[PATCH 7/8] ACPI: scan: Add support for LoongArch in acpi_iommu_configure_id()

[Bibo Mao]

acpi_iommu_configure_id() currently supports only IORT (ARM) and VIOT.
Add support for IOVT (LoongArch) as well.

Signed-off-by: Bibo Mao <maobibo@xxxxxxxxxxx>
---
 drivers/acpi/loongarch/iovt.c | 48 +++++++++++++++++++++++++++++++++++
 drivers/acpi/scan.c           |  3 +++
 include/linux/acpi_iovt.h     | 13 ++++++++++
 3 files changed, 64 insertions(+)
 create mode 100644 include/linux/acpi_iovt.h

diff --git a/drivers/acpi/loongarch/iovt.c b/drivers/acpi/loongarch/iovt.c
index 7deedb8219b2..c769cfc74310 100644
--- a/drivers/acpi/loongarch/iovt.c
+++ b/drivers/acpi/loongarch/iovt.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-only
 
 #include <linux/acpi.h>
+#include <linux/acpi_iovt.h>
 #include <linux/pci.h>
 #include "init.h"
 
@@ -224,3 +225,50 @@ void __init acpi_iovt_late_init(void)
 	iovt_init_devices(hdr);
 	acpi_put_table(hdr);
 }
+
+static int iovt_pci_dev_iommu_init(struct pci_dev *pdev, u16 dev_id, void *data)
+{
+	u32 epid;
+	struct iovt_fwnode *np;
+	struct device *aliased_dev = data;
+	u32 domain = pci_domain_nr(pdev->bus);
+	struct iovt_device_entry *entry;
+
+	list_for_each_entry(np, &iovt_fwnode_list, list) {
+		if (domain != np->segment)
+			continue;
+
+		/* We're not translating ourself */
+		if (dev_id == np->devid)
+			return -EINVAL;
+
+		epid = (domain << 16) + dev_id;
+		if (np->flag & ACPI_IOVT_MAGAGE_BY_SEGMENT)
+			return acpi_iommu_fwspec_init(aliased_dev, epid, np->fwnode);
+
+		list_for_each_entry(entry, &np->ep_list, list) {
+			if (dev_id >= entry->start_devid && dev_id <= entry->end_devid)
+				return acpi_iommu_fwspec_init(aliased_dev, epid, np->fwnode);
+		}
+	}
+
+	return -ENODEV;
+}
+
+/*
+ * iovt_iommu_configure_id - Set-up IOMMU configuration for a device.
+ *
+ * @dev: device to configure
+ * @id_in: optional input id const value pointer
+ *
+ * Returns: 0 on success, <0 on failure
+ */
+int iovt_iommu_configure_id(struct device *dev, const u32 *id_in)
+{
+	int err = -ENODEV;
+
+	if (!dev_is_pci(dev))
+		return err;
+
+	return pci_for_each_dma_alias(to_pci_dev(dev), iovt_pci_dev_iommu_init, dev);
+}
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 9a7ac2eb9ce0..508575f25e10 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -13,6 +13,7 @@
 #include <linux/kernel.h>
 #include <linux/acpi.h>
 #include <linux/acpi_iort.h>
+#include <linux/acpi_iovt.h>
 #include <linux/acpi_rimt.h>
 #include <linux/acpi_viot.h>
 #include <linux/iommu.h>
@@ -1629,6 +1630,8 @@ static int acpi_iommu_configure_id(struct device *dev, const u32 *id_in)
 		err = rimt_iommu_configure_id(dev, id_in);
 	if (err && err != -EPROBE_DEFER)
 		err = viot_iommu_configure(dev);
+	if (err && err != -EPROBE_DEFER)
+		err = iovt_iommu_configure_id(dev, id_in);
 
 	mutex_unlock(&iommu_probe_device_lock);
 
diff --git a/include/linux/acpi_iovt.h b/include/linux/acpi_iovt.h
new file mode 100644
index 000000000000..25a846b96260
--- /dev/null
+++ b/include/linux/acpi_iovt.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __ACPI_IOVT_H__
+#define __ACPI_IOVT_H__
+
+#if defined(CONFIG_IOMMU_API) && defined(CONFIG_ACPI_IOVT)
+int iovt_iommu_configure_id(struct device *dev, const u32 *id_in);
+#else
+static inline int iovt_iommu_configure_id(struct device *dev, const u32 *id_in)
+{ return -ENODEV; }
+#endif
+
+#endif
-- 
2.39.3