xref: /linux/arch/s390/kernel/processor.c (revision a8fe58cec351c25e09c393bf46117c0c47b5a17c)
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/diag.h>
15 #include <asm/elf.h>
16 #include <asm/lowcore.h>
17 #include <asm/param.h>
18 #include <asm/smp.h>
19 
20 static DEFINE_PER_CPU(struct cpuid, cpu_id);
21 
22 void notrace cpu_relax(void)
23 {
24 	if (!smp_cpu_mtid && MACHINE_HAS_DIAG44) {
25 		diag_stat_inc(DIAG_STAT_X044);
26 		asm volatile("diag 0,0,0x44");
27 	}
28 	barrier();
29 }
30 EXPORT_SYMBOL(cpu_relax);
31 
32 /*
33  * cpu_init - initializes state that is per-CPU.
34  */
35 void cpu_init(void)
36 {
37 	struct cpuid *id = this_cpu_ptr(&cpu_id);
38 
39 	get_cpu_id(id);
40 	atomic_inc(&init_mm.mm_count);
41 	current->active_mm = &init_mm;
42 	BUG_ON(current->mm);
43 	enter_lazy_tlb(&init_mm, current);
44 }
45 
46 /*
47  * cpu_have_feature - Test CPU features on module initialization
48  */
49 int cpu_have_feature(unsigned int num)
50 {
51 	return elf_hwcap & (1UL << num);
52 }
53 EXPORT_SYMBOL(cpu_have_feature);
54 
55 /*
56  * show_cpuinfo - Get information on one CPU for use by procfs.
57  */
58 static int show_cpuinfo(struct seq_file *m, void *v)
59 {
60 	static const char *hwcap_str[] = {
61 		"esan3", "zarch", "stfle", "msa", "ldisp", "eimm", "dfp",
62 		"edat", "etf3eh", "highgprs", "te", "vx"
63 	};
64 	static const char * const int_hwcap_str[] = {
65 		"sie"
66 	};
67 	unsigned long n = (unsigned long) v - 1;
68 	int i;
69 
70 	if (!n) {
71 		s390_adjust_jiffies();
72 		seq_printf(m, "vendor_id       : IBM/S390\n"
73 			   "# processors    : %i\n"
74 			   "bogomips per cpu: %lu.%02lu\n",
75 			   num_online_cpus(), loops_per_jiffy/(500000/HZ),
76 			   (loops_per_jiffy/(5000/HZ))%100);
77 		seq_puts(m, "features\t: ");
78 		for (i = 0; i < ARRAY_SIZE(hwcap_str); i++)
79 			if (hwcap_str[i] && (elf_hwcap & (1UL << i)))
80 				seq_printf(m, "%s ", hwcap_str[i]);
81 		for (i = 0; i < ARRAY_SIZE(int_hwcap_str); i++)
82 			if (int_hwcap_str[i] && (int_hwcap & (1UL << i)))
83 				seq_printf(m, "%s ", int_hwcap_str[i]);
84 		seq_puts(m, "\n");
85 		show_cacheinfo(m);
86 	}
87 	get_online_cpus();
88 	if (cpu_online(n)) {
89 		struct cpuid *id = &per_cpu(cpu_id, n);
90 		seq_printf(m, "processor %li: "
91 			   "version = %02X,  "
92 			   "identification = %06X,  "
93 			   "machine = %04X\n",
94 			   n, id->version, id->ident, id->machine);
95 	}
96 	put_online_cpus();
97 	return 0;
98 }
99 
100 static void *c_start(struct seq_file *m, loff_t *pos)
101 {
102 	return *pos < nr_cpu_ids ? (void *)((unsigned long) *pos + 1) : NULL;
103 }
104 
105 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
106 {
107 	++*pos;
108 	return c_start(m, pos);
109 }
110 
111 static void c_stop(struct seq_file *m, void *v)
112 {
113 }
114 
115 const struct seq_operations cpuinfo_op = {
116 	.start	= c_start,
117 	.next	= c_next,
118 	.stop	= c_stop,
119 	.show	= show_cpuinfo,
120 };
121 
122