1 /* 2 * Performance event support for s390x 3 * 4 * Copyright IBM Corp. 2012 5 * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License (version 2 only) 9 * as published by the Free Software Foundation. 10 */ 11 #define KMSG_COMPONENT "perf" 12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 13 14 #include <linux/kernel.h> 15 #include <linux/perf_event.h> 16 #include <linux/percpu.h> 17 #include <linux/export.h> 18 #include <asm/irq.h> 19 #include <asm/cpu_mf.h> 20 #include <asm/lowcore.h> 21 #include <asm/processor.h> 22 23 const char *perf_pmu_name(void) 24 { 25 if (cpum_cf_avail() || cpum_sf_avail()) 26 return "CPU-measurement facilities (CPUMF)"; 27 return "pmu"; 28 } 29 EXPORT_SYMBOL(perf_pmu_name); 30 31 int perf_num_counters(void) 32 { 33 int num = 0; 34 35 if (cpum_cf_avail()) 36 num += PERF_CPUM_CF_MAX_CTR; 37 38 return num; 39 } 40 EXPORT_SYMBOL(perf_num_counters); 41 42 void perf_event_print_debug(void) 43 { 44 struct cpumf_ctr_info cf_info; 45 unsigned long flags; 46 int cpu; 47 48 if (!cpum_cf_avail()) 49 return; 50 51 local_irq_save(flags); 52 53 cpu = smp_processor_id(); 54 memset(&cf_info, 0, sizeof(cf_info)); 55 if (!qctri(&cf_info)) { 56 pr_info("CPU[%i] CPUM_CF: ver=%u.%u A=%04x E=%04x C=%04x\n", 57 cpu, cf_info.cfvn, cf_info.csvn, 58 cf_info.auth_ctl, cf_info.enable_ctl, cf_info.act_ctl); 59 print_hex_dump_bytes("CPUMF Query: ", DUMP_PREFIX_OFFSET, 60 &cf_info, sizeof(cf_info)); 61 } 62 63 local_irq_restore(flags); 64 } 65 66 /* See also arch/s390/kernel/traps.c */ 67 static unsigned long __store_trace(struct perf_callchain_entry *entry, 68 unsigned long sp, 69 unsigned long low, unsigned long high) 70 { 71 struct stack_frame *sf; 72 struct pt_regs *regs; 73 74 while (1) { 75 sp = sp & PSW_ADDR_INSN; 76 if (sp < low || sp > high - sizeof(*sf)) 77 return sp; 78 sf = (struct stack_frame *) sp; 79 perf_callchain_store(entry, sf->gprs[8] & PSW_ADDR_INSN); 80 /* Follow the backchain. */ 81 while (1) { 82 low = sp; 83 sp = sf->back_chain & PSW_ADDR_INSN; 84 if (!sp) 85 break; 86 if (sp <= low || sp > high - sizeof(*sf)) 87 return sp; 88 sf = (struct stack_frame *) sp; 89 perf_callchain_store(entry, 90 sf->gprs[8] & PSW_ADDR_INSN); 91 } 92 /* Zero backchain detected, check for interrupt frame. */ 93 sp = (unsigned long) (sf + 1); 94 if (sp <= low || sp > high - sizeof(*regs)) 95 return sp; 96 regs = (struct pt_regs *) sp; 97 perf_callchain_store(entry, sf->gprs[8] & PSW_ADDR_INSN); 98 low = sp; 99 sp = regs->gprs[15]; 100 } 101 } 102 103 void perf_callchain_kernel(struct perf_callchain_entry *entry, 104 struct pt_regs *regs) 105 { 106 unsigned long head; 107 struct stack_frame *head_sf; 108 109 if (user_mode(regs)) 110 return; 111 112 head = regs->gprs[15]; 113 head_sf = (struct stack_frame *) head; 114 115 if (!head_sf || !head_sf->back_chain) 116 return; 117 118 head = head_sf->back_chain; 119 head = __store_trace(entry, head, S390_lowcore.async_stack - ASYNC_SIZE, 120 S390_lowcore.async_stack); 121 122 __store_trace(entry, head, S390_lowcore.thread_info, 123 S390_lowcore.thread_info + THREAD_SIZE); 124 } 125