linux/drivers/net/wwan/t7xx/t7xx_port_trace.c
Jinjian Song d785ed945d net: wwan: t7xx: PCIe reset rescan
WWAN device is programmed to boot in normal mode or fastboot mode,
when triggering a device reset through ACPI call or fastboot switch
command. Maintain state machine synchronization and reprobe logic
after a device reset.

The PCIe device reset triggered by several ways.
E.g.:
 - fastboot: echo "fastboot_switching" > /sys/bus/pci/devices/${bdf}/t7xx_mode.
 - reset: echo "reset" > /sys/bus/pci/devices/${bdf}/t7xx_mode.
 - IRQ: PCIe device request driver to reset itself by an interrupt request.

Use pci_reset_function() as a generic way to reset device, save and
restore the PCIe configuration before and after reset device to ensure
the reprobe process.

Suggestion from Bjorn:
Link: https://lore.kernel.org/all/20230127133034.GA1364550@bhelgaas/

Signed-off-by: Jinjian Song <jinjian.song@fibocom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-21 12:57:24 +01:00

118 lines
2.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2022 Intel Corporation.
*/
#include <linux/debugfs.h>
#include <linux/relay.h>
#include <linux/skbuff.h>
#include <linux/wwan.h>
#include "t7xx_port.h"
#include "t7xx_port_proxy.h"
#include "t7xx_state_monitor.h"
#define T7XX_TRC_SUB_BUFF_SIZE 131072
#define T7XX_TRC_N_SUB_BUFF 32
static struct dentry *t7xx_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);
}
static int t7xx_trace_remove_buf_file_handler(struct dentry *dentry)
{
debugfs_remove(dentry);
return 0;
}
static int t7xx_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;
}
static struct rchan_callbacks relay_callbacks = {
.subbuf_start = t7xx_trace_subbuf_start_handler,
.create_buf_file = t7xx_trace_create_buf_file_handler,
.remove_buf_file = t7xx_trace_remove_buf_file_handler,
};
static void t7xx_trace_port_uninit(struct t7xx_port *port)
{
struct dentry *debugfs_dir = port->t7xx_dev->debugfs_dir;
struct rchan *relaych = port->log.relaych;
if (!relaych)
return;
relay_close(relaych);
debugfs_remove_recursive(debugfs_dir);
port->log.relaych = NULL;
}
static int t7xx_trace_port_recv_skb(struct t7xx_port *port, struct sk_buff *skb)
{
struct rchan *relaych = port->log.relaych;
if (!relaych)
return -EINVAL;
relay_write(relaych, skb->data, skb->len);
dev_kfree_skb(skb);
return 0;
}
static void t7xx_port_trace_md_state_notify(struct t7xx_port *port, unsigned int state)
{
struct rchan *relaych = port->log.relaych;
struct dentry *debugfs_wwan_dir;
struct dentry *debugfs_dir;
if (state != MD_STATE_READY || relaych)
return;
debugfs_wwan_dir = wwan_get_debugfs_dir(port->dev);
if (IS_ERR(debugfs_wwan_dir))
return;
debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, debugfs_wwan_dir);
if (IS_ERR_OR_NULL(debugfs_dir)) {
wwan_put_debugfs_dir(debugfs_wwan_dir);
dev_err(port->dev, "Unable to create debugfs for trace");
return;
}
relaych = relay_open("relay_ch", debugfs_dir, T7XX_TRC_SUB_BUFF_SIZE,
T7XX_TRC_N_SUB_BUFF, &relay_callbacks, NULL);
if (!relaych)
goto err_rm_debugfs_dir;
wwan_put_debugfs_dir(debugfs_wwan_dir);
port->log.relaych = relaych;
port->t7xx_dev->debugfs_dir = debugfs_dir;
return;
err_rm_debugfs_dir:
debugfs_remove_recursive(debugfs_dir);
wwan_put_debugfs_dir(debugfs_wwan_dir);
dev_err(port->dev, "Unable to create trace port %s", port->port_conf->name);
}
struct port_ops t7xx_trace_port_ops = {
.recv_skb = t7xx_trace_port_recv_skb,
.uninit = t7xx_trace_port_uninit,
.md_state_notify = t7xx_port_trace_md_state_notify,
};