aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/net/wwan/iosm/iosm_ipc_trace.c
blob: eeecfa3d10c5abcaaea901280641fb2e39ec7f99 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2020-2021 Intel Corporation.
 */

#include <linux/wwan.h>
#include "iosm_ipc_trace.h"

/* sub buffer size and number of sub buffer */
#define IOSM_TRC_SUB_BUFF_SIZE 131072
#define IOSM_TRC_N_SUB_BUFF 32

#define IOSM_TRC_FILE_PERM 0600

#define IOSM_TRC_DEBUGFS_TRACE "trace"
#define IOSM_TRC_DEBUGFS_TRACE_CTRL "trace_ctrl"

/**
 * ipc_trace_port_rx - Receive trace packet from cp and write to relay buffer
 * @ipc_imem:   Pointer to iosm_imem structure
 * @skb:        Pointer to struct sk_buff
 */
void ipc_trace_port_rx(struct iosm_imem *ipc_imem, struct sk_buff *skb)
{
	struct iosm_trace *ipc_trace = ipc_imem->trace;

	if (ipc_trace->ipc_rchan)
		relay_write(ipc_trace->ipc_rchan, skb->data, skb->len);

	dev_kfree_skb(skb);
}

/* Creates relay file in debugfs. */
static struct dentry *
ipc_trace_create_buf_file_handler(const char *filename,
				  struct dentry *parent,
				  umode_t mode,
				  struct rchan_buf *buf,
				  int *is_global)
{
	*is_global = 1;
	return debugfs_create_file(filename, mode, parent, buf,
				   &relay_file_operations);
}

/* Removes relay file from debugfs. */
static int ipc_trace_remove_buf_file_handler(struct dentry *dentry)
{
	debugfs_remove(dentry);
	return 0;
}

static int ipc_trace_subbuf_start_handler(struct rchan_buf *buf, void *subbuf,
					  void *prev_subbuf,
					  size_t prev_padding)
{
	if (relay_buf_full(buf)) {
		pr_err_ratelimited("Relay_buf full dropping traces");
		return 0;
	}

	return 1;
}

/* Relay interface callbacks */
static struct rchan_callbacks relay_callbacks = {
	.subbuf_start = ipc_trace_subbuf_start_handler,
	.create_buf_file = ipc_trace_create_buf_file_handler,
	.remove_buf_file = ipc_trace_remove_buf_file_handler,
};

/* Copy the trace control mode to user buffer */
static ssize_t ipc_trace_ctrl_file_read(struct file *filp, char __user *buffer,
					size_t count, loff_t *ppos)
{
	struct iosm_trace *ipc_trace = filp->private_data;
	char buf[16];
	int len;

	mutex_lock(&ipc_trace->trc_mutex);
	len = snprintf(buf, sizeof(buf), "%d\n", ipc_trace->mode);
	mutex_unlock(&ipc_trace->trc_mutex);

	return simple_read_from_buffer(buffer, count, ppos, buf, len);
}

/* Open and close the trace channel depending on user input */
static ssize_t ipc_trace_ctrl_file_write(struct file *filp,
					 const char __user *buffer,
					 size_t count, loff_t *ppos)
{
	struct iosm_trace *ipc_trace = filp->private_data;
	unsigned long val;
	int ret;

	ret = kstrtoul_from_user(buffer, count, 10, &val);
	if (ret)
		return ret;

	mutex_lock(&ipc_trace->trc_mutex);
	if (val == TRACE_ENABLE && ipc_trace->mode != TRACE_ENABLE) {
		ipc_trace->channel = ipc_imem_sys_port_open(ipc_trace->ipc_imem,
							    ipc_trace->chl_id,
							    IPC_HP_CDEV_OPEN);
		if (!ipc_trace->channel) {
			ret = -EIO;
			goto unlock;
		}
		ipc_trace->mode = TRACE_ENABLE;
	} else if (val == TRACE_DISABLE && ipc_trace->mode != TRACE_DISABLE) {
		ipc_trace->mode = TRACE_DISABLE;
		/* close trace channel */
		ipc_imem_sys_port_close(ipc_trace->ipc_imem,
					ipc_trace->channel);
		relay_flush(ipc_trace->ipc_rchan);
	}
	ret = count;
unlock:
	mutex_unlock(&ipc_trace->trc_mutex);
	return ret;
}

static const struct file_operations ipc_trace_fops = {
	.open = simple_open,
	.write = ipc_trace_ctrl_file_write,
	.read  = ipc_trace_ctrl_file_read,
};

/**
 * ipc_trace_init - Create trace interface & debugfs entries
 * @ipc_imem:   Pointer to iosm_imem structure
 *
 * Returns: Pointer to trace instance on success else NULL
 */
struct iosm_trace *ipc_trace_init(struct iosm_imem *ipc_imem)
{
	struct ipc_chnl_cfg chnl_cfg = { 0 };
	struct iosm_trace *ipc_trace;

	ipc_chnl_cfg_get(&chnl_cfg, IPC_MEM_CTRL_CHL_ID_3);
	ipc_imem_channel_init(ipc_imem, IPC_CTYPE_CTRL, chnl_cfg,
			      IRQ_MOD_OFF);

	ipc_trace = kzalloc(sizeof(*ipc_trace), GFP_KERNEL);
	if (!ipc_trace)
		return NULL;

	ipc_trace->mode = TRACE_DISABLE;
	ipc_trace->dev = ipc_imem->dev;
	ipc_trace->ipc_imem = ipc_imem;
	ipc_trace->chl_id = IPC_MEM_CTRL_CHL_ID_3;

	mutex_init(&ipc_trace->trc_mutex);

	ipc_trace->ctrl_file = debugfs_create_file(IOSM_TRC_DEBUGFS_TRACE_CTRL,
						   IOSM_TRC_FILE_PERM,
						   ipc_imem->debugfs_dir,
						   ipc_trace, &ipc_trace_fops);

	ipc_trace->ipc_rchan = relay_open(IOSM_TRC_DEBUGFS_TRACE,
					  ipc_imem->debugfs_dir,
					  IOSM_TRC_SUB_BUFF_SIZE,
					  IOSM_TRC_N_SUB_BUFF,
					  &relay_callbacks, NULL);

	return ipc_trace;
}

/**
 * ipc_trace_deinit - Closing relayfs, removing debugfs entries
 * @ipc_trace: Pointer to the iosm_trace data struct
 */
void ipc_trace_deinit(struct iosm_trace *ipc_trace)
{
	if (!ipc_trace)
		return;

	debugfs_remove(ipc_trace->ctrl_file);
	relay_close(ipc_trace->ipc_rchan);
	mutex_destroy(&ipc_trace->trc_mutex);
	kfree(ipc_trace);
}