arch/s390/kernel/perf_event.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Performance event support for s390x
   4  *
   5  *  Copyright IBM Corp. 2012, 2013
   6  *  Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
   7  */
   8 #define KMSG_COMPONENT  "perf"
   9 #define pr_fmt(fmt)     KMSG_COMPONENT ": " fmt
  10
  11 #include <linux/kernel.h>
  12 #include <linux/perf_event.h>
  13 #include <linux/kvm_host.h>
  14 #include <linux/percpu.h>
  15 #include <linux/export.h>
  16 #include <linux/seq_file.h>
  17 #include <linux/spinlock.h>
  18 #include <linux/sysfs.h>
  19 #include <asm/irq.h>
  20 #include <asm/cpu_mf.h>
  21 #include <asm/lowcore.h>
  22 #include <asm/processor.h>
  23 #include <asm/sysinfo.h>
  24
  25 const char *perf_pmu_name(void)
  26 {
  27         if (cpum_cf_avail() || cpum_sf_avail())
  28                 return "CPU-Measurement Facilities (CPU-MF)";
  29         return "pmu";
  30 }
  31 EXPORT_SYMBOL(perf_pmu_name);
  32
  33 int perf_num_counters(void)
  34 {
  35         int num = 0;
  36
  37         if (cpum_cf_avail())
  38                 num += PERF_CPUM_CF_MAX_CTR;
  39         if (cpum_sf_avail())
  40                 num += PERF_CPUM_SF_MAX_CTR;
  41
  42         return num;
  43 }
  44 EXPORT_SYMBOL(perf_num_counters);
  45
  46 static struct kvm_s390_sie_block *sie_block(struct pt_regs *regs)
  47 {
  48         struct stack_frame *stack = (struct stack_frame *) regs->gprs[15];
  49
  50         if (!stack)
  51                 return NULL;
  52
  53         return (struct kvm_s390_sie_block *) stack->empty1[0];
  54 }
  55
  56 static bool is_in_guest(struct pt_regs *regs)
  57 {
  58         if (user_mode(regs))
  59                 return false;
  60 #if IS_ENABLED(CONFIG_KVM)
  61         return instruction_pointer(regs) == (unsigned long) &sie_exit;
  62 #else
  63         return false;
  64 #endif
  65 }
  66
  67 static unsigned long guest_is_user_mode(struct pt_regs *regs)
  68 {
  69         return sie_block(regs)->gpsw.mask & PSW_MASK_PSTATE;
  70 }
  71
  72 static unsigned long instruction_pointer_guest(struct pt_regs *regs)
  73 {
  74         return sie_block(regs)->gpsw.addr;
  75 }
  76
  77 unsigned long perf_instruction_pointer(struct pt_regs *regs)
  78 {
  79         return is_in_guest(regs) ? instruction_pointer_guest(regs)
  80                                  : instruction_pointer(regs);
  81 }
  82
  83 static unsigned long perf_misc_guest_flags(struct pt_regs *regs)
  84 {
  85         return guest_is_user_mode(regs) ? PERF_RECORD_MISC_GUEST_USER
  86                                         : PERF_RECORD_MISC_GUEST_KERNEL;
  87 }
  88
  89 static unsigned long perf_misc_flags_sf(struct pt_regs *regs)
  90 {
  91         struct perf_sf_sde_regs *sde_regs;
  92         unsigned long flags;
  93
  94         sde_regs = (struct perf_sf_sde_regs *) &regs->int_parm_long;
  95         if (sde_regs->in_guest)
  96                 flags = user_mode(regs) ? PERF_RECORD_MISC_GUEST_USER
  97                                         : PERF_RECORD_MISC_GUEST_KERNEL;
  98         else
  99                 flags = user_mode(regs) ? PERF_RECORD_MISC_USER
 100                                         : PERF_RECORD_MISC_KERNEL;
 101         return flags;
 102 }
 103
 104 unsigned long perf_misc_flags(struct pt_regs *regs)
 105 {
 106         /* Check if the cpum_sf PMU has created the pt_regs structure.
 107          * In this case, perf misc flags can be easily extracted.  Otherwise,
 108          * do regular checks on the pt_regs content.
 109          */
 110         if (regs->int_code == 0x1407 && regs->int_parm == CPU_MF_INT_SF_PRA)
 111                 if (!regs->gprs[15])
 112                         return perf_misc_flags_sf(regs);
 113
 114         if (is_in_guest(regs))
 115                 return perf_misc_guest_flags(regs);
 116
 117         return user_mode(regs) ? PERF_RECORD_MISC_USER
 118                                : PERF_RECORD_MISC_KERNEL;
 119 }
 120
 121 static void print_debug_cf(void)
 122 {
 123         struct cpumf_ctr_info cf_info;
 124         int cpu = smp_processor_id();
 125
 126         memset(&cf_info, 0, sizeof(cf_info));
 127         if (!qctri(&cf_info))
 128                 pr_info("CPU[%i] CPUM_CF: ver=%u.%u A=%04x E=%04x C=%04x\n",
 129                         cpu, cf_info.cfvn, cf_info.csvn,
 130                         cf_info.auth_ctl, cf_info.enable_ctl, cf_info.act_ctl);
 131 }
 132
 133 static void print_debug_sf(void)
 134 {
 135         struct hws_qsi_info_block si;
 136         int cpu = smp_processor_id();
 137
 138         memset(&si, 0, sizeof(si));
 139         if (qsi(&si))
 140                 return;
 141
 142         pr_info("CPU[%i] CPUM_SF: basic=%i diag=%i min=%lu max=%lu cpu_speed=%u\n",
 143                 cpu, si.as, si.ad, si.min_sampl_rate, si.max_sampl_rate,
 144                 si.cpu_speed);
 145
 146         if (si.as)
 147                 pr_info("CPU[%i] CPUM_SF: Basic-sampling: a=%i e=%i c=%i"
 148                         " bsdes=%i tear=%016lx dear=%016lx\n", cpu,
 149                         si.as, si.es, si.cs, si.bsdes, si.tear, si.dear);
 150         if (si.ad)
 151                 pr_info("CPU[%i] CPUM_SF: Diagnostic-sampling: a=%i e=%i c=%i"
 152                         " dsdes=%i tear=%016lx dear=%016lx\n", cpu,
 153                         si.ad, si.ed, si.cd, si.dsdes, si.tear, si.dear);
 154 }
 155
 156 void perf_event_print_debug(void)
 157 {
 158         unsigned long flags;
 159
 160         local_irq_save(flags);
 161         if (cpum_cf_avail())
 162                 print_debug_cf();
 163         if (cpum_sf_avail())
 164                 print_debug_sf();
 165         local_irq_restore(flags);
 166 }
 167
 168 /* Service level infrastructure */
 169 static void sl_print_counter(struct seq_file *m)
 170 {
 171         struct cpumf_ctr_info ci;
 172
 173         memset(&ci, 0, sizeof(ci));
 174         if (qctri(&ci))
 175                 return;
 176
 177         seq_printf(m, "CPU-MF: Counter facility: version=%u.%u "
 178                    "authorization=%04x\n", ci.cfvn, ci.csvn, ci.auth_ctl);
 179 }
 180
 181 static void sl_print_sampling(struct seq_file *m)
 182 {
 183         struct hws_qsi_info_block si;
 184
 185         memset(&si, 0, sizeof(si));
 186         if (qsi(&si))
 187                 return;
 188
 189         if (!si.as && !si.ad)
 190                 return;
 191
 192         seq_printf(m, "CPU-MF: Sampling facility: min_rate=%lu max_rate=%lu"
 193                    " cpu_speed=%u\n", si.min_sampl_rate, si.max_sampl_rate,
 194                    si.cpu_speed);
 195         if (si.as)
 196                 seq_printf(m, "CPU-MF: Sampling facility: mode=basic"
 197                            " sample_size=%u\n", si.bsdes);
 198         if (si.ad)
 199                 seq_printf(m, "CPU-MF: Sampling facility: mode=diagnostic"
 200                            " sample_size=%u\n", si.dsdes);
 201 }
 202
 203 static void service_level_perf_print(struct seq_file *m,
 204                                      struct service_level *sl)
 205 {
 206         if (cpum_cf_avail())
 207                 sl_print_counter(m);
 208         if (cpum_sf_avail())
 209                 sl_print_sampling(m);
 210 }
 211
 212 static struct service_level service_level_perf = {
 213         .seq_print = service_level_perf_print,
 214 };
 215
 216 static int __init service_level_perf_register(void)
 217 {
 218         return register_service_level(&service_level_perf);
 219 }
 220 arch_initcall(service_level_perf_register);
 221
 222 static int __perf_callchain_kernel(void *data, unsigned long address, int reliable)
 223 {
 224         struct perf_callchain_entry_ctx *entry = data;
 225
 226         perf_callchain_store(entry, address);
 227         return 0;
 228 }
 229
 230 void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
 231                            struct pt_regs *regs)
 232 {
 233         if (user_mode(regs))
 234                 return;
 235         dump_trace(__perf_callchain_kernel, entry, NULL, regs->gprs[15]);
 236 }
 237
 238 /* Perf definitions for PMU event attributes in sysfs */
 239 ssize_t cpumf_events_sysfs_show(struct device *dev,
 240                                 struct device_attribute *attr, char *page)
 241 {
 242         struct perf_pmu_events_attr *pmu_attr;
 243
 244         pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
 245         return sprintf(page, "event=0x%04llx\n", pmu_attr->id);
 246 }