Commit 0b017708 authored by Jason Wang's avatar Jason Wang Committed by Michael S. Tsirkin
Browse files

virtio-pci-modern: introduce helpers for setting and getting features 



This patch introduces helpers for setting and getting features.

Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-8-jasowang@redhat.com


Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent e3669129

drivers/virtio/virtio_pci_modern.c

+33 −10
Original line number Diff line number Diff line
@@ -137,12 +137,16 @@ static void __iomem *map_capability(struct pci_dev *dev, int off, 
	return p;

}



/* virtio config->get_features() implementation */

static u64 vp_get_features(struct virtio_device *vdev)

/*

 * vp_modern_get_features - get features from device

 * @mdev: the modern virtio-pci device

 *

 * Returns the features read from the device

 */

static u64 vp_modern_get_features(struct virtio_pci_modern_device *mdev)

{

	struct virtio_pci_device *vp_dev = to_vp_device(vdev);

	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;

	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;



	u64 features;



	vp_iowrite32(0, &cfg->device_feature_select);
@@ -153,6 +157,14 @@ static u64 vp_get_features(struct virtio_device *vdev) 
	return features;

}



/* virtio config->get_features() implementation */

static u64 vp_get_features(struct virtio_device *vdev)

{

	struct virtio_pci_device *vp_dev = to_vp_device(vdev);



	return vp_modern_get_features(&vp_dev->mdev);

}



static void vp_transport_features(struct virtio_device *vdev, u64 features)

{

	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
@@ -163,12 +175,26 @@ static void vp_transport_features(struct virtio_device *vdev, u64 features) 
		__virtio_set_bit(vdev, VIRTIO_F_SR_IOV);

}



/*

 * vp_modern_set_features - set features to device

 * @mdev: the modern virtio-pci device

 * @features: the features set to device

 */

static void vp_modern_set_features(struct virtio_pci_modern_device *mdev,

				   u64 features)

{

	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;



	vp_iowrite32(0, &cfg->guest_feature_select);

	vp_iowrite32((u32)features, &cfg->guest_feature);

	vp_iowrite32(1, &cfg->guest_feature_select);

	vp_iowrite32(features >> 32, &cfg->guest_feature);

}



/* virtio config->finalize_features() implementation */

static int vp_finalize_features(struct virtio_device *vdev)

{

	struct virtio_pci_device *vp_dev = to_vp_device(vdev);

	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;

	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;

	u64 features = vdev->features;



	/* Give virtio_ring a chance to accept features. */
@@ -183,10 +209,7 @@ static int vp_finalize_features(struct virtio_device *vdev) 
		return -EINVAL;

	}



	vp_iowrite32(0, &cfg->guest_feature_select);

	vp_iowrite32((u32)vdev->features, &cfg->guest_feature);

	vp_iowrite32(1, &cfg->guest_feature_select);

	vp_iowrite32(vdev->features >> 32, &cfg->guest_feature);

	vp_modern_set_features(&vp_dev->mdev, vdev->features);



	return 0;

}