/* * Performance event support for s390x * * Copyright IBM Corp. 2012 * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License (version 2 only) * as published by the Free Software Foundation. */ #define KMSG_COMPONENT "perf" #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt #include <linux/kernel.h> #include <linux/perf_event.h> #include <linux/percpu.h> #include <linux/export.h> #include <asm/irq.h> #include <asm/cpu_mf.h> #include <asm/lowcore.h> #include <asm/processor.h> const char *perf_pmu_name(void) { if (cpum_cf_avail() || cpum_sf_avail()) return "CPU-measurement facilities (CPUMF)"; return "pmu"; } EXPORT_SYMBOL(perf_pmu_name); int perf_num_counters(void) { int num = 0; if (cpum_cf_avail()) num += PERF_CPUM_CF_MAX_CTR; return num; } EXPORT_SYMBOL(perf_num_counters); void perf_event_print_debug(void) { struct cpumf_ctr_info cf_info; unsigned long flags; int cpu; if (!cpum_cf_avail()) return; local_irq_save(flags); cpu = smp_processor_id(); memset(&cf_info, 0, sizeof(cf_info)); if (!qctri(&cf_info)) { pr_info("CPU[%i] CPUM_CF: ver=%u.%u A=%04x E=%04x C=%04x\n", cpu, cf_info.cfvn, cf_info.csvn, cf_info.auth_ctl, cf_info.enable_ctl, cf_info.act_ctl); print_hex_dump_bytes("CPUMF Query: ", DUMP_PREFIX_OFFSET, &cf_info, sizeof(cf_info)); } local_irq_restore(flags); } /* See also arch/s390/kernel/traps.c */ static unsigned long __store_trace(struct perf_callchain_entry *entry, unsigned long sp, unsigned long low, unsigned long high) { struct stack_frame *sf; struct pt_regs *regs; while (1) { sp = sp & PSW_ADDR_INSN; if (sp < low || sp > high - sizeof(*sf)) return sp; sf = (struct stack_frame *) sp; perf_callchain_store(entry, sf->gprs[8] & PSW_ADDR_INSN); /* Follow the backchain. */ while (1) { low = sp; sp = sf->back_chain & PSW_ADDR_INSN; if (!sp) break; if (sp <= low || sp > high - sizeof(*sf)) return sp; sf = (struct stack_frame *) sp; perf_callchain_store(entry, sf->gprs[8] & PSW_ADDR_INSN); } /* Zero backchain detected, check for interrupt frame. */ sp = (unsigned long) (sf + 1); if (sp <= low || sp > high - sizeof(*regs)) return sp; regs = (struct pt_regs *) sp; perf_callchain_store(entry, sf->gprs[8] & PSW_ADDR_INSN); low = sp; sp = regs->gprs[15]; } } void perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs) { unsigned long head; struct stack_frame *head_sf; if (user_mode(regs)) return; head = regs->gprs[15]; head_sf = (struct stack_frame *) head; if (!head_sf || !head_sf->back_chain) return; head = head_sf->back_chain; head = __store_trace(entry, head, S390_lowcore.async_stack - ASYNC_SIZE, S390_lowcore.async_stack); __store_trace(entry, head, S390_lowcore.thread_info, S390_lowcore.thread_info + THREAD_SIZE); }