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From:   Peter Hilber <peter.hilber@opensynergy.com>
To:     <linux-arm-kernel@lists.infradead.org>,
        <devicetree@vger.kernel.org>
CC:     Rob Herring <robh+dt@kernel.org>, <linux-kernel@vger.kernel.org>,
        <sudeep.holla@arm.com>, <souvik.chakravarty@arm.com>,
        <alex.bennee@linaro.org>, <jean-philippe@linaro.org>,
        <igor.skalkin@opensynergy.com>, <mikhail.golubev@opensynergy.com>,
        <anton.yakovlev@opensynergy.com>,
        Peter Hilber <peter.hilber@opensynergy.com>
Subject: [RFC PATCH 4/7] firmware: arm_scmi: Add per message transport data
Date:   Fri, 18 Sep 2020 18:54:41 +0200
Message-ID: <20200918165441.256940-1-peter.hilber@opensynergy.com>
In-Reply-To: <20200918162311.254564-1-peter.hilber@opensynergy.com>
References: <20200918162311.254564-1-peter.hilber@opensynergy.com>
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From: Igor Skalkin <igor.skalkin@opensynergy.com>

The virtio transport in this patch series can be simplified by using the
scmi_xfer tx/rx buffers for data exchange with the virtio device, and
for saving the message state. But the virtio transport requires
prepending a transport-specific header. Also, for data exchange using
virtqueues, the tx and rx buffers should not overlap.

The first step to solve the aforementioned issues is to add a
transport-specific data pointer to scmi_xfer.

Co-developed-by: Peter Hilber <peter.hilber@opensynergy.com>
Signed-off-by: Peter Hilber <peter.hilber@opensynergy.com>
Signed-off-by: Igor Skalkin <igor.skalkin@opensynergy.com>
---
 drivers/firmware/arm_scmi/common.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index 0f1540cb2d84..e3ccec954e93 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -131,6 +131,7 @@ struct scmi_msg {
  *	buffer for the rx path as we use for the tx path.
  * @done: command message transmit completion event
  * @async_done: pointer to delayed response message received event completion
+ * @extra_data: Transport-specific private data pointer
  */
 struct scmi_xfer {
 	int transfer_id;
@@ -139,6 +140,7 @@ struct scmi_xfer {
 	struct scmi_msg rx;
 	struct completion done;
 	struct completion *async_done;
+	void *extra_data;
 };
 
 void scmi_xfer_put(const struct scmi_handle *h, struct scmi_xfer *xfer);
-- 
2.25.1