Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

6 files changed, 1505 insertions, 0 deletions

diff --git a/drivers/misc/mic/cosm/Makefile b/drivers/misc/mic/cosm/Makefile
new file mode 100644
index 000000000..97d74cb12
--- /dev/null
+++ b/drivers/misc/mic/cosm/Makefile
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile - Intel MIC Coprocessor State Management (COSM) Driver
+# Copyright(c) 2015, Intel Corporation.
+#
+obj-$(CONFIG_MIC_COSM) += mic_cosm.o
+
+mic_cosm-objs := cosm_main.o
+mic_cosm-objs += cosm_debugfs.o
+mic_cosm-objs += cosm_sysfs.o
+mic_cosm-objs += cosm_scif_server.o
diff --git a/drivers/misc/mic/cosm/cosm_debugfs.c b/drivers/misc/mic/cosm/cosm_debugfs.c
new file mode 100644
index 000000000..216cb3cd2
--- /dev/null
+++ b/drivers/misc/mic/cosm/cosm_debugfs.c
@@ -0,0 +1,156 @@
+/*
+ * 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/debugfs.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include "cosm_main.h"
+
+/* Debugfs parent dir */
+static struct dentry *cosm_dbg;
+
+/**
+ * cosm_log_buf_show - Display MIC kernel log buffer
+ *
+ * log_buf addr/len is read from System.map by user space
+ * and populated in sysfs entries.
+ */
+static int cosm_log_buf_show(struct seq_file *s, void *unused)
+{
+	void __iomem *log_buf_va;
+	int __iomem *log_buf_len_va;
+	struct cosm_device *cdev = s->private;
+	void *kva;
+	int size;
+	u64 aper_offset;
+
+	if (!cdev || !cdev->log_buf_addr || !cdev->log_buf_len)
+		goto done;
+
+	mutex_lock(&cdev->cosm_mutex);
+	switch (cdev->state) {
+	case MIC_BOOTING:
+	case MIC_ONLINE:
+	case MIC_SHUTTING_DOWN:
+		break;
+	default:
+		goto unlock;
+	}
+
+	/*
+	 * Card kernel will never be relocated and any kernel text/data mapping
+	 * can be translated to phys address by subtracting __START_KERNEL_map.
+	 */
+	aper_offset = (u64)cdev->log_buf_len - __START_KERNEL_map;
+	log_buf_len_va = cdev->hw_ops->aper(cdev)->va + aper_offset;
+	aper_offset = (u64)cdev->log_buf_addr - __START_KERNEL_map;
+	log_buf_va = cdev->hw_ops->aper(cdev)->va + aper_offset;
+
+	size = ioread32(log_buf_len_va);
+	kva = kmalloc(size, GFP_KERNEL);
+	if (!kva)
+		goto unlock;
+
+	memcpy_fromio(kva, log_buf_va, size);
+	seq_write(s, kva, size);
+	kfree(kva);
+unlock:
+	mutex_unlock(&cdev->cosm_mutex);
+done:
+	return 0;
+}
+
+static int cosm_log_buf_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, cosm_log_buf_show, inode->i_private);
+}
+
+static const struct file_operations log_buf_ops = {
+	.owner   = THIS_MODULE,
+	.open    = cosm_log_buf_open,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = single_release
+};
+
+/**
+ * cosm_force_reset_show - Force MIC reset
+ *
+ * Invokes the force_reset COSM bus op instead of the standard reset
+ * op in case a force reset of the MIC device is required
+ */
+static int cosm_force_reset_show(struct seq_file *s, void *pos)
+{
+	struct cosm_device *cdev = s->private;
+
+	cosm_stop(cdev, true);
+	return 0;
+}
+
+static int cosm_force_reset_debug_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, cosm_force_reset_show, inode->i_private);
+}
+
+static const struct file_operations force_reset_ops = {
+	.owner   = THIS_MODULE,
+	.open    = cosm_force_reset_debug_open,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = single_release
+};
+
+void cosm_create_debug_dir(struct cosm_device *cdev)
+{
+	char name[16];
+
+	if (!cosm_dbg)
+		return;
+
+	scnprintf(name, sizeof(name), "mic%d", cdev->index);
+	cdev->dbg_dir = debugfs_create_dir(name, cosm_dbg);
+	if (!cdev->dbg_dir)
+		return;
+
+	debugfs_create_file("log_buf", 0444, cdev->dbg_dir, cdev, &log_buf_ops);
+	debugfs_create_file("force_reset", 0444, cdev->dbg_dir, cdev,
+			    &force_reset_ops);
+}
+
+void cosm_delete_debug_dir(struct cosm_device *cdev)
+{
+	if (!cdev->dbg_dir)
+		return;
+
+	debugfs_remove_recursive(cdev->dbg_dir);
+}
+
+void cosm_init_debugfs(void)
+{
+	cosm_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL);
+	if (!cosm_dbg)
+		pr_err("can't create debugfs dir\n");
+}
+
+void cosm_exit_debugfs(void)
+{
+	debugfs_remove(cosm_dbg);
+}
diff --git a/drivers/misc/mic/cosm/cosm_main.c b/drivers/misc/mic/cosm/cosm_main.c
new file mode 100644
index 000000000..7005cb1e0
--- /dev/null
+++ b/drivers/misc/mic/cosm/cosm_main.c
@@ -0,0 +1,393 @@
+/*
+ * 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.
+		 */
+		u8 state = cdev->state == MIC_RESETTING ?
+					cdev->prev_state : cdev->state;
+		bool call_hw_ops = state != MIC_RESET_FAILED &&
+					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) {
+		if (cdev->state != MIC_RESETTING) {
+			cdev->prev_state = cdev->state;
+			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");
diff --git a/drivers/misc/mic/cosm/cosm_main.h b/drivers/misc/mic/cosm/cosm_main.h
new file mode 100644
index 000000000..aa78cdf25
--- /dev/null
+++ b/drivers/misc/mic/cosm/cosm_main.h
@@ -0,0 +1,73 @@
+/*
+ * 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
+ *
+ */
+#ifndef _COSM_COSM_H_
+#define _COSM_COSM_H_
+
+#include <linux/scif.h>
+#include "../bus/cosm_bus.h"
+
+#define COSM_HEARTBEAT_SEND_SEC 30
+#define SCIF_COSM_LISTEN_PORT  201
+
+/**
+ * enum COSM msg id's
+ * @COSM_MSG_SHUTDOWN: host->card trigger shutdown
+ * @COSM_MSG_SYNC_TIME: host->card send host time to card to sync time
+ * @COSM_MSG_HEARTBEAT: card->host heartbeat
+ * @COSM_MSG_SHUTDOWN_STATUS: card->host with shutdown status as payload
+ */
+enum cosm_msg_id {
+	COSM_MSG_SHUTDOWN,
+	COSM_MSG_SYNC_TIME,
+	COSM_MSG_HEARTBEAT,
+	COSM_MSG_SHUTDOWN_STATUS,
+};
+
+struct cosm_msg {
+	u64 id;
+	union {
+		u64 shutdown_status;
+		struct {
+			u64 tv_sec;
+			u64 tv_nsec;
+		} timespec;
+	};
+};
+
+extern const char * const cosm_state_string[];
+extern const char * const cosm_shutdown_status_string[];
+
+void cosm_sysfs_init(struct cosm_device *cdev);
+int cosm_start(struct cosm_device *cdev);
+void cosm_stop(struct cosm_device *cdev, bool force);
+int cosm_reset(struct cosm_device *cdev);
+int cosm_shutdown(struct cosm_device *cdev);
+void cosm_set_state(struct cosm_device *cdev, u8 state);
+void cosm_set_shutdown_status(struct cosm_device *cdev, u8 status);
+void cosm_init_debugfs(void);
+void cosm_exit_debugfs(void);
+void cosm_create_debug_dir(struct cosm_device *cdev);
+void cosm_delete_debug_dir(struct cosm_device *cdev);
+int cosm_scif_init(void);
+void cosm_scif_exit(void);
+void cosm_scif_work(struct work_struct *work);
+
+#endif
diff --git a/drivers/misc/mic/cosm/cosm_scif_server.c b/drivers/misc/mic/cosm/cosm_scif_server.c
new file mode 100644
index 000000000..e94b7eac4
--- /dev/null
+++ b/drivers/misc/mic/cosm/cosm_scif_server.c
@@ -0,0 +1,411 @@
+/*
+ * 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/kthread.h>
+#include <linux/sched/signal.h>
+
+#include "cosm_main.h"
+
+/*
+ * The COSM driver uses SCIF to communicate between the management node and the
+ * MIC cards. SCIF is used to (a) Send a shutdown command to the card (b)
+ * receive a shutdown status back from the card upon completion of shutdown and
+ * (c) receive periodic heartbeat messages from the card used to deduce if the
+ * card has crashed.
+ *
+ * A COSM server consisting of a SCIF listening endpoint waits for incoming
+ * connections from the card. Upon acceptance of the connection, a separate
+ * work-item is scheduled to handle SCIF message processing for that card. The
+ * life-time of this work-item is therefore the time from which the connection
+ * from a card is accepted to the time at which the connection is closed. A new
+ * work-item starts each time the card boots and is alive till the card (a)
+ * shuts down (b) is reset (c) crashes (d) cosm_client driver on the card is
+ * unloaded.
+ *
+ * From the point of view of COSM interactions with SCIF during card
+ * shutdown, reset and crash are as follows:
+ *
+ * Card shutdown
+ * -------------
+ * 1. COSM client on the card invokes orderly_poweroff() in response to SHUTDOWN
+ *    message from the host.
+ * 2. Card driver shutdown callback invokes scif_unregister_device(..) resulting
+ *    in scif_remove(..) getting called on the card
+ * 3. scif_remove -> scif_stop -> scif_handle_remove_node ->
+ *    scif_peer_unregister_device -> device_unregister for the host peer device
+ * 4. During device_unregister remove(..) method of cosm_client is invoked which
+ *    closes the COSM SCIF endpoint on the card. This results in a SCIF_DISCNCT
+ *    message being sent to host SCIF. SCIF_DISCNCT message processing on the
+ *    host SCIF sets the host COSM SCIF endpoint state to DISCONNECTED and wakes
+ *    up the host COSM thread blocked in scif_poll(..) resulting in
+ *    scif_poll(..)  returning EPOLLHUP.
+ * 5. On the card, scif_peer_release_dev is next called which results in an
+ *    SCIF_EXIT message being sent to the host and after receiving the
+ *    SCIF_EXIT_ACK from the host the peer device teardown on the card is
+ *    complete.
+ * 6. As part of the SCIF_EXIT message processing on the host, host sends a
+ *    SCIF_REMOVE_NODE to itself corresponding to the card being removed. This
+ *    starts a similar SCIF peer device teardown sequence on the host
+ *    corresponding to the card being shut down.
+ *
+ * Card reset
+ * ----------
+ * The case of interest here is when the card has not been previously shut down
+ * since most of the steps below are skipped in that case:
+
+ * 1. cosm_stop(..) invokes hw_ops->stop(..) method of the base PCIe driver
+ *    which unregisters the SCIF HW device resulting in scif_remove(..) being
+ *    called on the host.
+ * 2. scif_remove(..) calls scif_disconnect_node(..) which results in a
+ *    SCIF_EXIT message being sent to the card.
+ * 3. The card executes scif_stop() as part of SCIF_EXIT message
+ *    processing. This results in the COSM endpoint on the card being closed and
+ *    the SCIF host peer device on the card getting unregistered similar to
+ *    steps 3, 4 and 5 for the card shutdown case above. scif_poll(..) on the
+ *    host returns EPOLLHUP as a result.
+ * 4. On the host, card peer device unregister and SCIF HW remove(..) also
+ *    subsequently complete.
+ *
+ * Card crash
+ * ----------
+ * If a reset is issued after the card has crashed, there is no SCIF_DISCNT
+ * message from the card which would result in scif_poll(..) returning
+ * EPOLLHUP. In this case when the host SCIF driver sends a SCIF_REMOVE_NODE
+ * message to itself resulting in the card SCIF peer device being unregistered,
+ * this results in a scif_peer_release_dev -> scif_cleanup_scifdev->
+ * scif_invalidate_ep call sequence which sets the endpoint state to
+ * DISCONNECTED and results in scif_poll(..) returning EPOLLHUP.
+ */
+
+#define COSM_SCIF_BACKLOG 16
+#define COSM_HEARTBEAT_CHECK_DELTA_SEC 10
+#define COSM_HEARTBEAT_TIMEOUT_SEC \
+		(COSM_HEARTBEAT_SEND_SEC + COSM_HEARTBEAT_CHECK_DELTA_SEC)
+#define COSM_HEARTBEAT_TIMEOUT_MSEC (COSM_HEARTBEAT_TIMEOUT_SEC * MSEC_PER_SEC)
+
+static struct task_struct *server_thread;
+static scif_epd_t listen_epd;
+
+/* Publish MIC card's shutdown status to user space MIC daemon */
+static void cosm_update_mic_status(struct cosm_device *cdev)
+{
+	if (cdev->shutdown_status_int != MIC_NOP) {
+		cosm_set_shutdown_status(cdev, cdev->shutdown_status_int);
+		cdev->shutdown_status_int = MIC_NOP;
+	}
+}
+
+/* Store MIC card's shutdown status internally when it is received */
+static void cosm_shutdown_status_int(struct cosm_device *cdev,
+				     enum mic_status shutdown_status)
+{
+	switch (shutdown_status) {
+	case MIC_HALTED:
+	case MIC_POWER_OFF:
+	case MIC_RESTART:
+	case MIC_CRASHED:
+		break;
+	default:
+		dev_err(&cdev->dev, "%s %d Unexpected shutdown_status %d\n",
+			__func__, __LINE__, shutdown_status);
+		return;
+	};
+	cdev->shutdown_status_int = shutdown_status;
+	cdev->heartbeat_watchdog_enable = false;
+
+	if (cdev->state != MIC_SHUTTING_DOWN)
+		cosm_set_state(cdev, MIC_SHUTTING_DOWN);
+}
+
+/* Non-blocking recv. Read and process all available messages */
+static void cosm_scif_recv(struct cosm_device *cdev)
+{
+	struct cosm_msg msg;
+	int rc;
+
+	while (1) {
+		rc = scif_recv(cdev->epd, &msg, sizeof(msg), 0);
+		if (!rc) {
+			break;
+		} else if (rc < 0) {
+			dev_dbg(&cdev->dev, "%s: %d rc %d\n",
+				__func__, __LINE__, rc);
+			break;
+		}
+		dev_dbg(&cdev->dev, "%s: %d rc %d id 0x%llx\n",
+			__func__, __LINE__, rc, msg.id);
+
+		switch (msg.id) {
+		case COSM_MSG_SHUTDOWN_STATUS:
+			cosm_shutdown_status_int(cdev, msg.shutdown_status);
+			break;
+		case COSM_MSG_HEARTBEAT:
+			/* Nothing to do, heartbeat only unblocks scif_poll */
+			break;
+		default:
+			dev_err(&cdev->dev, "%s: %d unknown msg.id %lld\n",
+				__func__, __LINE__, msg.id);
+			break;
+		}
+	}
+}
+
+/* Publish crashed status for this MIC card */
+static void cosm_set_crashed(struct cosm_device *cdev)
+{
+	dev_err(&cdev->dev, "node alive timeout\n");
+	cosm_shutdown_status_int(cdev, MIC_CRASHED);
+	cosm_update_mic_status(cdev);
+}
+
+/* Send host time to the MIC card to sync system time between host and MIC */
+static void cosm_send_time(struct cosm_device *cdev)
+{
+	struct cosm_msg msg = { .id = COSM_MSG_SYNC_TIME };
+	struct timespec64 ts;
+	int rc;
+
+	ktime_get_real_ts64(&ts);
+	msg.timespec.tv_sec = ts.tv_sec;
+	msg.timespec.tv_nsec = ts.tv_nsec;
+
+	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);
+}
+
+/*
+ * Close this cosm_device's endpoint after its peer endpoint on the card has
+ * been closed. In all cases except MIC card crash EPOLLHUP on the host is
+ * triggered by the client's endpoint being closed.
+ */
+static void cosm_scif_close(struct cosm_device *cdev)
+{
+	/*
+	 * Because SHUTDOWN_STATUS message is sent by the MIC cards in the
+	 * reboot notifier when shutdown is still not complete, we notify mpssd
+	 * to reset the card when SCIF endpoint is closed.
+	 */
+	cosm_update_mic_status(cdev);
+	scif_close(cdev->epd);
+	cdev->epd = NULL;
+	dev_dbg(&cdev->dev, "%s %d\n", __func__, __LINE__);
+}
+
+/*
+ * Set card state to ONLINE when a new SCIF connection from a MIC card is
+ * received. Normally the state is BOOTING when the connection comes in, but can
+ * be ONLINE if cosm_client driver on the card was unloaded and then reloaded.
+ */
+static int cosm_set_online(struct cosm_device *cdev)
+{
+	int rc = 0;
+
+	if (MIC_BOOTING == cdev->state || MIC_ONLINE == cdev->state) {
+		cdev->heartbeat_watchdog_enable = cdev->sysfs_heartbeat_enable;
+		cdev->epd = cdev->newepd;
+		if (cdev->state == MIC_BOOTING)
+			cosm_set_state(cdev, MIC_ONLINE);
+		cosm_send_time(cdev);
+		dev_dbg(&cdev->dev, "%s %d\n", __func__, __LINE__);
+	} else {
+		dev_warn(&cdev->dev, "%s %d not going online in state: %s\n",
+			 __func__, __LINE__, cosm_state_string[cdev->state]);
+		rc = -EINVAL;
+	}
+	/* Drop reference acquired by bus_find_device in the server thread */
+	put_device(&cdev->dev);
+	return rc;
+}
+
+/*
+ * Work function for handling work for a SCIF connection from a particular MIC
+ * card. It first sets the card state to ONLINE and then calls scif_poll to
+ * block on activity such as incoming messages on the SCIF endpoint. When the
+ * endpoint is closed, the work function exits, completing its life cycle, from
+ * MIC card boot to card shutdown/reset/crash.
+ */
+void cosm_scif_work(struct work_struct *work)
+{
+	struct cosm_device *cdev = container_of(work, struct cosm_device,
+						scif_work);
+	struct scif_pollepd pollepd;
+	int rc;
+
+	mutex_lock(&cdev->cosm_mutex);
+	if (cosm_set_online(cdev))
+		goto exit;
+
+	while (1) {
+		pollepd.epd = cdev->epd;
+		pollepd.events = EPOLLIN;
+
+		/* Drop the mutex before blocking in scif_poll(..) */
+		mutex_unlock(&cdev->cosm_mutex);
+		/* poll(..) with timeout on our endpoint */
+		rc = scif_poll(&pollepd, 1, COSM_HEARTBEAT_TIMEOUT_MSEC);
+		mutex_lock(&cdev->cosm_mutex);
+		if (rc < 0) {
+			dev_err(&cdev->dev, "%s %d scif_poll rc %d\n",
+				__func__, __LINE__, rc);
+			continue;
+		}
+
+		/* There is a message from the card */
+		if (pollepd.revents & EPOLLIN)
+			cosm_scif_recv(cdev);
+
+		/* The peer endpoint is closed or this endpoint disconnected */
+		if (pollepd.revents & EPOLLHUP) {
+			cosm_scif_close(cdev);
+			break;
+		}
+
+		/* Did we timeout from poll? */
+		if (!rc && cdev->heartbeat_watchdog_enable)
+			cosm_set_crashed(cdev);
+	}
+exit:
+	dev_dbg(&cdev->dev, "%s %d exiting\n", __func__, __LINE__);
+	mutex_unlock(&cdev->cosm_mutex);
+}
+
+/*
+ * COSM SCIF server thread function. Accepts incoming SCIF connections from MIC
+ * cards, finds the correct cosm_device to associate that connection with and
+ * schedules individual work items for each MIC card.
+ */
+static int cosm_scif_server(void *unused)
+{
+	struct cosm_device *cdev;
+	scif_epd_t newepd;
+	struct scif_port_id port_id;
+	int rc;
+
+	allow_signal(SIGKILL);
+
+	while (!kthread_should_stop()) {
+		rc = scif_accept(listen_epd, &port_id, &newepd,
+				 SCIF_ACCEPT_SYNC);
+		if (rc < 0) {
+			if (-ERESTARTSYS != rc)
+				pr_err("%s %d rc %d\n", __func__, __LINE__, rc);
+			continue;
+		}
+
+		/*
+		 * Associate the incoming connection with a particular
+		 * cosm_device, COSM device ID == SCIF node ID - 1
+		 */
+		cdev = cosm_find_cdev_by_id(port_id.node - 1);
+		if (!cdev)
+			continue;
+		cdev->newepd = newepd;
+		schedule_work(&cdev->scif_work);
+	}
+
+	pr_debug("%s %d Server thread stopped\n", __func__, __LINE__);
+	return 0;
+}
+
+static int cosm_scif_listen(void)
+{
+	int rc;
+
+	listen_epd = scif_open();
+	if (!listen_epd) {
+		pr_err("%s %d scif_open failed\n", __func__, __LINE__);
+		return -ENOMEM;
+	}
+
+	rc = scif_bind(listen_epd, SCIF_COSM_LISTEN_PORT);
+	if (rc < 0) {
+		pr_err("%s %d scif_bind failed rc %d\n",
+		       __func__, __LINE__, rc);
+		goto err;
+	}
+
+	rc = scif_listen(listen_epd, COSM_SCIF_BACKLOG);
+	if (rc < 0) {
+		pr_err("%s %d scif_listen rc %d\n", __func__, __LINE__, rc);
+		goto err;
+	}
+	pr_debug("%s %d listen_epd set up\n", __func__, __LINE__);
+	return 0;
+err:
+	scif_close(listen_epd);
+	listen_epd = NULL;
+	return rc;
+}
+
+static void cosm_scif_listen_exit(void)
+{
+	pr_debug("%s %d closing listen_epd\n", __func__, __LINE__);
+	if (listen_epd) {
+		scif_close(listen_epd);
+		listen_epd = NULL;
+	}
+}
+
+/*
+ * Create a listening SCIF endpoint and a server kthread which accepts incoming
+ * SCIF connections from MIC cards
+ */
+int cosm_scif_init(void)
+{
+	int rc = cosm_scif_listen();
+
+	if (rc) {
+		pr_err("%s %d cosm_scif_listen rc %d\n",
+		       __func__, __LINE__, rc);
+		goto err;
+	}
+
+	server_thread = kthread_run(cosm_scif_server, NULL, "cosm_server");
+	if (IS_ERR(server_thread)) {
+		rc = PTR_ERR(server_thread);
+		pr_err("%s %d kthread_run rc %d\n", __func__, __LINE__, rc);
+		goto listen_exit;
+	}
+	return 0;
+listen_exit:
+	cosm_scif_listen_exit();
+err:
+	return rc;
+}
+
+/* Stop the running server thread and close the listening SCIF endpoint */
+void cosm_scif_exit(void)
+{
+	int rc;
+
+	if (!IS_ERR_OR_NULL(server_thread)) {
+		rc = send_sig(SIGKILL, server_thread, 0);
+		if (rc) {
+			pr_err("%s %d send_sig rc %d\n",
+			       __func__, __LINE__, rc);
+			return;
+		}
+		kthread_stop(server_thread);
+	}
+
+	cosm_scif_listen_exit();
+}
diff --git a/drivers/misc/mic/cosm/cosm_sysfs.c b/drivers/misc/mic/cosm/cosm_sysfs.c
new file mode 100644
index 000000000..29d6863b6
--- /dev/null
+++ b/drivers/misc/mic/cosm/cosm_sysfs.c
@@ -0,0 +1,461 @@
+/*
+ * 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/slab.h>
+#include "cosm_main.h"
+
+/*
+ * A state-to-string lookup table, for exposing a human readable state
+ * via sysfs. Always keep in sync with enum cosm_states
+ */
+const char * const cosm_state_string[] = {
+	[MIC_READY] = "ready",
+	[MIC_BOOTING] = "booting",
+	[MIC_ONLINE] = "online",
+	[MIC_SHUTTING_DOWN] = "shutting_down",
+	[MIC_RESETTING] = "resetting",
+	[MIC_RESET_FAILED] = "reset_failed",
+};
+
+/*
+ * A shutdown-status-to-string lookup table, for exposing a human
+ * readable state via sysfs. Always keep in sync with enum cosm_shutdown_status
+ */
+const char * const cosm_shutdown_status_string[] = {
+	[MIC_NOP] = "nop",
+	[MIC_CRASHED] = "crashed",
+	[MIC_HALTED] = "halted",
+	[MIC_POWER_OFF] = "poweroff",
+	[MIC_RESTART] = "restart",
+};
+
+void cosm_set_shutdown_status(struct cosm_device *cdev, u8 shutdown_status)
+{
+	dev_dbg(&cdev->dev, "Shutdown Status %s -> %s\n",
+		cosm_shutdown_status_string[cdev->shutdown_status],
+		cosm_shutdown_status_string[shutdown_status]);
+	cdev->shutdown_status = shutdown_status;
+}
+
+void cosm_set_state(struct cosm_device *cdev, u8 state)
+{
+	dev_dbg(&cdev->dev, "State %s -> %s\n",
+		cosm_state_string[cdev->state],
+		cosm_state_string[state]);
+	cdev->state = state;
+	sysfs_notify_dirent(cdev->state_sysfs);
+}
+
+static ssize_t
+family_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct cosm_device *cdev = dev_get_drvdata(dev);
+
+	if (!cdev)
+		return -EINVAL;
+
+	return cdev->hw_ops->family(cdev, buf);
+}
+static DEVICE_ATTR_RO(family);
+
+static ssize_t
+stepping_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct cosm_device *cdev = dev_get_drvdata(dev);
+
+	if (!cdev)
+		return -EINVAL;
+
+	return cdev->hw_ops->stepping(cdev, buf);
+}
+static DEVICE_ATTR_RO(stepping);
+
+static ssize_t
+state_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct cosm_device *cdev = dev_get_drvdata(dev);
+
+	if (!cdev || cdev->state >= MIC_LAST)
+		return -EINVAL;
+
+	return scnprintf(buf, PAGE_SIZE, "%s\n",
+		cosm_state_string[cdev->state]);
+}
+
+static ssize_t
+state_store(struct device *dev, struct device_attribute *attr,
+	    const char *buf, size_t count)
+{
+	struct cosm_device *cdev = dev_get_drvdata(dev);
+	int rc;
+
+	if (!cdev)
+		return -EINVAL;
+
+	if (sysfs_streq(buf, "boot")) {
+		rc = cosm_start(cdev);
+		goto done;
+	}
+	if (sysfs_streq(buf, "reset")) {
+		rc = cosm_reset(cdev);
+		goto done;
+	}
+
+	if (sysfs_streq(buf, "shutdown")) {
+		rc = cosm_shutdown(cdev);
+		goto done;
+	}
+	rc = -EINVAL;
+done:
+	if (rc)
+		count = rc;
+	return count;
+}
+static DEVICE_ATTR_RW(state);
+
+static ssize_t shutdown_status_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct cosm_device *cdev = dev_get_drvdata(dev);
+
+	if (!cdev || cdev->shutdown_status >= MIC_STATUS_LAST)
+		return -EINVAL;
+
+	return scnprintf(buf, PAGE_SIZE, "%s\n",
+		cosm_shutdown_status_string[cdev->shutdown_status]);
+}
+static DEVICE_ATTR_RO(shutdown_status);
+
+static ssize_t
+heartbeat_enable_show(struct device *dev,
+		      struct device_attribute *attr, char *buf)
+{
+	struct cosm_device *cdev = dev_get_drvdata(dev);
+
+	if (!cdev)
+		return -EINVAL;
+
+	return scnprintf(buf, PAGE_SIZE, "%d\n", cdev->sysfs_heartbeat_enable);
+}
+
+static ssize_t
+heartbeat_enable_store(struct device *dev,
+		       struct device_attribute *attr,
+		       const char *buf, size_t count)
+{
+	struct cosm_device *cdev = dev_get_drvdata(dev);
+	int enable;
+	int ret;
+
+	if (!cdev)
+		return -EINVAL;
+
+	mutex_lock(&cdev->cosm_mutex);
+	ret = kstrtoint(buf, 10, &enable);
+	if (ret)
+		goto unlock;
+
+	cdev->sysfs_heartbeat_enable = enable;
+	/* if state is not online, cdev->heartbeat_watchdog_enable is 0 */
+	if (cdev->state == MIC_ONLINE)
+		cdev->heartbeat_watchdog_enable = enable;
+	ret = count;
+unlock:
+	mutex_unlock(&cdev->cosm_mutex);
+	return ret;
+}
+static DEVICE_ATTR_RW(heartbeat_enable);
+
+static ssize_t
+cmdline_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct cosm_device *cdev = dev_get_drvdata(dev);
+	char *cmdline;
+
+	if (!cdev)
+		return -EINVAL;
+
+	cmdline = cdev->cmdline;
+
+	if (cmdline)
+		return scnprintf(buf, PAGE_SIZE, "%s\n", cmdline);
+	return 0;
+}
+
+static ssize_t
+cmdline_store(struct device *dev, struct device_attribute *attr,
+	      const char *buf, size_t count)
+{
+	struct cosm_device *cdev = dev_get_drvdata(dev);
+
+	if (!cdev)
+		return -EINVAL;
+
+	mutex_lock(&cdev->cosm_mutex);
+	kfree(cdev->cmdline);
+
+	cdev->cmdline = kmalloc(count + 1, GFP_KERNEL);
+	if (!cdev->cmdline) {
+		count = -ENOMEM;
+		goto unlock;
+	}
+
+	strncpy(cdev->cmdline, buf, count);
+
+	if (cdev->cmdline[count - 1] == '\n')
+		cdev->cmdline[count - 1] = '\0';
+	else
+		cdev->cmdline[count] = '\0';
+unlock:
+	mutex_unlock(&cdev->cosm_mutex);
+	return count;
+}
+static DEVICE_ATTR_RW(cmdline);
+
+static ssize_t
+firmware_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct cosm_device *cdev = dev_get_drvdata(dev);
+	char *firmware;
+
+	if (!cdev)
+		return -EINVAL;
+
+	firmware = cdev->firmware;
+
+	if (firmware)
+		return scnprintf(buf, PAGE_SIZE, "%s\n", firmware);
+	return 0;
+}
+
+static ssize_t
+firmware_store(struct device *dev, struct device_attribute *attr,
+	       const char *buf, size_t count)
+{
+	struct cosm_device *cdev = dev_get_drvdata(dev);
+
+	if (!cdev)
+		return -EINVAL;
+
+	mutex_lock(&cdev->cosm_mutex);
+	kfree(cdev->firmware);
+
+	cdev->firmware = kmalloc(count + 1, GFP_KERNEL);
+	if (!cdev->firmware) {
+		count = -ENOMEM;
+		goto unlock;
+	}
+	strncpy(cdev->firmware, buf, count);
+
+	if (cdev->firmware[count - 1] == '\n')
+		cdev->firmware[count - 1] = '\0';
+	else
+		cdev->firmware[count] = '\0';
+unlock:
+	mutex_unlock(&cdev->cosm_mutex);
+	return count;
+}
+static DEVICE_ATTR_RW(firmware);
+
+static ssize_t
+ramdisk_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct cosm_device *cdev = dev_get_drvdata(dev);
+	char *ramdisk;
+
+	if (!cdev)
+		return -EINVAL;
+
+	ramdisk = cdev->ramdisk;
+
+	if (ramdisk)
+		return scnprintf(buf, PAGE_SIZE, "%s\n", ramdisk);
+	return 0;
+}
+
+static ssize_t
+ramdisk_store(struct device *dev, struct device_attribute *attr,
+	      const char *buf, size_t count)
+{
+	struct cosm_device *cdev = dev_get_drvdata(dev);
+
+	if (!cdev)
+		return -EINVAL;
+
+	mutex_lock(&cdev->cosm_mutex);
+	kfree(cdev->ramdisk);
+
+	cdev->ramdisk = kmalloc(count + 1, GFP_KERNEL);
+	if (!cdev->ramdisk) {
+		count = -ENOMEM;
+		goto unlock;
+	}
+
+	strncpy(cdev->ramdisk, buf, count);
+
+	if (cdev->ramdisk[count - 1] == '\n')
+		cdev->ramdisk[count - 1] = '\0';
+	else
+		cdev->ramdisk[count] = '\0';
+unlock:
+	mutex_unlock(&cdev->cosm_mutex);
+	return count;
+}
+static DEVICE_ATTR_RW(ramdisk);
+
+static ssize_t
+bootmode_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct cosm_device *cdev = dev_get_drvdata(dev);
+	char *bootmode;
+
+	if (!cdev)
+		return -EINVAL;
+
+	bootmode = cdev->bootmode;
+
+	if (bootmode)
+		return scnprintf(buf, PAGE_SIZE, "%s\n", bootmode);
+	return 0;
+}
+
+static ssize_t
+bootmode_store(struct device *dev, struct device_attribute *attr,
+	       const char *buf, size_t count)
+{
+	struct cosm_device *cdev = dev_get_drvdata(dev);
+
+	if (!cdev)
+		return -EINVAL;
+
+	if (!sysfs_streq(buf, "linux") && !sysfs_streq(buf, "flash"))
+		return -EINVAL;
+
+	mutex_lock(&cdev->cosm_mutex);
+	kfree(cdev->bootmode);
+
+	cdev->bootmode = kmalloc(count + 1, GFP_KERNEL);
+	if (!cdev->bootmode) {
+		count = -ENOMEM;
+		goto unlock;
+	}
+
+	strncpy(cdev->bootmode, buf, count);
+
+	if (cdev->bootmode[count - 1] == '\n')
+		cdev->bootmode[count - 1] = '\0';
+	else
+		cdev->bootmode[count] = '\0';
+unlock:
+	mutex_unlock(&cdev->cosm_mutex);
+	return count;
+}
+static DEVICE_ATTR_RW(bootmode);
+
+static ssize_t
+log_buf_addr_show(struct device *dev, struct device_attribute *attr,
+		  char *buf)
+{
+	struct cosm_device *cdev = dev_get_drvdata(dev);
+
+	if (!cdev)
+		return -EINVAL;
+
+	return scnprintf(buf, PAGE_SIZE, "%p\n", cdev->log_buf_addr);
+}
+
+static ssize_t
+log_buf_addr_store(struct device *dev, struct device_attribute *attr,
+		   const char *buf, size_t count)
+{
+	struct cosm_device *cdev = dev_get_drvdata(dev);
+	int ret;
+	unsigned long addr;
+
+	if (!cdev)
+		return -EINVAL;
+
+	ret = kstrtoul(buf, 16, &addr);
+	if (ret)
+		goto exit;
+
+	cdev->log_buf_addr = (void *)addr;
+	ret = count;
+exit:
+	return ret;
+}
+static DEVICE_ATTR_RW(log_buf_addr);
+
+static ssize_t
+log_buf_len_show(struct device *dev, struct device_attribute *attr,
+		 char *buf)
+{
+	struct cosm_device *cdev = dev_get_drvdata(dev);
+
+	if (!cdev)
+		return -EINVAL;
+
+	return scnprintf(buf, PAGE_SIZE, "%p\n", cdev->log_buf_len);
+}
+
+static ssize_t
+log_buf_len_store(struct device *dev, struct device_attribute *attr,
+		  const char *buf, size_t count)
+{
+	struct cosm_device *cdev = dev_get_drvdata(dev);
+	int ret;
+	unsigned long addr;
+
+	if (!cdev)
+		return -EINVAL;
+
+	ret = kstrtoul(buf, 16, &addr);
+	if (ret)
+		goto exit;
+
+	cdev->log_buf_len = (int *)addr;
+	ret = count;
+exit:
+	return ret;
+}
+static DEVICE_ATTR_RW(log_buf_len);
+
+static struct attribute *cosm_default_attrs[] = {
+	&dev_attr_family.attr,
+	&dev_attr_stepping.attr,
+	&dev_attr_state.attr,
+	&dev_attr_shutdown_status.attr,
+	&dev_attr_heartbeat_enable.attr,
+	&dev_attr_cmdline.attr,
+	&dev_attr_firmware.attr,
+	&dev_attr_ramdisk.attr,
+	&dev_attr_bootmode.attr,
+	&dev_attr_log_buf_addr.attr,
+	&dev_attr_log_buf_len.attr,
+
+	NULL
+};
+
+ATTRIBUTE_GROUPS(cosm_default);
+
+void cosm_sysfs_init(struct cosm_device *cdev)
+{
+	cdev->attr_group = cosm_default_groups;
+}