From: Boqun Feng <boqun.feng@gmail.com>
Date: Wed, 16 Sep 2020 11:48:15 +0800
Patch-mainline: v5.10-rc1
References: jsc#sle-12891
Subject: HID: hyperv: Use VMBUS_RING_SIZE() for ringbuffer sizes
Git-commit: d02a26991ecee772f8e510ce46ccac87ce480554

For a Hyper-V vmbus, the size of the ringbuffer has two requirements:

1) it has to take one PAGE_SIZE for the header

2) it has to be PAGE_SIZE aligned so that double-mapping can work

VMBUS_RING_SIZE() could calculate a correct ringbuffer size which
fulfills both requirements, therefore use it to make sure vmbus work
when PAGE_SIZE != HV_HYP_PAGE_SIZE (4K).

Note that since the argument for VMBUS_RING_SIZE() is the size of
payload (data part), so it will be minus 4k (the size of header when
PAGE_SIZE = 4k) than the original value to keep the ringbuffer total
size unchanged when PAGE_SIZE = 4k.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200916034817.30282-10-boqun.feng@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Olaf Hering <ohering@suse.de>
---
 drivers/hid/hid-hyperv.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/hid/hid-hyperv.c b/drivers/hid/hid-hyperv.c
--- a/drivers/hid/hid-hyperv.c
+++ b/drivers/hid/hid-hyperv.c
@@ -104,8 +104,8 @@ struct synthhid_input_report {
 
 #pragma pack(pop)
 
-#define INPUTVSC_SEND_RING_BUFFER_SIZE		(40 * 1024)
-#define INPUTVSC_RECV_RING_BUFFER_SIZE		(40 * 1024)
+#define INPUTVSC_SEND_RING_BUFFER_SIZE	VMBUS_RING_SIZE(36 * 1024)
+#define INPUTVSC_RECV_RING_BUFFER_SIZE	VMBUS_RING_SIZE(36 * 1024)
 
 
 enum pipe_prot_msg_type {