| // 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(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; |
| } |
| |
| 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); |
| |