[PATCH 06/16] arm64/efi: Use CONFIG_EFI_STUB_IMAGE_INFO for code_size

[Jason Gunthorpe <jgg@nvidia.com>]

Pass code_size to zboot through struct efi_image_info instead of the
custom objcopy trick and remove the objcopy way.

The linker still computes code_size, it just gets placed into the struct.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
 arch/arm64/Kconfig                          |  1 +
 arch/arm64/boot/Makefile                    |  3 ---
 arch/arm64/include/asm/image.h              | 11 +++++++++++
 arch/arm64/kernel/image-vars.h              |  8 +++-----
 arch/arm64/kernel/vmlinux.lds.S             |  4 ++++
 drivers/firmware/efi/libstub/Makefile.zboot |  2 +-
 drivers/firmware/efi/libstub/arm64-stub.c   |  5 ++++-
 drivers/firmware/efi/libstub/arm64.c        |  4 ++--
 drivers/firmware/efi/libstub/zboot.lds      |  3 ---
 9 files changed, 26 insertions(+), 15 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index b5a51b0ef9440a..4a752835ce1116 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -2532,6 +2532,7 @@ config EFI
 	select EFI_PARAMS_FROM_FDT
 	select EFI_RUNTIME_WRAPPERS
 	select EFI_STUB
+	select EFI_STUB_IMAGE_INFO
 	select EFI_GENERIC_STUB
 	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
 	default y
diff --git a/arch/arm64/boot/Makefile b/arch/arm64/boot/Makefile
index b5a08333bc57b5..cfbad0c210fa04 100644
--- a/arch/arm64/boot/Makefile
+++ b/arch/arm64/boot/Makefile
@@ -51,7 +51,4 @@ EFI_ZBOOT_BFD_TARGET	:= elf64-littleaarch64
 EFI_ZBOOT_MACH_TYPE	:= ARM64
 EFI_ZBOOT_FORWARD_CFI	:= $(CONFIG_ARM64_BTI_KERNEL)
 
-EFI_ZBOOT_OBJCOPY_FLAGS	= --add-symbol zboot_code_size=0x$$( \
-				$(NM) vmlinux|grep _kernel_codesize|cut -d' ' -f1)
-
 include $(srctree)/drivers/firmware/efi/libstub/Makefile.zboot
diff --git a/arch/arm64/include/asm/image.h b/arch/arm64/include/asm/image.h
index 9ba85173f85765..4a220c71f76c6a 100644
--- a/arch/arm64/include/asm/image.h
+++ b/arch/arm64/include/asm/image.h
@@ -5,6 +5,8 @@
 
 #define ARM64_IMAGE_MAGIC	"ARM\x64"
 
+#define EFI_IMAGE_INFO_SIZE	8
+
 #define ARM64_IMAGE_FLAG_BE_SHIFT		0
 #define ARM64_IMAGE_FLAG_PAGE_SIZE_SHIFT	(ARM64_IMAGE_FLAG_BE_SHIFT + 1)
 #define ARM64_IMAGE_FLAG_PHYS_BASE_SHIFT \
@@ -54,6 +56,15 @@ struct arm64_image_header {
 	__le32 res5;
 };
 
+/*
+ * This struct is filled in by the linker, see EFI_IMAGE_INFO.
+ * Any change requires updating arch/arm64/kernel/vmlinux.lds.S
+ */
+struct efi_image_info {
+	__le64 code_size;
+};
+static_assert(sizeof(struct efi_image_info) == EFI_IMAGE_INFO_SIZE);
+
 #endif /* __ASSEMBLER__ */
 
 #endif /* __ASM_IMAGE_H */
diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h
index 14beb7b9d304c1..13c0b77627d82e 100644
--- a/arch/arm64/kernel/image-vars.h
+++ b/arch/arm64/kernel/image-vars.h
@@ -35,8 +35,10 @@ PROVIDE(__efistub_caches_clean_inval_pou = __pi_caches_clean_inval_pou);
 
 PROVIDE(__efistub__text			= _text);
 PROVIDE(__efistub__end			= _end);
-PROVIDE(__efistub___inittext_end       	= __inittext_end);
 PROVIDE(__efistub__edata		= _edata);
+#ifdef CONFIG_EFI_STUB_IMAGE_INFO
+PROVIDE(__efistub_efi_image_info_offset = __efi_image_info_offset);
+#endif
 #if defined(CONFIG_EFI_EARLYCON) || defined(CONFIG_SYSFB)
 PROVIDE(__efistub_sysfb_primary_display	= sysfb_primary_display);
 #endif
@@ -150,10 +152,6 @@ KVM_NVHE_ALIAS(kvm_protected_mode_initialized);
 
 #endif /* CONFIG_KVM */
 
-#ifdef CONFIG_EFI_ZBOOT
-_kernel_codesize = ABSOLUTE(__inittext_end - _text);
-#endif
-
 /*
  * LLD will occasionally error out with a '__init_end does not converge' error
  * if INIT_IDMAP_DIR_SIZE is defined in terms of _end, as this results in a
diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index af1d720209764f..8305b47995954b 100644
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -282,6 +282,10 @@ SECTIONS
 		CON_INITCALL
 		INIT_RAM_FS
 		*(.init.altinstructions .init.bss)	/* from the EFI stub */
+		EFI_IMAGE_INFO(
+			/* code_size */
+			EFI_IMAGE_INFO_OFFSET(__inittext_end);
+		)
 	}
 	.exit.data : {
 		EXIT_DATA
diff --git a/drivers/firmware/efi/libstub/Makefile.zboot b/drivers/firmware/efi/libstub/Makefile.zboot
index 6eebac66b73b18..de89d3d84465b5 100644
--- a/drivers/firmware/efi/libstub/Makefile.zboot
+++ b/drivers/firmware/efi/libstub/Makefile.zboot
@@ -35,7 +35,7 @@ efi-zboot-objcopy-flags-$(CONFIG_EFI_STUB_IMAGE_INFO) = \
 		awk '$$3 == "_efi_image_info_offset" { print $$1 }')
 
 # avoid eager evaluation to prevent references to non-existent build artifacts
-OBJCOPYFLAGS_vmlinuz.o = -I binary -O $(EFI_ZBOOT_BFD_TARGET) $(EFI_ZBOOT_OBJCOPY_FLAGS) \
+OBJCOPYFLAGS_vmlinuz.o = -I binary -O $(EFI_ZBOOT_BFD_TARGET) \
 			  $(efi-zboot-objcopy-flags-y) \
 			  --rename-section .data=.gzdata,load,alloc,readonly,contents
 $(obj)/vmlinuz.o: $(obj)/vmlinuz FORCE
diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c
index 2c38693561475c..1d3fc8ac13efa7 100644
--- a/drivers/firmware/efi/libstub/arm64-stub.c
+++ b/drivers/firmware/efi/libstub/arm64-stub.c
@@ -9,6 +9,7 @@
 
 #include <linux/efi.h>
 #include <asm/efi.h>
+#include <asm/image.h>
 #include <asm/memory.h>
 #include <asm/sections.h>
 
@@ -21,6 +22,7 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
 				 efi_loaded_image_t *image,
 				 efi_handle_t image_handle)
 {
+	const struct efi_image_info *info;
 	unsigned long kernel_size, kernel_codesize, kernel_memsize;
 
 	if (image->image_base != _text) {
@@ -33,7 +35,8 @@ efi_status_t handle_kernel_image(unsigned long *image_addr,
 			SEGMENT_ALIGN >> 10);
 
 	kernel_size = _edata - _text;
-	kernel_codesize = __inittext_end - _text;
+	info = efi_get_image_info((unsigned long)_text);
+	kernel_codesize = le64_to_cpu(info->code_size);
 	kernel_memsize = kernel_size + (_end - _edata);
 	*reserve_size = kernel_memsize;
 	*image_addr = (unsigned long)_text;
diff --git a/drivers/firmware/efi/libstub/arm64.c b/drivers/firmware/efi/libstub/arm64.c
index e57cd3de0a00f4..67d66fdea77122 100644
--- a/drivers/firmware/efi/libstub/arm64.c
+++ b/drivers/firmware/efi/libstub/arm64.c
@@ -88,11 +88,11 @@ efi_status_t check_platform_features(void)
 #define DCTYPE	"cvau"
 #endif
 
-u32 __weak code_size;
-
 void efi_cache_sync_image(unsigned long image_base,
 			  unsigned long alloc_size)
 {
+	const struct efi_image_info *info = efi_get_image_info(image_base);
+	unsigned long code_size = le64_to_cpu(info->code_size);
 	u32 ctr = read_cpuid_effective_cachetype();
 	u64 lsize = 4 << cpuid_feature_extract_unsigned_field(ctr,
 						CTR_EL0_DminLine_SHIFT);
diff --git a/drivers/firmware/efi/libstub/zboot.lds b/drivers/firmware/efi/libstub/zboot.lds
index cc55aa8fb0630f..c7c2f4dd144301 100644
--- a/drivers/firmware/efi/libstub/zboot.lds
+++ b/drivers/firmware/efi/libstub/zboot.lds
@@ -2,7 +2,6 @@
 
 ENTRY(__efistub_efi_zboot_header);
 
-PROVIDE(zboot_code_size = ABSOLUTE(0));
 PROVIDE(efi_zboot_image_info_offset = ABSOLUTE(0));
 
 SECTIONS
@@ -23,8 +22,6 @@ SECTIONS
 		*(.rodata* .init.rodata* .srodata*)
 
 		. = ALIGN(4);
-		__efistub_code_size = .;
-		LONG(zboot_code_size);
 		__efistub_efi_image_info_offset = .;
 		LONG(efi_zboot_image_info_offset);
 
-- 
2.43.0