virtio: use u32, not bitmap for features

It seemed like a good idea to use bitmap for features
in struct virtio_device, but it's actually a pain,
and seems to become even more painful when we get more
than 32 feature bits.  Just change it to a u32 for now.

Based on patch by Rusty.

Suggested-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
This commit is contained in:
Michael S. Tsirkin
2014-10-07 16:39:42 +02:00
parent d4024af56f
commit e16e12be34
16 changed files with 42 additions and 74 deletions

View File

@@ -49,9 +49,9 @@ static ssize_t features_show(struct device *_d,
/* We actually represent this as a bitstring, as it could be
* arbitrary length in future. */
for (i = 0; i < ARRAY_SIZE(dev->features)*BITS_PER_LONG; i++)
for (i = 0; i < sizeof(dev->features)*8; i++)
len += sprintf(buf+len, "%c",
test_bit(i, dev->features) ? '1' : '0');
__virtio_test_bit(dev, i) ? '1' : '0');
len += sprintf(buf+len, "\n");
return len;
}
@@ -168,18 +168,18 @@ static int virtio_dev_probe(struct device *_d)
device_features = dev->config->get_features(dev);
/* Features supported by both device and driver into dev->features. */
memset(dev->features, 0, sizeof(dev->features));
dev->features = 0;
for (i = 0; i < drv->feature_table_size; i++) {
unsigned int f = drv->feature_table[i];
BUG_ON(f >= 32);
if (device_features & (1 << f))
set_bit(f, dev->features);
__virtio_set_bit(dev, f);
}
/* Transport features always preserved to pass to finalize_features. */
for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++)
if (device_features & (1 << i))
set_bit(i, dev->features);
__virtio_set_bit(dev, i);
dev->config->finalize_features(dev);