x86/apic: Add Hygon Dhyana support

Add Hygon Dhyana support to the APIC subsystem. When running in 32 bit
mode, bigsmp should be enabled if there are more than 8 cores online.
Signed-off-by: Pu Wen <puwen@hygon.cn>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-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/7a557265a8c7c9e842fe60f9d8e064458801aef3.1537533369.git.puwen@hygon.cn

arch/x86/kernel/apic/apic.c

@@ -224,6 +224,11 @@ static int modern_apic(void)
 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
 	    boot_cpu_data.x86 >= 0xf)
 		return 1;
+
+	/* Hygon systems use modern APIC */
+	if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
+		return 1;
+
 	return lapic_get_version() >= 0x14;
 }
 
@@ -1912,6 +1917,8 @@ static int __init detect_init_APIC(void)
 		    (boot_cpu_data.x86 >= 15))
 			break;
 		goto no_apic;
+	case X86_VENDOR_HYGON:
+		break;
 	case X86_VENDOR_INTEL:
 		if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
 		    (boot_cpu_data.x86 == 5 && boot_cpu_has(X86_FEATURE_APIC)))

arch/x86/kernel/apic/probe_32.c

@@ -185,6 +185,7 @@ void __init default_setup_apic_routing(void)
 				break;
 			}
 			/* If P4 and above fall through */
+		case X86_VENDOR_HYGON:
 		case X86_VENDOR_AMD:
 			def_to_bigsmp = 1;
 		}