diff options
Diffstat (limited to 'drivers/net/wwan/iosm/iosm_ipc_trace.c')
| -rw-r--r-- | drivers/net/wwan/iosm/iosm_ipc_trace.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/drivers/net/wwan/iosm/iosm_ipc_trace.c b/drivers/net/wwan/iosm/iosm_ipc_trace.c new file mode 100644 index 000000000000..c5fa12599c2b --- /dev/null +++ b/drivers/net/wwan/iosm/iosm_ipc_trace.c @@ -0,0 +1,173 @@ +// 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_trace: Pointer to the ipc trace data-struct + * @skb: Pointer to struct sk_buff + */ +void ipc_trace_port_rx(struct iosm_trace *ipc_trace, struct sk_buff *skb) +{ + 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 iosm_trace *ipc_trace = kzalloc(sizeof(*ipc_trace), GFP_KERNEL); + struct dentry *debugfs_pdev; + + 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); + debugfs_pdev = wwan_get_debugfs_dir(ipc_imem->dev); + + ipc_trace->ctrl_file = debugfs_create_file(IOSM_TRC_DEBUGFS_TRACE_CTRL, + IOSM_TRC_FILE_PERM, + debugfs_pdev, + ipc_trace, &ipc_trace_fops); + + ipc_trace->ipc_rchan = relay_open(IOSM_TRC_DEBUGFS_TRACE, + debugfs_pdev, + 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) +{ + debugfs_remove(ipc_trace->ctrl_file); + relay_close(ipc_trace->ipc_rchan); + mutex_destroy(&ipc_trace->trc_mutex); + kfree(ipc_trace); +} |