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authorStefan Agner <stefan.agner@toradex.com>2017-09-26 16:04:08 +0200
committerStefan Agner <stefan.agner@toradex.com>2017-09-26 18:11:18 +0200
commit1f4d46cea2bc1886a13ae9adfcd9e4243eed6a4c (patch)
tree2001999c70f8e46b192fc552590810aab35710e3 /drivers/net/virtio_net.c
parentd152ae9d4704d8c7b3775e3b1a20e62aa3b1eed8 (diff)
parentb52c9082f2eb3a6f7fbbc86fad3eaa2a1725da66 (diff)
Merge tag 'v4.4.88' into toradex_vf_4.4-next
This is the 4.4.88 stable release
Diffstat (limited to 'drivers/net/virtio_net.c')
-rw-r--r--drivers/net/virtio_net.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 7f7c87762bc6..8dfc75250583 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -47,8 +47,16 @@ module_param(gso, bool, 0444);
*/
DECLARE_EWMA(pkt_len, 1, 64)
+/* With mergeable buffers we align buffer address and use the low bits to
+ * encode its true size. Buffer size is up to 1 page so we need to align to
+ * square root of page size to ensure we reserve enough bits to encode the true
+ * size.
+ */
+#define MERGEABLE_BUFFER_MIN_ALIGN_SHIFT ((PAGE_SHIFT + 1) / 2)
+
/* Minimum alignment for mergeable packet buffers. */
-#define MERGEABLE_BUFFER_ALIGN max(L1_CACHE_BYTES, 256)
+#define MERGEABLE_BUFFER_ALIGN max(L1_CACHE_BYTES, \
+ 1 << MERGEABLE_BUFFER_MIN_ALIGN_SHIFT)
#define VIRTNET_DRIVER_VERSION "1.0.0"