linux/arch/mips/kernel/perf_event.c
Thomas Gleixner d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  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

  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 #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00

68 lines
1.7 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* 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.
*/
#include <linux/perf_event.h>
#include <linux/sched/task_stack.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_ctx *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 >= entry->max_stack)
break;
}
}
}
void perf_callchain_kernel(struct perf_callchain_entry_ctx *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 >= entry->max_stack)
break;
pc = unwind_stack(current, &sp, pc, &ra);
} while (pc);
#else
save_raw_perf_callchain(entry, sp);
#endif
}