Platform devices in the Linux kernel are usually managed by the DT
interface. This patch forms the base to support these kind of devices
with VFIO.
Signed-off-by: Antonios Motakis <a.motakis@xxxxxxxxxxxxxxxxxxxxxx>
---
drivers/vfio/Kconfig | 10 +++
drivers/vfio/Makefile | 1 +
drivers/vfio/vfio_dt.c | 187 ++++++++++++++++++++++++++++++++++++++++++++++
include/uapi/linux/vfio.h | 1 +
4 files changed, 199 insertions(+)
create mode 100644 drivers/vfio/vfio_dt.c
diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig
index 1f84eda..a77a2e4 100644
--- a/drivers/vfio/Kconfig
+++ b/drivers/vfio/Kconfig
@@ -13,4 +13,14 @@ menuconfig VFIO
If you don't know what to do here, say N.
+config VFIO_DT
+ tristate "VFIO support for Device Tree devices"
+ depends on VFIO && EVENTFD
+ help
+ Support for the VFIO Device Tree driver. This is required to make
+ use of platform devices present on Device Tree nodes using the VFIO
+ framework.
+
+ If you don't know what to do here, say N.
+
source "drivers/vfio/pci/Kconfig"
diff --git a/drivers/vfio/Makefile b/drivers/vfio/Makefile
index 2398d4a..d599a67 100644
--- a/drivers/vfio/Makefile
+++ b/drivers/vfio/Makefile
@@ -1,3 +1,4 @@
obj-$(CONFIG_VFIO) += vfio.o
obj-$(CONFIG_VFIO_IOMMU_TYPE1) += vfio_iommu_type1.o
obj-$(CONFIG_VFIO_PCI) += pci/
+obj-$(CONFIG_VFIO_DT) += vfio_dt.o
diff --git a/drivers/vfio/vfio_dt.c b/drivers/vfio/vfio_dt.c
new file mode 100644
index 0000000..ad4d31d
--- /dev/null
+++ b/drivers/vfio/vfio_dt.c
@@ -0,0 +1,187 @@
+/*
+ * Copyright (C) 2013 - Virtual Open Systems
+ * Author: Antonios Motakis <a.motakis@xxxxxxxxxxxxxxxxxxxxxx>
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include <linux/device.h>
+#include <linux/eventfd.h>
+#include <linux/interrupt.h>
+#include <linux/iommu.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/notifier.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include <linux/vfio.h>
+
+#define DRIVER_VERSION "0.1"
+#define DRIVER_AUTHOR "Antonios Motakis <a.motakis@xxxxxxxxxxxxxxxxxxxxxx>"
+#define DRIVER_DESC "VFIO Device Tree devices - User Level meta-driver"
+
+struct vfio_dt_device {
+ struct platform_device *pdev;
+};
+
+static void vfio_dt_release(void *device_data)
+{
+ module_put(THIS_MODULE);
+}
+
+static int vfio_dt_open(void *device_data)
+{
+ if (!try_module_get(THIS_MODULE))
+ return -ENODEV;
+
+ return 0;
+}
+
+static long vfio_dt_ioctl(void *device_data,
+ unsigned int cmd, unsigned long arg)
+{
+ struct vfio_dt_device *vdev = device_data;
+ unsigned long minsz;
+
+ if (cmd == VFIO_DEVICE_GET_INFO) {
+ struct vfio_device_info info;
+
+ minsz = offsetofend(struct vfio_device_info, num_irqs);
+
+ if (copy_from_user(&info, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if (info.argsz < minsz)
+ return -EINVAL;
+
+ info.flags = VFIO_DEVICE_FLAGS_DT;
+ info.num_regions = 0;
+ info.num_irqs = 0;
+
+ return copy_to_user((void __user *)arg, &info, minsz);
+
+ } else if (cmd == VFIO_DEVICE_GET_REGION_INFO)
+ return -EINVAL;
+
+ else if (cmd == VFIO_DEVICE_GET_IRQ_INFO)
+ return -EINVAL;
+
+ else if (cmd == VFIO_DEVICE_SET_IRQS)
+ return -EINVAL;
+
+ else if (cmd == VFIO_DEVICE_RESET)
+ return -EINVAL;
+
+ return -ENOTTY;
+}
+
+static ssize_t vfio_dt_read(void *device_data, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ return 0;
+}
+
+static ssize_t vfio_dt_write(void *device_data, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ return 0;
+}
+
+static int vfio_dt_mmap(void *device_data, struct vm_area_struct *vma)
+{
+ return -EINVAL;
+}
+
+static const struct vfio_device_ops vfio_dt_ops = {
+ .name = "vfio-dts",
+ .open = vfio_dt_open,
+ .release = vfio_dt_release,
+ .ioctl = vfio_dt_ioctl,
+ .read = vfio_dt_read,
+ .write = vfio_dt_write,
+ .mmap = vfio_dt_mmap,
+};
+
+static int vfio_dt_probe(struct platform_device *pdev)
+{
+ struct vfio_dt_device *vdev;
+ struct iommu_group *group;
+ int ret;
+
+ group = iommu_group_get(&pdev->dev);
+ if (!group) {
+ pr_err("VFIO: No IOMMU group for device %s\n", pdev->name);
+ return -EINVAL;
+ }
+
+ vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
+ if (!vdev) {
+ iommu_group_put(group);
+ return -ENOMEM;
+ }
+
+ vdev->pdev = pdev;
+
+ ret = vfio_add_group_dev(&pdev->dev, &vfio_dt_ops, vdev);
+ if (ret) {
+ iommu_group_put(group);
+ kfree(vdev);
+ }
+
+ return ret;
+}
+
+static int vfio_dt_remove(struct platform_device *pdev)
+{
+ struct vfio_dt_device *vdev;
+
+ vdev = vfio_del_group_dev(&pdev->dev);
+ if (!vdev)
+ return -EINVAL;
+
+ iommu_group_put(pdev->dev.iommu_group);
+ kfree(vdev);
+
+ return 0;
+}
+
+static const struct of_device_id vfio_dt_match[] = {
+ /* In the future, we can implement a better mechanism to bind the
+ * module to any device. For now add the compatible property to the
+ * dtb of the devices we want to use. */
+ {
+ .compatible = "vfio-dt",
+ },
+ {},
+};
+MODULE_DEVICE_TABLE(of, vfio_dt_match);
+
+static struct platform_driver vfio_dt_driver = {
+ .probe = vfio_dt_probe,
+ .remove = vfio_dt_remove,
+ .driver = {
+ .name = "vfio-dt",
+ .owner = THIS_MODULE,
+ .of_match_table = vfio_dt_match,
+ },
+};
+
+module_platform_driver(vfio_dt_driver);
+
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 284ff24..1e4bef2 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -147,6 +147,7 @@ struct vfio_device_info {
__u32 flags;
#define VFIO_DEVICE_FLAGS_RESET (1 << 0) /* Device supports reset */
#define VFIO_DEVICE_FLAGS_PCI (1 << 1) /* vfio-pci device */
+#define VFIO_DEVICE_FLAGS_DT (1 << 2) /* vfio-dt device */
__u32 num_regions; /* Max region index + 1 */
__u32 num_irqs; /* Max IRQ index + 1 */
};
--
1.8.1.2
--
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