1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2022 Intel Corporation.
4 */
5
6#include <linux/debugfs.h>
7#include <linux/relay.h>
8#include <linux/skbuff.h>
9#include <linux/wwan.h>
10
11#include "t7xx_port.h"
12#include "t7xx_port_proxy.h"
13#include "t7xx_state_monitor.h"
14
15#define T7XX_TRC_SUB_BUFF_SIZE 131072
16#define T7XX_TRC_N_SUB_BUFF 32
17
18static struct dentry *t7xx_trace_create_buf_file_handler(const char *filename,
19 struct dentry *parent,
20 umode_t mode,
21 struct rchan_buf *buf,
22 int *is_global)
23{
24 *is_global = 1;
25 return debugfs_create_file(name: filename, mode, parent, data: buf,
26 fops: &relay_file_operations);
27}
28
29static int t7xx_trace_remove_buf_file_handler(struct dentry *dentry)
30{
31 debugfs_remove(dentry);
32 return 0;
33}
34
35static int t7xx_trace_subbuf_start_handler(struct rchan_buf *buf, void *subbuf,
36 void *prev_subbuf, size_t prev_padding)
37{
38 if (relay_buf_full(buf)) {
39 pr_err_ratelimited("Relay_buf full dropping traces");
40 return 0;
41 }
42
43 return 1;
44}
45
46static struct rchan_callbacks relay_callbacks = {
47 .subbuf_start = t7xx_trace_subbuf_start_handler,
48 .create_buf_file = t7xx_trace_create_buf_file_handler,
49 .remove_buf_file = t7xx_trace_remove_buf_file_handler,
50};
51
52static void t7xx_trace_port_uninit(struct t7xx_port *port)
53{
54 struct dentry *debugfs_dir = port->t7xx_dev->debugfs_dir;
55 struct rchan *relaych = port->log.relaych;
56
57 if (!relaych)
58 return;
59
60 relay_close(chan: relaych);
61 debugfs_remove_recursive(dentry: debugfs_dir);
62}
63
64static int t7xx_trace_port_recv_skb(struct t7xx_port *port, struct sk_buff *skb)
65{
66 struct rchan *relaych = port->log.relaych;
67
68 if (!relaych)
69 return -EINVAL;
70
71 relay_write(chan: relaych, data: skb->data, length: skb->len);
72 dev_kfree_skb(skb);
73 return 0;
74}
75
76static void t7xx_port_trace_md_state_notify(struct t7xx_port *port, unsigned int state)
77{
78 struct rchan *relaych = port->log.relaych;
79 struct dentry *debugfs_wwan_dir;
80 struct dentry *debugfs_dir;
81
82 if (state != MD_STATE_READY || relaych)
83 return;
84
85 debugfs_wwan_dir = wwan_get_debugfs_dir(parent: port->dev);
86 if (IS_ERR(ptr: debugfs_wwan_dir))
87 return;
88
89 debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, parent: debugfs_wwan_dir);
90 if (IS_ERR_OR_NULL(ptr: debugfs_dir)) {
91 wwan_put_debugfs_dir(dir: debugfs_wwan_dir);
92 dev_err(port->dev, "Unable to create debugfs for trace");
93 return;
94 }
95
96 relaych = relay_open(base_filename: "relay_ch", parent: debugfs_dir, T7XX_TRC_SUB_BUFF_SIZE,
97 T7XX_TRC_N_SUB_BUFF, cb: &relay_callbacks, NULL);
98 if (!relaych)
99 goto err_rm_debugfs_dir;
100
101 wwan_put_debugfs_dir(dir: debugfs_wwan_dir);
102 port->log.relaych = relaych;
103 port->t7xx_dev->debugfs_dir = debugfs_dir;
104 return;
105
106err_rm_debugfs_dir:
107 debugfs_remove_recursive(dentry: debugfs_dir);
108 wwan_put_debugfs_dir(dir: debugfs_wwan_dir);
109 dev_err(port->dev, "Unable to create trace port %s", port->port_conf->name);
110}
111
112struct port_ops t7xx_trace_port_ops = {
113 .recv_skb = t7xx_trace_port_recv_skb,
114 .uninit = t7xx_trace_port_uninit,
115 .md_state_notify = t7xx_port_trace_md_state_notify,
116};
117

source code of linux/drivers/net/wwan/t7xx/t7xx_port_trace.c