[RFC PATCH 1/5] efi: Move arm-stub to a common file

[Atish Patra <atish.patra@wdc.com>]

Most of the arm-stub code is written in an architecture independent manner.
As a result, RISC-V can reuse most of the arm-stub code.

Rename the arm-stub.c to efi-stub.c so that ARM, ARM64 and RISC-V can use it.
This patch doesn't introduce any functional changes.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
---
 arch/arm/Kconfig                                     |  2 +-
 arch/arm64/Kconfig                                   |  2 +-
 drivers/firmware/efi/Kconfig                         |  6 +++---
 drivers/firmware/efi/libstub/Makefile                | 12 ++++++------
 .../firmware/efi/libstub/{arm-stub.c => efi-stub.c}  |  7 ++++++-
 5 files changed, 17 insertions(+), 12 deletions(-)
 rename drivers/firmware/efi/libstub/{arm-stub.c => efi-stub.c} (98%)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 97864aabc2a6..9931fea06076 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1955,7 +1955,7 @@ config EFI
 	select UCS2_STRING
 	select EFI_PARAMS_FROM_FDT
 	select EFI_STUB
-	select EFI_ARMSTUB
+	select EFI_GENERIC_ARCH_STUB
 	select EFI_RUNTIME_WRAPPERS
 	---help---
 	  This option provides support for runtime services provided
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 0b30e884e088..ae776d8ef2f9 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1720,7 +1720,7 @@ config EFI
 	select EFI_PARAMS_FROM_FDT
 	select EFI_RUNTIME_WRAPPERS
 	select EFI_STUB
-	select EFI_ARMSTUB
+	select EFI_GENERIC_ARCH_STUB
 	default y
 	help
 	  This option provides support for runtime services provided
diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig
index ecc83e2f032c..1bcedb7812da 100644
--- a/drivers/firmware/efi/Kconfig
+++ b/drivers/firmware/efi/Kconfig
@@ -106,12 +106,12 @@ config EFI_PARAMS_FROM_FDT
 config EFI_RUNTIME_WRAPPERS
 	bool
 
-config EFI_ARMSTUB
+config EFI_GENERIC_ARCH_STUB
 	bool
 
-config EFI_ARMSTUB_DTB_LOADER
+config EFI_STUB_DTB_LOADER
 	bool "Enable the DTB loader"
-	depends on EFI_ARMSTUB
+	depends on EFI_GENERIC_ARCH_STUB
 	default y
 	help
 	  Select this config option to add support for the dtb= command
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 4d6246c6f651..2c5b76787126 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -22,7 +22,7 @@ cflags-$(CONFIG_ARM)		:= $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \
 				   -fno-builtin -fpic \
 				   $(call cc-option,-mno-single-pic-base)
 
-cflags-$(CONFIG_EFI_ARMSTUB)	+= -I$(srctree)/scripts/dtc/libfdt
+cflags-$(CONFIG_EFI_GENERIC_ARCH_STUB)	+= -I$(srctree)/scripts/dtc/libfdt
 
 KBUILD_CFLAGS			:= $(cflags-y) -DDISABLE_BRANCH_PROFILING \
 				   -include $(srctree)/drivers/firmware/efi/libstub/hidden.h \
@@ -44,13 +44,13 @@ lib-y				:= efi-stub-helper.o gop.o secureboot.o tpm.o \
 				   skip_spaces.o lib-cmdline.o lib-ctype.o
 
 # include the stub's generic dependencies from lib/ when building for ARM/arm64
-arm-deps-y := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c
+efi-deps-y := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c
 
 $(obj)/lib-%.o: $(srctree)/lib/%.c FORCE
 	$(call if_changed_rule,cc_o_c)
 
-lib-$(CONFIG_EFI_ARMSTUB)	+= arm-stub.o fdt.o string.o \
-				   $(patsubst %.c,lib-%.o,$(arm-deps-y))
+lib-$(CONFIG_EFI_GENERIC_ARCH_STUB)		+= efi-stub.o fdt.o string.o \
+				   $(patsubst %.c,lib-%.o,$(efi-deps-y))
 
 lib-$(CONFIG_ARM)		+= arm32-stub.o
 lib-$(CONFIG_ARM64)		+= arm64-stub.o
@@ -72,8 +72,8 @@ CFLAGS_arm64-stub.o		:= -DTEXT_OFFSET=$(TEXT_OFFSET)
 # a verification pass to see if any absolute relocations exist in any of the
 # object files.
 #
-extra-$(CONFIG_EFI_ARMSTUB)	:= $(lib-y)
-lib-$(CONFIG_EFI_ARMSTUB)	:= $(patsubst %.o,%.stub.o,$(lib-y))
+extra-$(CONFIG_EFI_GENERIC_ARCH_STUB)	:= $(lib-y)
+lib-$(CONFIG_EFI_GENERIC_ARCH_STUB)	:= $(patsubst %.o,%.stub.o,$(lib-y))
 
 STUBCOPY_FLAGS-$(CONFIG_ARM64)	+= --prefix-alloc-sections=.init \
 				   --prefix-symbols=__efistub_
diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/efi-stub.c
similarity index 98%
rename from drivers/firmware/efi/libstub/arm-stub.c
rename to drivers/firmware/efi/libstub/efi-stub.c
index 13559c7e6643..b87c3f70430c 100644
--- a/drivers/firmware/efi/libstub/arm-stub.c
+++ b/drivers/firmware/efi/libstub/efi-stub.c
@@ -15,6 +15,7 @@
 
 #include "efistub.h"
 
+#if IS_ENABLED(CONFIG_ARM64) || IS_ENABLED(CONFIG_ARM)
 /*
  * This is the base address at which to start allocating virtual memory ranges
  * for UEFI Runtime Services. This is in the low TTBR0 range so that we can use
@@ -27,6 +28,10 @@
  * entire footprint of the UEFI runtime services memory regions)
  */
 #define EFI_RT_VIRTUAL_BASE	SZ_512M
+#else
+#define EFI_RT_VIRTUAL_BASE	SZ_2G
+#endif
+
 #define EFI_RT_VIRTUAL_SIZE	SZ_512M
 
 #ifdef CONFIG_ARM64
@@ -243,7 +248,7 @@ efi_status_t efi_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg)
 	 * 'dtb=' unless UEFI Secure Boot is disabled.  We assume that secure
 	 * boot is enabled if we can't determine its state.
 	 */
-	if (!IS_ENABLED(CONFIG_EFI_ARMSTUB_DTB_LOADER) ||
+	if (!IS_ENABLED(CONFIG_EFI_STUB_DTB_LOADER) ||
 	     secure_boot != efi_secureboot_mode_disabled) {
 		if (strstr(cmdline_ptr, "dtb="))
 			pr_efi("Ignoring DTB from command line.\n");
-- 
2.24.0