1 files changed, 388 insertions, 0 deletions
diff --git a/drivers/misc/mic/cosm/cosm_main.c b/drivers/misc/mic/cosm/cosm_main.c
new file mode 100644
index 000000000000..4b4b356c797d
--- /dev/null
+++ b/drivers/misc/mic/cosm/cosm_main.c
@@ -0,0 +1,388 @@
+/*
+ * Intel MIC Platform Software Stack (MPSS)
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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.
+ *
+ * The full GNU General Public License is included in this distribution in
+ * the file called "COPYING".
+ *
+ * Intel MIC Coprocessor State Management (COSM) Driver
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/idr.h>
+#include <linux/slab.h>
+#include <linux/cred.h>
+#include "cosm_main.h"
+
+static const char cosm_driver_name[] = "mic";
+
+/* COSM ID allocator */
+static struct ida g_cosm_ida;
+/* Class of MIC devices for sysfs accessibility. */
+static struct class *g_cosm_class;
+/* Number of MIC devices */
+static atomic_t g_num_dev;
+
+/**
+ * cosm_hw_reset - Issue a HW reset for the MIC device
+ * @cdev: pointer to cosm_device instance
+ */
+static void cosm_hw_reset(struct cosm_device *cdev, bool force)
+{
+	int i;
+
+#define MIC_RESET_TO (45)
+	if (force && cdev->hw_ops->force_reset)
+		cdev->hw_ops->force_reset(cdev);
+	else
+		cdev->hw_ops->reset(cdev);
+
+	for (i = 0; i < MIC_RESET_TO; i++) {
+		if (cdev->hw_ops->ready(cdev)) {
+			cosm_set_state(cdev, MIC_READY);
+			return;
+		}
+		/*
+		 * Resets typically take 10s of seconds to complete.
+		 * Since an MMIO read is required to check if the
+		 * firmware is ready or not, a 1 second delay works nicely.
+		 */
+		msleep(1000);
+	}
+	cosm_set_state(cdev, MIC_RESET_FAILED);
+}
+
+/**
+ * cosm_start - Start the MIC
+ * @cdev: pointer to cosm_device instance
+ *
+ * This function prepares an MIC for boot and initiates boot.
+ * RETURNS: An appropriate -ERRNO error value on error, or 0 for success.
+ */
+int cosm_start(struct cosm_device *cdev)
+{
+	const struct cred *orig_cred;
+	struct cred *override_cred;
+	int rc;
+
+	mutex_lock(&cdev->cosm_mutex);
+	if (!cdev->bootmode) {
+		dev_err(&cdev->dev, "%s %d bootmode not set\n",
+			__func__, __LINE__);
+		rc = -EINVAL;
+		goto unlock_ret;
+	}
+retry:
+	if (cdev->state != MIC_READY) {
+		dev_err(&cdev->dev, "%s %d MIC state not READY\n",
+			__func__, __LINE__);
+		rc = -EINVAL;
+		goto unlock_ret;
+	}
+	if (!cdev->hw_ops->ready(cdev)) {
+		cosm_hw_reset(cdev, false);
+		/*
+		 * The state will either be MIC_READY if the reset succeeded
+		 * or MIC_RESET_FAILED if the firmware reset failed.
+		 */
+		goto retry;
+	}
+
+	/*
+	 * Set credentials to root to allow non-root user to download initramsfs
+	 * with 600 permissions
+	 */
+	override_cred = prepare_creds();
+	if (!override_cred) {
+		dev_err(&cdev->dev, "%s %d prepare_creds failed\n",
+			__func__, __LINE__);
+		rc = -ENOMEM;
+		goto unlock_ret;
+	}
+	override_cred->fsuid = GLOBAL_ROOT_UID;
+	orig_cred = override_creds(override_cred);
+
+	rc = cdev->hw_ops->start(cdev, cdev->index);
+
+	revert_creds(orig_cred);
+	put_cred(override_cred);
+	if (rc)
+		goto unlock_ret;
+
+	/*
+	 * If linux is being booted, card is treated 'online' only
+	 * when the scif interface in the card is up. If anything else
+	 * is booted, we set card to 'online' immediately.
+	 */
+	if (!strcmp(cdev->bootmode, "linux"))
+		cosm_set_state(cdev, MIC_BOOTING);
+	else
+		cosm_set_state(cdev, MIC_ONLINE);
+unlock_ret:
+	mutex_unlock(&cdev->cosm_mutex);
+	if (rc)
+		dev_err(&cdev->dev, "cosm_start failed rc %d\n", rc);
+	return rc;
+}
+
+/**
+ * cosm_stop - Prepare the MIC for reset and trigger reset
+ * @cdev: pointer to cosm_device instance
+ * @force: force a MIC to reset even if it is already reset and ready.
+ *
+ * RETURNS: None
+ */
+void cosm_stop(struct cosm_device *cdev, bool force)
+{
+	mutex_lock(&cdev->cosm_mutex);
+	if (cdev->state != MIC_READY || force) {
+		/*
+		 * Don't call hw_ops if they have been called previously.
+		 * stop(..) calls device_unregister and will crash the system if
+		 * called multiple times.
+		 */
+		bool call_hw_ops = cdev->state != MIC_RESET_FAILED &&
+					cdev->state != MIC_READY;
+
+		if (cdev->state != MIC_RESETTING)
+			cosm_set_state(cdev, MIC_RESETTING);
+		cdev->heartbeat_watchdog_enable = false;
+		if (call_hw_ops)
+			cdev->hw_ops->stop(cdev, force);
+		cosm_hw_reset(cdev, force);
+		cosm_set_shutdown_status(cdev, MIC_NOP);
+		if (call_hw_ops && cdev->hw_ops->post_reset)
+			cdev->hw_ops->post_reset(cdev, cdev->state);
+	}
+	mutex_unlock(&cdev->cosm_mutex);
+	flush_work(&cdev->scif_work);
+}
+
+/**
+ * cosm_reset_trigger_work - Trigger MIC reset
+ * @work: The work structure
+ *
+ * This work is scheduled whenever the host wants to reset the MIC.
+ */
+static void cosm_reset_trigger_work(struct work_struct *work)
+{
+	struct cosm_device *cdev = container_of(work, struct cosm_device,
+						reset_trigger_work);
+	cosm_stop(cdev, false);
+}
+
+/**
+ * cosm_reset - Schedule MIC reset
+ * @cdev: pointer to cosm_device instance
+ *
+ * RETURNS: An -EINVAL if the card is already READY or 0 for success.
+ */
+int cosm_reset(struct cosm_device *cdev)
+{
+	int rc = 0;
+
+	mutex_lock(&cdev->cosm_mutex);
+	if (cdev->state != MIC_READY) {
+		cosm_set_state(cdev, MIC_RESETTING);
+		schedule_work(&cdev->reset_trigger_work);
+	} else {
+		dev_err(&cdev->dev, "%s %d MIC is READY\n", __func__, __LINE__);
+		rc = -EINVAL;
+	}
+	mutex_unlock(&cdev->cosm_mutex);
+	return rc;
+}
+
+/**
+ * cosm_shutdown - Initiate MIC shutdown.
+ * @cdev: pointer to cosm_device instance
+ *
+ * RETURNS: None
+ */
+int cosm_shutdown(struct cosm_device *cdev)
+{
+	struct cosm_msg msg = { .id = COSM_MSG_SHUTDOWN };
+	int rc = 0;
+
+	mutex_lock(&cdev->cosm_mutex);
+	if (cdev->state != MIC_ONLINE) {
+		rc = -EINVAL;
+		dev_err(&cdev->dev, "%s %d skipping shutdown in state: %s\n",
+			__func__, __LINE__, cosm_state_string[cdev->state]);
+		goto err;
+	}
+
+	if (!cdev->epd) {
+		rc = -ENOTCONN;
+		dev_err(&cdev->dev, "%s %d scif endpoint not connected rc %d\n",
+			__func__, __LINE__, rc);
+		goto err;
+	}
+
+	rc = scif_send(cdev->epd, &msg, sizeof(msg), SCIF_SEND_BLOCK);
+	if (rc < 0) {
+		dev_err(&cdev->dev, "%s %d scif_send failed rc %d\n",
+			__func__, __LINE__, rc);
+		goto err;
+	}
+	cdev->heartbeat_watchdog_enable = false;
+	cosm_set_state(cdev, MIC_SHUTTING_DOWN);
+	rc = 0;
+err:
+	mutex_unlock(&cdev->cosm_mutex);
+	return rc;
+}
+
+static int cosm_driver_probe(struct cosm_device *cdev)
+{
+	int rc;
+
+	/* Initialize SCIF server at first probe */
+	if (atomic_add_return(1, &g_num_dev) == 1) {
+		rc = cosm_scif_init();
+		if (rc)
+			goto scif_exit;
+	}
+	mutex_init(&cdev->cosm_mutex);
+	INIT_WORK(&cdev->reset_trigger_work, cosm_reset_trigger_work);
+	INIT_WORK(&cdev->scif_work, cosm_scif_work);
+	cdev->sysfs_heartbeat_enable = true;
+	cosm_sysfs_init(cdev);
+	cdev->sdev = device_create_with_groups(g_cosm_class, cdev->dev.parent,
+			       MKDEV(0, cdev->index), cdev, cdev->attr_group,
+			       "mic%d", cdev->index);
+	if (IS_ERR(cdev->sdev)) {
+		rc = PTR_ERR(cdev->sdev);
+		dev_err(&cdev->dev, "device_create_with_groups failed rc %d\n",
+			rc);
+		goto scif_exit;
+	}
+
+	cdev->state_sysfs = sysfs_get_dirent(cdev->sdev->kobj.sd,
+		"state");
+	if (!cdev->state_sysfs) {
+		rc = -ENODEV;
+		dev_err(&cdev->dev, "sysfs_get_dirent failed rc %d\n", rc);
+		goto destroy_device;
+	}
+	cosm_create_debug_dir(cdev);
+	return 0;
+destroy_device:
+	device_destroy(g_cosm_class, MKDEV(0, cdev->index));
+scif_exit:
+	if (atomic_dec_and_test(&g_num_dev))
+		cosm_scif_exit();
+	return rc;
+}
+
+static void cosm_driver_remove(struct cosm_device *cdev)
+{
+	cosm_delete_debug_dir(cdev);
+	sysfs_put(cdev->state_sysfs);
+	device_destroy(g_cosm_class, MKDEV(0, cdev->index));
+	flush_work(&cdev->reset_trigger_work);
+	cosm_stop(cdev, false);
+	if (atomic_dec_and_test(&g_num_dev))
+		cosm_scif_exit();
+
+	/* These sysfs entries might have allocated */
+	kfree(cdev->cmdline);
+	kfree(cdev->firmware);
+	kfree(cdev->ramdisk);
+	kfree(cdev->bootmode);
+}
+
+static int cosm_suspend(struct device *dev)
+{
+	struct cosm_device *cdev = dev_to_cosm(dev);
+
+	mutex_lock(&cdev->cosm_mutex);
+	switch (cdev->state) {
+	/**
+	 * Suspend/freeze hooks in userspace have already shutdown the card.
+	 * Card should be 'ready' in most cases. It is however possible that
+	 * some userspace application initiated a boot. In those cases, we
+	 * simply reset the card.
+	 */
+	case MIC_ONLINE:
+	case MIC_BOOTING:
+	case MIC_SHUTTING_DOWN:
+		mutex_unlock(&cdev->cosm_mutex);
+		cosm_stop(cdev, false);
+		break;
+	default:
+		mutex_unlock(&cdev->cosm_mutex);
+		break;
+	}
+	return 0;
+}
+
+static const struct dev_pm_ops cosm_pm_ops = {
+	.suspend = cosm_suspend,
+	.freeze = cosm_suspend
+};
+
+static struct cosm_driver cosm_driver = {
+	.driver = {
+		.name =  KBUILD_MODNAME,
+		.owner = THIS_MODULE,
+		.pm = &cosm_pm_ops,
+	},
+	.probe = cosm_driver_probe,
+	.remove = cosm_driver_remove
+};
+
+static int __init cosm_init(void)
+{
+	int ret;
+
+	cosm_init_debugfs();
+
+	g_cosm_class = class_create(THIS_MODULE, cosm_driver_name);
+	if (IS_ERR(g_cosm_class)) {
+		ret = PTR_ERR(g_cosm_class);
+		pr_err("class_create failed ret %d\n", ret);
+		goto cleanup_debugfs;
+	}
+
+	ida_init(&g_cosm_ida);
+	ret = cosm_register_driver(&cosm_driver);
+	if (ret) {
+		pr_err("cosm_register_driver failed ret %d\n", ret);
+		goto ida_destroy;
+	}
+	return 0;
+ida_destroy:
+	ida_destroy(&g_cosm_ida);
+	class_destroy(g_cosm_class);
+cleanup_debugfs:
+	cosm_exit_debugfs();
+	return ret;
+}
+
+static void __exit cosm_exit(void)
+{
+	cosm_unregister_driver(&cosm_driver);
+	ida_destroy(&g_cosm_ida);
+	class_destroy(g_cosm_class);
+	cosm_exit_debugfs();
+}
+
+module_init(cosm_init);
+module_exit(cosm_exit);
+
+MODULE_AUTHOR("Intel Corporation");
+MODULE_DESCRIPTION("Intel(R) MIC Coprocessor State Management (COSM) Driver");
+MODULE_LICENSE("GPL v2");