diff options
| author | Andi Kleen <ak@suse.de> | 2005-07-29 08:15:48 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-07-29 08:46:02 +0400 |
| commit | 3829ee6b1be03d5aa3005fe7d19f30088b539836 (patch) | |
| tree | be7a9f93c38662905509f1033ef935436d8b02a3 /arch/x86_64/kernel/head.S | |
| parent | 3ba80e7595f3e308e5e7135445b513779fc0ba3b (diff) | |
| download | linux-3829ee6b1be03d5aa3005fe7d19f30088b539836.tar.xz | |
[PATCH] x86_64: Small assembly improvements
Save a byte here and there. Ultimatively useless, but these things always
catch my eyes when reading the code so just fix them for now.
Also I got at least one patch fixing of them already, which gives a good
excuse.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/x86_64/kernel/head.S')
| -rw-r--r-- | arch/x86_64/kernel/head.S | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/arch/x86_64/kernel/head.S b/arch/x86_64/kernel/head.S index 8d765aa77a26..98ff5eb32b9a 100644 --- a/arch/x86_64/kernel/head.S +++ b/arch/x86_64/kernel/head.S @@ -137,14 +137,14 @@ startup_64: wrmsr /* Setup cr0 */ - xorq %rax, %rax - btsq $31, %rax /* Enable paging */ - btsq $0, %rax /* Enable protected mode */ - btsq $1, %rax /* Enable MP */ - btsq $4, %rax /* Enable ET */ - btsq $5, %rax /* Enable NE */ - btsq $16, %rax /* Enable WP */ - btsq $18, %rax /* Enable AM */ +#define CR0_PM 1 /* protected mode */ +#define CR0_MP (1<<1) +#define CR0_ET (1<<4) +#define CR0_NE (1<<5) +#define CR0_WP (1<<16) +#define CR0_AM (1<<18) +#define CR0_PAGING (1<<31) + movl $CR0_PM|CR0_MP|CR0_ET|CR0_NE|CR0_WP|CR0_AM|CR0_PAGING,%eax /* Make changes effective */ movq %rax, %cr0 |