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 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 29 static int t7xx_trace_remove_buf_file_handler(struct dentry *dentry) 30 { 31 debugfs_remove(dentry); 32 return 0; 33 } 34 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 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 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 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