[PATCH 00/12] arm64: Remove unused big-endian support

Tue Aug 11 08:11:47 PDT 2026

On Tue, Aug 11, 2026, at 16:01, Will Deacon wrote:
> Hi folks,
>
> Big-endian support on arm64 (CONFIG_CPU_BIG_ENDIAN) has depended on
> BROKEN since 1cf89b6bf660 ("arm64: Kconfig: Make CPU_BIG_ENDIAN depend
> on BROKEN") and has already seen some clean-up patches removing some of
> the unused support code (e.g. 5276ea17a23c ("lib/crc: arm64: Assume a
> little-endian kernel")).
>
> Finish the job, and remove the remaining big-endian support code from
> arm64. Note that the SETEND emulation for 32-bit tasks remains and so
> some of the mixed-endian EL0 helpers are retained.

I had not expected the removal to come this soon, but I'm not
complaining about that. I assume you are planning this for 7.4,
leaving 7.3-LTS to still have the code in case someone wants to
still use it, right?

Not sure if you saw

https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/arch/arm/mm/Kconfig?id=fe91e4e9da70765420538d9cbcf6d9a970237a8d

https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/arch/arm/mach-ixp4xx/Kconfig?id=2262f02ac2aa545560a7f182c8e6b5c98e72763c

so for 7.3, we have marked big-endian mode in arm32 as deprecated
as well, and also managed to get ixp4xx working again in little-endian
mode, which was slightly broken for a few years. It may be good to
add a reference to your series for context.

My suggestions there was to possibly remove arm32 big-endian mode at
the same time as on arm64, but that does feel a little rushed if
ixp4xx only has one release of supporting both, and removing be8
but leaving be32 for a little while longer is probably not worth it.

> I've broken this down into fairly coarse chunks, as it seemed a lot
> easier to manage than one giant patch (even with the Kconfig being
> effectively disabled already) and not all of it is just mindless
> deletion. Despite that, I'm anticipating the whole thing going via the
> arm64 tree.

I would have done even larger patches, this does already feel fairly
fine-grained to me ;-). I had a look at the individual patches to make
sure this all makes sense, and I found nothing wrong here.

For a 7.4 (or later) merge:

Acked-by: Arnd Bergmann <arnd at arndb.de>

There are also a few arm64 specific drivers that I think no
longer need a dependency, but none of that is important:

diff --git a/drivers/crypto/hisilicon/Kconfig b/drivers/crypto/hisilicon/Kconfig
index aeff08ccbadd..1ae7b146b241 100644
--- a/drivers/crypto/hisilicon/Kconfig
+++ b/drivers/crypto/hisilicon/Kconfig
@@ -53,7 +53,6 @@ config CRYPTO_DEV_HISI_ZIP
 	tristate "Support for HiSilicon ZIP accelerator"
 	depends on PCI_MSI
 	depends on ARM64 || (COMPILE_TEST && 64BIT)
-	depends on !CPU_BIG_ENDIAN || COMPILE_TEST
 	depends on UACCE || UACCE=n
 	depends on ACPI
 	select CRYPTO_DEV_HISI_QM
diff --git a/drivers/firmware/qcom/Kconfig b/drivers/firmware/qcom/Kconfig
index c7f8413ab996..f0c1061b0005 100644
--- a/drivers/firmware/qcom/Kconfig
+++ b/drivers/firmware/qcom/Kconfig
@@ -18,7 +18,6 @@ config QCOM_PAS_TEE
 	tristate "Qualcomm PAS TEE interface driver"
 	select QCOM_PAS
 	depends on TEE
-	depends on !CPU_BIG_ENDIAN
 	default m if ARCH_QCOM
 	help
 	  Enable the generic Peripheral Authentication Service (PAS) provided
diff --git a/drivers/firmware/tegra/Kconfig b/drivers/firmware/tegra/Kconfig
index 3a9162706439..e9271d706726 100644
--- a/drivers/firmware/tegra/Kconfig
+++ b/drivers/firmware/tegra/Kconfig
@@ -14,7 +14,6 @@ config TEGRA_IVC
 config TEGRA_BPMP
 	bool "Tegra BPMP driver"
 	depends on ARCH_TEGRA && TEGRA_HSP_MBOX
-	depends on !CPU_BIG_ENDIAN
 	select TEGRA_IVC
 	help
 	  BPMP (Boot and Power Management Processor) is designed to off-loading
diff --git a/drivers/soc/tegra/Kconfig b/drivers/soc/tegra/Kconfig
index 8b6fdb9ad1ea..318e7b604342 100644
--- a/drivers/soc/tegra/Kconfig
+++ b/drivers/soc/tegra/Kconfig
@@ -102,7 +102,6 @@ config ARCH_TEGRA_210_SOC
 config ARCH_TEGRA_186_SOC
 	bool "NVIDIA Tegra186 SoC"
 	default ARCH_TEGRA
-	depends on !CPU_BIG_ENDIAN
 	select PINCTRL_TEGRA186
 	select MAILBOX
 	select SOC_TEGRA_PMC
@@ -117,7 +116,6 @@ config ARCH_TEGRA_186_SOC
 config ARCH_TEGRA_194_SOC
 	bool "NVIDIA Tegra194 SoC"
 	default ARCH_TEGRA
-	depends on !CPU_BIG_ENDIAN
 	select MAILBOX
 	select PINCTRL_TEGRA194
 	select SOC_TEGRA_PMC
@@ -127,7 +125,6 @@ config ARCH_TEGRA_194_SOC
 config ARCH_TEGRA_234_SOC
 	bool "NVIDIA Tegra234 SoC"
 	default ARCH_TEGRA
-	depends on !CPU_BIG_ENDIAN
 	select MAILBOX
 	select PINCTRL_TEGRA234
 	select SOC_TEGRA_PMC
@@ -137,7 +134,6 @@ config ARCH_TEGRA_234_SOC
 config ARCH_TEGRA_238_SOC
 	bool "NVIDIA Tegra238 SoC"
 	default ARCH_TEGRA
-	depends on !CPU_BIG_ENDIAN
 	select MAILBOX
 	select SOC_TEGRA_PMC
 	help
@@ -152,7 +148,6 @@ config ARCH_TEGRA_241_SOC
 config ARCH_TEGRA_264_SOC
 	bool "NVIDIA Tegra264 SoC"
 	default ARCH_TEGRA
-	depends on !CPU_BIG_ENDIAN
 	select MAILBOX
 	select SOC_TEGRA_PMC
 	help
diff --git a/drivers/tee/qcomtee/Kconfig b/drivers/tee/qcomtee/Kconfig
index 9f19dee08db4..bd9be3e9a9ac 100644
--- a/drivers/tee/qcomtee/Kconfig
+++ b/drivers/tee/qcomtee/Kconfig
@@ -3,7 +3,6 @@
 config QCOMTEE
 	tristate "Qualcomm TEE Support"
 	depends on ARCH_QCOM || COMPILE_TEST
-	depends on !CPU_BIG_ENDIAN
 	select QCOM_SCM
 	select QCOM_TZMEM_MODE_SHMBRIDGE
 	help

