irqchip/gic-v3: Rename GICv3 ITS MSI parent

The GICv5 ITS will reuse some GICv3 ITS MSI parent functions therefore
it makes sense to keep the code functionality in a compilation unit
shared by the two drivers.

Rename the GICv3 ITS MSI parent file and update the related
Kconfig/Makefile entries to pave the way for code sharing.

Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250703-gicv5-host-v7-26-12e71f1b3528@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>

6 files changed, 19 insertions, 4 deletions

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 3e4fb08b7a4d..f9eae1a645c9 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -41,10 +41,14 @@ config ARM_GIC_V3
 	select HAVE_ARM_SMCCC_DISCOVERY
 	select IRQ_MSI_IOMMU
 
+config ARM_GIC_ITS_PARENT
+	bool
+
 config ARM_GIC_V3_ITS
 	bool
 	select GENERIC_MSI_IRQ
 	select IRQ_MSI_LIB
+	select ARM_GIC_ITS_PARENT
 	default ARM_GIC_V3
 	select IRQ_MSI_IOMMU
 
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 7a0e6cee09e1..3ce6ea9a371b 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -33,7 +33,8 @@ obj-$(CONFIG_ARCH_REALVIEW)		+= irq-gic-realview.o
 obj-$(CONFIG_IRQ_MSI_LIB)		+= irq-msi-lib.o
 obj-$(CONFIG_ARM_GIC_V2M)		+= irq-gic-v2m.o
 obj-$(CONFIG_ARM_GIC_V3)		+= irq-gic-v3.o irq-gic-v3-mbi.o irq-gic-common.o
-obj-$(CONFIG_ARM_GIC_V3_ITS)		+= irq-gic-v3-its.o irq-gic-v4.o irq-gic-v3-its-msi-parent.o
+obj-$(CONFIG_ARM_GIC_ITS_PARENT)	+= irq-gic-its-msi-parent.o
+obj-$(CONFIG_ARM_GIC_V3_ITS)		+= irq-gic-v3-its.o irq-gic-v4.o
 obj-$(CONFIG_ARM_GIC_V3_ITS_FSL_MC)	+= irq-gic-v3-its-fsl-mc-msi.o
 obj-$(CONFIG_PARTITION_PERCPU)		+= irq-partition-percpu.o
 obj-$(CONFIG_ARM_GIC_V5)		+= irq-gic-v5.o irq-gic-v5-irs.o
diff --git a/drivers/irqchip/irq-gic-common.h b/drivers/irqchip/irq-gic-common.h
index 020ecdf16901..710cab61d919 100644
--- a/drivers/irqchip/irq-gic-common.h
+++ b/drivers/irqchip/irq-gic-common.h
@@ -29,8 +29,6 @@ void gic_enable_quirks(u32 iidr, const struct gic_quirk *quirks,
 void gic_enable_of_quirks(const struct device_node *np,
 			  const struct gic_quirk *quirks, void *data);
 
-extern const struct msi_parent_ops gic_v3_its_msi_parent_ops;
-
 #define RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING    (1 << 0)
 #define RDIST_FLAGS_RD_TABLES_PREALLOCATED     (1 << 1)
 #define RDIST_FLAGS_FORCE_NON_SHAREABLE        (1 << 2)
diff --git a/drivers/irqchip/irq-gic-v3-its-msi-parent.c b/drivers/irqchip/irq-gic-its-msi-parent.c
index a5e110ffdd88..8beecfed2b84 100644
--- a/drivers/irqchip/irq-gic-v3-its-msi-parent.c
+++ b/drivers/irqchip/irq-gic-its-msi-parent.c
@@ -7,7 +7,7 @@
 #include <linux/acpi_iort.h>
 #include <linux/pci.h>
 
-#include "irq-gic-common.h"
+#include "irq-gic-its-msi-parent.h"
 #include <linux/irqchip/irq-msi-lib.h>
 
 #define ITS_MSI_FLAGS_REQUIRED  (MSI_FLAG_USE_DEF_DOM_OPS |	\
diff --git a/drivers/irqchip/irq-gic-its-msi-parent.h b/drivers/irqchip/irq-gic-its-msi-parent.h
new file mode 100644
index 000000000000..75e223e673ce
--- /dev/null
+++ b/drivers/irqchip/irq-gic-its-msi-parent.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2024 ARM Limited, All Rights Reserved.
+ */
+
+#ifndef _IRQ_GIC_ITS_MSI_PARENT_H
+#define _IRQ_GIC_ITS_MSI_PARENT_H
+
+extern const struct msi_parent_ops gic_v3_its_msi_parent_ops;
+
+#endif /* _IRQ_GIC_ITS_MSI_PARENT_H */
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index d54fa0638dc4..467cb78435a9 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -41,6 +41,7 @@
 #include <asm/exception.h>
 
 #include "irq-gic-common.h"
+#include "irq-gic-its-msi-parent.h"
 #include <linux/irqchip/irq-msi-lib.h>
 
 #define ITS_FLAGS_CMDQ_NEEDS_FLUSHING		(1ULL << 0)