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authorStephen Hemminger <sthemmin@microsoft.com>2016-09-09 12:45:24 -0700
committerDavid S. Miller <davem@davemloft.net>2016-09-10 21:23:00 -0700
commit3a8963acc70e69606729404713cfa9a03b58b18c (patch)
tree7b919be02daae7e80363a5997dc1ddd32685cb46 /include/linux/hyperv.h
parent55fdbb01b19fbc16e633ae4f5bc3d61f18dce897 (diff)
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Revert "hv_netvsc: make inline functions static"
These functions are used by other code misc-next tree. This reverts commit 30d1de08c87ddde6f73936c3350e7e153988fe02. Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/hyperv.h')
-rw-r--r--include/linux/hyperv.h84
1 files changed, 84 insertions, 0 deletions
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index b01c8c3dd531..5df444b1ac18 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -1429,4 +1429,88 @@ static inline bool hv_need_to_signal_on_read(struct hv_ring_buffer_info *rbi)
return false;
}
+/*
+ * An API to support in-place processing of incoming VMBUS packets.
+ */
+#define VMBUS_PKT_TRAILER 8
+
+static inline struct vmpacket_descriptor *
+get_next_pkt_raw(struct vmbus_channel *channel)
+{
+ struct hv_ring_buffer_info *ring_info = &channel->inbound;
+ u32 read_loc = ring_info->priv_read_index;
+ void *ring_buffer = hv_get_ring_buffer(ring_info);
+ struct vmpacket_descriptor *cur_desc;
+ u32 packetlen;
+ u32 dsize = ring_info->ring_datasize;
+ u32 delta = read_loc - ring_info->ring_buffer->read_index;
+ u32 bytes_avail_toread = (hv_get_bytes_to_read(ring_info) - delta);
+
+ if (bytes_avail_toread < sizeof(struct vmpacket_descriptor))
+ return NULL;
+
+ if ((read_loc + sizeof(*cur_desc)) > dsize)
+ return NULL;
+
+ cur_desc = ring_buffer + read_loc;
+ packetlen = cur_desc->len8 << 3;
+
+ /*
+ * If the packet under consideration is wrapping around,
+ * return failure.
+ */
+ if ((read_loc + packetlen + VMBUS_PKT_TRAILER) > (dsize - 1))
+ return NULL;
+
+ return cur_desc;
+}
+
+/*
+ * A helper function to step through packets "in-place"
+ * This API is to be called after each successful call
+ * get_next_pkt_raw().
+ */
+static inline void put_pkt_raw(struct vmbus_channel *channel,
+ struct vmpacket_descriptor *desc)
+{
+ struct hv_ring_buffer_info *ring_info = &channel->inbound;
+ u32 read_loc = ring_info->priv_read_index;
+ u32 packetlen = desc->len8 << 3;
+ u32 dsize = ring_info->ring_datasize;
+
+ if ((read_loc + packetlen + VMBUS_PKT_TRAILER) > dsize)
+ BUG();
+ /*
+ * Include the packet trailer.
+ */
+ ring_info->priv_read_index += packetlen + VMBUS_PKT_TRAILER;
+}
+
+/*
+ * This call commits the read index and potentially signals the host.
+ * Here is the pattern for using the "in-place" consumption APIs:
+ *
+ * while (get_next_pkt_raw() {
+ * process the packet "in-place";
+ * put_pkt_raw();
+ * }
+ * if (packets processed in place)
+ * commit_rd_index();
+ */
+static inline void commit_rd_index(struct vmbus_channel *channel)
+{
+ struct hv_ring_buffer_info *ring_info = &channel->inbound;
+ /*
+ * Make sure all reads are done before we update the read index since
+ * the writer may start writing to the read area once the read index
+ * is updated.
+ */
+ virt_rmb();
+ ring_info->ring_buffer->read_index = ring_info->priv_read_index;
+
+ if (hv_need_to_signal_on_read(ring_info))
+ vmbus_set_event(channel);
+}
+
+
#endif /* _HYPERV_H */