[PATCH] irqchip/gicv3-its: use IORT only if IOMMU support is enabled

[Arnd Bergmann]

When the IOMMU subsystem is disabled, we cannot build ARM64 kernels with ACPI:

drivers/acpi/arm64/iort.c: In function 'iort_iommu_xlate':
drivers/acpi/arm64/iort.c:647:22: error: 'struct iommu_fwspec' has no member named 'ops'

This adds a Kconfig dependency to only enable ACPI_IORT when it acutally
builds, along with addititonal dummy helper functions to make its
users build without IOMMU/IORT.

Fixes: 3f010cf19732 ("irqchip/gicv3-its: Probe ITS in the ACPI way")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
 drivers/irqchip/Kconfig   | 2 +-
 include/linux/acpi_iort.h | 5 ++++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 478f8ace2664..f0516740c03f 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -39,7 +39,7 @@ config ARM_GIC_V3_ITS
 	bool
 	depends on PCI
 	depends on PCI_MSI
-	select ACPI_IORT if ACPI
+	select ACPI_IORT if ACPI && IOMMU
 
 config ARM_NVIC
 	bool
diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h
index 3ff9acea8616..918906d189d3 100644
--- a/include/linux/acpi_iort.h
+++ b/include/linux/acpi_iort.h
@@ -26,10 +26,10 @@
 #define IORT_IRQ_MASK(irq)		(irq & 0xffffffffULL)
 #define IORT_IRQ_TRIGGER_MASK(irq)	((irq >> 32) & 0xffffffffULL)
 
+#ifdef CONFIG_ACPI_IORT
 int iort_register_domain_token(int trans_id, struct fwnode_handle *fw_node);
 void iort_deregister_domain_token(int trans_id);
 struct fwnode_handle *iort_find_domain_token(int trans_id);
-#ifdef CONFIG_ACPI_IORT
 void acpi_iort_init(void);
 bool iort_node_match(u8 type);
 u32 iort_msi_map_rid(struct device *dev, u32 req_id);
@@ -40,6 +40,9 @@ int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id);
 void iort_set_dma_mask(struct device *dev);
 const struct iommu_ops *iort_iommu_configure(struct device *dev);
 #else
+static inline int iort_register_domain_token(int trans_id, struct fwnode_handle *fw_node) { return -ENOSYS; }
+static inline void iort_deregister_domain_token(int trans_id) {}
+static inline struct fwnode_handle *iort_find_domain_token(int trans_id) { return NULL;}
 static inline void acpi_iort_init(void) { }
 static inline bool iort_node_match(u8 type) { return false; }
 static inline u32 iort_msi_map_rid(struct device *dev, u32 req_id)
-- 
2.9.0