1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright IBM Corp. 2008
4 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
5 */
6
7 #define KMSG_COMPONENT "cpu"
8 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
9
10 #include <linux/stop_machine.h>
11 #include <linux/cpufeature.h>
12 #include <linux/bitops.h>
13 #include <linux/kernel.h>
14 #include <linux/sched/mm.h>
15 #include <linux/init.h>
16 #include <linux/seq_file.h>
17 #include <linux/mm_types.h>
18 #include <linux/delay.h>
19 #include <linux/cpu.h>
20
21 #include <asm/diag.h>
22 #include <asm/facility.h>
23 #include <asm/elf.h>
24 #include <asm/lowcore.h>
25 #include <asm/param.h>
26 #include <asm/smp.h>
27
28 struct cpu_info {
29 unsigned int cpu_mhz_dynamic;
30 unsigned int cpu_mhz_static;
31 struct cpuid cpu_id;
32 };
33
34 static DEFINE_PER_CPU(struct cpu_info, cpu_info);
35 static DEFINE_PER_CPU(int, cpu_relax_retry);
36
37 static bool machine_has_cpu_mhz;
38
cpu_detect_mhz_feature(void)39 void __init cpu_detect_mhz_feature(void)
40 {
41 if (test_facility(34) && __ecag(ECAG_CPU_ATTRIBUTE, 0) != -1UL)
42 machine_has_cpu_mhz = true;
43 }
44
update_cpu_mhz(void * arg)45 static void update_cpu_mhz(void *arg)
46 {
47 unsigned long mhz;
48 struct cpu_info *c;
49
50 mhz = __ecag(ECAG_CPU_ATTRIBUTE, 0);
51 c = this_cpu_ptr(&cpu_info);
52 c->cpu_mhz_dynamic = mhz >> 32;
53 c->cpu_mhz_static = mhz & 0xffffffff;
54 }
55
s390_update_cpu_mhz(void)56 void s390_update_cpu_mhz(void)
57 {
58 s390_adjust_jiffies();
59 if (machine_has_cpu_mhz)
60 on_each_cpu(update_cpu_mhz, NULL, 0);
61 }
62
stop_machine_yield(const struct cpumask * cpumask)63 void notrace stop_machine_yield(const struct cpumask *cpumask)
64 {
65 int cpu, this_cpu;
66
67 this_cpu = smp_processor_id();
68 if (__this_cpu_inc_return(cpu_relax_retry) >= spin_retry) {
69 __this_cpu_write(cpu_relax_retry, 0);
70 cpu = cpumask_next_wrap(this_cpu, cpumask, this_cpu, false);
71 if (cpu >= nr_cpu_ids)
72 return;
73 if (arch_vcpu_is_preempted(cpu))
74 smp_yield_cpu(cpu);
75 }
76 }
77
78 /*
79 * cpu_init - initializes state that is per-CPU.
80 */
cpu_init(void)81 void cpu_init(void)
82 {
83 struct cpuid *id = this_cpu_ptr(&cpu_info.cpu_id);
84
85 get_cpu_id(id);
86 if (machine_has_cpu_mhz)
87 update_cpu_mhz(NULL);
88 mmgrab(&init_mm);
89 current->active_mm = &init_mm;
90 BUG_ON(current->mm);
91 enter_lazy_tlb(&init_mm, current);
92 }
93
94 /*
95 * cpu_have_feature - Test CPU features on module initialization
96 */
cpu_have_feature(unsigned int num)97 int cpu_have_feature(unsigned int num)
98 {
99 return elf_hwcap & (1UL << num);
100 }
101 EXPORT_SYMBOL(cpu_have_feature);
102
show_facilities(struct seq_file * m)103 static void show_facilities(struct seq_file *m)
104 {
105 unsigned int bit;
106 long *facilities;
107
108 facilities = (long *)&S390_lowcore.stfle_fac_list;
109 seq_puts(m, "facilities :");
110 for_each_set_bit_inv(bit, facilities, MAX_FACILITY_BIT)
111 seq_printf(m, " %d", bit);
112 seq_putc(m, '\n');
113 }
114
show_cpu_summary(struct seq_file * m,void * v)115 static void show_cpu_summary(struct seq_file *m, void *v)
116 {
117 static const char *hwcap_str[] = {
118 "esan3", "zarch", "stfle", "msa", "ldisp", "eimm", "dfp",
119 "edat", "etf3eh", "highgprs", "te", "vx", "vxd", "vxe", "gs",
120 "vxe2", "vxp", "sort", "dflt"
121 };
122 static const char * const int_hwcap_str[] = {
123 "sie"
124 };
125 int i, cpu;
126
127 seq_printf(m, "vendor_id : IBM/S390\n"
128 "# processors : %i\n"
129 "bogomips per cpu: %lu.%02lu\n",
130 num_online_cpus(), loops_per_jiffy/(500000/HZ),
131 (loops_per_jiffy/(5000/HZ))%100);
132 seq_printf(m, "max thread id : %d\n", smp_cpu_mtid);
133 seq_puts(m, "features\t: ");
134 for (i = 0; i < ARRAY_SIZE(hwcap_str); i++)
135 if (hwcap_str[i] && (elf_hwcap & (1UL << i)))
136 seq_printf(m, "%s ", hwcap_str[i]);
137 for (i = 0; i < ARRAY_SIZE(int_hwcap_str); i++)
138 if (int_hwcap_str[i] && (int_hwcap & (1UL << i)))
139 seq_printf(m, "%s ", int_hwcap_str[i]);
140 seq_puts(m, "\n");
141 show_facilities(m);
142 show_cacheinfo(m);
143 for_each_online_cpu(cpu) {
144 struct cpuid *id = &per_cpu(cpu_info.cpu_id, cpu);
145
146 seq_printf(m, "processor %d: "
147 "version = %02X, "
148 "identification = %06X, "
149 "machine = %04X\n",
150 cpu, id->version, id->ident, id->machine);
151 }
152 }
153
show_cpu_topology(struct seq_file * m,unsigned long n)154 static void show_cpu_topology(struct seq_file *m, unsigned long n)
155 {
156 #ifdef CONFIG_SCHED_TOPOLOGY
157 seq_printf(m, "physical id : %d\n", topology_physical_package_id(n));
158 seq_printf(m, "core id : %d\n", topology_core_id(n));
159 seq_printf(m, "book id : %d\n", topology_book_id(n));
160 seq_printf(m, "drawer id : %d\n", topology_drawer_id(n));
161 seq_printf(m, "dedicated : %d\n", topology_cpu_dedicated(n));
162 seq_printf(m, "address : %d\n", smp_cpu_get_cpu_address(n));
163 seq_printf(m, "siblings : %d\n", cpumask_weight(topology_core_cpumask(n)));
164 seq_printf(m, "cpu cores : %d\n", topology_booted_cores(n));
165 #endif /* CONFIG_SCHED_TOPOLOGY */
166 }
167
show_cpu_ids(struct seq_file * m,unsigned long n)168 static void show_cpu_ids(struct seq_file *m, unsigned long n)
169 {
170 struct cpuid *id = &per_cpu(cpu_info.cpu_id, n);
171
172 seq_printf(m, "version : %02X\n", id->version);
173 seq_printf(m, "identification : %06X\n", id->ident);
174 seq_printf(m, "machine : %04X\n", id->machine);
175 }
176
show_cpu_mhz(struct seq_file * m,unsigned long n)177 static void show_cpu_mhz(struct seq_file *m, unsigned long n)
178 {
179 struct cpu_info *c = per_cpu_ptr(&cpu_info, n);
180
181 if (!machine_has_cpu_mhz)
182 return;
183 seq_printf(m, "cpu MHz dynamic : %d\n", c->cpu_mhz_dynamic);
184 seq_printf(m, "cpu MHz static : %d\n", c->cpu_mhz_static);
185 }
186
187 /*
188 * show_cpuinfo - Get information on one CPU for use by procfs.
189 */
show_cpuinfo(struct seq_file * m,void * v)190 static int show_cpuinfo(struct seq_file *m, void *v)
191 {
192 unsigned long n = (unsigned long) v - 1;
193 unsigned long first = cpumask_first(cpu_online_mask);
194
195 if (n == first)
196 show_cpu_summary(m, v);
197 seq_printf(m, "\ncpu number : %ld\n", n);
198 show_cpu_topology(m, n);
199 show_cpu_ids(m, n);
200 show_cpu_mhz(m, n);
201 return 0;
202 }
203
c_update(loff_t * pos)204 static inline void *c_update(loff_t *pos)
205 {
206 if (*pos)
207 *pos = cpumask_next(*pos - 1, cpu_online_mask);
208 else
209 *pos = cpumask_first(cpu_online_mask);
210 return *pos < nr_cpu_ids ? (void *)*pos + 1 : NULL;
211 }
212
c_start(struct seq_file * m,loff_t * pos)213 static void *c_start(struct seq_file *m, loff_t *pos)
214 {
215 get_online_cpus();
216 return c_update(pos);
217 }
218
c_next(struct seq_file * m,void * v,loff_t * pos)219 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
220 {
221 ++*pos;
222 return c_update(pos);
223 }
224
c_stop(struct seq_file * m,void * v)225 static void c_stop(struct seq_file *m, void *v)
226 {
227 put_online_cpus();
228 }
229
230 const struct seq_operations cpuinfo_op = {
231 .start = c_start,
232 .next = c_next,
233 .stop = c_stop,
234 .show = show_cpuinfo,
235 };
236
s390_isolate_bp(void)237 int s390_isolate_bp(void)
238 {
239 if (!test_facility(82))
240 return -EOPNOTSUPP;
241 set_thread_flag(TIF_ISOLATE_BP);
242 return 0;
243 }
244 EXPORT_SYMBOL(s390_isolate_bp);
245
s390_isolate_bp_guest(void)246 int s390_isolate_bp_guest(void)
247 {
248 if (!test_facility(82))
249 return -EOPNOTSUPP;
250 set_thread_flag(TIF_ISOLATE_BP_GUEST);
251 return 0;
252 }
253 EXPORT_SYMBOL(s390_isolate_bp_guest);
254