diff options
| author | Ard Biesheuvel <ardb@kernel.org> | 2020-01-13 20:22:33 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-01-20 10:13:00 +0300 |
| commit | 796eb8d26a57f917bf22d781666aeab491f5c4f1 (patch) | |
| tree | 680ccf6ddb5f9298be52bb13f399fa4415edfbbc /arch/x86/boot/compressed/head_64.S | |
| parent | a786810cc864e31237a755b933e8872ba3e118bc (diff) | |
| download | linux-796eb8d26a57f917bf22d781666aeab491f5c4f1.tar.xz | |
efi/libstub/x86: Use const attribute for efi_is_64bit()
Reshuffle the x86 stub code a bit so that we can tag the efi_is_64bit()
function with the 'const' attribute, which permits the compiler to
optimize away any redundant calls. Since we have two different entry
points for 32 and 64 bit firmware in the startup code, this also
simplifies the C code since we'll enter it with the efi_is64 variable
already set.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200113172245.27925-2-ardb@kernel.org
Diffstat (limited to 'arch/x86/boot/compressed/head_64.S')
| -rw-r--r-- | arch/x86/boot/compressed/head_64.S | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index 44a6bb6964b5..1f1f6c8139b3 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -211,10 +211,9 @@ SYM_FUNC_START(startup_32) movl efi32_boot_args(%ebp), %edi cmp $0, %edi jz 1f - leal handover_entry(%ebp), %eax + leal efi64_stub_entry(%ebp), %eax movl %esi, %edx movl efi32_boot_args+4(%ebp), %esi - movl $0x0, %ecx 1: #endif pushl %eax @@ -242,6 +241,7 @@ SYM_FUNC_START(efi32_stub_entry) movl %ecx, efi32_boot_args(%ebp) movl %edx, efi32_boot_args+4(%ebp) sgdtl efi32_boot_gdt(%ebp) + movb $0, efi_is64(%ebp) /* Disable paging */ movl %cr0, %eax @@ -452,8 +452,6 @@ SYM_CODE_END(startup_64) .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 @@ -632,6 +630,7 @@ SYM_DATA_END_LABEL(gdt, SYM_L_LOCAL, gdt_end) #ifdef CONFIG_EFI_MIXED SYM_DATA_LOCAL(efi32_boot_args, .long 0, 0) +SYM_DATA(efi_is64, .byte 1) #endif /* |