s390/kernel/perf_event.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Performance event support for s390x
0004  *
0005  *  Copyright IBM Corp. 2012, 2013
0006  *  Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
0007  */
0008 #define KMSG_COMPONENT  "perf"
0009 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
0010
0011 #include <linux/kernel.h>
0012 #include <linux/perf_event.h>
0013 #include <linux/kvm_host.h>
0014 #include <linux/percpu.h>
0015 #include <linux/export.h>
0016 #include <linux/seq_file.h>
0017 #include <linux/spinlock.h>
0018 #include <linux/sysfs.h>
0019 #include <asm/irq.h>
0020 #include <asm/cpu_mf.h>
0021 #include <asm/lowcore.h>
0022 #include <asm/processor.h>
0023 #include <asm/sysinfo.h>
0024 #include <asm/unwind.h>
0025
0026 static struct kvm_s390_sie_block *sie_block(struct pt_regs *regs)
0027 {
0028     struct stack_frame *stack = (struct stack_frame *) regs->gprs[15];
0029
0030     if (!stack)
0031         return NULL;
0032
0033     return (struct kvm_s390_sie_block *)stack->sie_control_block;
0034 }
0035
0036 static bool is_in_guest(struct pt_regs *regs)
0037 {
0038     if (user_mode(regs))
0039         return false;
0040 #if IS_ENABLED(CONFIG_KVM)
0041     return instruction_pointer(regs) == (unsigned long) &sie_exit;
0042 #else
0043     return false;
0044 #endif
0045 }
0046
0047 static unsigned long guest_is_user_mode(struct pt_regs *regs)
0048 {
0049     return sie_block(regs)->gpsw.mask & PSW_MASK_PSTATE;
0050 }
0051
0052 static unsigned long instruction_pointer_guest(struct pt_regs *regs)
0053 {
0054     return sie_block(regs)->gpsw.addr;
0055 }
0056
0057 unsigned long perf_instruction_pointer(struct pt_regs *regs)
0058 {
0059     return is_in_guest(regs) ? instruction_pointer_guest(regs)
0060                  : instruction_pointer(regs);
0061 }
0062
0063 static unsigned long perf_misc_guest_flags(struct pt_regs *regs)
0064 {
0065     return guest_is_user_mode(regs) ? PERF_RECORD_MISC_GUEST_USER
0066                     : PERF_RECORD_MISC_GUEST_KERNEL;
0067 }
0068
0069 static unsigned long perf_misc_flags_sf(struct pt_regs *regs)
0070 {
0071     struct perf_sf_sde_regs *sde_regs;
0072     unsigned long flags;
0073
0074     sde_regs = (struct perf_sf_sde_regs *) &regs->int_parm_long;
0075     if (sde_regs->in_guest)
0076         flags = user_mode(regs) ? PERF_RECORD_MISC_GUEST_USER
0077                     : PERF_RECORD_MISC_GUEST_KERNEL;
0078     else
0079         flags = user_mode(regs) ? PERF_RECORD_MISC_USER
0080                     : PERF_RECORD_MISC_KERNEL;
0081     return flags;
0082 }
0083
0084 unsigned long perf_misc_flags(struct pt_regs *regs)
0085 {
0086     /* Check if the cpum_sf PMU has created the pt_regs structure.
0087      * In this case, perf misc flags can be easily extracted.  Otherwise,
0088      * do regular checks on the pt_regs content.
0089      */
0090     if (regs->int_code == 0x1407 && regs->int_parm == CPU_MF_INT_SF_PRA)
0091         if (!regs->gprs[15])
0092             return perf_misc_flags_sf(regs);
0093
0094     if (is_in_guest(regs))
0095         return perf_misc_guest_flags(regs);
0096
0097     return user_mode(regs) ? PERF_RECORD_MISC_USER
0098                    : PERF_RECORD_MISC_KERNEL;
0099 }
0100
0101 static void print_debug_cf(void)
0102 {
0103     struct cpumf_ctr_info cf_info;
0104     int cpu = smp_processor_id();
0105
0106     memset(&cf_info, 0, sizeof(cf_info));
0107     if (!qctri(&cf_info))
0108         pr_info("CPU[%i] CPUM_CF: ver=%u.%u A=%04x E=%04x C=%04x\n",
0109             cpu, cf_info.cfvn, cf_info.csvn,
0110             cf_info.auth_ctl, cf_info.enable_ctl, cf_info.act_ctl);
0111 }
0112
0113 static void print_debug_sf(void)
0114 {
0115     struct hws_qsi_info_block si;
0116     int cpu = smp_processor_id();
0117
0118     memset(&si, 0, sizeof(si));
0119     if (qsi(&si))
0120         return;
0121
0122     pr_info("CPU[%i] CPUM_SF: basic=%i diag=%i min=%lu max=%lu cpu_speed=%u\n",
0123         cpu, si.as, si.ad, si.min_sampl_rate, si.max_sampl_rate,
0124         si.cpu_speed);
0125
0126     if (si.as)
0127         pr_info("CPU[%i] CPUM_SF: Basic-sampling: a=%i e=%i c=%i"
0128             " bsdes=%i tear=%016lx dear=%016lx\n", cpu,
0129             si.as, si.es, si.cs, si.bsdes, si.tear, si.dear);
0130     if (si.ad)
0131         pr_info("CPU[%i] CPUM_SF: Diagnostic-sampling: a=%i e=%i c=%i"
0132             " dsdes=%i tear=%016lx dear=%016lx\n", cpu,
0133             si.ad, si.ed, si.cd, si.dsdes, si.tear, si.dear);
0134 }
0135
0136 void perf_event_print_debug(void)
0137 {
0138     unsigned long flags;
0139
0140     local_irq_save(flags);
0141     if (cpum_cf_avail())
0142         print_debug_cf();
0143     if (cpum_sf_avail())
0144         print_debug_sf();
0145     local_irq_restore(flags);
0146 }
0147
0148 /* Service level infrastructure */
0149 static void sl_print_counter(struct seq_file *m)
0150 {
0151     struct cpumf_ctr_info ci;
0152
0153     memset(&ci, 0, sizeof(ci));
0154     if (qctri(&ci))
0155         return;
0156
0157     seq_printf(m, "CPU-MF: Counter facility: version=%u.%u "
0158            "authorization=%04x\n", ci.cfvn, ci.csvn, ci.auth_ctl);
0159 }
0160
0161 static void sl_print_sampling(struct seq_file *m)
0162 {
0163     struct hws_qsi_info_block si;
0164
0165     memset(&si, 0, sizeof(si));
0166     if (qsi(&si))
0167         return;
0168
0169     if (!si.as && !si.ad)
0170         return;
0171
0172     seq_printf(m, "CPU-MF: Sampling facility: min_rate=%lu max_rate=%lu"
0173            " cpu_speed=%u\n", si.min_sampl_rate, si.max_sampl_rate,
0174            si.cpu_speed);
0175     if (si.as)
0176         seq_printf(m, "CPU-MF: Sampling facility: mode=basic"
0177                " sample_size=%u\n", si.bsdes);
0178     if (si.ad)
0179         seq_printf(m, "CPU-MF: Sampling facility: mode=diagnostic"
0180                " sample_size=%u\n", si.dsdes);
0181 }
0182
0183 static void service_level_perf_print(struct seq_file *m,
0184                      struct service_level *sl)
0185 {
0186     if (cpum_cf_avail())
0187         sl_print_counter(m);
0188     if (cpum_sf_avail())
0189         sl_print_sampling(m);
0190 }
0191
0192 static struct service_level service_level_perf = {
0193     .seq_print = service_level_perf_print,
0194 };
0195
0196 static int __init service_level_perf_register(void)
0197 {
0198     return register_service_level(&service_level_perf);
0199 }
0200 arch_initcall(service_level_perf_register);
0201
0202 void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
0203                struct pt_regs *regs)
0204 {
0205     struct unwind_state state;
0206     unsigned long addr;
0207
0208     unwind_for_each_frame(&state, current, regs, 0) {
0209         addr = unwind_get_return_address(&state);
0210         if (!addr || perf_callchain_store(entry, addr))
0211             return;
0212     }
0213 }
0214
0215 /* Perf definitions for PMU event attributes in sysfs */
0216 ssize_t cpumf_events_sysfs_show(struct device *dev,
0217                 struct device_attribute *attr, char *page)
0218 {
0219     struct perf_pmu_events_attr *pmu_attr;
0220
0221     pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
0222     return sprintf(page, "event=0x%04llx\n", pmu_attr->id);
0223 }