arm64: Enable EFI secret area Securityfs support

Enable EFI COCO secrets support. Provide the ioremap_encrypted() support required
by the driver.

Cc: Sami Mujawar <sami.mujawar@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Tested-by: Sami Mujawar <sami.mujawar@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>

arch/arm64/include/asm/io.h

@@ -274,6 +274,10 @@ int arm64_ioremap_prot_hook_register(const ioremap_prot_hook_t hook);
 #define ioremap_np(addr, size)	\
 	ioremap_prot((addr), (size), __pgprot(PROT_DEVICE_nGnRnE))
 
+
+#define ioremap_encrypted(addr, size)	\
+	ioremap_prot((addr), (size), PAGE_KERNEL)
+
 /*
  * io{read,write}{16,32,64}be() macros
  */

drivers/virt/coco/efi_secret/Kconfig

@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 config EFI_SECRET
 	tristate "EFI secret area securityfs support"
-	depends on EFI && X86_64
+	depends on EFI && (X86_64 || ARM64)
 	select EFI_COCO_SECRET
 	select SECURITYFS
 	help