clear-pkgs-linux-iot-lts2018/0637-hyper_dmabuf-virtio-Adapt-to-the-new-state-transitio.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Mateusz Polrola <mateuszx.potrola@intel.com>
Date: Thu, 20 Sep 2018 12:12:52 +0200
Subject: [PATCH] hyper_dmabuf/virtio: Adapt to the new state transition of VHM
 requests

Instead of using two members (namely ''valid'' and ''processed''), the
new state transition uses a single member (i.e. ''processed) following the
transition pattern below.

    FREE -> PENDING -> PROCESSING -> COMPLETE -> FREE -> ...

Additionally atomic operations should be used to access the state.

Signed-off-by: Mateusz Polrola <mateuszx.potrola@intel.com>
---
 .../hyper_dmabuf/virtio/hyper_dmabuf_virtio_be_drv.c        | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/dma-buf/hyper_dmabuf/virtio/hyper_dmabuf_virtio_be_drv.c b/drivers/dma-buf/hyper_dmabuf/virtio/hyper_dmabuf_virtio_be_drv.c
index 51dd8ed8271a..400c6e702005 100644
--- a/drivers/dma-buf/hyper_dmabuf/virtio/hyper_dmabuf_virtio_be_drv.c
+++ b/drivers/dma-buf/hyper_dmabuf/virtio/hyper_dmabuf_virtio_be_drv.c
@@ -179,15 +179,15 @@ static int virtio_be_handle_kick(int client_id, int req_cnt)
 
 	for (i = 0; i < fe_info->max_vcpu; ++i) {
 		req = &fe_info->req_buf[i];
-		if (req->valid &&
-		    req->processed == REQ_STATE_PROCESSING &&
+		if (atomic_read(&req->processed) == REQ_STATE_PROCESSING &&
 		    req->client == fe_info->client_id) {
 			if (req->reqs.pio_request.direction == REQUEST_READ)
 				req->reqs.pio_request.value = 0;
 			else
 				val = req->reqs.pio_request.value;
 
-			req->processed = REQ_STATE_SUCCESS;
+			smp_mb();
+			atomic_set(&req->processed, REQ_STATE_COMPLETE);
 			acrn_ioreq_complete_request(fe_info->client_id, i);
 		}
 	}
-- 
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