[PATCH 1/5] x86/CPU: Add native CPUID variants returning a single datum

From: Borislav Petkov
Date: Mon Jan 09 2017 - 06:43:50 EST


From: Borislav Petkov <bp@xxxxxxx>

... similarly to the cpuid_<reg>() variants.

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
---
arch/x86/include/asm/processor.h | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index eaf100508c36..1be64da0384e 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -219,6 +219,24 @@ static inline void native_cpuid(unsigned int *eax, unsigned int *ebx,
: "memory");
}

+#define native_cpuid_reg(reg) \
+static inline unsigned int native_cpuid_##reg(unsigned int op) \
+{ \
+ unsigned int eax = op, ebx, ecx = 0, edx; \
+ \
+ native_cpuid(&eax, &ebx, &ecx, &edx); \
+ \
+ return reg; \
+}
+
+/*
+ * Native CPUID functions returning a single datum.
+ */
+native_cpuid_reg(eax)
+native_cpuid_reg(ebx)
+native_cpuid_reg(ecx)
+native_cpuid_reg(edx)
+
static inline void load_cr3(pgd_t *pgdir)
{
write_cr3(__pa(pgdir));
--
2.11.0