From: Jean-Philippe Brucker <jean-philippe@linaro.org>
Date: Wed, 15 Jan 2020 13:52:30 +0100
Subject: ACPI/IORT: Parse SSID property of named component node
Patch-mainline: v5.6-rc1
Git-commit: da22565d1d733e87e3e57127caab1bab250dcb70
References: jsc#SLE-16407

Named component nodes in the IORT tables describe the number of
Substream ID bits (aka. PASID) supported by the device. Propagate this
value to the fwspec structure in order to enable PASID for platform
devices.

Acked-by: Hanjun Guo <guohanjun@huawei.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Will Deacon <will@kernel.org>
Acked-by: Lee, Chun-Yi <jlee@suse.com>
---
 drivers/acpi/arm64/iort.c |   18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -11,6 +11,7 @@
 #define pr_fmt(fmt)	"ACPI: IORT: " fmt
 
 #include <linux/acpi_iort.h>
+#include <linux/bitfield.h>
 #include <linux/iommu.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
@@ -976,6 +977,20 @@ static int iort_pci_iommu_init(struct pc
 	return iort_iommu_xlate(info->dev, parent, streamid);
 }
 
+static void iort_named_component_init(struct device *dev,
+				      struct acpi_iort_node *node)
+{
+	struct acpi_iort_named_component *nc;
+	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+
+	if (!fwspec)
+		return;
+
+	nc = (struct acpi_iort_named_component *)node->node_data;
+	fwspec->num_pasid_bits = FIELD_GET(ACPI_IORT_NC_PASID_BITS,
+					   nc->node_flags);
+}
+
 /**
  * iort_iommu_configure - Set-up IOMMU configuration for a device.
  *
@@ -1030,6 +1045,9 @@ const struct iommu_ops *iort_iommu_confi
 			if (parent)
 				err = iort_iommu_xlate(dev, parent, streamid);
 		} while (parent && !err);
+
+		if (!err)
+			iort_named_component_init(dev, node);
 	}
 
 	/*