1/* 2 * Performance event callchain support - SuperH architecture code 3 * 4 * Copyright (C) 2009 Paul Mundt 5 * 6 * This file is subject to the terms and conditions of the GNU General Public 7 * License. See the file "COPYING" in the main directory of this archive 8 * for more details. 9 */ 10#include <linux/kernel.h> 11#include <linux/sched.h> 12#include <linux/perf_event.h> 13#include <linux/percpu.h> 14#include <asm/unwinder.h> 15#include <asm/ptrace.h> 16 17static inline void callchain_store(struct perf_callchain_entry *entry, u64 ip) 18{ 19 if (entry->nr < PERF_MAX_STACK_DEPTH) 20 entry->ip[entry->nr++] = ip; 21} 22 23static void callchain_warning(void *data, char *msg) 24{ 25} 26 27static void 28callchain_warning_symbol(void *data, char *msg, unsigned long symbol) 29{ 30} 31 32static int callchain_stack(void *data, char *name) 33{ 34 return 0; 35} 36 37static void callchain_address(void *data, unsigned long addr, int reliable) 38{ 39 struct perf_callchain_entry *entry = data; 40 41 if (reliable) 42 callchain_store(entry, addr); 43} 44 45static const struct stacktrace_ops callchain_ops = { 46 .warning = callchain_warning, 47 .warning_symbol = callchain_warning_symbol, 48 .stack = callchain_stack, 49 .address = callchain_address, 50}; 51 52static void 53perf_callchain_kernel(struct pt_regs *regs, struct perf_callchain_entry *entry) 54{ 55 callchain_store(entry, PERF_CONTEXT_KERNEL); 56 callchain_store(entry, regs->pc); 57 58 unwind_stack(NULL, regs, NULL, &callchain_ops, entry); 59} 60 61static void 62perf_do_callchain(struct pt_regs *regs, struct perf_callchain_entry *entry) 63{ 64 int is_user; 65 66 if (!regs) 67 return; 68 69 is_user = user_mode(regs); 70 71 if (is_user && current->state != TASK_RUNNING) 72 return; 73 74 /* 75 * Only the kernel side is implemented for now. 76 */ 77 if (!is_user) 78 perf_callchain_kernel(regs, entry); 79} 80 81/* 82 * No need for separate IRQ and NMI entries. 83 */ 84static DEFINE_PER_CPU(struct perf_callchain_entry, callchain); 85 86struct perf_callchain_entry *perf_callchain(struct pt_regs *regs) 87{ 88 struct perf_callchain_entry *entry = &__get_cpu_var(callchain); 89 90 entry->nr = 0; 91 92 perf_do_callchain(regs, entry); 93 94 return entry; 95} 96