1 files changed, 398 insertions, 0 deletions

diff --git a/drivers/misc/mei/init.c b/drivers/misc/mei/init.c
new file mode 100644
index 000000000..bcee77768
--- /dev/null
+++ b/drivers/misc/mei/init.c
@@ -0,0 +1,398 @@
+// 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_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 */
+	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);
+