// SPDX-License-Identifier: GPL-2.0+
// Debug logs for the ChromeOS EC
//
// Copyright (C) 2015 Google, Inc.
#include <linux/circ_buf.h>
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/platform_data/cros_ec_commands.h>
#include <linux/platform_data/cros_ec_proto.h>
#include <linux/platform_device.h>
#include <linux/poll.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/wait.h>
#define DRV_NAME "cros-ec-debugfs"
#define LOG_SHIFT 14
#define LOG_SIZE (1 << LOG_SHIFT)
#define LOG_POLL_SEC 10
#define CIRC_ADD(idx, size, value) (((idx) + (value)) & ((size) - 1))
static unsigned int log_poll_period_ms = LOG_POLL_SEC * MSEC_PER_SEC;
module_param(log_poll_period_ms, uint, 0644);
MODULE_PARM_DESC(log_poll_period_ms, "EC log polling period(ms)");
/* waitqueue for log readers */
static DECLARE_WAIT_QUEUE_HEAD(cros_ec_debugfs_log_wq);
/**
* struct cros_ec_debugfs - EC debugging information.
*
* @ec: EC device this debugfs information belongs to
* @dir: dentry for debugfs files
* @log_buffer: circular buffer for console log information
* @read_msg: preallocated EC command and buffer to read console log
* @log_mutex: mutex to protect circular buffer
* @log_poll_work: recurring task to poll EC for new console log data
* @panicinfo_blob: panicinfo debugfs blob
* @notifier_panic: notifier_block to let kernel to flush buffered log
* when EC panic
*/
struct cros_ec_debugfs {
struct cros_ec_dev *ec;
struct dentry *dir;
/* EC log */
struct circ_buf log_buffer;
struct cros_ec_command *read_msg;
struct mutex log_mutex;
struct delayed_work log_poll_work;
/* EC panicinfo */
struct debugfs_blob_wrapper panicinfo_blob;
struct notifier_block notifier_panic;
};
/*
* We need to make sure that the EC log buffer on the UART is large enough,
* so that it is unlikely enough to overlow within log_poll_period_ms.
*/
static void cros_ec_console_log_work(struct work_struct *__work)
{
struct cros_ec_debugfs *debug_info =
container_of(to_delayed_work(__work),
struct cros_ec_debugfs,
log_poll_work);
struct cros_ec_dev *ec = debug_info->ec;
struct circ_buf *cb = &debug_info->log_buffer;
struct cros_ec_command snapshot_msg = {
.command = EC_CMD_CONSOLE_SNAPSHOT + ec->cmd_offset,
};
struct ec_params_console_read_v1 *read_params =
(struct ec_params_console_read_v1 *)debug_info->read_msg->data;
uint8_t *ec_buffer = (uint8_t *)debug_info->read_msg->data;
int idx;
int buf_space;
int ret;
ret = cros_ec_cmd_xfer_status(ec->ec_dev, &snapshot_msg);
if (ret < 0)
goto resched;
/* Loop until we have read everything, or there's an error. */
mutex_lock(&debug_info->log_mutex);
buf_space = CIRC_SPACE(cb->head, cb->tail, LOG_SIZE);
while (1) {
if (!buf_space) {
dev_info_once(ec->dev,
"Some logs may have been dropped...\n");
break;
}
memset(read_params, '\0', sizeof(*read_params));
read_params->subcmd = CONSOLE_READ_RECENT;
ret = cros_ec_cmd_xfer_status(ec->ec_dev,
debug_info->read_msg);
if (ret < 0)
break;
/* If the buffer is empty, we're done here. */
if (ret == 0 || ec_buffer[0] == '\0')
break;
idx = 0;
while (idx < ret && ec_buffer[idx] != '\0' && buf_space > 0) {
cb->buf[cb->head] = ec_buffer[idx];
cb->head = CIRC_ADD(cb->head, LOG_SIZE, 1);
idx++;
buf_space--;
}
wake_up(&cros_ec_debugfs_log_wq);
}
mutex_unlock(&debug_info->log_mutex);
resched:
schedule_delayed_work(&debug_info->log_poll_work,
msecs_to_jiffies(log_poll_period_ms));
}
static int cros_ec_console_log_open(struct inode *inode, struct file *file)
{
file->private_data = inode->i_private;
return stream_open(inode, file);
}
static ssize_t cros_ec_console_log_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
struct cros_ec_debugfs *debug_info = file->private_data;
struct circ_buf *cb = &debug_info->log_buffer;
ssize_t ret;
mutex_lock(&debug_info->log_mutex);
while (!CIRC_CNT(cb->head, cb->tail, LOG_SIZE)) {
if (file->f_flags & O_NONBLOCK) {
ret = -EAGAIN;
goto error;
}
mutex_unlock(&debug_info->log_mutex);
ret = wait_event_interruptible(cros_ec_debugfs_log_wq,
CIRC_CNT(cb->head, cb->tail, LOG_SIZE));
if (ret < 0)
return ret;
mutex_lock(&debug_info->log_mutex);
}
/* Only copy until the end of the circular buffer, and let userspace
* retry to get the rest of the data.
*/
ret = min_t(size_t, CIRC_CNT_TO_END(cb->head, cb->tail, LOG_SIZE),
count);
if (copy_to_user(buf, cb->buf + cb->tail, ret)) {
ret = -EFAULT;
goto error;
}
cb->tail = CIRC_ADD(cb->tail, LOG_SIZE, ret);
error:
mutex_unlock(&debug_info->log_mutex);
return ret;
}
static __poll_t cros_ec_console_log_poll(struct file *file,
poll_table *wait)
{
struct cros_ec_debugfs *debug_info = file->private_data;
__poll_t mask = 0;
poll_wait(file, &cros_ec_debugfs_log_wq, wait);
mutex_lock(&debug_info->log_mutex);
if (CIRC_CNT(debug_info->log_buffer.head,
debug_info->log_buffer.tail,
LOG_SIZE))
mask |= EPOLLIN | EPOLLRDNORM;
mutex_unlock(&debug_info->log_mutex);
return mask;
}
static int cros_ec_console_log_release(struct inode *inode, struct file *file)
{
return 0;
}
static ssize_t cros_ec_pdinfo_read(struct file *file,
char __user *user_buf,
size_t count,
loff_t *ppos)
{
char read_buf[EC_USB_PD_MAX_PORTS * 40], *p = read_buf;
struct cros_ec_debugfs *debug_info = file->private_data;
struct cros_ec_device *ec_dev = debug_info->ec->ec_dev;
struct {
struct cros_ec_command msg;
union {
struct ec_response_usb_pd_control_v1 resp;
struct ec_params_usb_pd_control params;
};
} __packed ec_buf;
struct cros_ec_command *msg;
struct ec_response_usb_pd_control_v1 *resp;
struct ec_params_usb_pd_control *params;
int i;
msg = &ec_buf.msg;
params = (struct ec_params_usb_pd_control *)msg->data;
resp = (struct ec_response_usb_pd_control_v1 *)msg->data;
msg->command = EC_CMD_USB_PD_CONTROL;
msg->version = 1;
msg->insize = sizeof(*resp);
msg->outsize = sizeof(*params);
/*
* Read status from all PD ports until failure, typically caused
* by attempting to read status on a port that doesn't exist.
*/
for (i = 0; i < EC_USB_PD_MAX_PORTS; ++i) {
params->port = i;
params->role = 0;
params->mux = 0;
params->swap = 0;
if (cros_ec_cmd_xfer_status(ec_dev, msg) < 0)
break;
p += scnprintf(p, sizeof(read_buf) + read_buf - p,
"p%d: %s en:%.2x role:%.2x pol:%.2x\n", i,
resp->state, resp->enabled, resp->role,
resp->polarity);
}
return simple_read_from_buffer(user_buf, count, ppos,
read_buf, p - read_buf);
}
static bool cros_ec_uptime_is_supported(struct cros_ec_device *ec_dev)
{
struct {
struct cros_ec_command cmd;
struct ec_response_uptime_info resp;
} __packed msg = {};
int ret;
msg.cmd.command = EC_CMD_GET_UPTIME_INFO;
msg.cmd.insize = sizeof(msg.resp);
ret = cros_ec_cmd_xfer_status(ec_dev, &msg.cmd);
if (ret == -EPROTO && msg.cmd.result == EC_RES_INVALID_COMMAND)
return false;
/* Other errors maybe a transient error, do not rule about support. */
return true;
}
static ssize_t cros_ec_uptime_read(struct file *file, char __user *user_buf,
size_t count, loff_t *ppos)
{
struct cros_ec_debugfs *debug_info = file->private_data;
struct cros_ec_device *ec_dev = debug_info->ec->ec_dev;
struct {
struct cros_ec_command cmd;
struct ec_response_uptime_info resp;
} __packed msg = {};
struct ec_response_uptime_info *resp;
char read_buf[32];
int ret;
resp = (struct ec_response_uptime_info *)&msg.resp;
msg.cmd.command = EC_CMD_GET_UPTIME_INFO;
msg.cmd.insize = sizeof(*resp);
ret = cros_ec_cmd_xfer_status(ec_dev, &msg.cmd);
if (ret < 0)
return ret;
ret = scnprintf(read_buf, sizeof(read_buf), "%u\n",
resp->time_since_ec_boot_ms);
return simple_read_from_buffer(user_buf, count, ppos, read_buf, ret);
}
static const struct file_operations cros_ec_console_log_fops = {
.owner = THIS_MODULE,
.open = cros_ec_console_log_open,
.read = cros_ec_console_log_read,
.poll = cros_ec_console_log_poll,
.release = cros_ec_console_log_release,
};
static const struct file_operations cros_ec_pdinfo_fops = {
.owner = THIS_MODULE,
.open = simple_open,
.read = cros_ec_pdinfo_read,
.llseek = default_llseek,
};
static const struct file_operations cros_ec_uptime_fops = {
.owner = THIS_MODULE,
.open = simple_open,
.read = cros_ec_uptime_read,
.llseek = default_llseek,
};
static int ec_read_version_supported(struct cros_ec_dev *ec)
{
struct ec_params_get_cmd_versions_v1 *params;
struct ec_response_get_cmd_versions *response;
int ret;
struct cros_ec_command *msg;
msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*response)),
GFP_KERNEL);
if (!msg)
return 0;
msg->version = 1;
msg->command = EC_CMD_GET_CMD_VERSIONS + ec->cmd_offset;
msg->outsize = sizeof(*params);
msg->insize = sizeof(*response);
params = (struct ec_params_get_cmd_versions_v1 *)msg->data;
params->cmd = EC_CMD_CONSOLE_READ;
response = (struct ec_response_get_cmd_versions *)msg->data;
ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg) >= 0 &&
response->version_mask & EC_VER_MASK(1);
kfree(msg);
return ret;
}
static int cros_ec_create_console_log(struct cros_ec_debugfs *debug_info)
{
struct cros_ec_dev *ec = debug_info->ec;
char *buf;
int read_params_size;
int read_response_size;
/*
* If the console log feature is not supported return silently and
* don't create the console_log entry.
*/
if (!ec_read_version_supported(ec))
return 0;
buf = devm_kzalloc(ec->dev, LOG_SIZE, GFP_KERNEL);
if (!buf)
return -ENOMEM;
read_params_size = sizeof(struct ec_params_console_read_v1);
read_response_size = ec->ec_dev->max_response;
debug_info->read_msg = devm_kzalloc(ec->dev,
sizeof(*debug_info->read_msg) +
max(read_params_size, read_response_size), GFP_KERNEL);
if (!debug_info->read_msg)
return -ENOMEM;
debug_info->read_msg->version = 1;
debug_info->read_msg->command = EC_CMD_CONSOLE_READ + ec->cmd_offset;
debug_info->read_msg->outsize = read_params_size;
debug_info->read_msg->insize = read_response_size;
debug_info->log_buffer.buf = buf;
debug_info->log_buffer.head = 0;
debug_info->log_buffer.tail = 0;
mutex_init(&debug_info->log_mutex);
debugfs_create_file("console_log", S_IFREG | 0444, debug_info->dir,
debug_info, &cros_ec_console_log_fops);
INIT_DELAYED_WORK(&debug_info->log_poll_work,
cros_ec_console_log_work);
schedule_delayed_work(&debug_info->log_poll_work, 0);
return 0;
}
static void cros_ec_cleanup_console_log(struct cros_ec_debugfs *debug_info)
{
if (debug_info->log_buffer.buf) {
cancel_delayed_work_sync(&debug_info->log_poll_work);
mutex_destroy(&debug_info->log_mutex);
}
}
/*
* Returns the size of the panicinfo data fetched from the EC
*/
static int cros_ec_get_panicinfo(struct cros_ec_device *ec_dev, uint8_t *data,
int data_size)
{
int ret;
struct cros_ec_command *msg;
if (!data || data_size <= 0 || data_size > ec_dev->max_response)
return -EINVAL;
msg = kzalloc(sizeof(*msg) + data_size, GFP_KERNEL);
if (!msg)
return -ENOMEM;
msg->command = EC_CMD_GET_PANIC_INFO;
msg->insize = data_size;
ret = cros_ec_cmd_xfer_status(ec_dev, msg);
if (ret < 0)
goto free;
memcpy(data, msg->data, data_size);
free:
kfree(msg);
return ret;
}
static int cros_ec_create_panicinfo(struct cros_ec_debugfs *debug_info)
{
struct cros_ec_device *ec_dev = debug_info->ec->ec_dev;
int ret;
void *data;
data = devm_kzalloc(debug_info->ec->dev, ec_dev->max_response,
GFP_KERNEL);
if (!data)
return -ENOMEM;
ret = cros_ec_get_panicinfo(ec_dev, data, ec_dev->max_response);
if (ret < 0) {
ret = 0;
goto free;
}
/* No panic data */
if (ret == 0)
goto free;
debug_info->panicinfo_blob.data = data;
debug_info->panicinfo_blob.size = ret;
debugfs_create_blob("panicinfo", 0444, debug_info->dir,
&debug_info->panicinfo_blob);
return 0;
free:
devm_kfree(debug_info->ec->dev, data);
return ret;
}
static int cros_ec_debugfs_panic_event(struct notifier_block *nb,
unsigned long queued_during_suspend, void *_notify)
{
struct cros_ec_debugfs *debug_info =
container_of(nb, struct cros_ec_debugfs, notifier_panic);
if (debug_info->log_buffer.buf) {
/* Force log poll work to run immediately */
mod_delayed_work(debug_info->log_poll_work.wq, &debug_info->log_poll_work, 0);
/* Block until log poll work finishes */
flush_delayed_work(&debug_info->log_poll_work);
}
return NOTIFY_DONE;
}
static int cros_ec_debugfs_probe(struct platform_device *pd)
{
struct cros_ec_dev *ec = dev_get_drvdata(pd->dev.parent);
struct cros_ec_platform *ec_platform = dev_get_platdata(ec->dev);
const char *name = ec_platform->ec_name;
struct cros_ec_debugfs *debug_info;
int ret;
debug_info = devm_kzalloc(ec->dev, sizeof(*debug_info), GFP_KERNEL);
if (!debug_info)
return -ENOMEM;
debug_info->ec = ec;
debug_info->dir = debugfs_create_dir(name, NULL);
ret = cros_ec_create_panicinfo(debug_info);
if (ret)
goto remove_debugfs;
ret = cros_ec_create_console_log(debug_info);
if (ret)
goto remove_debugfs;
debugfs_create_file("pdinfo", 0444, debug_info->dir, debug_info,
&cros_ec_pdinfo_fops);
if (cros_ec_uptime_is_supported(ec->ec_dev))
debugfs_create_file("uptime", 0444, debug_info->dir, debug_info,
&cros_ec_uptime_fops);
debugfs_create_x32("last_resume_result", 0444, debug_info->dir,
&ec->ec_dev->last_resume_result);
debugfs_create_u16("suspend_timeout_ms", 0664, debug_info->dir,
&ec->ec_dev->suspend_timeout_ms);
debug_info->notifier_panic.notifier_call = cros_ec_debugfs_panic_event;
ret = blocking_notifier_chain_register(&ec->ec_dev->panic_notifier,
&debug_info->notifier_panic);
if (ret)
goto remove_debugfs;
ec->debug_info = debug_info;
dev_set_drvdata(&pd->dev, ec);
return 0;
remove_debugfs:
debugfs_remove_recursive(debug_info->dir);
return ret;
}
static void cros_ec_debugfs_remove(struct platform_device *pd)
{
struct cros_ec_dev *ec = dev_get_drvdata(pd->dev.parent);
debugfs_remove_recursive(ec->debug_info->dir);
cros_ec_cleanup_console_log(ec->debug_info);
}
static int __maybe_unused cros_ec_debugfs_suspend(struct device *dev)
{
struct cros_ec_dev *ec = dev_get_drvdata(dev);
if (ec->debug_info->log_buffer.buf)
cancel_delayed_work_sync(&ec->debug_info->log_poll_work);
return 0;
}
static int __maybe_unused cros_ec_debugfs_resume(struct device *dev)
{
struct cros_ec_dev *ec = dev_get_drvdata(dev);
if (ec->debug_info->log_buffer.buf)
schedule_delayed_work(&ec->debug_info->log_poll_work, 0);
return 0;
}
static SIMPLE_DEV_PM_OPS(cros_ec_debugfs_pm_ops,
cros_ec_debugfs_suspend, cros_ec_debugfs_resume);
static const struct platform_device_id cros_ec_debugfs_id[] = {
{ DRV_NAME, 0 },
{}
};
MODULE_DEVICE_TABLE(platform, cros_ec_debugfs_id);
static struct platform_driver cros_ec_debugfs_driver = {
.driver = {
.name = DRV_NAME,
.pm = &cros_ec_debugfs_pm_ops,
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
},
.probe = cros_ec_debugfs_probe,
.remove_new = cros_ec_debugfs_remove,
.id_table = cros_ec_debugfs_id,
};
module_platform_driver(cros_ec_debugfs_driver);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Debug logs for ChromeOS EC");
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