diff options
| author | Denys Vlasenko <dvlasenk@redhat.com> | 2015-03-31 19:00:10 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-04-01 13:17:39 +0200 |
| commit | a734b4a23e4b5a5bba577d11b6e2ff21f6ca4fce (patch) | |
| tree | 3f37abc5fe869f2f347d9cf93c14e78cdcaafd88 /arch/x86/kernel/relocate_kernel_64.S | |
| parent | 36acef2510853e2831047ca9e22d333ba7a1047b (diff) | |
| download | lwn-a734b4a23e4b5a5bba577d11b6e2ff21f6ca4fce.tar.gz lwn-a734b4a23e4b5a5bba577d11b6e2ff21f6ca4fce.zip | |
x86/asm: Replace "MOVQ $imm, %reg" with MOVL
There is no reason to use MOVQ to load a non-negative immediate
constant value into a 64-bit register. MOVL does the same, since
the upper 32 bits are zero-extended by the CPU.
This makes the code a bit smaller, while leaving functionality
unchanged.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1427821211-25099-8-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/relocate_kernel_64.S')
| -rw-r--r-- | arch/x86/kernel/relocate_kernel_64.S | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S index 04cb1790a596..98111b38ebfd 100644 --- a/arch/x86/kernel/relocate_kernel_64.S +++ b/arch/x86/kernel/relocate_kernel_64.S @@ -123,7 +123,7 @@ identity_mapped: * Set cr4 to a known state: * - physical address extension enabled */ - movq $X86_CR4_PAE, %rax + movl $X86_CR4_PAE, %eax movq %rax, %cr4 jmp 1f @@ -246,17 +246,17 @@ swap_pages: movq %rsi, %rax movq %r10, %rdi - movq $512, %rcx + movl $512, %ecx rep ; movsq movq %rax, %rdi movq %rdx, %rsi - movq $512, %rcx + movl $512, %ecx rep ; movsq movq %rdx, %rdi movq %r10, %rsi - movq $512, %rcx + movl $512, %ecx rep ; movsq lea PAGE_SIZE(%rax), %rsi |