[PATCH V3 07/19] virtio-pci-modern: introduce helpers for setting and getting features

From: Jason Wang
Date: Mon Jan 04 2021 - 01:57:42 EST


This patch introduces helpers for setting and getting features.

Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
drivers/virtio/virtio_pci_modern.c | 43 +++++++++++++++++++++++-------
1 file changed, 33 insertions(+), 10 deletions(-)

diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
index ccde0a41209a..cb14fc334a9c 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -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;
}
--
2.25.1