diff options
author | Ard Biesheuvel <ardb@kernel.org> | 2020-01-03 12:39:42 +0100 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2020-01-10 18:55:02 +0100 |
commit | e5f930fe8dafd2055220c95958926af16ee20713 (patch) | |
tree | 9f6c51bdecd6b109e2a004ef9213343975018a72 /arch/x86/platform/efi/efi_stub_64.S | |
parent | a46d674068b69b3897fc0d659e25f74b7ab52647 (diff) |
efi/x86: Simplify 64-bit EFI firmware call wrapper
The efi_call() wrapper used to invoke EFI runtime services serves
a number of purposes:
- realign the stack to 16 bytes
- preserve FP and CR0 register state
- translate from SysV to MS calling convention.
Preserving CR0.TS is no longer necessary in Linux, and preserving the
FP register state is also redundant in most cases, since efi_call() is
almost always used from within the scope of a pair of kernel_fpu_begin()/
kernel_fpu_end() calls, with the exception of the early call to
SetVirtualAddressMap() and the SGI UV support code.
So let's add a pair of kernel_fpu_begin()/_end() calls there as well,
and remove the unnecessary code from the assembly implementation of
efi_call(), and only keep the pieces that deal with the stack
alignment and the ABI translation.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Matthew Garrett <mjg59@google.com>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20200103113953.9571-10-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/platform/efi/efi_stub_64.S')
-rw-r--r-- | arch/x86/platform/efi/efi_stub_64.S | 39 |
1 files changed, 4 insertions, 35 deletions
diff --git a/arch/x86/platform/efi/efi_stub_64.S b/arch/x86/platform/efi/efi_stub_64.S index b1d2313fe3bf..e7e1020f4ccb 100644 --- a/arch/x86/platform/efi/efi_stub_64.S +++ b/arch/x86/platform/efi/efi_stub_64.S @@ -8,41 +8,12 @@ */ #include <linux/linkage.h> -#include <asm/segment.h> -#include <asm/msr.h> -#include <asm/processor-flags.h> -#include <asm/page_types.h> - -#define SAVE_XMM \ - mov %rsp, %rax; \ - subq $0x70, %rsp; \ - and $~0xf, %rsp; \ - mov %rax, (%rsp); \ - mov %cr0, %rax; \ - clts; \ - mov %rax, 0x8(%rsp); \ - movaps %xmm0, 0x60(%rsp); \ - movaps %xmm1, 0x50(%rsp); \ - movaps %xmm2, 0x40(%rsp); \ - movaps %xmm3, 0x30(%rsp); \ - movaps %xmm4, 0x20(%rsp); \ - movaps %xmm5, 0x10(%rsp) - -#define RESTORE_XMM \ - movaps 0x60(%rsp), %xmm0; \ - movaps 0x50(%rsp), %xmm1; \ - movaps 0x40(%rsp), %xmm2; \ - movaps 0x30(%rsp), %xmm3; \ - movaps 0x20(%rsp), %xmm4; \ - movaps 0x10(%rsp), %xmm5; \ - mov 0x8(%rsp), %rsi; \ - mov %rsi, %cr0; \ - mov (%rsp), %rsp +#include <asm/nospec-branch.h> SYM_FUNC_START(efi_call) pushq %rbp movq %rsp, %rbp - SAVE_XMM + and $~0xf, %rsp mov 16(%rbp), %rax subq $48, %rsp mov %r9, 32(%rsp) @@ -50,9 +21,7 @@ SYM_FUNC_START(efi_call) mov %r8, %r9 mov %rcx, %r8 mov %rsi, %rcx - call *%rdi - addq $48, %rsp - RESTORE_XMM - popq %rbp + CALL_NOSPEC %rdi + leave ret SYM_FUNC_END(efi_call) |