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
19#include <asm/stacktrace.h>
20
21/* Callchain handling code. */
22
23/*
24 * Leave userspace callchain empty for now. When we find a way to trace
25 * the user stack callchains, we will add it here.
26 */
27
28static void save_raw_perf_callchain(struct perf_callchain_entry *entry,
29	unsigned long reg29)
30{
31	unsigned long *sp = (unsigned long *)reg29;
32	unsigned long addr;
33
34	while (!kstack_end(sp)) {
35		addr = *sp++;
36		if (__kernel_text_address(addr)) {
37			perf_callchain_store(entry, addr);
38			if (entry->nr >= PERF_MAX_STACK_DEPTH)
39				break;
40		}
41	}
42}
43
44void perf_callchain_kernel(struct perf_callchain_entry *entry,
45		      struct pt_regs *regs)
46{
47	unsigned long sp = regs->regs[29];
48#ifdef CONFIG_KALLSYMS
49	unsigned long ra = regs->regs[31];
50	unsigned long pc = regs->cp0_epc;
51
52	if (raw_show_trace || !__kernel_text_address(pc)) {
53		unsigned long stack_page =
54			(unsigned long)task_stack_page(current);
55		if (stack_page && sp >= stack_page &&
56		    sp <= stack_page + THREAD_SIZE - 32)
57			save_raw_perf_callchain(entry, sp);
58		return;
59	}
60	do {
61		perf_callchain_store(entry, pc);
62		if (entry->nr >= PERF_MAX_STACK_DEPTH)
63			break;
64		pc = unwind_stack(current, &sp, pc, &ra);
65	} while (pc);
66#else
67	save_raw_perf_callchain(entry, sp);
68#endif
69}

 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}