1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * CPU-Measurement Counter Facility Support - Common Layer
4 *
5 * Copyright IBM Corp. 2019
6 * Author(s): Hendrik Brueckner <brueckner@linux.ibm.com>
7 */
8 #define KMSG_COMPONENT "cpum_cf_common"
9 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
10
11 #include <linux/kernel.h>
12 #include <linux/kernel_stat.h>
13 #include <linux/percpu.h>
14 #include <linux/notifier.h>
15 #include <linux/init.h>
16 #include <linux/export.h>
17 #include <asm/ctl_reg.h>
18 #include <asm/irq.h>
19 #include <asm/cpu_mcf.h>
20
21 /* Per-CPU event structure for the counter facility */
22 DEFINE_PER_CPU(struct cpu_cf_events, cpu_cf_events) = {
23 .ctr_set = {
24 [CPUMF_CTR_SET_BASIC] = ATOMIC_INIT(0),
25 [CPUMF_CTR_SET_USER] = ATOMIC_INIT(0),
26 [CPUMF_CTR_SET_CRYPTO] = ATOMIC_INIT(0),
27 [CPUMF_CTR_SET_EXT] = ATOMIC_INIT(0),
28 [CPUMF_CTR_SET_MT_DIAG] = ATOMIC_INIT(0),
29 },
30 .alert = ATOMIC64_INIT(0),
31 .state = 0,
32 .dev_state = 0,
33 .flags = 0,
34 .used = 0,
35 .usedss = 0,
36 .sets = 0
37 };
38 /* Indicator whether the CPU-Measurement Counter Facility Support is ready */
39 static bool cpum_cf_initalized;
40
41 /* CPU-measurement alerts for the counter facility */
cpumf_measurement_alert(struct ext_code ext_code,unsigned int alert,unsigned long unused)42 static void cpumf_measurement_alert(struct ext_code ext_code,
43 unsigned int alert, unsigned long unused)
44 {
45 struct cpu_cf_events *cpuhw;
46
47 if (!(alert & CPU_MF_INT_CF_MASK))
48 return;
49
50 inc_irq_stat(IRQEXT_CMC);
51 cpuhw = this_cpu_ptr(&cpu_cf_events);
52
53 /* Measurement alerts are shared and might happen when the PMU
54 * is not reserved. Ignore these alerts in this case. */
55 if (!(cpuhw->flags & PMU_F_RESERVED))
56 return;
57
58 /* counter authorization change alert */
59 if (alert & CPU_MF_INT_CF_CACA)
60 qctri(&cpuhw->info);
61
62 /* loss of counter data alert */
63 if (alert & CPU_MF_INT_CF_LCDA)
64 pr_err("CPU[%i] Counter data was lost\n", smp_processor_id());
65
66 /* loss of MT counter data alert */
67 if (alert & CPU_MF_INT_CF_MTDA)
68 pr_warn("CPU[%i] MT counter data was lost\n",
69 smp_processor_id());
70
71 /* store alert for special handling by in-kernel users */
72 atomic64_or(alert, &cpuhw->alert);
73 }
74
75 #define PMC_INIT 0
76 #define PMC_RELEASE 1
cpum_cf_setup_cpu(void * flags)77 static void cpum_cf_setup_cpu(void *flags)
78 {
79 struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
80
81 switch (*((int *) flags)) {
82 case PMC_INIT:
83 memset(&cpuhw->info, 0, sizeof(cpuhw->info));
84 qctri(&cpuhw->info);
85 cpuhw->flags |= PMU_F_RESERVED;
86 break;
87
88 case PMC_RELEASE:
89 cpuhw->flags &= ~PMU_F_RESERVED;
90 break;
91 }
92
93 /* Disable CPU counter sets */
94 lcctl(0);
95 }
96
kernel_cpumcf_avail(void)97 bool kernel_cpumcf_avail(void)
98 {
99 return cpum_cf_initalized;
100 }
101 EXPORT_SYMBOL(kernel_cpumcf_avail);
102
103 /* Initialize the CPU-measurement counter facility */
__kernel_cpumcf_begin(void)104 int __kernel_cpumcf_begin(void)
105 {
106 int flags = PMC_INIT;
107
108 on_each_cpu(cpum_cf_setup_cpu, &flags, 1);
109 irq_subclass_register(IRQ_SUBCLASS_MEASUREMENT_ALERT);
110
111 return 0;
112 }
113 EXPORT_SYMBOL(__kernel_cpumcf_begin);
114
115 /* Obtain the CPU-measurement alerts for the counter facility */
kernel_cpumcf_alert(int clear)116 unsigned long kernel_cpumcf_alert(int clear)
117 {
118 struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events);
119 unsigned long alert;
120
121 alert = atomic64_read(&cpuhw->alert);
122 if (clear)
123 atomic64_set(&cpuhw->alert, 0);
124
125 return alert;
126 }
127 EXPORT_SYMBOL(kernel_cpumcf_alert);
128
129 /* Release the CPU-measurement counter facility */
__kernel_cpumcf_end(void)130 void __kernel_cpumcf_end(void)
131 {
132 int flags = PMC_RELEASE;
133
134 on_each_cpu(cpum_cf_setup_cpu, &flags, 1);
135 irq_subclass_unregister(IRQ_SUBCLASS_MEASUREMENT_ALERT);
136 }
137 EXPORT_SYMBOL(__kernel_cpumcf_end);
138
cpum_cf_setup(unsigned int cpu,int flags)139 static int cpum_cf_setup(unsigned int cpu, int flags)
140 {
141 local_irq_disable();
142 cpum_cf_setup_cpu(&flags);
143 local_irq_enable();
144 return 0;
145 }
146
cpum_cf_online_cpu(unsigned int cpu)147 static int cpum_cf_online_cpu(unsigned int cpu)
148 {
149 cpum_cf_setup(cpu, PMC_INIT);
150 return cfset_online_cpu(cpu);
151 }
152
cpum_cf_offline_cpu(unsigned int cpu)153 static int cpum_cf_offline_cpu(unsigned int cpu)
154 {
155 cfset_offline_cpu(cpu);
156 return cpum_cf_setup(cpu, PMC_RELEASE);
157 }
158
159 /* Return the maximum possible counter set size (in number of 8 byte counters)
160 * depending on type and model number.
161 */
cpum_cf_ctrset_size(enum cpumf_ctr_set ctrset,struct cpumf_ctr_info * info)162 size_t cpum_cf_ctrset_size(enum cpumf_ctr_set ctrset,
163 struct cpumf_ctr_info *info)
164 {
165 size_t ctrset_size = 0;
166
167 switch (ctrset) {
168 case CPUMF_CTR_SET_BASIC:
169 if (info->cfvn >= 1)
170 ctrset_size = 6;
171 break;
172 case CPUMF_CTR_SET_USER:
173 if (info->cfvn == 1)
174 ctrset_size = 6;
175 else if (info->cfvn >= 3)
176 ctrset_size = 2;
177 break;
178 case CPUMF_CTR_SET_CRYPTO:
179 if (info->csvn >= 1 && info->csvn <= 5)
180 ctrset_size = 16;
181 else if (info->csvn == 6)
182 ctrset_size = 20;
183 break;
184 case CPUMF_CTR_SET_EXT:
185 if (info->csvn == 1)
186 ctrset_size = 32;
187 else if (info->csvn == 2)
188 ctrset_size = 48;
189 else if (info->csvn >= 3 && info->csvn <= 5)
190 ctrset_size = 128;
191 else if (info->csvn == 6)
192 ctrset_size = 160;
193 break;
194 case CPUMF_CTR_SET_MT_DIAG:
195 if (info->csvn > 3)
196 ctrset_size = 48;
197 break;
198 case CPUMF_CTR_SET_MAX:
199 break;
200 }
201
202 return ctrset_size;
203 }
204
cpum_cf_init(void)205 static int __init cpum_cf_init(void)
206 {
207 int rc;
208
209 if (!cpum_cf_avail())
210 return -ENODEV;
211
212 /* clear bit 15 of cr0 to unauthorize problem-state to
213 * extract measurement counters */
214 ctl_clear_bit(0, 48);
215
216 /* register handler for measurement-alert interruptions */
217 rc = register_external_irq(EXT_IRQ_MEASURE_ALERT,
218 cpumf_measurement_alert);
219 if (rc) {
220 pr_err("Registering for CPU-measurement alerts "
221 "failed with rc=%i\n", rc);
222 return rc;
223 }
224
225 rc = cpuhp_setup_state(CPUHP_AP_PERF_S390_CF_ONLINE,
226 "perf/s390/cf:online",
227 cpum_cf_online_cpu, cpum_cf_offline_cpu);
228 if (!rc)
229 cpum_cf_initalized = true;
230
231 return rc;
232 }
233 early_initcall(cpum_cf_init);
234