vfio: platform: probe to devices on the platform bus

Driver to bind to Linux platform devices, and callbacks to discover their
resources to be used by the main VFIO PLATFORM code.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Tested-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

2 files changed, 104 insertions, 0 deletions

diff --git a/drivers/vfio/platform/vfio_platform.c b/drivers/vfio/platform/vfio_platform.c
new file mode 100644
index 000000000000..cef645c83996
--- /dev/null
+++ b/drivers/vfio/platform/vfio_platform.c
@@ -0,0 +1,103 @@
+/*
+ * Copyright (C) 2013 - Virtual Open Systems
+ * Author: Antonios Motakis <a.motakis@virtualopensystems.com>
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/vfio.h>
+#include <linux/platform_device.h>
+
+#include "vfio_platform_private.h"
+
+#define DRIVER_VERSION  "0.10"
+#define DRIVER_AUTHOR   "Antonios Motakis <a.motakis@virtualopensystems.com>"
+#define DRIVER_DESC     "VFIO for platform devices - User Level meta-driver"
+
+/* probing devices from the linux platform bus */
+
+static struct resource *get_platform_resource(struct vfio_platform_device *vdev,
+                                              int num)
+{
+        struct platform_device *dev = (struct platform_device *) vdev->opaque;
+        int i;
+
+        for (i = 0; i < dev->num_resources; i++) {
+                struct resource *r = &dev->resource[i];
+
+                if (resource_type(r) & (IORESOURCE_MEM|IORESOURCE_IO)) {
+                        if (!num)
+                                return r;
+
+                        num--;
+                }
+        }
+        return NULL;
+}
+
+static int get_platform_irq(struct vfio_platform_device *vdev, int i)
+{
+        struct platform_device *pdev = (struct platform_device *) vdev->opaque;
+
+        return platform_get_irq(pdev, i);
+}
+
+static int vfio_platform_probe(struct platform_device *pdev)
+{
+        struct vfio_platform_device *vdev;
+        int ret;
+
+        vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
+        if (!vdev)
+                return -ENOMEM;
+
+        vdev->opaque = (void *) pdev;
+        vdev->name = pdev->name;
+        vdev->flags = VFIO_DEVICE_FLAGS_PLATFORM;
+        vdev->get_resource = get_platform_resource;
+        vdev->get_irq = get_platform_irq;
+
+        ret = vfio_platform_probe_common(vdev, &pdev->dev);
+        if (ret)
+                kfree(vdev);
+
+        return ret;
+}
+
+static int vfio_platform_remove(struct platform_device *pdev)
+{
+        struct vfio_platform_device *vdev;
+
+        vdev = vfio_platform_remove_common(&pdev->dev);
+        if (vdev) {
+                kfree(vdev);
+                return 0;
+        }
+
+        return -EINVAL;
+}
+
+static struct platform_driver vfio_platform_driver = {
+        .probe          = vfio_platform_probe,
+        .remove         = vfio_platform_remove,
+        .driver = {
+                .name   = "vfio-platform",
+                .owner  = THIS_MODULE,
+        },
+};
+
+module_platform_driver(vfio_platform_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 82889c30f4f5..ea9514b6bb5c 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -160,6 +160,7 @@ 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_PLATFORM (1 << 2)     /* vfio-platform device */
         __u32   num_regions;    /* Max region index + 1 */
         __u32   num_irqs;       /* Max IRQ index + 1 */
 };