VFIO: platform: add reset callback

A new reset callback is introduced. If this callback is populated,
the reset is invoked on device first open/last close or upon userspace
ioctl.  The modality is exposed on VFIO_DEVICE_GET_INFO.

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

diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
index 611597e..6393581 100644 (file)
--- a/drivers/vfio/platform/vfio_platform_common.c
+++ b/drivers/vfio/platform/vfio_platform_common.c
@@ -103,6 +103,8 @@ static void vfio_platform_release(void *device_data)
        mutex_lock(&driver_lock);
 
        if (!(--vdev->refcnt)) {
+               if (vdev->reset)
+                       vdev->reset(vdev);
                vfio_platform_regions_cleanup(vdev);
                vfio_platform_irq_cleanup(vdev);
        }
@@ -130,6 +132,9 @@ static int vfio_platform_open(void *device_data)
                ret = vfio_platform_irq_init(vdev);
                if (ret)
                        goto err_irq;
+
+               if (vdev->reset)
+                       vdev->reset(vdev);
        }
 
        vdev->refcnt++;
@@ -162,6 +167,8 @@ static long vfio_platform_ioctl(void *device_data,
                if (info.argsz < minsz)
                        return -EINVAL;
 
+               if (vdev->reset)
+                       vdev->flags |= VFIO_DEVICE_FLAGS_RESET;
                info.flags = vdev->flags;
                info.num_regions = vdev->num_regions;
                info.num_irqs = vdev->num_irqs;
@@ -255,8 +262,12 @@ static long vfio_platform_ioctl(void *device_data,
 
                return ret;
 
-       } else if (cmd == VFIO_DEVICE_RESET)
-               return -EINVAL;
+       } else if (cmd == VFIO_DEVICE_RESET) {
+               if (vdev->reset)
+                       return vdev->reset(vdev);
+               else
+                       return -EINVAL;
+       }
 
        return -ENOTTY;
 }

diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
index 9e37b9f..1c9b3d5 100644 (file)
--- a/drivers/vfio/platform/vfio_platform_private.h
+++ b/drivers/vfio/platform/vfio_platform_private.h
@@ -67,6 +67,7 @@ struct vfio_platform_device {
        struct resource*
                (*get_resource)(struct vfio_platform_device *vdev, int i);
        int     (*get_irq)(struct vfio_platform_device *vdev, int i);
+       int     (*reset)(struct vfio_platform_device *vdev);
 };
 
 struct vfio_platform_reset_combo {