rpmsg: glink: Make RX FIFO peak accessor to take an offset

To fully read the received rx data from FIFO both the command and data
has to be read. Currently we read command, data separately and process
them. By adding an offset parameter to RX FIFO peak accessor, command
and data can be read together, simplifying things.  So introduce this.
Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

drivers/rpmsg/qcom_glink_native.c

@@ -233,9 +233,9 @@ static size_t qcom_glink_rx_avail(struct qcom_glink *glink)
 }
 
 static void qcom_glink_rx_peak(struct qcom_glink *glink,
-			       void *data, size_t count)
+			       void *data, unsigned int offset, size_t count)
 {
-	glink->rx_pipe->peak(glink->rx_pipe, data, count);
+	glink->rx_pipe->peak(glink->rx_pipe, data, offset, count);
 }
 
 static void qcom_glink_rx_advance(struct qcom_glink *glink, size_t count)
@@ -600,7 +600,7 @@ static int qcom_glink_rx_defer(struct qcom_glink *glink, size_t extra)
 
 	INIT_LIST_HEAD(&dcmd->node);
 
-	qcom_glink_rx_peak(glink, &dcmd->msg, sizeof(dcmd->msg) + extra);
+	qcom_glink_rx_peak(glink, &dcmd->msg, 0, sizeof(dcmd->msg) + extra);
 
 	spin_lock(&glink->rx_lock);
 	list_add_tail(&dcmd->node, &glink->rx_queue);
@@ -633,7 +633,7 @@ static int qcom_glink_rx_data(struct qcom_glink *glink, size_t avail)
 		return -EAGAIN;
 	}
 
-	qcom_glink_rx_peak(glink, &hdr, sizeof(hdr));
+	qcom_glink_rx_peak(glink, &hdr, 0, sizeof(hdr));
 	chunk_size = le32_to_cpu(hdr.chunk_size);
 	left_size = le32_to_cpu(hdr.left_size);
 
@@ -700,9 +700,8 @@ static int qcom_glink_rx_data(struct qcom_glink *glink, size_t avail)
 		goto advance_rx;
 	}
 
-	qcom_glink_rx_advance(glink, ALIGN(sizeof(hdr), 8));
 	qcom_glink_rx_peak(glink, intent->data + intent->offset,
-			   chunk_size);
+			   sizeof(hdr), chunk_size);
 	intent->offset += chunk_size;
 
 	/* Handle message when no fragments remain to be received */
@@ -722,7 +721,7 @@ static int qcom_glink_rx_data(struct qcom_glink *glink, size_t avail)
 	}
 
 advance_rx:
-	qcom_glink_rx_advance(glink, ALIGN(chunk_size, 8));
+	qcom_glink_rx_advance(glink, ALIGN(sizeof(hdr) + chunk_size, 8));
 
 	return ret;
 }
@@ -759,7 +758,7 @@ static irqreturn_t qcom_glink_native_intr(int irq, void *data)
 		if (avail < sizeof(msg))
 			break;
 
-		qcom_glink_rx_peak(glink, &msg, sizeof(msg));
+		qcom_glink_rx_peak(glink, &msg, 0, sizeof(msg));
 
 		cmd = le16_to_cpu(msg.cmd);
 		param1 = le16_to_cpu(msg.param1);

drivers/rpmsg/qcom_glink_native.h

@@ -24,7 +24,7 @@ struct qcom_glink_pipe {
 	size_t (*avail)(struct qcom_glink_pipe *glink_pipe);
 
 	void (*peak)(struct qcom_glink_pipe *glink_pipe, void *data,
-		     size_t count);
+		     unsigned int offset, size_t count);
 	void (*advance)(struct qcom_glink_pipe *glink_pipe, size_t count);
 
 	void (*write)(struct qcom_glink_pipe *glink_pipe,

drivers/rpmsg/qcom_glink_rpm.c

@@ -77,13 +77,16 @@ static size_t glink_rpm_rx_avail(struct qcom_glink_pipe *glink_pipe)
 }
 
 static void glink_rpm_rx_peak(struct qcom_glink_pipe *glink_pipe,
-			      void *data, size_t count)
+			      void *data, unsigned int offset, size_t count)
 {
 	struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
 	unsigned int tail;
 	size_t len;
 
 	tail = readl(pipe->tail);
+	tail += offset;
+	if (tail >= pipe->native.length)
+		tail -= pipe->native.length;
 
 	len = min_t(size_t, count, pipe->native.length - tail);
 	if (len) {

drivers/rpmsg/qcom_glink_smem.c

@@ -87,13 +87,16 @@ static size_t glink_smem_rx_avail(struct qcom_glink_pipe *np)
 }
 
 static void glink_smem_rx_peak(struct qcom_glink_pipe *np,
-			       void *data, size_t count)
+			       void *data, unsigned int offset, size_t count)
 {
 	struct glink_smem_pipe *pipe = to_smem_pipe(np);
 	size_t len;
 	u32 tail;
 
 	tail = le32_to_cpu(*pipe->tail);
+	tail += offset;
+	if (tail >= pipe->native.length)
+		tail -= pipe->native.length;
 
 	len = min_t(size_t, count, pipe->native.length - tail);
 	if (len) {