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x86, realmode: read cr4 and EFER from kernel for 64-bit trampoline

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This patch changes 64-bit trampoline so that CR4 and
EFER are provided by the kernel instead of using fixed
values.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-24-git-send-email-jarkko.sakkinen@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This commit is contained in:
Jarkko Sakkinen 2012-05-08 21:22:46 +03:00 • committed by H. Peter Anvin
parent bf8b88e977
commit cda846f101
7 changed files with 49 additions and 28 deletions
Download patch file Download diff file Expand all files Collapse all files

7
arch/x86/include/asm/processor.h
View file

@ -544,13 +544,16 @@ static inline void load_sp0(struct tss_struct *tss,
* enable), so that any CPU's that boot up
* after us can get the correct flags.
*/
extern unsigned long mmu_cr4_features;
extern unsigned long mmu_cr4_features;
extern u32 *trampoline_cr4_features;
static inline void set_in_cr4(unsigned long mask)
{
unsigned long cr4;
mmu_cr4_features |= mask;
if (trampoline_cr4_features)
*trampoline_cr4_features = mmu_cr4_features;
cr4 = read_cr4();
cr4 |= mask;
write_cr4(cr4);
@ -561,6 +564,8 @@ static inline void clear_in_cr4(unsigned long mask)
unsigned long cr4;
mmu_cr4_features &= ~mask;
if (trampoline_cr4_features)
*trampoline_cr4_features = mmu_cr4_features;
cr4 = read_cr4();
cr4 &= ~mask;
write_cr4(cr4);

8
arch/x86/include/asm/realmode.h
View file

@ -24,18 +24,22 @@ struct real_mode_header {
#ifdef CONFIG_X86_32
u32 machine_real_restart_asm;
#endif
} __attribute__((__packed__));
};
/* This must match data at trampoline_32/64.S */
struct trampoline_header {
#ifdef CONFIG_X86_32
u32 start;
u16 gdt_pad;
u16 gdt_limit;
u32 gdt_base;
#else
u64 start;
u32 cr4;
u32 efer_low;
u32 efer_high;
#endif
} __attribute__((__packed__));
};
extern struct real_mode_header *real_mode_header;
extern unsigned char real_mode_blob_end[];