Virtualization - Oct 2022 - [PATCH 2/2] virtio_ring: use helper function is_power_of_2()

From: Shaoqin Huang <shaoqin.huang at intel.com>

Use helper function is_power_of_2() to check if num is power of two.
Minor readability improvement.

Shaoqin Huang (2):
  virtio_pci: use helper function is_power_of_2()
  virtio_ring: use helper function is_power_of_2()

 drivers/virtio/virtio_pci_modern.c | 2 +-
 drivers/virtio/virtio_ring.c       | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

-- 
2.34.1

From: Shaoqin Huang <shaoqin.huang at intel.com>

Use helper function is_power_of_2() to check if num is power of two.
Minor readability improvement.

Signed-off-by: Shaoqin Huang <shaoqin.huang at intel.com>
---
 drivers/virtio/virtio_pci_modern.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/virtio/virtio_pci_modern.c
b/drivers/virtio/virtio_pci_modern.c
index c3b9f2761849..207294bd7b9d 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -310,7 +310,7 @@ static struct virtqueue *setup_vq(struct virtio_pci_device
*vp_dev,
 	if (!num || vp_modern_get_queue_enable(mdev, index))
 		return ERR_PTR(-ENOENT);
 
-	if (num & (num - 1)) {
+	if (!is_power_of_2(num)) {
 		dev_warn(&vp_dev->pci_dev->dev, "bad queue size %u",
num);
 		return ERR_PTR(-EINVAL);
 	}
-- 
2.34.1

From: Shaoqin Huang <shaoqin.huang at intel.com>

Use helper function is_power_of_2() to check if num is power of two.
Minor readability improvement.

Signed-off-by: Shaoqin Huang <shaoqin.huang at intel.com>
---
 drivers/virtio/virtio_ring.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 2e7689bb933b..723c4e29e1d3 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1052,7 +1052,7 @@ static int vring_alloc_queue_split(struct
vring_virtqueue_split *vring_split,
 	dma_addr_t dma_addr;
 
 	/* We assume num is a power of 2. */
-	if (num & (num - 1)) {
+	if (!is_power_of_2(num)) {
 		dev_warn(&vdev->dev, "Bad virtqueue length %u\n", num);
 		return -EINVAL;
 	}
-- 
2.34.1