vfio/fsl-mc: Add VFIO framework for fsl-mc devices

commit f8adf3ce07cf0623b3e8e0df67f3bc12a110416f
[context adjustment]

This patch add framework of VFIO support for FSL-MC devices.
Subsequent patches will add support for binding and secure
assigning these devices using VFIO.

FSL-MC is a new bus (driver/bus/fsl-mc/) which is different
from PCI and Platform bus.

Signed-off-by: Bharat Bhushan <Bharat.Bhushan@nxp.com>
Integrated-by: Zhao Qiang <qiang.zhao@nxp.com>

2 files changed, 194 insertions, 0 deletions

diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
new file mode 100644
index 0000000..26b8c29
--- /dev/null
+++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
@@ -0,0 +1,174 @@
+/*
+ * Freescale Management Complex (MC) device passthrough using VFIO
+ *
+ * Copyright (C) 2013-2016 Freescale Semiconductor, Inc.
+ * Copyright 2016-2017 NXP
+ * Author: Bharat Bhushan <bharat.bhushan@nxp.com>
+ *
+ * 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 <linux/device.h>
+#include <linux/iommu.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/vfio.h>
+
+#include "../../staging/fsl-mc/include/mc.h"
+#include "vfio_fsl_mc_private.h"
+
+#define DRIVER_VERSION	"0.10"
+#define DRIVER_AUTHOR	"Bharat Bhushan <bharat.bhushan@nxp.com>"
+#define DRIVER_DESC	"VFIO for FSL-MC devices - User Level meta-driver"
+
+static int vfio_fsl_mc_open(void *device_data)
+{
+	if (!try_module_get(THIS_MODULE))
+		return -ENODEV;
+
+	return 0;
+}
+
+static void vfio_fsl_mc_release(void *device_data)
+{
+	module_put(THIS_MODULE);
+}
+
+static long vfio_fsl_mc_ioctl(void *device_data, unsigned int cmd,
+			      unsigned long arg)
+{
+	switch (cmd) {
+	case VFIO_DEVICE_GET_INFO:
+	{
+		return -EINVAL;
+	}
+	case VFIO_DEVICE_GET_REGION_INFO:
+	{
+		return -EINVAL;
+	}
+	case VFIO_DEVICE_GET_IRQ_INFO:
+	{
+		return -EINVAL;
+	}
+	case VFIO_DEVICE_SET_IRQS:
+	{
+		return -EINVAL;
+	}
+	case VFIO_DEVICE_RESET:
+	{
+		return -EINVAL;
+	}
+	default:
+		return -EINVAL;
+	}
+}
+
+static ssize_t vfio_fsl_mc_read(void *device_data, char __user *buf,
+				size_t count, loff_t *ppos)
+{
+	return -EINVAL;
+}
+
+static ssize_t vfio_fsl_mc_write(void *device_data, const char __user *buf,
+				 size_t count, loff_t *ppos)
+{
+	return -EINVAL;
+}
+
+static int vfio_fsl_mc_mmap(void *device_data, struct vm_area_struct *vma)
+{
+	return -EINVAL;
+}
+
+static const struct vfio_device_ops vfio_fsl_mc_ops = {
+	.name		= "vfio-fsl-mc",
+	.open		= vfio_fsl_mc_open,
+	.release	= vfio_fsl_mc_release,
+	.ioctl		= vfio_fsl_mc_ioctl,
+	.read		= vfio_fsl_mc_read,
+	.write		= vfio_fsl_mc_write,
+	.mmap		= vfio_fsl_mc_mmap,
+};
+
+static int vfio_fsl_mc_probe(struct fsl_mc_device *mc_dev)
+{
+	struct iommu_group *group;
+	struct vfio_fsl_mc_device *vdev;
+	struct device *dev = &mc_dev->dev;
+	int ret;
+
+	group = vfio_iommu_group_get(dev);
+	if (!group) {
+		dev_err(dev, "%s: VFIO: No IOMMU group\n", __func__);
+		return -EINVAL;
+	}
+
+	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
+	if (!vdev) {
+		vfio_iommu_group_put(group, dev);
+		return -ENOMEM;
+	}
+
+	vdev->mc_dev = mc_dev;
+
+	ret = vfio_add_group_dev(dev, &vfio_fsl_mc_ops, vdev);
+	if (ret) {
+		dev_err(dev, "%s: Failed to add to vfio group\n", __func__);
+		kfree(vdev);
+		vfio_iommu_group_put(group, dev);
+		return ret;
+	}
+
+	return ret;
+}
+
+static int vfio_fsl_mc_remove(struct fsl_mc_device *mc_dev)
+{
+	struct vfio_fsl_mc_device *vdev;
+	struct device *dev = &mc_dev->dev;
+
+	vdev = vfio_del_group_dev(dev);
+	if (!vdev)
+		return -EINVAL;
+
+	vfio_iommu_group_put(mc_dev->dev.iommu_group, dev);
+	kfree(vdev);
+
+	return 0;
+}
+
+/*
+ * vfio-fsl_mc is a meta-driver, so use driver_override interface to
+ * bind a fsl_mc container with this driver and match_id_table is NULL.
+ */
+static struct fsl_mc_driver vfio_fsl_mc_driver = {
+	.probe		= vfio_fsl_mc_probe,
+	.remove		= vfio_fsl_mc_remove,
+	.match_id_table = NULL,
+	.driver	= {
+		.name	= "vfio-fsl-mc",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init vfio_fsl_mc_driver_init(void)
+{
+	return fsl_mc_driver_register(&vfio_fsl_mc_driver);
+}
+
+static void __exit vfio_fsl_mc_driver_exit(void)
+{
+	fsl_mc_driver_unregister(&vfio_fsl_mc_driver);
+}
+
+module_init(vfio_fsl_mc_driver_init);
+module_exit(vfio_fsl_mc_driver_exit);
+
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h b/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
new file mode 100644
index 0000000..e680f8e
--- /dev/null
+++ b/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
@@ -0,0 +1,20 @@
+/*
+ * Freescale Management Complex VFIO private declarations
+ *
+ * Copyright (C) 2013-2016 Freescale Semiconductor, Inc.
+ * Copyright 2016 NXP
+ * Author: Bharat Bhushan <bharat.bhushan@nxp.com>
+ *
+ * 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 VFIO_FSL_MC_PRIVATE_H
+#define VFIO_FSL_MC_PRIVATE_H
+
+struct vfio_fsl_mc_device {
+	struct fsl_mc_device		*mc_dev;
+};
+
+#endif /* VFIO_PCI_PRIVATE_H */