Re: [tip:x86/urgent] x86/CPU: Add native CPUID variants returning a single datum

[hpa@zytor.com]

On January 9, 2017 2:16:07 PM PST, tip-bot for Borislav Petkov <tipbot@zytor.com> wrote:
>Commit-ID:  5dedade6dfa243c130b85d1e4daba6f027805033
>Gitweb:    
>http://git.kernel.org/tip/5dedade6dfa243c130b85d1e4daba6f027805033
>Author:     Borislav Petkov <bp@suse.de>
>AuthorDate: Mon, 9 Jan 2017 12:41:43 +0100
>Committer:  Thomas Gleixner <tglx@linutronix.de>
>CommitDate: Mon, 9 Jan 2017 23:11:13 +0100
>
>x86/CPU: Add native CPUID variants returning a single datum
>
>... similarly to the cpuid_<reg>() variants.
>
>Signed-off-by: Borislav Petkov <bp@suse.de>
>Link: http://lkml.kernel.org/r/20170109114147.5082-2-bp@alien8.de
>Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
>
>---
> 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 eaf1005..1be64da 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));

Any reason to not make these interfaces (leaf, subleaf) from the start?
-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.