diff options
Diffstat (limited to 'drivers/misc/mei/init.c')
| -rw-r--r-- | drivers/misc/mei/init.c | 418 |
1 files changed, 418 insertions, 0 deletions
diff --git a/drivers/misc/mei/init.c b/drivers/misc/mei/init.c new file mode 100644 index 000000000..bac8852aa --- /dev/null +++ b/drivers/misc/mei/init.c @@ -0,0 +1,418 @@ +// 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); + +/** + * 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; + } + + 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; + + /* + * 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); + |