| /* Copyright (c) 2014,2017 The Linux Foundation. All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 and |
| * only version 2 as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| */ |
| #include <linux/perf_event.h> |
| #include <linux/types.h> |
| #include <linux/tracepoint.h> |
| #include <linux/fs.h> |
| #include <linux/debugfs.h> |
| #include <linux/preempt.h> |
| #include <linux/stat.h> |
| #include <asm/uaccess.h> |
| |
| #define CREATE_TRACE_POINTS |
| #include "perf_trace_user.h" |
| |
| #undef TRACE_SYSTEM |
| #define TRACE_SYSTEM perf_trace_counters |
| |
| #define TRACE_USER_MAX_BUF_SIZE 100 |
| |
| static ssize_t perf_trace_write(struct file *file, |
| const char __user *user_string_in, |
| size_t len, loff_t *ppos) |
| { |
| u32 cnten_val; |
| int rc; |
| char buf[TRACE_USER_MAX_BUF_SIZE + 1]; |
| ssize_t length; |
| |
| if (len == 0) |
| return 0; |
| |
| length = len > TRACE_USER_MAX_BUF_SIZE ? TRACE_USER_MAX_BUF_SIZE : len; |
| |
| rc = copy_from_user(buf, user_string_in, length); |
| if (rc) { |
| pr_err("%s copy_from_user failed, rc=%d\n", __func__, rc); |
| return length; |
| } |
| |
| /* Remove any trailing newline and make sure string is terminated */ |
| if (buf[length - 1] == '\n') |
| buf[length - 1] = '\0'; |
| else |
| buf[length] = '\0'; |
| |
| /* |
| * Disable preemption to ensure that all the performance counter |
| * accesses happen on the same cpu |
| */ |
| preempt_disable(); |
| /* stop counters, call the trace function, restart them */ |
| |
| cnten_val = read_sysreg(pmcntenset_el0); |
| /* Disable all the counters that were enabled */ |
| write_sysreg(cnten_val, pmcntenclr_el0); |
| |
| trace_perf_trace_user(buf, cnten_val); |
| |
| /* Enable all the counters that were disabled */ |
| write_sysreg(cnten_val, pmcntenset_el0); |
| preempt_enable(); |
| |
| return length; |
| } |
| |
| static const struct file_operations perf_trace_fops = { |
| .write = perf_trace_write |
| }; |
| |
| static int __init init_perf_trace(void) |
| { |
| struct dentry *dir; |
| struct dentry *file; |
| unsigned int value = 1; |
| |
| dir = debugfs_create_dir("msm_perf", NULL); |
| if (!dir) |
| return -ENOMEM; |
| file = debugfs_create_file("trace_marker", 0220, dir, |
| &value, &perf_trace_fops); |
| if (!file) |
| return -ENOMEM; |
| |
| return 0; |
| } |
| |
| late_initcall(init_perf_trace); |