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| author |   Cyrill Gorcunov <gorcunov@gmail.com> | 2009-01-28 23:21:25 +0300 |
|---|---|---|
| committer |   Ingo Molnar <mingo@elte.hu> | 2009-01-29 14:37:01 +0100 |
| commit | 0a1e8869f453ceda121a1ff8d6c4380832377be7 (patch) | |
| tree | e895cb1e5caa7ca2b1542f8de1e056004ea4f512 /arch/x86/kernel/trampoline_64.S | |
| parent | x86: micro-optimize __raw_read_trylock() (diff) | |
| download | linux-dev-0a1e8869f453ceda121a1ff8d6c4380832377be7.tar.xz linux-dev-0a1e8869f453ceda121a1ff8d6c4380832377be7.zip | |
x86: trampoline_64.S - use predefined constants with simplification
Impact: cleanup
We may use macros from processor-flags.h instead
of hardcoding bits. Actually it's not direct mapping
of old instructions with new ones -- BTS does change
CF flag while MOV does not. But i didn't find any
dependency on CF in this code.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/trampoline_64.S')
| -rw-r--r-- | arch/x86/kernel/trampoline_64.S | 19 |
1 files changed, 9 insertions, 10 deletions
diff --git a/arch/x86/kernel/trampoline_64.S b/arch/x86/kernel/trampoline_64.S index 894293c598db..95a012a4664e 100644 --- a/arch/x86/kernel/trampoline_64.S +++ b/arch/x86/kernel/trampoline_64.S @@ -29,6 +29,7 @@ #include <asm/page.h> #include <asm/msr.h> #include <asm/segment.h> +#include <asm/processor-flags.h> .section .rodata, "a", @progbits @@ -37,7 +38,7 @@ ENTRY(trampoline_data) r_base = . cli # We should be safe anyway - wbinvd + wbinvd mov %cs, %ax # Code and data in the same place mov %ax, %ds mov %ax, %es @@ -73,9 +74,8 @@ r_base = . lidtl tidt - r_base # load idt with 0, 0 lgdtl tgdt - r_base # load gdt with whatever is appropriate - xor %ax, %ax - inc %ax # protected mode (PE) bit - lmsw %ax # into protected mode + mov $X86_CR0_PE, %ax # protected mode (PE) bit + lmsw %ax # into protected mode # flush prefetch and jump to startup_32 ljmpl *(startup_32_vector - r_base) @@ -86,9 +86,8 @@ startup_32: movl $__KERNEL_DS, %eax # Initialize the %ds segment register movl %eax, %ds - xorl %eax, %eax - btsl $5, %eax # Enable PAE mode - movl %eax, %cr4 + movl $X86_CR4_PAE, %eax + movl %eax, %cr4 # Enable PAE mode # Setup trampoline 4 level pagetables leal (trampoline_level4_pgt - r_base)(%esi), %eax @@ -99,9 +98,9 @@ startup_32: xorl %edx, %edx wrmsr - xorl %eax, %eax - btsl $31, %eax # Enable paging and in turn activate Long Mode - btsl $0, %eax # Enable protected mode + # Enable paging and in turn activate Long Mode + # Enable protected mode + movl $(X86_CR0_PG | X86_CR0_PE), %eax movl %eax, %cr0 /* |