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 #include <asm/unwind.h>
  25
  26 static struct kvm_s390_sie_block *sie_block(struct pt_regs *regs)
  27 {
  28         struct stack_frame *stack = (struct stack_frame *) regs->gprs[15];
  29
  30         if (!stack)
  31                 return NULL;
  32
  33         return (struct kvm_s390_sie_block *) stack->empty1[0];
  34 }
  35
  36 static bool is_in_guest(struct pt_regs *regs)
  37 {
  38         if (user_mode(regs))
  39                 return false;
  40 #if IS_ENABLED(CONFIG_KVM)
  41         return instruction_pointer(regs) == (unsigned long) &sie_exit;
  42 #else
  43         return false;
  44 #endif
  45 }
  46
  47 static unsigned long guest_is_user_mode(struct pt_regs *regs)
  48 {
  49         return sie_block(regs)->gpsw.mask & PSW_MASK_PSTATE;
  50 }
  51
  52 static unsigned long instruction_pointer_guest(struct pt_regs *regs)
  53 {
  54         return sie_block(regs)->gpsw.addr;
  55 }
  56
  57 unsigned long perf_instruction_pointer(struct pt_regs *regs)
  58 {
  59         return is_in_guest(regs) ? instruction_pointer_guest(regs)
  60                                  : instruction_pointer(regs);
  61 }
  62
  63 static unsigned long perf_misc_guest_flags(struct pt_regs *regs)
  64 {
  65         return guest_is_user_mode(regs) ? PERF_RECORD_MISC_GUEST_USER
  66                                         : PERF_RECORD_MISC_GUEST_KERNEL;
  67 }
  68
  69 static unsigned long perf_misc_flags_sf(struct pt_regs *regs)
  70 {
  71         struct perf_sf_sde_regs *sde_regs;
  72         unsigned long flags;
  73
  74         sde_regs = (struct perf_sf_sde_regs *) &regs->int_parm_long;
  75         if (sde_regs->in_guest)
  76                 flags = user_mode(regs) ? PERF_RECORD_MISC_GUEST_USER
  77                                         : PERF_RECORD_MISC_GUEST_KERNEL;
  78         else
  79                 flags = user_mode(regs) ? PERF_RECORD_MISC_USER
  80                                         : PERF_RECORD_MISC_KERNEL;
  81         return flags;
  82 }
  83
  84 unsigned long perf_misc_flags(struct pt_regs *regs)
  85 {
  86         /* Check if the cpum_sf PMU has created the pt_regs structure.
  87          * In this case, perf misc flags can be easily extracted.  Otherwise,
  88          * do regular checks on the pt_regs content.
  89          */
  90         if (regs->int_code == 0x1407 && regs->int_parm == CPU_MF_INT_SF_PRA)
  91                 if (!regs->gprs[15])
  92                         return perf_misc_flags_sf(regs);
  93
  94         if (is_in_guest(regs))
  95                 return perf_misc_guest_flags(regs);
  96
  97         return user_mode(regs) ? PERF_RECORD_MISC_USER
  98                                : PERF_RECORD_MISC_KERNEL;
  99 }
 100
 101 static void print_debug_cf(void)
 102 {
 103         struct cpumf_ctr_info cf_info;
 104         int cpu = smp_processor_id();
 105
 106         memset(&cf_info, 0, sizeof(cf_info));
 107         if (!qctri(&cf_info))
 108                 pr_info("CPU[%i] CPUM_CF: ver=%u.%u A=%04x E=%04x C=%04x\n",
 109                         cpu, cf_info.cfvn, cf_info.csvn,
 110                         cf_info.auth_ctl, cf_info.enable_ctl, cf_info.act_ctl);
 111 }
 112
 113 static void print_debug_sf(void)
 114 {
 115         struct hws_qsi_info_block si;
 116         int cpu = smp_processor_id();
 117
 118         memset(&si, 0, sizeof(si));
 119         if (qsi(&si))
 120                 return;
 121
 122         pr_info("CPU[%i] CPUM_SF: basic=%i diag=%i min=%lu max=%lu cpu_speed=%u\n",
 123                 cpu, si.as, si.ad, si.min_sampl_rate, si.max_sampl_rate,
 124                 si.cpu_speed);
 125
 126         if (si.as)
 127                 pr_info("CPU[%i] CPUM_SF: Basic-sampling: a=%i e=%i c=%i"
 128                         " bsdes=%i tear=%016lx dear=%016lx\n", cpu,
 129                         si.as, si.es, si.cs, si.bsdes, si.tear, si.dear);
 130         if (si.ad)
 131                 pr_info("CPU[%i] CPUM_SF: Diagnostic-sampling: a=%i e=%i c=%i"
 132                         " dsdes=%i tear=%016lx dear=%016lx\n", cpu,
 133                         si.ad, si.ed, si.cd, si.dsdes, si.tear, si.dear);
 134 }
 135
 136 void perf_event_print_debug(void)
 137 {
 138         unsigned long flags;
 139
 140         local_irq_save(flags);
 141         if (cpum_cf_avail())
 142                 print_debug_cf();
 143         if (cpum_sf_avail())
 144                 print_debug_sf();
 145         local_irq_restore(flags);
 146 }
 147
 148 /* Service level infrastructure */
 149 static void sl_print_counter(struct seq_file *m)
 150 {
 151         struct cpumf_ctr_info ci;
 152
 153         memset(&ci, 0, sizeof(ci));
 154         if (qctri(&ci))
 155                 return;
 156
 157         seq_printf(m, "CPU-MF: Counter facility: version=%u.%u "
 158                    "authorization=%04x\n", ci.cfvn, ci.csvn, ci.auth_ctl);
 159 }
 160
 161 static void sl_print_sampling(struct seq_file *m)
 162 {
 163         struct hws_qsi_info_block si;
 164
 165         memset(&si, 0, sizeof(si));
 166         if (qsi(&si))
 167                 return;
 168
 169         if (!si.as && !si.ad)
 170                 return;
 171
 172         seq_printf(m, "CPU-MF: Sampling facility: min_rate=%lu max_rate=%lu"
 173                    " cpu_speed=%u\n", si.min_sampl_rate, si.max_sampl_rate,
 174                    si.cpu_speed);
 175         if (si.as)
 176                 seq_printf(m, "CPU-MF: Sampling facility: mode=basic"
 177                            " sample_size=%u\n", si.bsdes);
 178         if (si.ad)
 179                 seq_printf(m, "CPU-MF: Sampling facility: mode=diagnostic"
 180                            " sample_size=%u\n", si.dsdes);
 181 }
 182
 183 static void service_level_perf_print(struct seq_file *m,
 184                                      struct service_level *sl)
 185 {
 186         if (cpum_cf_avail())
 187                 sl_print_counter(m);
 188         if (cpum_sf_avail())
 189                 sl_print_sampling(m);
 190 }
 191
 192 static struct service_level service_level_perf = {
 193         .seq_print = service_level_perf_print,
 194 };
 195
 196 static int __init service_level_perf_register(void)
 197 {
 198         return register_service_level(&service_level_perf);
 199 }
 200 arch_initcall(service_level_perf_register);
 201
 202 void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
 203                            struct pt_regs *regs)
 204 {
 205         struct unwind_state state;
 206         unsigned long addr;
 207
 208         unwind_for_each_frame(&state, current, regs, 0) {
 209                 addr = unwind_get_return_address(&state);
 210                 if (!addr || perf_callchain_store(entry, addr))
 211                         return;
 212         }
 213 }
 214
 215 /* Perf definitions for PMU event attributes in sysfs */
 216 ssize_t cpumf_events_sysfs_show(struct device *dev,
 217                                 struct device_attribute *attr, char *page)
 218 {
 219         struct perf_pmu_events_attr *pmu_attr;
 220
 221         pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
 222         return sprintf(page, "event=0x%04llx\n", pmu_attr->id);
 223 }