diff options
Diffstat (limited to 'kernel/arch/mips/kernel/perf_event.c')
-rw-r--r-- | kernel/arch/mips/kernel/perf_event.c | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/kernel/arch/mips/kernel/perf_event.c b/kernel/arch/mips/kernel/perf_event.c new file mode 100644 index 000000000..c1cf9c6c3 --- /dev/null +++ b/kernel/arch/mips/kernel/perf_event.c @@ -0,0 +1,69 @@ +/* + * Linux performance counter support for MIPS. + * + * Copyright (C) 2010 MIPS Technologies, Inc. + * Author: Deng-Cheng Zhu + * + * This code is based on the implementation for ARM, which is in turn + * based on the sparc64 perf event code and the x86 code. Performance + * counter access is based on the MIPS Oprofile code. And the callchain + * support references the code of MIPS stacktrace.c. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/perf_event.h> + +#include <asm/stacktrace.h> + +/* Callchain handling code. */ + +/* + * Leave userspace callchain empty for now. When we find a way to trace + * the user stack callchains, we will add it here. + */ + +static void save_raw_perf_callchain(struct perf_callchain_entry *entry, + unsigned long reg29) +{ + unsigned long *sp = (unsigned long *)reg29; + unsigned long addr; + + while (!kstack_end(sp)) { + addr = *sp++; + if (__kernel_text_address(addr)) { + perf_callchain_store(entry, addr); + if (entry->nr >= PERF_MAX_STACK_DEPTH) + break; + } + } +} + +void perf_callchain_kernel(struct perf_callchain_entry *entry, + struct pt_regs *regs) +{ + unsigned long sp = regs->regs[29]; +#ifdef CONFIG_KALLSYMS + unsigned long ra = regs->regs[31]; + unsigned long pc = regs->cp0_epc; + + if (raw_show_trace || !__kernel_text_address(pc)) { + unsigned long stack_page = + (unsigned long)task_stack_page(current); + if (stack_page && sp >= stack_page && + sp <= stack_page + THREAD_SIZE - 32) + save_raw_perf_callchain(entry, sp); + return; + } + do { + perf_callchain_store(entry, pc); + if (entry->nr >= PERF_MAX_STACK_DEPTH) + break; + pc = unwind_stack(current, &sp, pc, &ra); + } while (pc); +#else + save_raw_perf_callchain(entry, sp); +#endif +} |