// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2012-2022, Intel Corporation. All rights reserved.
* Intel Management Engine Interface (Intel MEI) Linux driver
*/
#include <linux/export.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/delay.h>
#include <linux/mei.h>
#include "mei_dev.h"
#include "hbm.h"
#include "client.h"
const char *mei_dev_state_str(int state)
{
#define MEI_DEV_STATE(state) case MEI_DEV_##state: return #state
switch (state) {
MEI_DEV_STATE(INITIALIZING);
MEI_DEV_STATE(INIT_CLIENTS);
MEI_DEV_STATE(ENABLED);
MEI_DEV_STATE(RESETTING);
MEI_DEV_STATE(DISABLED);
MEI_DEV_STATE(POWERING_DOWN);
MEI_DEV_STATE(POWER_DOWN);
MEI_DEV_STATE(POWER_UP);
default:
return "unknown";
}
#undef MEI_DEV_STATE
}
const char *mei_pg_state_str(enum mei_pg_state state)
{
#define MEI_PG_STATE(state) case MEI_PG_##state: return #state
switch (state) {
MEI_PG_STATE(OFF);
MEI_PG_STATE(ON);
default:
return "unknown";
}
#undef MEI_PG_STATE
}
/**
* mei_fw_status2str - convert fw status registers to printable string
*
* @fw_status: firmware status
* @buf: string buffer at minimal size MEI_FW_STATUS_STR_SZ
* @len: buffer len must be >= MEI_FW_STATUS_STR_SZ
*
* Return: number of bytes written or -EINVAL if buffer is to small
*/
ssize_t mei_fw_status2str(struct mei_fw_status *fw_status,
char *buf, size_t len)
{
ssize_t cnt = 0;
int i;
buf[0] = '\0';
if (len < MEI_FW_STATUS_STR_SZ)
return -EINVAL;
for (i = 0; i < fw_status->count; i++)
cnt += scnprintf(buf + cnt, len - cnt, "%08X ",
fw_status->status[i]);
/* drop last space */
buf[cnt] = '\0';
return cnt;
}
EXPORT_SYMBOL_GPL(mei_fw_status2str);
/**
* mei_cancel_work - Cancel mei background jobs
*
* @dev: the device structure
*/
void mei_cancel_work(struct mei_device *dev)
{
cancel_work_sync(&dev->reset_work);
cancel_work_sync(&dev->bus_rescan_work);
cancel_delayed_work_sync(&dev->timer_work);
}
EXPORT_SYMBOL_GPL(mei_cancel_work);
static void mei_save_fw_status(struct mei_device *dev)
{
struct mei_fw_status fw_status;
int ret;
ret = mei_fw_status(dev, &fw_status);
if (ret) {
dev_err(dev->dev, "failed to read firmware status: %d\n", ret);
return;
}
dev->saved_dev_state = dev->dev_state;
dev->saved_fw_status_flag = true;
memcpy(&dev->saved_fw_status, &fw_status, sizeof(fw_status));
}
/**
* mei_reset - resets host and fw.
*
* @dev: the device structure
*
* Return: 0 on success or < 0 if the reset hasn't succeeded
*/
int mei_reset(struct mei_device *dev)
{
enum mei_dev_state state = dev->dev_state;
bool interrupts_enabled;
int ret;
if (state != MEI_DEV_INITIALIZING &&
state != MEI_DEV_DISABLED &&
state != MEI_DEV_POWER_DOWN &&
state != MEI_DEV_POWER_UP) {
char fw_sts_str[MEI_FW_STATUS_STR_SZ];
mei_fw_status_str(dev, fw_sts_str, MEI_FW_STATUS_STR_SZ);
if (kind_is_gsc(dev) || kind_is_gscfi(dev)) {
dev_dbg(dev->dev, "unexpected reset: dev_state = %s fw status = %s\n",
mei_dev_state_str(state), fw_sts_str);
mei_save_fw_status(dev);
} else {
dev_warn(dev->dev, "unexpected reset: dev_state = %s fw status = %s\n",
mei_dev_state_str(state), fw_sts_str);
}
}
mei_clear_interrupts(dev);
/* we're already in reset, cancel the init timer
* if the reset was called due the hbm protocol error
* we need to call it before hw start
* so the hbm watchdog won't kick in
*/
mei_hbm_idle(dev);
/* enter reset flow */
interrupts_enabled = state != MEI_DEV_POWER_DOWN;
mei_set_devstate(dev, MEI_DEV_RESETTING);
dev->reset_count++;
if (dev->reset_count > MEI_MAX_CONSEC_RESET) {
dev_err(dev->dev, "reset: reached maximal consecutive resets: disabling the device\n");
mei_set_devstate(dev, MEI_DEV_DISABLED);
return -ENODEV;
}
ret = mei_hw_reset(dev, interrupts_enabled);
/* fall through and remove the sw state even if hw reset has failed */
/* no need to clean up software state in case of power up */
if (state != MEI_DEV_INITIALIZING && state != MEI_DEV_POWER_UP)
mei_cl_all_disconnect(dev);
mei_hbm_reset(dev);
/* clean stale FW version */
dev->fw_ver_received = 0;
memset(dev->rd_msg_hdr, 0, sizeof(dev->rd_msg_hdr));
if (ret) {
dev_err(dev->dev, "hw_reset failed ret = %d\n", ret);
return ret;
}
if (state == MEI_DEV_POWER_DOWN) {
dev_dbg(dev->dev, "powering down: end of reset\n");
mei_set_devstate(dev, MEI_DEV_DISABLED);
return 0;
}
ret = mei_hw_start(dev);
if (ret) {
char fw_sts_str[MEI_FW_STATUS_STR_SZ];
mei_fw_status_str(dev, fw_sts_str, MEI_FW_STATUS_STR_SZ);
dev_err(dev->dev, "hw_start failed ret = %d fw status = %s\n", ret, fw_sts_str);
return ret;
}
if (dev->dev_state != MEI_DEV_RESETTING) {
dev_dbg(dev->dev, "wrong state = %d on link start\n", dev->dev_state);
return 0;
}
dev_dbg(dev->dev, "link is established start sending messages.\n");
mei_set_devstate(dev, MEI_DEV_INIT_CLIENTS);
ret = mei_hbm_start_req(dev);
if (ret) {
dev_err(dev->dev, "hbm_start failed ret = %d\n", ret);
mei_set_devstate(dev, MEI_DEV_RESETTING);
return ret;
}
return 0;
}
EXPORT_SYMBOL_GPL(mei_reset);
/**
* mei_start - initializes host and fw to start work.
*
* @dev: the device structure
*
* Return: 0 on success, <0 on failure.
*/
int mei_start(struct mei_device *dev)
{
int ret;
mutex_lock(&dev->device_lock);
/* acknowledge interrupt and stop interrupts */
mei_clear_interrupts(dev);
ret = mei_hw_config(dev);
if (ret)
goto err;
dev_dbg(dev->dev, "reset in start the mei device.\n");
dev->reset_count = 0;
do {
mei_set_devstate(dev, MEI_DEV_INITIALIZING);
ret = mei_reset(dev);
if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
dev_err(dev->dev, "reset failed ret = %d", ret);
goto err;
}
} while (ret);
if (mei_hbm_start_wait(dev)) {
dev_err(dev->dev, "HBM haven't started");
goto err;
}
if (!mei_hbm_version_is_supported(dev)) {
dev_dbg(dev->dev, "MEI start failed.\n");
goto err;
}
dev_dbg(dev->dev, "link layer has been established.\n");
mutex_unlock(&dev->device_lock);
return 0;
err:
dev_err(dev->dev, "link layer initialization failed.\n");
mei_set_devstate(dev, MEI_DEV_DISABLED);
mutex_unlock(&dev->device_lock);
return -ENODEV;
}
EXPORT_SYMBOL_GPL(mei_start);
/**
* mei_restart - restart device after suspend
*
* @dev: the device structure
*
* Return: 0 on success or -ENODEV if the restart hasn't succeeded
*/
int mei_restart(struct mei_device *dev)
{
int err;
mutex_lock(&dev->device_lock);
mei_set_devstate(dev, MEI_DEV_POWER_UP);
dev->reset_count = 0;
err = mei_reset(dev);
mutex_unlock(&dev->device_lock);
if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
dev_err(dev->dev, "device disabled = %d\n", err);
return -ENODEV;
}
/* try to start again */
if (err)
schedule_work(&dev->reset_work);
return 0;
}
EXPORT_SYMBOL_GPL(mei_restart);
static void mei_reset_work(struct work_struct *work)
{
struct mei_device *dev =
container_of(work, struct mei_device, reset_work);
int ret;
mei_clear_interrupts(dev);
mei_synchronize_irq(dev);
mutex_lock(&dev->device_lock);
ret = mei_reset(dev);
mutex_unlock(&dev->device_lock);
if (dev->dev_state == MEI_DEV_DISABLED) {
dev_err(dev->dev, "device disabled = %d\n", ret);
return;
}
/* retry reset in case of failure */
if (ret)
schedule_work(&dev->reset_work);
}
void mei_stop(struct mei_device *dev)
{
dev_dbg(dev->dev, "stopping the device.\n");
mutex_lock(&dev->device_lock);
mei_set_devstate(dev, MEI_DEV_POWERING_DOWN);
mutex_unlock(&dev->device_lock);
mei_cl_bus_remove_devices(dev);
mutex_lock(&dev->device_lock);
mei_set_devstate(dev, MEI_DEV_POWER_DOWN);
mutex_unlock(&dev->device_lock);
mei_cancel_work(dev);
mei_clear_interrupts(dev);
mei_synchronize_irq(dev);
/* to catch HW-initiated reset */
mei_cancel_work(dev);
mutex_lock(&dev->device_lock);
mei_reset(dev);
/* move device to disabled state unconditionally */
mei_set_devstate(dev, MEI_DEV_DISABLED);
mutex_unlock(&dev->device_lock);
}
EXPORT_SYMBOL_GPL(mei_stop);
/**
* mei_write_is_idle - check if the write queues are idle
*
* @dev: the device structure
*
* Return: true of there is no pending write
*/
bool mei_write_is_idle(struct mei_device *dev)
{
bool idle = (dev->dev_state == MEI_DEV_ENABLED &&
list_empty(&dev->ctrl_wr_list) &&
list_empty(&dev->write_list) &&
list_empty(&dev->write_waiting_list));
dev_dbg(dev->dev, "write pg: is idle[%d] state=%s ctrl=%01d write=%01d wwait=%01d\n",
idle,
mei_dev_state_str(dev->dev_state),
list_empty(&dev->ctrl_wr_list),
list_empty(&dev->write_list),
list_empty(&dev->write_waiting_list));
return idle;
}
EXPORT_SYMBOL_GPL(mei_write_is_idle);
/**
* mei_device_init - initialize mei_device structure
*
* @dev: the mei device
* @device: the device structure
* @slow_fw: configure longer timeouts as FW is slow
* @hw_ops: hw operations
*/
void mei_device_init(struct mei_device *dev,
struct device *device,
bool slow_fw,
const struct mei_hw_ops *hw_ops)
{
/* setup our list array */
INIT_LIST_HEAD(&dev->file_list);
INIT_LIST_HEAD(&dev->device_list);
INIT_LIST_HEAD(&dev->me_clients);
mutex_init(&dev->device_lock);
init_rwsem(&dev->me_clients_rwsem);
mutex_init(&dev->cl_bus_lock);
init_waitqueue_head(&dev->wait_hw_ready);
init_waitqueue_head(&dev->wait_pg);
init_waitqueue_head(&dev->wait_hbm_start);
dev->dev_state = MEI_DEV_INITIALIZING;
dev->reset_count = 0;
INIT_LIST_HEAD(&dev->write_list);
INIT_LIST_HEAD(&dev->write_waiting_list);
INIT_LIST_HEAD(&dev->ctrl_wr_list);
INIT_LIST_HEAD(&dev->ctrl_rd_list);
dev->tx_queue_limit = MEI_TX_QUEUE_LIMIT_DEFAULT;
INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
INIT_WORK(&dev->reset_work, mei_reset_work);
INIT_WORK(&dev->bus_rescan_work, mei_cl_bus_rescan_work);
bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
dev->open_handle_count = 0;
dev->pxp_mode = MEI_DEV_PXP_DEFAULT;
dev->gsc_reset_to_pxp = MEI_DEV_RESET_TO_PXP_DEFAULT;
/*
* Reserving the first client ID
* 0: Reserved for MEI Bus Message communications
*/
bitmap_set(dev->host_clients_map, 0, 1);
dev->pg_event = MEI_PG_EVENT_IDLE;
dev->ops = hw_ops;
dev->dev = device;
dev->timeouts.hw_ready = mei_secs_to_jiffies(MEI_HW_READY_TIMEOUT);
dev->timeouts.connect = MEI_CONNECT_TIMEOUT;
dev->timeouts.client_init = MEI_CLIENTS_INIT_TIMEOUT;
dev->timeouts.pgi = mei_secs_to_jiffies(MEI_PGI_TIMEOUT);
dev->timeouts.d0i3 = mei_secs_to_jiffies(MEI_D0I3_TIMEOUT);
if (slow_fw) {
dev->timeouts.cl_connect = mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT_SLOW);
dev->timeouts.hbm = mei_secs_to_jiffies(MEI_HBM_TIMEOUT_SLOW);
dev->timeouts.mkhi_recv = msecs_to_jiffies(MKHI_RCV_TIMEOUT_SLOW);
} else {
dev->timeouts.cl_connect = mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT);
dev->timeouts.hbm = mei_secs_to_jiffies(MEI_HBM_TIMEOUT);
dev->timeouts.mkhi_recv = msecs_to_jiffies(MKHI_RCV_TIMEOUT);
}
}
EXPORT_SYMBOL_GPL(mei_device_init);
Codebase Browser
linux