x86/mce: Include the PPIN in MCE records when available

Intel Xeons from Ivy Bridge onwards support a processor identification
number set in the factory. To the user this is a handy unique number to
identify a particular CPU. Intel can decode this to the fab/production
run to track errors. On systems that have it, include it in the machine
check record. I'm told that this would be helpful for users that run
large data centers with multi-socket servers to keep track of which CPUs
are seeing errors.

Boris:
* Add some clarifying comments and spacing.
* Mask out [63:2] in the disabled-but-not-locked case
* Call the MSR variable "val" for more readability.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: x86-ml <x86@kernel.org>
Link: http://lkml.kernel.org/r/20161123114855.njguoaygp3qnbkia@pd.tnic
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/include/uapi/asm/mce.h

@@ -28,6 +28,7 @@ struct mce {
 	__u64 mcgcap;	/* MCGCAP MSR: machine check capabilities of CPU */
 	__u64 synd;	/* MCA_SYND MSR: only valid on SMCA systems */
 	__u64 ipid;	/* MCA_IPID MSR: only valid on SMCA systems */
+	__u64 ppin;	/* Protected Processor Inventory Number */
 };
 
 #define MCE_GET_RECORD_LEN   _IOR('M', 1, int)