[PATCH v4 06/12] Drivers: hv: vmbus: Add a helper function is_sub_channel()

From: Dexuan Cui
Date: Mon Sep 02 2019 - 20:23:59 EST


The existing method of telling if a channel is sub-channel in
vmbus_process_offer() is cumbersome. This new simple helper function
is preferred in future.

Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
---
include/linux/hyperv.h | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 6256cc3..2d39248 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -245,7 +245,10 @@ struct vmbus_channel_offer {
} pipe;
} u;
/*
- * The sub_channel_index is defined in win8.
+ * The sub_channel_index is defined in Win8: a value of zero means a
+ * primary channel and a value of non-zero means a sub-channel.
+ *
+ * Before Win8, the field is reserved, meaning it's always zero.
*/
u16 sub_channel_index;
u16 reserved3;
@@ -934,6 +937,11 @@ static inline bool is_hvsock_channel(const struct vmbus_channel *c)
VMBUS_CHANNEL_TLNPI_PROVIDER_OFFER);
}

+static inline bool is_sub_channel(const struct vmbus_channel *c)
+{
+ return c->offermsg.offer.sub_channel_index != 0;
+}
+
static inline void set_channel_affinity_state(struct vmbus_channel *c,
enum hv_numa_policy policy)
{
--
1.8.3.1