misc: mic: MIC COSM bus

The MIC COSM bus allows the co-processor state management (COSM)
functionality to be shared between multiple generations of Intel MIC
products. The COSM driver registers itself on the COSM bus. The base
PCIe drivers implement the bus ops and register COSM devices on the
bus, resulting in the COSM driver being probed with the COSM devices.
COSM bus ops, e.g. start, stop, ready, reset, therefore abstract out
common functionality from its specific implementation for individual
generations of MIC products.

Reviewed-by: Nikhil Rao <nikhil.rao@intel.com>
Reviewed-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 141 insertions, 0 deletions

diff --git a/drivers/misc/mic/bus/cosm_bus.c b/drivers/misc/mic/bus/cosm_bus.c
new file mode 100644
index 000000000000..1e36830f1a4e
--- /dev/null
+++ b/drivers/misc/mic/bus/cosm_bus.c
@@ -0,0 +1,141 @@
+/*
+ * 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 COSM Bus Driver
+ */
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/idr.h>
+#include "cosm_bus.h"
+
+/* Unique numbering for cosm devices. */
+static DEFINE_IDA(cosm_index_ida);
+
+static int cosm_dev_probe(struct device *d)
+{
+	struct cosm_device *dev = dev_to_cosm(d);
+	struct cosm_driver *drv = drv_to_cosm(dev->dev.driver);
+
+	return drv->probe(dev);
+}
+
+static int cosm_dev_remove(struct device *d)
+{
+	struct cosm_device *dev = dev_to_cosm(d);
+	struct cosm_driver *drv = drv_to_cosm(dev->dev.driver);
+
+	drv->remove(dev);
+	return 0;
+}
+
+static struct bus_type cosm_bus = {
+	.name  = "cosm_bus",
+	.probe = cosm_dev_probe,
+	.remove = cosm_dev_remove,
+};
+
+int cosm_register_driver(struct cosm_driver *driver)
+{
+	driver->driver.bus = &cosm_bus;
+	return driver_register(&driver->driver);
+}
+EXPORT_SYMBOL_GPL(cosm_register_driver);
+
+void cosm_unregister_driver(struct cosm_driver *driver)
+{
+	driver_unregister(&driver->driver);
+}
+EXPORT_SYMBOL_GPL(cosm_unregister_driver);
+
+static inline void cosm_release_dev(struct device *d)
+{
+	struct cosm_device *cdev = dev_to_cosm(d);
+
+	kfree(cdev);
+}
+
+struct cosm_device *
+cosm_register_device(struct device *pdev, struct cosm_hw_ops *hw_ops)
+{
+	struct cosm_device *cdev;
+	int ret;
+
+	cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
+	if (!cdev)
+		return ERR_PTR(-ENOMEM);
+
+	cdev->dev.parent = pdev;
+	cdev->dev.release = cosm_release_dev;
+	cdev->hw_ops = hw_ops;
+	dev_set_drvdata(&cdev->dev, cdev);
+	cdev->dev.bus = &cosm_bus;
+
+	/* Assign a unique device index and hence name */
+	ret = ida_simple_get(&cosm_index_ida, 0, 0, GFP_KERNEL);
+	if (ret < 0)
+		goto free_cdev;
+
+	cdev->index = ret;
+	cdev->dev.id = ret;
+	dev_set_name(&cdev->dev, "cosm-dev%u", cdev->index);
+
+	ret = device_register(&cdev->dev);
+	if (ret)
+		goto ida_remove;
+	return cdev;
+ida_remove:
+	ida_simple_remove(&cosm_index_ida, cdev->index);
+free_cdev:
+	kfree(cdev);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(cosm_register_device);
+
+void cosm_unregister_device(struct cosm_device *dev)
+{
+	int index = dev->index; /* save for after device release */
+
+	device_unregister(&dev->dev);
+	ida_simple_remove(&cosm_index_ida, index);
+}
+EXPORT_SYMBOL_GPL(cosm_unregister_device);
+
+struct cosm_device *cosm_find_cdev_by_id(int id)
+{
+	struct device *dev = subsys_find_device_by_id(&cosm_bus, id, NULL);
+
+	return dev ? container_of(dev, struct cosm_device, dev) : NULL;
+}
+EXPORT_SYMBOL_GPL(cosm_find_cdev_by_id);
+
+static int __init cosm_init(void)
+{
+	return bus_register(&cosm_bus);
+}
+
+static void __exit cosm_exit(void)
+{
+	bus_unregister(&cosm_bus);
+	ida_destroy(&cosm_index_ida);
+}
+
+core_initcall(cosm_init);
+module_exit(cosm_exit);
+
+MODULE_AUTHOR("Intel Corporation");
+MODULE_DESCRIPTION("Intel(R) MIC card OS state management bus driver");
+MODULE_LICENSE("GPL v2");