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git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/blob - arch/mips/kernel/perf_event.c
2 * Linux performance counter support for MIPS.
4 * Copyright (C) 2010 MIPS Technologies, Inc.
5 * Author: Deng-Cheng Zhu
7 * This code is based on the implementation for ARM, which is in turn
8 * based on the sparc64 perf event code and the x86 code. Performance
9 * counter access is based on the MIPS Oprofile code. And the callchain
10 * support references the code of MIPS stacktrace.c.
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
17 #include <linux/perf_event.h>
18 #include <linux/sched/task_stack.h>
20 #include <asm/stacktrace.h>
22 /* Callchain handling code. */
25 * Leave userspace callchain empty for now. When we find a way to trace
26 * the user stack callchains, we will add it here.
29 static void save_raw_perf_callchain(struct perf_callchain_entry_ctx
*entry
,
32 unsigned long *sp
= (unsigned long *)reg29
;
35 while (!kstack_end(sp
)) {
37 if (__kernel_text_address(addr
)) {
38 perf_callchain_store(entry
, addr
);
39 if (entry
->nr
>= entry
->max_stack
)
45 void perf_callchain_kernel(struct perf_callchain_entry_ctx
*entry
,
48 unsigned long sp
= regs
->regs
[29];
49 #ifdef CONFIG_KALLSYMS
50 unsigned long ra
= regs
->regs
[31];
51 unsigned long pc
= regs
->cp0_epc
;
53 if (raw_show_trace
|| !__kernel_text_address(pc
)) {
54 unsigned long stack_page
=
55 (unsigned long)task_stack_page(current
);
56 if (stack_page
&& sp
>= stack_page
&&
57 sp
<= stack_page
+ THREAD_SIZE
- 32)
58 save_raw_perf_callchain(entry
, sp
);
62 perf_callchain_store(entry
, pc
);
63 if (entry
->nr
>= entry
->max_stack
)
65 pc
= unwind_stack(current
, &sp
, pc
, &ra
);
68 save_raw_perf_callchain(entry
, sp
);