From cda846f101fb1396b6924f1d9b68ac3d42de5403 Mon Sep 17 00:00:00 2001 From: Jarkko Sakkinen Date: Tue, 8 May 2012 21:22:46 +0300 Subject: x86, realmode: read cr4 and EFER from kernel for 64-bit trampoline 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 Link: http://lkml.kernel.org/r/1336501366-28617-24-git-send-email-jarkko.sakkinen@intel.com Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/processor.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'arch/x86/include/asm/processor.h') diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 4fa7dcceb6c0..404583ccf0cf 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -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); -- cgit v1.2.3