[PATCH V3 06/19] virtio-pci-modern: introduce helpers for setting and getting status

From: Jason Wang
Date: Mon Jan 04 2021 - 01:57:41 EST


This patch introduces helpers to allow set and get device status.

Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
drivers/virtio/virtio_pci_modern.c | 37 +++++++++++++++++++++++-------
1 file changed, 29 insertions(+), 8 deletions(-)

diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
index 2e37bfc89655..ccde0a41209a 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -275,41 +275,62 @@ static u32 vp_generation(struct virtio_device *vdev)
return vp_ioread8(&cfg->config_generation);
}

+/*
+ * vp_modern_get_status - get the device status
+ * @mdev: the modern virtio-pci device
+ *
+ * Returns the status read from device
+ */
+static u8 vp_modern_get_status(struct virtio_pci_modern_device *mdev)
+{
+ struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
+
+ return vp_ioread8(&cfg->device_status);
+}
+
/* config->{get,set}_status() implementations */
static u8 vp_get_status(struct virtio_device *vdev)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
- struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
+
+ return vp_modern_get_status(&vp_dev->mdev);
+}
+
+/*
+ * vp_modern_set_status - set status to device
+ * @mdev: the modern virtio-pci device
+ * @status: the status set to device
+ */
+static void vp_modern_set_status(struct virtio_pci_modern_device *mdev,
+ u8 status)
+{
struct virtio_pci_common_cfg __iomem *cfg = mdev->common;

- return vp_ioread8(&cfg->device_status);
+ vp_iowrite8(status, &cfg->device_status);
}

static void vp_set_status(struct virtio_device *vdev, u8 status)
{
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;

/* We should never be setting status to 0. */
BUG_ON(status == 0);
- vp_iowrite8(status, &cfg->device_status);
+ vp_modern_set_status(&vp_dev->mdev, status);
}

static void vp_reset(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;

/* 0 status means a reset. */
- vp_iowrite8(0, &cfg->device_status);
+ vp_modern_set_status(mdev, 0);
/* After writing 0 to device_status, the driver MUST wait for a read of
* device_status to return 0 before reinitializing the device.
* This will flush out the status write, and flush in device writes,
* including MSI-X interrupts, if any.
*/
- while (vp_ioread8(&cfg->device_status))
+ while (vp_modern_get_status(mdev))
msleep(1);
/* Flush pending VQ/configuration callbacks. */
vp_synchronize_vectors(vdev);
--
2.25.1