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(filename, mode, parent, buf,
26				   &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(relaych);
61	debugfs_remove_recursive(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(relaych, skb->data, 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(port->dev);
86	if (IS_ERR(debugfs_wwan_dir))
87		return;
88
89	debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, debugfs_wwan_dir);
90	if (IS_ERR_OR_NULL(debugfs_dir)) {
91		wwan_put_debugfs_dir(debugfs_wwan_dir);
92		dev_err(port->dev, "Unable to create debugfs for trace");
93		return;
94	}
95
96	relaych = relay_open("relay_ch", debugfs_dir, T7XX_TRC_SUB_BUFF_SIZE,
97			     T7XX_TRC_N_SUB_BUFF, &relay_callbacks, NULL);
98	if (!relaych)
99		goto err_rm_debugfs_dir;
100
101	wwan_put_debugfs_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(debugfs_dir);
108	wwan_put_debugfs_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