1/*
 2 * Linux performance counter support for MIPS.
 3 *
 4 * Copyright (C) 2010 MIPS Technologies, Inc.
 5 * Author: Deng-Cheng Zhu
 6 *
 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.
11 *
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.
15 */
16
17#include <linux/perf_event.h>
18#include <linux/sched/task_stack.h>
19
20#include <asm/stacktrace.h>
21
22/* Callchain handling code. */
23
24/*
25 * Leave userspace callchain empty for now. When we find a way to trace
26 * the user stack callchains, we will add it here.
27 */
28
29static void save_raw_perf_callchain(struct perf_callchain_entry_ctx *entry,
30				    unsigned long reg29)
31{
32	unsigned long *sp = (unsigned long *)reg29;
33	unsigned long addr;
34
35	while (!kstack_end(sp)) {
36		addr = *sp++;
37		if (__kernel_text_address(addr)) {
38			perf_callchain_store(entry, addr);
39			if (entry->nr >= entry->max_stack)
40				break;
41		}
42	}
43}
44
45void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
46			   struct pt_regs *regs)
47{
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;
52
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);
59		return;
60	}
61	do {
62		perf_callchain_store(entry, pc);
63		if (entry->nr >= entry->max_stack)
64			break;
65		pc = unwind_stack(current, &sp, pc, &ra);
66	} while (pc);
67#else
68	save_raw_perf_callchain(entry, sp);
69#endif
70}

 1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Linux performance counter support for MIPS.
 4 *
 5 * Copyright (C) 2010 MIPS Technologies, Inc.
 6 * Author: Deng-Cheng Zhu
 7 *
 8 * This code is based on the implementation for ARM, which is in turn
 9 * based on the sparc64 perf event code and the x86 code. Performance
10 * counter access is based on the MIPS Oprofile code. And the callchain
11 * support references the code of MIPS stacktrace.c.
 
 
 
 
12 */
13
14#include <linux/perf_event.h>
15#include <linux/sched/task_stack.h>
16
17#include <asm/stacktrace.h>
18
19/* Callchain handling code. */
20
21/*
22 * Leave userspace callchain empty for now. When we find a way to trace
23 * the user stack callchains, we will add it here.
24 */
25
26static void save_raw_perf_callchain(struct perf_callchain_entry_ctx *entry,
27				    unsigned long reg29)
28{
29	unsigned long *sp = (unsigned long *)reg29;
30	unsigned long addr;
31
32	while (!kstack_end(sp)) {
33		addr = *sp++;
34		if (__kernel_text_address(addr)) {
35			perf_callchain_store(entry, addr);
36			if (entry->nr >= entry->max_stack)
37				break;
38		}
39	}
40}
41
42void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
43			   struct pt_regs *regs)
44{
45	unsigned long sp = regs->regs[29];
46#ifdef CONFIG_KALLSYMS
47	unsigned long ra = regs->regs[31];
48	unsigned long pc = regs->cp0_epc;
49
50	if (raw_show_trace || !__kernel_text_address(pc)) {
51		unsigned long stack_page =
52			(unsigned long)task_stack_page(current);
53		if (stack_page && sp >= stack_page &&
54		    sp <= stack_page + THREAD_SIZE - 32)
55			save_raw_perf_callchain(entry, sp);
56		return;
57	}
58	do {
59		perf_callchain_store(entry, pc);
60		if (entry->nr >= entry->max_stack)
61			break;
62		pc = unwind_stack(current, &sp, pc, &ra);
63	} while (pc);
64#else
65	save_raw_perf_callchain(entry, sp);
66#endif
67}