x86/cpu: Create Hygon Dhyana architecture support file

Add x86 architecture support for a new processor: Hygon Dhyana Family
18h. Carve out initialization code needed by Dhyana into a separate
compilation unit.

To identify Hygon Dhyana CPU, add a new vendor type X86_VENDOR_HYGON.

Since Dhyana uses AMD functionality to a large degree, select
CPU_SUP_AMD which provides that functionality.

 [ bp: drop explicit license statement as it has an SPDX tag already. ]
Signed-off-by: Pu Wen <puwen@hygon.cn>
Reviewed-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: tglx@linutronix.de
Cc: mingo@redhat.com
Cc: hpa@zytor.com
Cc: x86@kernel.org
Cc: thomas.lendacky@amd.com
Link: https://lkml.kernel.org/r/1a882065223bacbde5726f3beaa70cebd8dcd814.1537533369.git.puwen@hygon.cn

MAINTAINERS

@@ -6762,6 +6762,12 @@ S:	Maintained
 F:	mm/memory-failure.c
 F:	mm/hwpoison-inject.c
 
+HYGON PROCESSOR SUPPORT
+M:	Pu Wen <puwen@hygon.cn>
+L:	linux-kernel@vger.kernel.org
+S:	Maintained
+F:	arch/x86/kernel/cpu/hygon.c
+
 Hyper-V CORE AND DRIVERS
 M:	"K. Y. Srinivasan" <kys@microsoft.com>
 M:	Haiyang Zhang <haiyangz@microsoft.com>

arch/x86/Kconfig.cpu

@@ -426,6 +426,20 @@ config CPU_SUP_AMD
 
 	  If unsure, say N.
 
+config CPU_SUP_HYGON
+	default y
+	bool "Support Hygon processors" if PROCESSOR_SELECT
+	select CPU_SUP_AMD
+	help
+	  This enables detection, tunings and quirks for Hygon processors
+
+	  You need this enabled if you want your kernel to run on an
+	  Hygon CPU. Disabling this option on other types of CPUs
+	  makes the kernel a tiny bit smaller. Disabling it on an Hygon
+	  CPU might render the kernel unbootable.
+
+	  If unsure, say N.
+
 config CPU_SUP_CENTAUR
 	default y
 	bool "Support Centaur processors" if PROCESSOR_SELECT

arch/x86/include/asm/processor.h

@@ -155,7 +155,8 @@ enum cpuid_regs_idx {
 #define X86_VENDOR_CENTAUR	5
 #define X86_VENDOR_TRANSMETA	7
 #define X86_VENDOR_NSC		8
-#define X86_VENDOR_NUM		9
+#define X86_VENDOR_HYGON	9
+#define X86_VENDOR_NUM		10
 
 #define X86_VENDOR_UNKNOWN	0xff
 

arch/x86/kernel/cpu/Makefile

@@ -30,6 +30,7 @@ obj-$(CONFIG_X86_FEATURE_NAMES) += capflags.o powerflags.o
 
 obj-$(CONFIG_CPU_SUP_INTEL)		+= intel.o intel_pconfig.o
 obj-$(CONFIG_CPU_SUP_AMD)		+= amd.o
+obj-$(CONFIG_CPU_SUP_HYGON)		+= hygon.o
 obj-$(CONFIG_CPU_SUP_CYRIX_32)		+= cyrix.o
 obj-$(CONFIG_CPU_SUP_CENTAUR)		+= centaur.o
 obj-$(CONFIG_CPU_SUP_TRANSMETA_32)	+= transmeta.o