openwrt/target/linux/layerscape/patches-5.4/701-net-0004-soc-fsl-qman-portal-map-CENA-area-in-the-iommu.patch

From 488b62aa444440690708e5ea823bb0d54c296c4f Mon Sep 17 00:00:00 2001
From: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Date: Tue, 3 Apr 2018 18:18:30 +0300
Subject: [PATCH] soc/fsl/qman-portal: map CENA area in the iommu

Add a one-to-one iommu mapping for qman portal CENA register area.
This is required for QMAN stashing to work without faults behind
an iommu.

Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
---
 drivers/soc/fsl/qbman/qman_portal.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

--- a/drivers/soc/fsl/qbman/qman_portal.c
+++ b/drivers/soc/fsl/qbman/qman_portal.c
@@ -29,6 +29,7 @@
  */
 
 #include "qman_priv.h"
+#include <linux/iommu.h>
 
 struct qman_portal *qman_dma_portal;
 EXPORT_SYMBOL(qman_dma_portal);
@@ -231,6 +232,7 @@ static int qman_portal_probe(struct plat
 {
 	struct device *dev = &pdev->dev;
 	struct device_node *node = dev->of_node;
+	struct iommu_domain *domain;
 	struct qm_portal_config *pcfg;
 	struct resource *addr_phys[2];
 	int irq, cpu, err, i;
@@ -294,6 +296,21 @@ static int qman_portal_probe(struct plat
 		goto err_ioremap2;
 	}
 
+	/* Create an 1-to-1 iommu mapping for cena portal area */
+	domain = iommu_get_domain_for_dev(dev);
+	if (domain) {
+		/*
+		 * Note: not mapping this as cacheable triggers the infamous
+		 * QMan CIDE error.
+		 */
+		err = iommu_map(domain,
+				addr_phys[0]->start, addr_phys[0]->start,
+				resource_size(addr_phys[0]),
+				IOMMU_READ | IOMMU_WRITE | IOMMU_CACHE);
+		if (err)
+			dev_warn(dev, "failed to iommu_map() %d\n", err);
+	}
+
 	pcfg->pools = qm_get_pools_sdqcr();
 
 	spin_lock(&qman_lock);