--- /dev/null
+/*
+ *
+ * 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->init_work);
+ cancel_work_sync(&dev->reset_work);
+
+ cancel_delayed_work(&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);
+ }
+
+ /* 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) {
+
+ /* remove all waiting requests */
+ mei_cl_all_write_clear(dev);
+
+ mei_cl_all_disconnect(dev);
+
+ /* wake up all readers and writers so they can be interrupted */
+ mei_cl_all_wakeup(dev);
+
+ /* remove entry if already in list */
+ dev_dbg(dev->dev, "remove iamthif and wd from the file list.\n");
+ mei_cl_unlink(&dev->wd_cl);
+ mei_cl_unlink(&dev->iamthif_cl);
+ mei_amthif_reset_params(dev);
+ }
+
+ mei_hbm_reset(dev);
+
+ dev->rd_msg_hdr = 0;
+ dev->wd_pending = false;
+
+ 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);
+
+ /* we cannot start the device w/o hbm start message completed */
+ if (dev->dev_state == MEI_DEV_DISABLED) {
+ dev_err(dev->dev, "reset failed");
+ goto err;
+ }
+
+ 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);
+
+ mei_clear_interrupts(dev);
+
+ 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;
+
+ 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");
+
+ mei_cancel_work(dev);
+
+ mei_nfc_host_exit(dev);
+
+ mei_cl_bus_remove_devices(dev);
+
+ mutex_lock(&dev->device_lock);
+
+ mei_wd_stop(dev);
+
+ dev->dev_state = MEI_DEV_POWER_DOWN;
+ mei_reset(dev);
+ /* move device to disabled state unconditionally */
+ dev->dev_state = MEI_DEV_DISABLED;
+
+ mutex_unlock(&dev->device_lock);
+
+ mei_watchdog_unregister(dev);
+}
+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) &&
+ list_empty(&dev->write_list.list));
+
+ dev_dbg(dev->dev, "write pg: is idle[%d] state=%s ctrl=%d write=%d\n",
+ idle,
+ mei_dev_state_str(dev->dev_state),
+ list_empty(&dev->ctrl_wr_list.list),
+ list_empty(&dev->write_list.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);
+ init_waitqueue_head(&dev->wait_hw_ready);
+ init_waitqueue_head(&dev->wait_pg);
+ init_waitqueue_head(&dev->wait_hbm_start);
+ init_waitqueue_head(&dev->wait_stop_wd);
+ dev->dev_state = MEI_DEV_INITIALIZING;
+ dev->reset_count = 0;
+
+ mei_io_list_init(&dev->write_list);
+ mei_io_list_init(&dev->write_waiting_list);
+ mei_io_list_init(&dev->ctrl_wr_list);
+ mei_io_list_init(&dev->ctrl_rd_list);
+
+ INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
+ INIT_WORK(&dev->init_work, mei_host_client_init);
+ INIT_WORK(&dev->reset_work, mei_reset_work);
+
+ INIT_LIST_HEAD(&dev->wd_cl.link);
+ INIT_LIST_HEAD(&dev->iamthif_cl.link);
+ mei_io_list_init(&dev->amthif_cmd_list);
+ mei_io_list_init(&dev->amthif_rd_complete_list);
+
+ 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);
+
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