eb81342c96)
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  * cpu_have_feature - Test CPU features on module initialization
45  */
46 int cpu_have_feature(unsigned int num)
47 {
48 	return elf_hwcap & (1UL << num);
49 }
50 EXPORT_SYMBOL(cpu_have_feature);
51 
52 /*
53  * show_cpuinfo - Get information on one CPU for use by procfs.
54  */
55 static int show_cpuinfo(struct seq_file *m, void *v)
56 {
57 	static const char *hwcap_str[] = {
58 		"esan3", "zarch", "stfle", "msa", "ldisp", "eimm", "dfp",
59 		"edat", "etf3eh", "highgprs", "te", "vx"
60 	};
61 	unsigned long n = (unsigned long) v - 1;
62 	int i;
63 
64 	if (!n) {
65 		s390_adjust_jiffies();
66 		seq_printf(m, "vendor_id       : IBM/S390\n"
67 			   "# processors    : %i\n"
68 			   "bogomips per cpu: %lu.%02lu\n",
69 			   num_online_cpus(), loops_per_jiffy/(500000/HZ),
70 			   (loops_per_jiffy/(5000/HZ))%100);
71 		seq_puts(m, "features\t: ");
72 		for (i = 0; i < ARRAY_SIZE(hwcap_str); i++)
73 			if (hwcap_str[i] && (elf_hwcap & (1UL << i)))
74 				seq_printf(m, "%s ", hwcap_str[i]);
75 		seq_puts(m, "\n");
76 		show_cacheinfo(m);
77 	}
78 	get_online_cpus();
79 	if (cpu_online(n)) {
80 		struct cpuid *id = &per_cpu(cpu_id, n);
81 		seq_printf(m, "processor %li: "
82 			   "version = %02X,  "
83 			   "identification = %06X,  "
84 			   "machine = %04X\n",
85 			   n, id->version, id->ident, id->machine);
86 	}
87 	put_online_cpus();
88 	return 0;
89 }
90 
91 static void *c_start(struct seq_file *m, loff_t *pos)
92 {
93 	return *pos < nr_cpu_ids ? (void *)((unsigned long) *pos + 1) : NULL;
94 }
95 
96 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
97 {
98 	++*pos;
99 	return c_start(m, pos);
100 }
101 
102 static void c_stop(struct seq_file *m, void *v)
103 {
104 }
105 
106 const struct seq_operations cpuinfo_op = {
107 	.start	= c_start,
108 	.next	= c_next,
109 	.stop	= c_stop,
110 	.show	= show_cpuinfo,
111 };
112 
113