x86/cpu: Unify CPU family, model, stepping calculation

Add generic functions which calc family, model and stepping from
the CPUID_1.EAX leaf and stick them into the library we have.

Rename those which do call CPUID with the prefix "x86_cpuid" as
suggested by Paolo Bonzini.

No functionality change.

Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1448273546-2567-2-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

2 files changed, 36 insertions, 1 deletions

diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index f2587888d987..a501fa25da41 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -16,7 +16,7 @@ clean-files := inat-tables.c
 
 obj-$(CONFIG_SMP) += msr-smp.o cache-smp.o
 
-lib-y := delay.o misc.o cmdline.o
+lib-y := delay.o misc.o cmdline.o cpu.o
 lib-y += usercopy_$(BITS).o usercopy.o getuser.o putuser.o
 lib-y += memcpy_$(BITS).o
 lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o
diff --git a/arch/x86/lib/cpu.c b/arch/x86/lib/cpu.c
new file mode 100644
index 000000000000..aa417a97511c
--- /dev/null
+++ b/arch/x86/lib/cpu.c
@@ -0,0 +1,35 @@
+#include <linux/module.h>
+
+unsigned int x86_family(unsigned int sig)
+{
+        unsigned int x86;
+
+        x86 = (sig >> 8) & 0xf;
+
+        if (x86 == 0xf)
+                x86 += (sig >> 20) & 0xff;
+
+        return x86;
+}
+EXPORT_SYMBOL_GPL(x86_family);
+
+unsigned int x86_model(unsigned int sig)
+{
+        unsigned int fam, model;
+
+         fam = x86_family(sig);
+
+        model = (sig >> 4) & 0xf;
+
+        if (fam >= 0x6)
+                model += ((sig >> 16) & 0xf) << 4;
+
+        return model;
+}
+EXPORT_SYMBOL_GPL(x86_model);
+
+unsigned int x86_stepping(unsigned int sig)
+{
+        return sig & 0xf;
+}
+EXPORT_SYMBOL_GPL(x86_stepping);