linux-kernel - [PATCH] x86/Kconfig: Implement ARCH_HAS_CC_CAN

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Message-Id: <20251222-cc-can-link-x86-v1-1-b7c11d77a8d1@linutronix.de>
Date: Mon, 22 Dec 2025 09:29:42 +0100
From: Thomas Weißschuh <thomas.weissschuh@...utronix.de>
To: Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>, 
 Borislav Petkov <bp@...en8.de>, Dave Hansen <dave.hansen@...ux.intel.com>, 
 x86@...nel.org, "H. Peter Anvin" <hpa@...or.com>
Cc: linux-kernel@...r.kernel.org, 
 Thomas Weißschuh <thomas.weissschuh@...utronix.de>
Subject: [PATCH] x86/Kconfig: Implement ARCH_HAS_CC_CAN_LINK

The generic CC_CAN_LINK detection does not work for all architectures.

Make the logic easier to understand and allow the simplification of the
generic CC_CAN_LINK by using a tailored implementation.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@...utronix.de>
---
 arch/x86/Kconfig | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 80527299f859..2a43e42e63fd 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -73,6 +73,7 @@ config X86
 	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
 	select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
 	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
+	select ARCH_HAS_CC_CAN_LINK
 	select ARCH_HAS_CPU_ATTACK_VECTORS	if CPU_MITIGATIONS
 	select ARCH_HAS_CACHE_LINE_SIZE
 	select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
@@ -3175,6 +3176,16 @@ config HAVE_ATOMIC_IOMAP
 	def_bool y
 	depends on X86_32

+config ARCH_CC_CAN_LINK
+	bool
+	default $(cc_can_link_user,-m64) if 64BIT
+	default $(cc_can_link_user,-m32)
+
+config ARCH_USERFLAGS
+	string
+	default "-m64" if 64BIT
+	default "-m32"
+
 source "arch/x86/kvm/Kconfig"

 source "arch/x86/Kconfig.cpufeatures"

---
base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
change-id: 20251222-cc-can-link-x86-fa7a15eec4db

Best regards,
-- 
Thomas Weißschuh <thomas.weissschuh@...utronix.de>