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
t7xx_trace_create_buf_file_handler(const char * filename,struct dentry * parent,umode_t mode,struct rchan_buf * buf,int * is_global)18 static 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
t7xx_trace_remove_buf_file_handler(struct dentry * dentry)29 static int t7xx_trace_remove_buf_file_handler(struct dentry *dentry)
30 {
31 debugfs_remove(dentry);
32 return 0;
33 }
34
t7xx_trace_subbuf_start_handler(struct rchan_buf * buf,void * subbuf,void * prev_subbuf,size_t prev_padding)35 static 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
46 static 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
t7xx_trace_port_uninit(struct t7xx_port * port)52 static 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 port->log.relaych = NULL;
63 }
64
t7xx_trace_port_recv_skb(struct t7xx_port * port,struct sk_buff * skb)65 static int t7xx_trace_port_recv_skb(struct t7xx_port *port, struct sk_buff *skb)
66 {
67 struct rchan *relaych = port->log.relaych;
68
69 if (!relaych)
70 return -EINVAL;
71
72 relay_write(relaych, skb->data, skb->len);
73 dev_kfree_skb(skb);
74 return 0;
75 }
76
t7xx_port_trace_md_state_notify(struct t7xx_port * port,unsigned int state)77 static void t7xx_port_trace_md_state_notify(struct t7xx_port *port, unsigned int state)
78 {
79 struct rchan *relaych = port->log.relaych;
80 struct dentry *debugfs_wwan_dir;
81 struct dentry *debugfs_dir;
82
83 if (state != MD_STATE_READY || relaych)
84 return;
85
86 debugfs_wwan_dir = wwan_get_debugfs_dir(port->dev);
87 if (IS_ERR(debugfs_wwan_dir))
88 return;
89
90 debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, debugfs_wwan_dir);
91 if (IS_ERR_OR_NULL(debugfs_dir)) {
92 wwan_put_debugfs_dir(debugfs_wwan_dir);
93 dev_err(port->dev, "Unable to create debugfs for trace");
94 return;
95 }
96
97 relaych = relay_open("relay_ch", debugfs_dir, T7XX_TRC_SUB_BUFF_SIZE,
98 T7XX_TRC_N_SUB_BUFF, &relay_callbacks, NULL);
99 if (!relaych)
100 goto err_rm_debugfs_dir;
101
102 wwan_put_debugfs_dir(debugfs_wwan_dir);
103 port->log.relaych = relaych;
104 port->t7xx_dev->debugfs_dir = debugfs_dir;
105 return;
106
107 err_rm_debugfs_dir:
108 debugfs_remove_recursive(debugfs_dir);
109 wwan_put_debugfs_dir(debugfs_wwan_dir);
110 dev_err(port->dev, "Unable to create trace port %s", port->port_conf->name);
111 }
112
113 struct port_ops t7xx_trace_port_ops = {
114 .recv_skb = t7xx_trace_port_recv_skb,
115 .uninit = t7xx_trace_port_uninit,
116 .md_state_notify = t7xx_port_trace_md_state_notify,
117 };
118