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 <hpa@linux.intel.com>
Cc: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c
index 0992779..cbca565 100644
--- a/arch/x86/realmode/init.c
+++ b/arch/x86/realmode/init.c
@@ -22,7 +22,7 @@
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 @@
* 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;