[PATCH v2 10/19] ARM: mark IWMMXT as deprecated

Arnd Bergmann <[email protected]> Wed, 1 Jul 2026 23:23:44 +0200
Newsgroups dev.linux.lists.soc,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
From: Arnd Bergmann <[email protected]>

With no remaining users and support getting removed from future compilers,
there seems little point in keeping iwmmxt around much longer.

On the other hand, the iwmmxt support in the kernel rarely gets in the
way, so there is little cost, so set a removal date of early 2027 for
the moment. If anyone is still using this, it can be extended as long
there is binutils support.

Signed-off-by: Arnd Bergmann <[email protected]>
---
 arch/arm/Kconfig | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 1f02183cff13..e2bdf2591c10 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -513,13 +513,21 @@ config PLAT_VERSATILE
 source "arch/arm/mm/Kconfig"
 
 config IWMMXT
-	bool "Enable iWMMXt support"
-	depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK
-	default y if PXA27x || PXA3xx || ARCH_MMP
+	bool "Enable iWMMXt support (DEPRECATED)"
+	depends on PXA27x || PXA3xx || ARCH_MMP
 	help
 	  Enable support for iWMMXt context switching at run time if
 	  running on a CPU that supports it.
 
+	  Machines that actually support this feature are very rare,
+	  and support is deprecated in new gcc-14.  While there were a
+	  few applications that used this in the past, none are known
+	  to still do so.
+
+	  If you use this, please send a patch to remove the
+	  deprecation, otherwise this will be removed in early
+	  2027.
+
 if !MMU
 source "arch/arm/Kconfig-nommu"
 endif
-- 
2.39.5