[PATCH 5/5] staging: fsl-mc: Management Complex restool driver

[Lijun Pan]

The kernel support for the restool (a user space resource management
tool) is a driver for the /dev/dprc.N device file.
Its purpose is to provide an ioctl interface,
which the restool uses to interact with the MC bus driver
and with the MC firmware.
We allocate a dpmcp at driver initialization,
and keep that dpmcp until driver exit.
We use that dpmcp by default.
If that dpmcp is in use, we create another portal at run time
and destroy the newly created portal after use.
The ioctl RESTOOL_SEND_MC_COMMAND sends user space command to fsl-mc
bus and utilizes the fsl-mc bus to communicate with MC firmware.
The ioctl RESTOOL_DPRC_SYNC request the mc-bus launch
objects scan under root dprc.
In order to support multiple root dprc, we utilize the bus notify
mechanism to scan fsl_mc_bus_type for the newly added root dprc.
After discovering the root dprc, it creates a miscdevice
/dev/dprc.N to associate with this root dprc.

Signed-off-by: Lijun Pan <Lijun.Pan@xxxxxxxxxxxxx>
---
 drivers/staging/fsl-mc/bus/Kconfig      |   7 +-
 drivers/staging/fsl-mc/bus/Makefile     |   3 +
 drivers/staging/fsl-mc/bus/mc-ioctl.h   |  24 ++
 drivers/staging/fsl-mc/bus/mc-restool.c | 488 ++++++++++++++++++++++++++++++++
 4 files changed, 521 insertions(+), 1 deletion(-)
 create mode 100644 drivers/staging/fsl-mc/bus/mc-ioctl.h
 create mode 100644 drivers/staging/fsl-mc/bus/mc-restool.c

diff --git a/drivers/staging/fsl-mc/bus/Kconfig b/drivers/staging/fsl-mc/bus/Kconfig
index 0d779d9..39c6ef9 100644
--- a/drivers/staging/fsl-mc/bus/Kconfig
+++ b/drivers/staging/fsl-mc/bus/Kconfig
@@ -21,4 +21,9 @@ config FSL_MC_BUS
 	  Only enable this option when building the kernel for
 	  Freescale QorQIQ LS2xxxx SoCs.
 
-
+config FSL_MC_RESTOOL
+        tristate "Freescale Management Complex (MC) restool driver"
+        depends on FSL_MC_BUS
+        help
+          Driver that provides kernel support for the Freescale Management
+	  Complex resource manager user-space tool.
diff --git a/drivers/staging/fsl-mc/bus/Makefile b/drivers/staging/fsl-mc/bus/Makefile
index 25433a9..28b5fc0 100644
--- a/drivers/staging/fsl-mc/bus/Makefile
+++ b/drivers/staging/fsl-mc/bus/Makefile
@@ -15,3 +15,6 @@ mc-bus-driver-objs := mc-bus.o \
 		      mc-allocator.o \
 		      dpmcp.o \
 		      dpbp.o
+
+# MC restool kernel support
+obj-$(CONFIG_FSL_MC_RESTOOL) += mc-restool.o
diff --git a/drivers/staging/fsl-mc/bus/mc-ioctl.h b/drivers/staging/fsl-mc/bus/mc-ioctl.h
new file mode 100644
index 0000000..e52f907
--- /dev/null
+++ b/drivers/staging/fsl-mc/bus/mc-ioctl.h
@@ -0,0 +1,24 @@
+/*
+ * Freescale Management Complex (MC) ioclt interface
+ *
+ * Copyright (C) 2014 Freescale Semiconductor, Inc.
+ * Author: Lijun Pan <Lijun.Pan@xxxxxxxxxxxxx>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+#ifndef _FSL_MC_IOCTL_H_
+#define _FSL_MC_IOCTL_H_
+
+#include <linux/ioctl.h>
+
+#define RESTOOL_IOCTL_TYPE   'R'
+
+#define RESTOOL_DPRC_SYNC \
+	_IO(RESTOOL_IOCTL_TYPE, 0x2)
+
+#define RESTOOL_SEND_MC_COMMAND \
+	_IOWR(RESTOOL_IOCTL_TYPE, 0x4, struct mc_command)
+
+#endif /* _FSL_MC_IOCTL_H_ */
diff --git a/drivers/staging/fsl-mc/bus/mc-restool.c b/drivers/staging/fsl-mc/bus/mc-restool.c
new file mode 100644
index 0000000..a219172
--- /dev/null
+++ b/drivers/staging/fsl-mc/bus/mc-restool.c
@@ -0,0 +1,488 @@
+/*
+ * Freescale Management Complex (MC) restool driver
+ *
+ * Copyright (C) 2014 Freescale Semiconductor, Inc.
+ * Author: Lijun Pan <Lijun.Pan@xxxxxxxxxxxxx>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include "../include/mc-private.h"
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include "mc-ioctl.h"
+#include "../include/mc-sys.h"
+#include "../include/mc-cmd.h"
+#include "../include/dpmng.h"
+
+/**
+ * Maximum number of DPRCs that can be opened at the same time
+ */
+#define MAX_DPRC_HANDLES	    64
+
+/**
+ * restool_misc - information associated with the newly added miscdevice
+ * @misc: newly created miscdevice associated with root dprc
+ * @miscdevt: device id of this miscdevice
+ * @list: a linked list node representing this miscdevcie
+ * @static_mc_io: pointer to the static MC I/O object used by the restool
+ * @dynamic_instance_count: number of dynamically created instances
+ * @static_instance_in_use: static instance is in use or not
+ * @mutex: mutex lock to serialze the operations
+ * @dev: root dprc associated with this miscdevice
+ */
+struct restool_misc {
+	struct miscdevice misc;
+	dev_t miscdevt;
+	struct list_head list;
+	struct fsl_mc_io *static_mc_io;
+	uint32_t dynamic_instance_count;
+	bool static_instance_in_use;
+	struct mutex mutex;
+	struct device *dev;
+};
+
+/*
+ * initialize a global list to link all
+ * the miscdevice nodes (struct restool_misc)
+ */
+LIST_HEAD(misc_list);
+
+static int fsl_mc_restool_dev_open(struct inode *inode, struct file *filep)
+{
+	struct fsl_mc_device *root_mc_dev;
+	int error = 0;
+	struct fsl_mc_io *dynamic_mc_io = NULL;
+	struct restool_misc *restool_misc;
+	struct restool_misc *restool_misc_cursor;
+
+	pr_debug("%s: inode's dev_t == %u\n", __func__, inode->i_rdev);
+
+	list_for_each_entry(restool_misc_cursor, &misc_list, list) {
+		if (restool_misc_cursor->miscdevt == inode->i_rdev) {
+			pr_debug("%s: Found the restool_misc\n", __func__);
+			restool_misc = restool_misc_cursor;
+			break;
+		}
+	}
+
+	if (!restool_misc)
+		return -EINVAL;
+
+	if (WARN_ON(restool_misc->dev == NULL))
+		return -EINVAL;
+
+	mutex_lock(&restool_misc->mutex);
+
+	if (!restool_misc->static_instance_in_use) {
+		restool_misc->static_instance_in_use = true;
+		filep->private_data = restool_misc->static_mc_io;
+	} else {
+		dynamic_mc_io = kzalloc(sizeof(struct fsl_mc_io), GFP_KERNEL);
+		if (dynamic_mc_io == NULL) {
+			error = -ENOMEM;
+			goto error;
+		}
+
+		root_mc_dev = to_fsl_mc_device(restool_misc->dev);
+		error = fsl_mc_portal_allocate(root_mc_dev, 0, &dynamic_mc_io);
+		if (error < 0) {
+			pr_err("Not able to allocate MC portal\n");
+			goto error;
+		}
+		++restool_misc->dynamic_instance_count;
+		filep->private_data = dynamic_mc_io;
+	}
+
+	mutex_unlock(&restool_misc->mutex);
+
+	return 0;
+error:
+	if (dynamic_mc_io != NULL) {
+		fsl_mc_portal_free(dynamic_mc_io);
+		kfree(dynamic_mc_io);
+	}
+
+	mutex_unlock(&restool_misc->mutex);
+
+	return error;
+}
+
+static int fsl_mc_restool_dev_release(struct inode *inode, struct file *filep)
+{
+	struct fsl_mc_io *local_mc_io = filep->private_data;
+	struct restool_misc *restool_misc;
+	struct restool_misc *restool_misc_cursor;
+
+	if (WARN_ON(filep->private_data == NULL))
+		return -EINVAL;
+
+	pr_debug("%s: inode's dev_t == %u\n", __func__, inode->i_rdev);
+
+	list_for_each_entry(restool_misc_cursor, &misc_list, list) {
+		if (restool_misc_cursor->miscdevt == inode->i_rdev) {
+			pr_debug("%s: Found the restool_misc\n", __func__);
+			restool_misc = restool_misc_cursor;
+			break;
+		}
+	}
+
+	if (!restool_misc)
+		return -EINVAL;
+
+	mutex_lock(&restool_misc->mutex);
+
+	if (WARN_ON(restool_misc->dynamic_instance_count == 0 &&
+	    !restool_misc->static_instance_in_use)) {
+		mutex_unlock(&restool_misc->mutex);
+		return -EINVAL;
+	}
+
+	/* Globally clean up opened/untracked handles */
+	fsl_mc_portal_reset(local_mc_io);
+
+	pr_debug("dynamic instance count: %d\n",
+		restool_misc->dynamic_instance_count);
+	pr_debug("static instance count: %d\n",
+		restool_misc->static_instance_in_use);
+
+	/*
+	 * must check
+	 * whether local_mc_io is dynamic or static instance
+	 * Otherwise it will free up the reserved portal by accident
+	 * or even not free up the dynamic allocated portal
+	 * if 2 or more instances running concurrently
+	 */
+	if (local_mc_io == restool_misc->static_mc_io) {
+		pr_debug("this is reserved portal");
+		pr_debug("reserved portal not in use\n");
+		restool_misc->static_instance_in_use = false;
+	} else {
+		pr_debug("this is dynamically allocated  portal");
+		pr_debug("free one dynamically allocated portal\n");
+		fsl_mc_portal_free(local_mc_io);
+		kfree(filep->private_data);
+		--restool_misc->dynamic_instance_count;
+	}
+
+	filep->private_data = NULL;
+	mutex_unlock(&restool_misc->mutex);
+
+	return 0;
+}
+
+static int restool_dprc_sync(struct inode *inode)
+{
+	int error = 0;
+	struct fsl_mc_device *root_mc_dev;
+	struct fsl_mc_bus *root_mc_bus;
+	struct restool_misc *restool_misc;
+	struct restool_misc *restool_misc_cursor;
+
+	pr_debug("%s: inode's dev_t == %u\n", __func__, inode->i_rdev);
+
+	list_for_each_entry(restool_misc_cursor, &misc_list, list) {
+		if (restool_misc_cursor->miscdevt == inode->i_rdev) {
+			pr_debug("%s: Found the restool_misc\n", __func__);
+			restool_misc = restool_misc_cursor;
+			break;
+		}
+	}
+
+	if (!restool_misc)
+		return -EINVAL;
+
+	root_mc_dev = to_fsl_mc_device(restool_misc->dev);
+	root_mc_bus = to_fsl_mc_bus(root_mc_dev);
+
+	mutex_lock(&root_mc_bus->scan_mutex);
+	error = dprc_scan_objects(root_mc_dev);
+	mutex_unlock(&root_mc_bus->scan_mutex);
+	pr_debug("sync_error = %d\n", error);
+
+	return error;
+}
+
+static int restool_send_mc_command(unsigned long arg,
+				struct fsl_mc_io *local_mc_io)
+{
+	int error = -EINVAL;
+	struct mc_command mc_cmd;
+
+	error = copy_from_user(&mc_cmd, (void __user *)arg, sizeof(mc_cmd));
+	if (error < 0) {
+		pr_err("copy_to_user() failed with error %d\n", error);
+		goto error;
+	}
+
+	/*
+	 * Send MC command to the MC:
+	 */
+	error = mc_send_command(local_mc_io, &mc_cmd);
+	if (error < 0)
+		goto error;
+
+	error = copy_to_user((void __user *)arg, &mc_cmd, sizeof(mc_cmd));
+	if (error < 0) {
+		pr_err("copy_to_user() failed with error %d\n", error);
+		goto error;
+	}
+
+	return 0;
+error:
+	return error;
+}
+
+static long
+fsl_mc_restool_dev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	int error = 0;
+
+	switch (cmd) {
+	case RESTOOL_DPRC_SYNC:
+		pr_debug("syncing...\n");
+		error = restool_dprc_sync(file->f_inode);
+		pr_debug("syncing finished...\n");
+		break;
+	case RESTOOL_SEND_MC_COMMAND:
+		error = restool_send_mc_command(arg, file->private_data);
+		break;
+	default:
+		pr_err("%s: unexpected ioctl call number\n", __func__);
+		error = -EINVAL;
+	}
+
+	return error;
+}
+
+static const struct file_operations fsl_mc_restool_dev_fops = {
+	.owner = THIS_MODULE,
+	.open = fsl_mc_restool_dev_open,
+	.release = fsl_mc_restool_dev_release,
+	.unlocked_ioctl = fsl_mc_restool_dev_ioctl,
+};
+
+static int restool_add_device_file(struct device *dev)
+{
+	uint32_t name1 = 0;
+	char name2[20] = {0};
+	int error = 0;
+	struct fsl_mc_device *root_mc_dev;
+	struct restool_misc *restool_misc;
+
+	pr_debug("newly scanned/notified device: %s, whose parent:%s\n",
+		 dev_name(dev), dev_name(dev->parent));
+
+	if (dev->bus == &platform_bus_type && dev->driver_data) {
+		if (sscanf(dev_name(dev), "%x.%s", &name1, name2) != 2) {
+			pr_err("sscanf failure\n");
+			return -EINVAL;
+		}
+		if (strcmp(name2, "fsl-mc") == 0)
+			pr_debug("platform's root dprc name is: %s\n",
+			dev_name(&(((struct fsl_mc *)(dev->driver_data))
+			->root_mc_bus_dev->dev)));
+	}
+
+	if (dev->bus == &fsl_mc_bus_type)
+		pr_debug("%s's bus type: fsl_mc_bus_type\n", dev_name(dev));
+	else if (dev->bus == &platform_bus_type)
+		pr_debug("%s's bus type: platform_bus_type\n", dev_name(dev));
+	else
+		pr_debug("%s's bus type: NEITHER fsl_mc_bus_type NOR platform_bus_type\n",
+			 dev_name(dev));
+
+	if (is_root_dprc(dev)) {
+		pr_debug("I am root dprc, create /dev/%s\n", dev_name(dev));
+		restool_misc = kzalloc(sizeof(struct restool_misc), GFP_KERNEL);
+		if (restool_misc == NULL)
+			return -ENOMEM;
+
+		restool_misc->dev = dev;
+		root_mc_dev = to_fsl_mc_device(dev);
+		error = fsl_mc_portal_allocate(root_mc_dev, 0,
+				&restool_misc->static_mc_io);
+		if (error < 0) {
+			pr_err("Not able to allocate MC portal\n");
+			goto err_portal;
+		}
+
+		restool_misc->misc.minor = MISC_DYNAMIC_MINOR;
+		restool_misc->misc.name = dev_name(dev);
+		restool_misc->misc.fops = &fsl_mc_restool_dev_fops;
+
+		error = misc_register(&restool_misc->misc);
+		if (error < 0) {
+			pr_err("misc_register() failed: %d\n", error);
+			goto err_reg;
+		}
+
+		restool_misc->miscdevt = restool_misc->misc.this_device->devt;
+		mutex_init(&restool_misc->mutex);
+		list_add(&restool_misc->list, &misc_list);
+		pr_info("/dev/%s driver registered\n", dev_name(dev));
+	} else
+		pr_info("%s is not root dprc, miscdevice cannot be created/associated\n",
+			dev_name(dev));
+
+	return 0;
+err_reg:
+	misc_deregister(&restool_misc->misc);
+
+err_portal:
+	if (restool_misc->static_mc_io)
+		fsl_mc_portal_free(restool_misc->static_mc_io);
+	if (restool_misc)
+		kfree(restool_misc);
+
+	return error;
+}
+
+static int restool_bus_notifier(struct notifier_block *nb,
+			      unsigned long action, void *data)
+{
+	struct device *dev = data;
+
+	pr_debug("entering %s...\n", __func__);
+	pr_debug("being notified by device: %s\n", dev_name(dev));
+
+	if (dev->bus == &fsl_mc_bus_type)
+		pr_debug("%s's bus type: fsl_mc_bus_type\n", dev_name(dev));
+	else if (dev->bus == &platform_bus_type)
+		pr_debug("%s's bus type: platform_bus_type\n", dev_name(dev));
+	else
+		pr_debug("%s's bus type: NEITHER fsl_mc_bus_type NOR platform_bus_type\n",
+			 dev_name(dev));
+
+	switch (action) {
+	case BUS_NOTIFY_ADD_DEVICE:
+		pr_info("bus notify device added: %s\n", dev_name(dev));
+		restool_add_device_file(dev);
+		break;
+	case BUS_NOTIFY_DEL_DEVICE:
+		pr_info("bus notify device to be removed: %s\n", dev_name(dev));
+		break;
+	case BUS_NOTIFY_REMOVED_DEVICE:
+		pr_info("bus notify device removed: %s\n", dev_name(dev));
+		break;
+	case BUS_NOTIFY_BIND_DRIVER:
+		pr_info("bus notify driver about to be bound to device: %s\n", dev_name(dev));
+		break;
+	case BUS_NOTIFY_BOUND_DRIVER:
+		pr_info("bus notify driver bound to device: %s\n", dev_name(dev));
+		break;
+	case BUS_NOTIFY_UNBIND_DRIVER:
+		pr_info("bus notify driver about to unbind from device: %s\n", dev_name(dev));
+		break;
+	case BUS_NOTIFY_UNBOUND_DRIVER:
+		pr_info("bus notify driver unbind from device: %s\n", dev_name(dev));
+		break;
+	default:
+		pr_err("%s: unrecognized device action from %s\n", __func__, dev_name(dev));
+		return -EINVAL;
+	}
+
+	pr_debug("leaving %s...\n", __func__);
+
+	return 0;
+}
+
+static int add_to_restool(struct device *dev, void *data)
+{
+	pr_debug("verify *data: %s\n", (char *)data);
+	restool_add_device_file(dev);
+	return 0;
+}
+
+static int __init fsl_mc_restool_driver_init(void)
+{
+	int error = 0;
+	struct notifier_block *nb;
+	char *data = "Add me to device file if I am a root dprc";
+
+	nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
+	if (!nb)
+		return -ENOMEM;
+
+	nb->notifier_call = restool_bus_notifier;
+	pr_debug("restool will register notifier...\n");
+	error = bus_register_notifier(&fsl_mc_bus_type, nb);
+	pr_debug("restool finish register notifier...\n");
+
+	if (error) {
+		kfree(nb);
+		return error;
+	}
+
+	pr_debug("restool scan bus for each device...\n");
+	/*
+	 * This driver runs after fsl-mc bus driver runs.
+	 * Hence, many of the root dprcs are already attached to fsl-mc bus
+	 * In order to make sure we find all the root dprcs,
+	 * we need to scan the fsl_mc_bus_type.
+	 */
+	error  = bus_for_each_dev(&fsl_mc_bus_type, NULL, data, add_to_restool);
+	if (error) {
+		bus_unregister_notifier(&fsl_mc_bus_type, nb);
+		kfree(nb);
+		pr_err("restool driver registration failure\n");
+		return error;
+	}
+	pr_debug("end restool scan bus for each device...\n");
+
+	return 0;
+}
+
+module_init(fsl_mc_restool_driver_init);
+
+static void __exit fsl_mc_restool_driver_exit(void)
+{
+	struct restool_misc *restool_misc;
+	struct restool_misc *restool_misc_tmp;
+	char name1[20] = {0};
+	uint32_t name2 = 0;
+
+	list_for_each_entry_safe(restool_misc, restool_misc_tmp,
+				 &misc_list, list) {
+		if (sscanf(restool_misc->misc.name, "%4s.%u", name1, &name2)
+		    != 2) {
+			pr_err("sscanf failure\n");
+			return;
+		}
+		pr_debug("name1=%s,name2=%u\n", name1, name2);
+		pr_debug("misc-device: %s\n", restool_misc->misc.name);
+		if (strcmp(name1, "dprc") == 0) {
+			if (WARN_ON(
+			    restool_misc->static_mc_io == NULL))
+				return;
+
+			if (WARN_ON(restool_misc->dynamic_instance_count != 0))
+				return;
+
+			if (WARN_ON(restool_misc->static_instance_in_use))
+				return;
+
+			misc_deregister(&restool_misc->misc);
+			pr_info("/dev/%s driver unregistered\n",
+				restool_misc->misc.name);
+			fsl_mc_portal_free(
+				restool_misc->static_mc_io);
+			list_del(&restool_misc->list);
+			kfree(restool_misc);
+		}
+	}
+}
+
+module_exit(fsl_mc_restool_driver_exit);
+
+MODULE_AUTHOR("Freescale Semiconductor Inc.");
+MODULE_DESCRIPTION("Freescale's MC restool driver");
+MODULE_LICENSE("GPL");
-- 
2.3.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/