iommu: Fix compilation without CONFIG_IOMMU_INTEL

When the kernel is comiled with CONFIG_IRQ_REMAP=y but without
CONFIG_IOMMU_INTEL compilation fails since commit def054b0 with an
undefined reference to device_rbtree_find(). This patch makes sure that
intel specific code is only compiled with CONFIG_IOMMU_INTEL=y.
Signed-off-by: Bert Karwatzki <spasswolf@web.de>
Fixes: 80a9b50c ("iommu/vt-d: Improve ITE fault handling if target  device isn't present")
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20240307194419.15801-1-spasswolf@web.deSigned-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/Kconfig

@@ -196,7 +196,7 @@ source "drivers/iommu/iommufd/Kconfig"
 config IRQ_REMAP
 	bool "Support for Interrupt Remapping"
 	depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI
-	select DMAR_TABLE
+	select DMAR_TABLE if INTEL_IOMMU
 	help
 	  Supports Interrupt remapping for IO-APIC and MSI devices.
 	  To use x2apic mode in the CPU's which support x2APIC enhancements or

drivers/iommu/intel/Makefile

@@ -5,5 +5,7 @@ obj-$(CONFIG_DMAR_TABLE) += trace.o cap_audit.o
 obj-$(CONFIG_DMAR_PERF) += perf.o
 obj-$(CONFIG_INTEL_IOMMU_DEBUGFS) += debugfs.o
 obj-$(CONFIG_INTEL_IOMMU_SVM) += svm.o
+ifdef CONFIG_INTEL_IOMMU
 obj-$(CONFIG_IRQ_REMAP) += irq_remapping.o
+endif
 obj-$(CONFIG_INTEL_IOMMU_PERF_EVENTS) += perfmon.o

drivers/iommu/irq_remapping.c

@@ -99,7 +99,8 @@ int __init irq_remapping_prepare(void)
 	if (disable_irq_remap)
 		return -ENOSYS;
 
-	if (intel_irq_remap_ops.prepare() == 0)
+	if (IS_ENABLED(CONFIG_INTEL_IOMMU) &&
+	    intel_irq_remap_ops.prepare() == 0)
 		remap_ops = &intel_irq_remap_ops;
 	else if (IS_ENABLED(CONFIG_AMD_IOMMU) &&
 		 amd_iommu_irq_ops.prepare() == 0)