arm64:ilp32: add ARM64_ILP32 to Kconfig

maillist inclusion
category: feature
bugzilla: 46790
CVE: NA

Reference: https://github.com/norov/linux/commits/ilp32-5.2

--------------------------------

This patch adds the config option for ILP32.
Signed-off-by: NAndrew Pinski <Andrew.Pinski@caviumnetworks.com>
Signed-off-by: NPhilipp Tomsich <philipp.tomsich@theobroma-systems.com>
Signed-off-by: NChristoph Muellner <christoph.muellner@theobroma-systems.com>
Signed-off-by: NYury Norov <ynorov@caviumnetworks.com>
Reviewed-by: NDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: NYury Norov <ynorov@marvell.com>

 Conflicts:
	arch/arm64/Kconfig
Signed-off-by: NXiongfeng Wang <wangxiongfeng2@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>

arch/arm64/Kconfig

@@ -1214,6 +1214,14 @@ config ARM64_TAGGED_ADDR_ABI
 	  to system calls as pointer arguments. For details, see
 	  Documentation/arm64/tagged-address-abi.rst.
 
+config ARM64_ILP32
+	bool "Kernel support for ILP32"
+	depends on !ARM64_PTR_AUTH
+	help
+	  This option enables support for AArch64 ILP32 user space.  ILP32
+	  is an ABI where long and pointers are 32bits but it uses the AARCH64
+	  instruction set.
+
 menuconfig AARCH32_EL0
 	bool "Kernel support for 32-bit EL0"
 	depends on ARM64_4K_PAGES || EXPERT
@@ -1893,7 +1901,7 @@ endmenu
 
 config COMPAT
 	def_bool y
-	depends on AARCH32_EL0
+	depends on AARCH32_EL0 || ARM64_ILP32
 
 config SYSVIPC_COMPAT
 	def_bool y