| /* | 
 |  * | 
 |  * Intel Management Engine Interface (Intel MEI) Linux driver | 
 |  * Copyright (c) 2003-2012, Intel Corporation. | 
 |  * | 
 |  * This program is free software; you can redistribute it and/or modify it | 
 |  * under the terms and conditions of the GNU General Public License, | 
 |  * version 2, as published by the Free Software Foundation. | 
 |  * | 
 |  * This program is distributed in the hope it will be useful, but WITHOUT | 
 |  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | 
 |  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for | 
 |  * more details. | 
 |  * | 
 |  */ | 
 |  | 
 | #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(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); | 
 |  | 
 | /** | 
 |  * 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); | 
 | 		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; | 
 | 	dev->dev_state = 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"); | 
 | 		dev->dev_state = 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); | 
 |  | 
 | 	dev->rd_msg_hdr = 0; | 
 |  | 
 | 	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"); | 
 | 		dev->dev_state = MEI_DEV_DISABLED; | 
 | 		return 0; | 
 | 	} | 
 |  | 
 | 	ret = mei_hw_start(dev); | 
 | 	if (ret) { | 
 | 		dev_err(dev->dev, "hw_start failed ret = %d\n", ret); | 
 | 		return ret; | 
 | 	} | 
 |  | 
 | 	dev_dbg(dev->dev, "link is established start sending messages.\n"); | 
 |  | 
 | 	dev->dev_state = MEI_DEV_INIT_CLIENTS; | 
 | 	ret = mei_hbm_start_req(dev); | 
 | 	if (ret) { | 
 | 		dev_err(dev->dev, "hbm_start failed ret = %d\n", ret); | 
 | 		dev->dev_state = 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); | 
 |  | 
 | 	mei_hw_config(dev); | 
 |  | 
 | 	dev_dbg(dev->dev, "reset in start the mei device.\n"); | 
 |  | 
 | 	dev->reset_count = 0; | 
 | 	do { | 
 | 		dev->dev_state = 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_host_is_ready(dev)) { | 
 | 		dev_err(dev->dev, "host is not ready.\n"); | 
 | 		goto err; | 
 | 	} | 
 |  | 
 | 	if (!mei_hw_is_ready(dev)) { | 
 | 		dev_err(dev->dev, "ME is not ready.\n"); | 
 | 		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"); | 
 | 	dev->dev_state = 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); | 
 |  | 
 | 	dev->dev_state = 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); | 
 | 	dev->dev_state = MEI_DEV_POWER_DOWN; | 
 | 	mutex_unlock(&dev->device_lock); | 
 | 	mei_cl_bus_remove_devices(dev); | 
 |  | 
 | 	mei_cancel_work(dev); | 
 |  | 
 | 	mei_clear_interrupts(dev); | 
 | 	mei_synchronize_irq(dev); | 
 |  | 
 | 	mutex_lock(&dev->device_lock); | 
 |  | 
 | 	mei_reset(dev); | 
 | 	/* move device to disabled state unconditionally */ | 
 | 	dev->dev_state = 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 | 
 |  * @hw_ops: hw operations | 
 |  */ | 
 | void mei_device_init(struct mei_device *dev, | 
 | 		     struct device *device, | 
 | 		     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; | 
 |  | 
 | 	/* | 
 | 	 * 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; | 
 | } | 
 | EXPORT_SYMBOL_GPL(mei_device_init); | 
 |  |