Gitweb: http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=dd7c7b...
Commit: dd7c7bc46211785a1aa7d70feb15830f62682b3c
Parent: faeba830b086bc9e58748869054e994cb09693cd
Author: Rusty Russell <rusty@rustcorp.com.au>
AuthorDate: Fri Jul 25 12:06:07 2008 -0500
Committer: Rusty Russell <rusty@rustcorp.com.au>
CommitDate: Fri Jul 25 12:06:07 2008 +1000
virtio: Formally reserve bits 28-31 to be 'transport' features.
We assign feature bits as required, but it makes sense to reserve some
for the particular transport, rather than the particular device.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
drivers/virtio/virtio.c | 5 +++++
include/linux/virtio_config.h | 6 ++++++
2 files changed, 11 insertions(+), 0 deletions(-)
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index fc85cba..baf1033 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -113,6 +113,11 @@ static int virtio_dev_probe(struct device *_d)
set_bit(f, dev->features);
}
+ /* Transport features are always preserved to pass to set_features. */
+ for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++)
+ if (device_features & (1 << i))
+ set_bit(i, dev->features);
+
err = drv->probe(dev);
if (err)
add_status(dev, VIRTIO_CONFIG_S_FAILED);
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 7eb4b34..5a30cfb 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -18,6 +18,12 @@
/* We've given up on this device. */
#define VIRTIO_CONFIG_S_FAILED 0x80
+/* Some virtio feature bits (currently bits 28 through 31) are reserved for the
+ * transport being used (eg. virtio_ring), the rest are per-device feature
+ * bits. */
+#define VIRTIO_TRANSPORT_F_START 28
+#define VIRTIO_TRANSPORT_F_END 32
+
/* Do we get callbacks when the ring is completely used, even if we've
* suppressed them? */
#define VIRTIO_F_NOTIFY_ON_EMPTY 24
--
To unsubscribe from this list: send the line "unsubscribe git-commits-head" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
