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};