|  | // SPDX-License-Identifier: GPL-2.0 | 
|  | /* | 
|  | * Copyright (c) 2012-2019, 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(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; | 
|  | 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); | 
|  |  | 
|  | 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) { | 
|  | dev_err(dev->dev, "hw_start failed ret = %d\n", ret); | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | 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_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"); | 
|  | 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); | 
|  |  | 
|  | 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 | 
|  | * @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); | 
|  |  |