efi/libstub/x86: Drop __efi_early() export and efi_config struct

The various pointers we stash in the efi_config struct which we
retrieve using __efi_early() are simply copies of the ones in
the EFI system table, which we have started accessing directly
in the previous patch. So drop all the __efi_early() related
plumbing, as well as all the assembly code dealing with efi_config,
which allows us to move the PE/COFF entry point to C code as well.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Borislav Petkov <bp@alien8.de>
Cc: James Morse <james.morse@arm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20191224151025.32482-18-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 13 insertions, 61 deletions

diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index ad57edeaeeb3..a6f3ee9ca61d 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -208,10 +208,14 @@ SYM_FUNC_START(startup_32)
 	pushl	$__KERNEL_CS
 	leal	startup_64(%ebp), %eax
 #ifdef CONFIG_EFI_MIXED
-	movl	efi32_config(%ebp), %ebx
+	movl	efi32_boot_args(%ebp), %ebx
 	cmp	$0, %ebx
 	jz	1f
 	leal	handover_entry(%ebp), %eax
+	movl	0(%ebx), %edi
+	movl	4(%ebx), %esi
+	movl	8(%ebx), %edx
+	movl	$0x0, %ecx
 1:
 #endif
 	pushl	%eax
@@ -228,22 +232,14 @@ SYM_FUNC_END(startup_32)
 	.org 0x190
 SYM_FUNC_START(efi32_stub_entry)
 	add	$0x4, %esp		/* Discard return address */
-	popl	%ecx
-	popl	%edx
-	popl	%esi
 
-	leal	(BP_scratch+4)(%esi), %esp
 	call	1f
 1:	pop	%ebp
 	subl	$1b, %ebp
 
-	movl	%ecx, efi32_config(%ebp)
-	movl	%edx, efi32_config+8(%ebp)
+	movl	%esp, efi32_boot_args(%ebp)
 	sgdtl	efi32_boot_gdt(%ebp)
 
-	leal	efi32_config(%ebp), %eax
-	movl	%eax, efi_config(%ebp)
-
 	/* Disable paging */
 	movl	%cr0, %eax
 	btrl	$X86_CR0_PG_BIT, %eax
@@ -450,51 +446,19 @@ trampoline_return:
 SYM_CODE_END(startup_64)
 
 #ifdef CONFIG_EFI_STUB
-
-/* The entry point for the PE/COFF executable is efi_pe_entry. */
-SYM_FUNC_START(efi_pe_entry)
-	movq	%rcx, efi64_config(%rip)	/* Handle */
-	movq	%rdx, efi64_config+8(%rip) /* EFI System table pointer */
-
-	leaq	efi64_config(%rip), %rax
-	movq	%rax, efi_config(%rip)
-
-	movq	%rax, %rdi
-	call	make_boot_params
-	cmpq	$0,%rax
-	je	fail
-	mov	%rax, %rsi
-	leaq	startup_32(%rip), %rax
-	movl	%eax, BP_code32_start(%rsi)
-
-handover_entry:
-	movq	efi_config(%rip), %rdi
+	.org 0x390
+SYM_FUNC_START(efi64_stub_entry)
+SYM_FUNC_START_ALIAS(efi_stub_entry)
+	movq	$1, %rcx
+SYM_INNER_LABEL(handover_entry, SYM_L_LOCAL)
 	and	$~0xf, %rsp			/* realign the stack */
 	call	efi_main
 	movq	%rax,%rsi
-	cmpq	$0,%rax
-	jne	2f
-fail:
-	/* EFI init failed, so hang. */
-	hlt
-	jmp	fail
-2:
 	movl	BP_code32_start(%esi), %eax
 	leaq	startup_64(%rax), %rax
 	jmp	*%rax
-SYM_FUNC_END(efi_pe_entry)
-
-	.org 0x390
-SYM_FUNC_START(efi64_stub_entry)
-	movq	%rdi, efi64_config(%rip)	/* Handle */
-	movq	%rsi, efi64_config+8(%rip) /* EFI System table pointer */
-
-	leaq	efi64_config(%rip), %rax
-	movq	%rax, efi_config(%rip)
-
-	movq	%rdx, %rsi
-	jmp	handover_entry
 SYM_FUNC_END(efi64_stub_entry)
+SYM_FUNC_END_ALIAS(efi_stub_entry)
 #endif
 
 	.text
@@ -663,22 +627,10 @@ SYM_DATA_START_LOCAL(gdt)
 	.quad   0x0000000000000000	/* TS continued */
 SYM_DATA_END_LABEL(gdt, SYM_L_LOCAL, gdt_end)
 
-#ifdef CONFIG_EFI_STUB
-SYM_DATA_LOCAL(efi_config, .quad 0)
-
 #ifdef CONFIG_EFI_MIXED
-SYM_DATA_START(efi32_config)
-	.fill	5,8,0
-	.byte	0
-SYM_DATA_END(efi32_config)
+SYM_DATA_LOCAL(efi32_boot_args, .long 0)
 #endif
 
-SYM_DATA_START(efi64_config)
-	.fill	5,8,0
-	.byte	1
-SYM_DATA_END(efi64_config)
-#endif /* CONFIG_EFI_STUB */
-
 /*
  * Stack and heap for uncompression
  */