LoongArch: efistub: Modify the address where efistub jumps to the main kernel

LoongArch inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I736HO

--------------------------------
Signed-off-by: NYouling Tang <tangyouling@loongson.cn>
Change-Id: I0c7f5360cea6837017de0bd5e3ec3220dfc68add

arch/loongarch/kernel/head.S

@@ -30,6 +30,7 @@ _head:
 pe_header:
 	__EFI_PE_HEADER
 
+SYM_DATA(kernel_entry_rel, .quad kernel_entry);
 SYM_DATA(kernel_asize, .long _end - _text);
 SYM_DATA(kernel_fsize, .long _edata - _text);
 SYM_DATA(kernel_offset, .long kernel_offset - _text);

arch/loongarch/kernel/image-vars.h

@@ -16,7 +16,7 @@ __efistub_strncat		= strncat;
 __efistub_strnstr		= strnstr;
 __efistub_strnlen		= strnlen;
 __efistub_strrchr		= strrchr;
-__efistub_kernel_entry		= kernel_entry;
+__efistub_kernel_entry		= kernel_entry_rel;
 __efistub_kernel_asize		= kernel_asize;
 __efistub_kernel_fsize		= kernel_fsize;
 __efistub_kernel_offset		= kernel_offset;

drivers/firmware/efi/libstub/loongarch-stub.c

@@ -49,8 +49,7 @@ void __noreturn efi_enter_kernel(unsigned long entrypoint, unsigned long fdt, un
 	csr_write64(CSR_DMW0_INIT, LOONGARCH_CSR_DMWIN0);
 	csr_write64(CSR_DMW1_INIT, LOONGARCH_CSR_DMWIN1);
 
-	real_kernel_entry = (kernel_entry_t)
-		((unsigned long)&kernel_entry - entrypoint + VMLINUX_LOAD_ADDRESS);
+	real_kernel_entry = (kernel_entry_t) kernel_entry;
 
 	real_kernel_entry(true, fdt, 0);
 }