From 902db088395b13ce620f5a201a751556b760c0ef Mon Sep 17 00:00:00 2001
From: Michal Orzel <michal.orzel@amd.com>
Date: Tue, 27 May 2025 10:21:17 +0200
Subject: [PATCH] device-tree: Move Arm's static-evtchn feature to common

There's nothing Arm specific about this feature. Move it to common as
part of a larger activity to commonalize device tree related features.
For now, select it only for ARM until others (e.g. RISC-V) verify it
works for them too.

Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
---
 xen/arch/arm/Kconfig                                      | 8 --------
 xen/arch/arm/Makefile                                     | 1 -
 xen/arch/arm/setup.c                                      | 2 +-
 xen/common/Kconfig                                        | 8 ++++++++
 xen/common/device-tree/Makefile                           | 1 +
 xen/{arch/arm => common/device-tree}/static-evtchn.c      | 3 +--
 xen/{arch/arm/include/asm => include/xen}/static-evtchn.h | 6 +++---
 7 files changed, 14 insertions(+), 15 deletions(-)
 rename xen/{arch/arm => common/device-tree}/static-evtchn.c (99%)
 rename xen/{arch/arm/include/asm => include/xen}/static-evtchn.h (77%)

diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
index a5aad97a68..57919d8b3a 100644
--- a/xen/arch/arm/Kconfig
+++ b/xen/arch/arm/Kconfig
@@ -253,14 +253,6 @@ config STATIC_SHM
 	help
 	  This option enables statically shared memory on a dom0less system.
 
-config STATIC_EVTCHN
-	bool "Static event channel support on a dom0less system"
-	depends on DOM0LESS_BOOT
-	default y
-	help
-	  This option enables establishing static event channel communication
-	  between domains on a dom0less system (domU-domU as well as domU-dom0).
-
 config PARTIAL_EMULATION
 	bool "Enable partial emulation of system/coprocessor registers"
 	default y
diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
index 129a109d6e..eeeac4e653 100644
--- a/xen/arch/arm/Makefile
+++ b/xen/arch/arm/Makefile
@@ -51,7 +51,6 @@ obj-y += setup.o
 obj-y += shutdown.o
 obj-y += smp.o
 obj-y += smpboot.o
-obj-$(CONFIG_STATIC_EVTCHN) += static-evtchn.init.o
 obj-$(CONFIG_STATIC_MEMORY) += static-memory.init.o
 obj-$(CONFIG_STATIC_SHM) += static-shmem.init.o
 obj-y += sysctl.o
diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index 10b46d0684..734e23da44 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -31,6 +31,7 @@
 #include <xen/version.h>
 #include <xen/vmap.h>
 #include <xen/stack-protector.h>
+#include <xen/static-evtchn.h>
 #include <xen/trace.h>
 #include <xen/libfdt/libfdt-xen.h>
 #include <xen/acpi.h>
@@ -39,7 +40,6 @@
 #include <asm/alternative.h>
 #include <asm/dom0less-build.h>
 #include <asm/page.h>
-#include <asm/static-evtchn.h>
 #include <asm/current.h>
 #include <asm/setup.h>
 #include <asm/gic.h>
diff --git a/xen/common/Kconfig b/xen/common/Kconfig
index 3d66d09397..0951d4c2f2 100644
--- a/xen/common/Kconfig
+++ b/xen/common/Kconfig
@@ -162,6 +162,14 @@ config STATIC_MEMORY
 
 	  If unsure, say N.
 
+config STATIC_EVTCHN
+	bool "Static event channel support on a dom0less system"
+	depends on DOM0LESS_BOOT && ARM
+	default y
+	help
+	  This option enables establishing static event channel communication
+	  between domains on a dom0less system (domU-domU as well as domU-dom0).
+
 menu "Speculative hardening"
 
 config INDIRECT_THUNK
diff --git a/xen/common/device-tree/Makefile b/xen/common/device-tree/Makefile
index ff54a8ef2b..57b9e6ca00 100644
--- a/xen/common/device-tree/Makefile
+++ b/xen/common/device-tree/Makefile
@@ -6,3 +6,4 @@ obj-$(CONFIG_DOM0LESS_BOOT) += dom0less-build.init.o
 obj-$(CONFIG_OVERLAY_DTB) += dt-overlay.o
 obj-y += intc.o
 obj-$(CONFIG_DOMAIN_BUILD_HELPERS) += kernel.o
+obj-$(CONFIG_STATIC_EVTCHN) += static-evtchn.init.o
diff --git a/xen/arch/arm/static-evtchn.c b/xen/common/device-tree/static-evtchn.c
similarity index 99%
rename from xen/arch/arm/static-evtchn.c
rename to xen/common/device-tree/static-evtchn.c
index 49db08d5c6..8b82e6b3d8 100644
--- a/xen/arch/arm/static-evtchn.c
+++ b/xen/common/device-tree/static-evtchn.c
@@ -1,8 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
 #include <xen/event.h>
-
-#include <asm/static-evtchn.h>
+#include <xen/static-evtchn.h>
 
 #define STATIC_EVTCHN_NODE_SIZE_CELLS 2
 
diff --git a/xen/arch/arm/include/asm/static-evtchn.h b/xen/include/xen/static-evtchn.h
similarity index 77%
rename from xen/arch/arm/include/asm/static-evtchn.h
rename to xen/include/xen/static-evtchn.h
index f964522f6a..31ae92741a 100644
--- a/xen/arch/arm/include/asm/static-evtchn.h
+++ b/xen/include/xen/static-evtchn.h
@@ -1,7 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
-#ifndef __ASM_STATIC_EVTCHN_H_
-#define __ASM_STATIC_EVTCHN_H_
+#ifndef XEN_STATIC_EVTCHN_H
+#define XEN_STATIC_EVTCHN_H
 
 #ifdef CONFIG_STATIC_EVTCHN
 
@@ -13,7 +13,7 @@ static inline void alloc_static_evtchn(void) {};
 
 #endif /* CONFIG_STATIC_EVTCHN */
 
-#endif /* __ASM_STATIC_EVTCHN_H_ */
+#endif /* XEN_STATIC_EVTCHN_H */
 
 /*
  * Local variables: