lkml.org 
[lkml]   [2014]   [Oct]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH RFC v4 10/17] virtio: simplify feature bit handling
Now that we use u64 for bits, we can simply & them together.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
drivers/virtio/virtio.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index a3df817..0f44cff 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -160,6 +160,7 @@ static int virtio_dev_probe(struct device *_d)
struct virtio_device *dev = dev_to_virtio(_d);
struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
u64 device_features;
+ u64 driver_features;
unsigned status;

/* We have a driver! */
@@ -168,15 +169,16 @@ static int virtio_dev_probe(struct device *_d)
/* Figure out what features the device supports. */
device_features = dev->config->get_features(dev);

- /* Features supported by both device and driver into dev->features. */
- dev->features = 0;
+ /* Figure out what features the driver supports. */
+ driver_features = 0;
for (i = 0; i < drv->feature_table_size; i++) {
unsigned int f = drv->feature_table[i];
BUG_ON(f >= 64);
- if (device_features & (1ULL << f))
- dev->features |= (1ULL << f);
+ driver_features |= (1ULL << f);
}

+ dev->features = driver_features & device_features;
+
/* Transport features always preserved to pass to finalize_features. */
for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++)
if (device_features & (1ULL << i))
--
MST


\
 
 \ /
  Last update: 2014-10-23 19:01    [W:0.103 / U:0.244 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site