MIPS: Optimize current_cpu_type() for better code.

 o Move current_cpu_type() to a separate header file
 o #ifdefing on supported CPU types lets modern GCC know that certain
   code in callers may be discarded ideally turning current_cpu_type() into
   a function returning a constant.
 o Use current_cpu_type() rather than direct access to struct cpuinfo_mips.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5833/
diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h
index fa44f3e..51680d1 100644
--- a/arch/mips/include/asm/cpu-features.h
+++ b/arch/mips/include/asm/cpu-features.h
@@ -13,12 +13,6 @@
 #include <asm/cpu-info.h>
 #include <cpu-feature-overrides.h>
 
-#ifndef current_cpu_type
-#define current_cpu_type()	current_cpu_data.cputype
-#endif
-
-#define boot_cpu_type()		cpu_data[0].cputype
-
 /*
  * SMP assumption: Options of CPU 0 are a superset of all processors.
  * This is true for all known MIPS systems.
diff --git a/arch/mips/include/asm/cpu-type.h b/arch/mips/include/asm/cpu-type.h
new file mode 100644
index 0000000..4a402cc
--- /dev/null
+++ b/arch/mips/include/asm/cpu-type.h
@@ -0,0 +1,203 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2003, 2004 Ralf Baechle
+ * Copyright (C) 2004  Maciej W. Rozycki
+ */
+#ifndef __ASM_CPU_TYPE_H
+#define __ASM_CPU_TYPE_H
+
+#include <linux/smp.h>
+#include <linux/compiler.h>
+
+static inline int __pure __get_cpu_type(const int cpu_type)
+{
+	switch (cpu_type) {
+#if defined(CONFIG_SYS_HAS_CPU_LOONGSON2E) || \
+    defined(CONFIG_SYS_HAS_CPU_LOONGSON2F)
+	case CPU_LOONGSON2:
+#endif
+
+#ifdef CONFIG_SYS_HAS_CPU_LOONGSON1B
+	case CPU_LOONGSON1:
+#endif
+
+#ifdef CONFIG_SYS_HAS_CPU_MIPS32_R1
+	case CPU_4KC:
+	case CPU_ALCHEMY:
+	case CPU_BMIPS3300:
+	case CPU_BMIPS4350:
+	case CPU_PR4450:
+	case CPU_BMIPS32:
+	case CPU_JZRISC:
+#endif
+
+#if defined(CONFIG_SYS_HAS_CPU_MIPS32_R1) || \
+    defined(CONFIG_SYS_HAS_CPU_MIPS32_R2)
+	case CPU_4KEC:
+#endif
+
+#ifdef CONFIG_SYS_HAS_CPU_MIPS32_R2
+	case CPU_4KSC:
+	case CPU_24K:
+	case CPU_34K:
+	case CPU_1004K:
+	case CPU_74K:
+	case CPU_M14KC:
+	case CPU_M14KEC:
+#endif
+
+#ifdef CONFIG_SYS_HAS_CPU_MIPS64_R1
+	case CPU_5KC:
+	case CPU_5KE:
+	case CPU_20KC:
+	case CPU_25KF:
+	case CPU_SB1:
+	case CPU_SB1A:
+#endif
+
+#ifdef CONFIG_SYS_HAS_CPU_MIPS64_R2
+	/*
+	 * All MIPS64 R2 processors have their own special symbols.  That is,
+	 * there currently is no pure R2 core
+	 */
+#endif
+
+#ifdef CONFIG_SYS_HAS_CPU_R3000
+	case CPU_R2000:
+	case CPU_R3000:
+	case CPU_R3000A:
+	case CPU_R3041:
+	case CPU_R3051:
+	case CPU_R3052:
+	case CPU_R3081:
+	case CPU_R3081E:
+#endif
+
+#ifdef CONFIG_SYS_HAS_CPU_TX39XX
+	case CPU_TX3912:
+	case CPU_TX3922:
+	case CPU_TX3927:
+#endif
+
+#ifdef CONFIG_SYS_HAS_CPU_VR41XX
+	case CPU_VR41XX:
+	case CPU_VR4111:
+	case CPU_VR4121:
+	case CPU_VR4122:
+	case CPU_VR4131:
+	case CPU_VR4133:
+	case CPU_VR4181:
+	case CPU_VR4181A:
+#endif
+
+#ifdef CONFIG_SYS_HAS_CPU_R4300
+	case CPU_R4300:
+	case CPU_R4310:
+#endif
+
+#ifdef CONFIG_SYS_HAS_CPU_R4X00
+	case CPU_R4000PC:
+	case CPU_R4000SC:
+	case CPU_R4000MC:
+	case CPU_R4200:
+	case CPU_R4400PC:
+	case CPU_R4400SC:
+	case CPU_R4400MC:
+	case CPU_R4600:
+	case CPU_R4700:
+	case CPU_R4640:
+	case CPU_R4650:
+#endif
+
+#ifdef CONFIG_SYS_HAS_CPU_TX49XX
+	case CPU_TX49XX:
+#endif
+
+#ifdef CONFIG_SYS_HAS_CPU_R5000
+	case CPU_R5000:
+#endif
+
+#ifdef CONFIG_SYS_HAS_CPU_R5432
+	case CPU_R5432:
+#endif
+
+#ifdef CONFIG_SYS_HAS_CPU_R5500
+	case CPU_R5500:
+#endif
+
+#ifdef CONFIG_SYS_HAS_CPU_R6000
+	case CPU_R6000:
+	case CPU_R6000A:
+#endif
+
+#ifdef CONFIG_SYS_HAS_CPU_NEVADA
+	case CPU_NEVADA:
+#endif
+
+#ifdef CONFIG_SYS_HAS_CPU_R8000
+	case CPU_R8000:
+#endif
+
+#ifdef CONFIG_SYS_HAS_CPU_R10000
+	case CPU_R10000:
+	case CPU_R12000:
+	case CPU_R14000:
+#endif
+#ifdef CONFIG_SYS_HAS_CPU_RM7000
+	case CPU_RM7000:
+	case CPU_SR71000:
+#endif
+#ifdef CONFIG_SYS_HAS_CPU_RM9000
+	case CPU_RM9000:
+#endif
+#ifdef CONFIG_SYS_HAS_CPU_SB1
+	case CPU_SB1:
+	case CPU_SB1A:
+#endif
+#ifdef CONFIG_SYS_HAS_CPU_CAVIUM_OCTEON
+	case CPU_CAVIUM_OCTEON:
+	case CPU_CAVIUM_OCTEON_PLUS:
+	case CPU_CAVIUM_OCTEON2:
+#endif
+
+#ifdef CONFIG_SYS_HAS_CPU_BMIPS4380
+	case CPU_BMIPS4380:
+#endif
+
+#ifdef CONFIG_SYS_HAS_CPU_BMIPS5000
+	case CPU_BMIPS5000:
+#endif
+
+#ifdef CONFIG_SYS_HAS_CPU_XLP
+	case CPU_XLP:
+#endif
+
+#ifdef CONFIG_SYS_HAS_CPU_XLR
+	case CPU_XLR:
+#endif
+		break;
+	default:
+		unreachable();
+	}
+
+	return cpu_type;
+}
+
+static inline int __pure current_cpu_type(void)
+{
+	const int cpu_type = current_cpu_data.cputype;
+
+	return __get_cpu_type(cpu_type);
+}
+
+static inline int __pure boot_cpu_type(void)
+{
+	const int cpu_type = cpu_data[0].cputype;
+
+	return __get_cpu_type(cpu_type);
+}
+
+#endif /* __ASM_CPU_TYPE_H */
diff --git a/arch/mips/include/asm/mach-ip22/cpu-feature-overrides.h b/arch/mips/include/asm/mach-ip22/cpu-feature-overrides.h
index f4caacd..1bcb642 100644
--- a/arch/mips/include/asm/mach-ip22/cpu-feature-overrides.h
+++ b/arch/mips/include/asm/mach-ip22/cpu-feature-overrides.h
@@ -8,6 +8,8 @@
 #ifndef __ASM_MACH_IP22_CPU_FEATURE_OVERRIDES_H
 #define __ASM_MACH_IP22_CPU_FEATURE_OVERRIDES_H
 
+#include <asm/cpu.h>
+
 /*
  * IP22 with a variety of processors so we can't use defaults for everything.
  */
diff --git a/arch/mips/include/asm/mach-ip27/cpu-feature-overrides.h b/arch/mips/include/asm/mach-ip27/cpu-feature-overrides.h
index 1d2b6ff..d6111aa 100644
--- a/arch/mips/include/asm/mach-ip27/cpu-feature-overrides.h
+++ b/arch/mips/include/asm/mach-ip27/cpu-feature-overrides.h
@@ -8,6 +8,8 @@
 #ifndef __ASM_MACH_IP27_CPU_FEATURE_OVERRIDES_H
 #define __ASM_MACH_IP27_CPU_FEATURE_OVERRIDES_H
 
+#include <asm/cpu.h>
+
 /*
  * IP27 only comes with R10000 family processors all using the same config
  */
diff --git a/arch/mips/include/asm/mach-ip28/cpu-feature-overrides.h b/arch/mips/include/asm/mach-ip28/cpu-feature-overrides.h
index 65e9c85..4cec06d 100644
--- a/arch/mips/include/asm/mach-ip28/cpu-feature-overrides.h
+++ b/arch/mips/include/asm/mach-ip28/cpu-feature-overrides.h
@@ -9,6 +9,8 @@
 #ifndef __ASM_MACH_IP28_CPU_FEATURE_OVERRIDES_H
 #define __ASM_MACH_IP28_CPU_FEATURE_OVERRIDES_H
 
+#include <asm/cpu.h>
+
 /*
  * IP28 only comes with R10000 family processors all using the same config
  */