diff mbox

[RFC,1/3] x86/cpu: Unify CPU family, model, stepping calculation

Message ID 1447497436-26424-2-git-send-email-bp@alien8.de (mailing list archive)
State New, archived
Headers show

Commit Message

Borislav Petkov Nov. 14, 2015, 10:37 a.m. UTC 
From: Borislav Petkov <bp@suse.de>

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

No functionality change.

Signed-off-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/include/asm/cpu.h            |  3 +++
 arch/x86/include/asm/microcode.h      | 31 +++----------------------------
 arch/x86/kernel/cpu/common.c          | 11 +++--------
 arch/x86/kernel/cpu/microcode/core.c  |  6 +++---
 arch/x86/kernel/cpu/microcode/intel.c | 16 ++++++----------
 arch/x86/lib/Makefile                 |  2 +-
 arch/x86/lib/cpu.c                    | 35 +++++++++++++++++++++++++++++++++++
 7 files changed, 54 insertions(+), 50 deletions(-)
 create mode 100644 arch/x86/lib/cpu.c

Comments

Paolo Bonzini Nov. 18, 2015, 11:10 a.m. UTC | #1 
On 14/11/2015 11:37, Borislav Petkov wrote:
>  	vendor = x86_vendor();
> -	family = x86_family();
> +	family = x86_family_cpuid();

What about renaming x86_vendor() so that this looks like

-	vendor = x86_vendor();
-	family = x86_family();
+	vendor = x86_cpuid_vendor();
+	family = x86_cpuid_family();

Otherwise looks good.

Paolo
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Borislav Petkov Nov. 18, 2015, 11:28 a.m. UTC | #2 
On Wed, Nov 18, 2015 at 12:10:08PM +0100, Paolo Bonzini wrote:
> On 14/11/2015 11:37, Borislav Petkov wrote:
> >  	vendor = x86_vendor();
> > -	family = x86_family();
> > +	family = x86_family_cpuid();
> 
> What about renaming x86_vendor() so that this looks like
> 
> -	vendor = x86_vendor();
> -	family = x86_family();
> +	vendor = x86_cpuid_vendor();
> +	family = x86_cpuid_family();

The idea is that x86_family_cpuid() gives the family *after* having
executed CPUID while x86_family() only computes the family from a
supplied CPUID_1_EAX. I.e., the last saves us the CPUID call.

Hmm, maybe I should make that more clear ...
Paolo Bonzini Nov. 18, 2015, 11:35 a.m. UTC | #3 
On 18/11/2015 12:28, Borislav Petkov wrote:
>> On 14/11/2015 11:37, Borislav Petkov wrote:
>>> > >  	vendor = x86_vendor();
>>> > > -	family = x86_family();
>>> > > +	family = x86_family_cpuid();
>> > 
>> > What about renaming x86_vendor() so that this looks like
>> > 
>> > -	vendor = x86_vendor();
>> > -	family = x86_family();
>> > +	vendor = x86_cpuid_vendor();
>> > +	family = x86_cpuid_family();
> 
> The idea is that x86_family_cpuid() gives the family *after* having
> executed CPUID while x86_family() only computes the family from a
> supplied CPUID_1_EAX. I.e., the last saves us the CPUID call.

Yes, exactly.  I'm suggesting that the same applies to x86_vendor().  I
also prefer x86_cpuid_* to x86_*_cpuid because, once you add two
functions in the same family it's nice that they share a prefix.

Paolo

> Hmm, maybe I should make that more clear ...
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diff mbox

Patch

diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h
index bf2caa1dedc5..678637ad7476 100644
--- a/arch/x86/include/asm/cpu.h
+++ b/arch/x86/include/asm/cpu.h
@@ -36,4 +36,7 @@  extern int _debug_hotplug_cpu(int cpu, int action);
 
 int mwait_usable(const struct cpuinfo_x86 *);
 
+unsigned int x86_family(unsigned int sig);
+unsigned int x86_model(unsigned int sig);
+unsigned int x86_stepping(unsigned int sig);
 #endif /* _ASM_X86_CPU_H */
diff --git a/arch/x86/include/asm/microcode.h b/arch/x86/include/asm/microcode.h
index 34e62b1dcfce..0419cc4ab4fd 100644
--- a/arch/x86/include/asm/microcode.h
+++ b/arch/x86/include/asm/microcode.h
@@ -1,6 +1,7 @@ 
 #ifndef _ASM_X86_MICROCODE_H
 #define _ASM_X86_MICROCODE_H
 
+#include <asm/cpu.h>
 #include <linux/earlycpio.h>
 
 #define native_rdmsr(msr, val1, val2)			\
@@ -118,40 +119,14 @@  static inline int x86_vendor(void)
 	return X86_VENDOR_UNKNOWN;
 }
 
-static inline unsigned int __x86_family(unsigned int sig)
-{
-	unsigned int x86;
-
-	x86 = (sig >> 8) & 0xf;
-
-	if (x86 == 0xf)
-		x86 += (sig >> 20) & 0xff;
-
-	return x86;
-}
-
-static inline unsigned int x86_family(void)
+static inline unsigned int x86_family_cpuid(void)
 {
 	u32 eax = 0x00000001;
 	u32 ebx, ecx = 0, edx;
 
 	native_cpuid(&eax, &ebx, &ecx, &edx);
 
-	return __x86_family(eax);
-}
-
-static inline unsigned int x86_model(unsigned int sig)
-{
-	unsigned int x86, model;
-
-	x86 = __x86_family(sig);
-
-	model = (sig >> 4) & 0xf;
-
-	if (x86 == 0x6 || x86 == 0xf)
-		model += ((sig >> 16) & 0xf) << 4;
-
-	return model;
+	return x86_family(eax);
 }
 
 #ifdef CONFIG_MICROCODE
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 4ddd780aeac9..c311b51efe15 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -582,14 +582,9 @@  void cpu_detect(struct cpuinfo_x86 *c)
 		u32 junk, tfms, cap0, misc;
 
 		cpuid(0x00000001, &tfms, &misc, &junk, &cap0);
-		c->x86 = (tfms >> 8) & 0xf;
-		c->x86_model = (tfms >> 4) & 0xf;
-		c->x86_mask = tfms & 0xf;
-
-		if (c->x86 == 0xf)
-			c->x86 += (tfms >> 20) & 0xff;
-		if (c->x86 >= 0x6)
-			c->x86_model += ((tfms >> 16) & 0xf) << 4;
+		c->x86		= x86_family(tfms);
+		c->x86_model	= x86_model(tfms);
+		c->x86_mask	= x86_stepping(tfms);
 
 		if (cap0 & (1<<19)) {
 			c->x86_clflush_size = ((misc >> 8) & 0xff) * 8;
diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index 7fc27f1cca58..e98c3487c9d3 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -130,7 +130,7 @@  void __init load_ucode_bsp(void)
 		return;
 
 	vendor = x86_vendor();
-	family = x86_family();
+	family = x86_family_cpuid();
 
 	switch (vendor) {
 	case X86_VENDOR_INTEL:
@@ -166,7 +166,7 @@  void load_ucode_ap(void)
 		return;
 
 	vendor = x86_vendor();
-	family = x86_family();
+	family = x86_family_cpuid();
 
 	switch (vendor) {
 	case X86_VENDOR_INTEL:
@@ -207,7 +207,7 @@  void reload_early_microcode(void)
 	int vendor, family;
 
 	vendor = x86_vendor();
-	family = x86_family();
+	family = x86_family_cpuid();
 
 	switch (vendor) {
 	case X86_VENDOR_INTEL:
diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index ce47402eb2f9..ee81c544ee0d 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -145,10 +145,10 @@  matching_model_microcode(struct microcode_header_intel *mc_header,
 	int ext_sigcount, i;
 	struct extended_signature *ext_sig;
 
-	fam   = __x86_family(sig);
+	fam   = x86_family(sig);
 	model = x86_model(sig);
 
-	fam_ucode   = __x86_family(mc_header->sig);
+	fam_ucode   = x86_family(mc_header->sig);
 	model_ucode = x86_model(mc_header->sig);
 
 	if (fam == fam_ucode && model == model_ucode)
@@ -163,7 +163,7 @@  matching_model_microcode(struct microcode_header_intel *mc_header,
 	ext_sigcount = ext_header->count;
 
 	for (i = 0; i < ext_sigcount; i++) {
-		fam_ucode   = __x86_family(ext_sig->sig);
+		fam_ucode   = x86_family(ext_sig->sig);
 		model_ucode = x86_model(ext_sig->sig);
 
 		if (fam == fam_ucode && model == model_ucode)
@@ -365,7 +365,7 @@  static int collect_cpu_info_early(struct ucode_cpu_info *uci)
 	native_cpuid(&eax, &ebx, &ecx, &edx);
 	csig.sig = eax;
 
-	family = __x86_family(csig.sig);
+	family = x86_family(csig.sig);
 	model  = x86_model(csig.sig);
 
 	if ((model >= 5) || (family > 6)) {
@@ -521,16 +521,12 @@  static bool __init load_builtin_intel_microcode(struct cpio_data *cp)
 {
 #ifdef CONFIG_X86_64
 	unsigned int eax = 0x00000001, ebx, ecx = 0, edx;
-	unsigned int family, model, stepping;
 	char name[30];
 
 	native_cpuid(&eax, &ebx, &ecx, &edx);
 
-	family   = __x86_family(eax);
-	model    = x86_model(eax);
-	stepping = eax & 0xf;
-
-	sprintf(name, "intel-ucode/%02x-%02x-%02x", family, model, stepping);
+	sprintf(name, "intel-ucode/%02x-%02x-%02x",
+		      x86_family(eax), x86_model(eax), x86_stepping(eax));
 
 	return get_builtin_firmware(cp, name);
 #else
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);