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authorDenys Vlasenko <dvlasenk@redhat.com>2015-03-31 19:00:10 +0200
committerIngo Molnar <mingo@kernel.org>2015-04-01 13:17:39 +0200
commita734b4a23e4b5a5bba577d11b6e2ff21f6ca4fce (patch)
tree3f37abc5fe869f2f347d9cf93c14e78cdcaafd88 /arch/x86/kernel/relocate_kernel_64.S
parent36acef2510853e2831047ca9e22d333ba7a1047b (diff)
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.S8
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