From 638d957b51c88852de72f15f7cd588d125e97dab Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Wed, 16 May 2012 14:02:05 -0700 Subject: [PATCH] x86, realmode: Change EFER to a single u64 field Change EFER to be a single u64 field instead of two u32 fields; change the order to maintain alignment. Note that on x86-64 cr4 is really also a 64-bit quantity, although we can only set the low 32 bits from the trampoline code since it is still executing in 32-bit mode at that point. Signed-off-by: H. Peter Anvin Cc: Jarkko Sakkinen --- arch/x86/include/asm/realmode.h | 3 +-- arch/x86/realmode/init.c | 7 +++---- arch/x86/realmode/rm/trampoline_64.S | 2 +- 3 files changed, 5 insertions(+), 7 deletions(-) diff --git a/arch/x86/include/asm/realmode.h b/arch/x86/include/asm/realmode.h index 937dc6071d76..fce3f4ae5bd6 100644 --- a/arch/x86/include/asm/realmode.h +++ b/arch/x86/include/asm/realmode.h @@ -35,9 +35,8 @@ struct trampoline_header { u32 gdt_base; #else u64 start; + u64 efer; u32 cr4; - u32 efer_low; - u32 efer_high; #endif }; diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c index 099277984b80..cbca565af5bd 100644 --- a/arch/x86/realmode/init.c +++ b/arch/x86/realmode/init.c @@ -22,7 +22,7 @@ void __init setup_real_mode(void) size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob); #ifdef CONFIG_X86_64 u64 *trampoline_pgd; - u32 efer_low, efer_high; + u64 efer; #endif /* Has to be in very low memory so we can execute real-mode AP code. */ @@ -70,9 +70,8 @@ void __init setup_real_mode(void) * Some AMD processors will #GP(0) if EFER.LMA is set in WRMSR * so we need to mask it out. */ - rdmsr(MSR_EFER, efer_low, efer_high); - trampoline_header->efer_low = efer_low & ~EFER_LMA; - trampoline_header->efer_high = efer_high; + rdmsrl(MSR_EFER, efer); + trampoline_header->efer = efer & ~EFER_LMA; trampoline_header->start = (u64) secondary_startup_64; trampoline_cr4_features = &trampoline_header->cr4; diff --git a/arch/x86/realmode/rm/trampoline_64.S b/arch/x86/realmode/rm/trampoline_64.S index 1b9e1bc1ac5e..bb360dc39d21 100644 --- a/arch/x86/realmode/rm/trampoline_64.S +++ b/arch/x86/realmode/rm/trampoline_64.S @@ -146,8 +146,8 @@ GLOBAL(trampoline_pgd) .space PAGE_SIZE .balign 8 GLOBAL(trampoline_header) tr_start: .space 8 - GLOBAL(tr_cr4) .space 4 GLOBAL(tr_efer) .space 8 + GLOBAL(tr_cr4) .space 4 END(trampoline_header) #include "trampoline_common.S" -- 2.39.5