powerpc/tau: Synchronize function prototypes and body

Some function prototypes and body for Thermal Assist Units were not in
sync. Update the function definition to match the existing function
declaration found in `setup-common.c`, changing an `int` return type to a
`u32` return type. Move the prototypes to a header file. Fix the following
warnings, treated as error with W=1:

  arch/powerpc/kernel/tau_6xx.c:257:5: error: no previous prototype for ‘cpu_temp_both’ [-Werror=missing-prototypes]
  arch/powerpc/kernel/tau_6xx.c:262:5: error: no previous prototype for ‘cpu_temp’ [-Werror=missing-prototypes]
  arch/powerpc/kernel/tau_6xx.c:267:5: error: no previous prototype for ‘tau_interrupts’ [-Werror=missing-prototypes]

Compile tested with CONFIG_TAU_INT.
Suggested-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/kernel/irq.c

@@ -89,7 +89,7 @@ atomic_t ppc_n_lost_interrupts;
 
 #ifdef CONFIG_TAU_INT
 extern int tau_initialized;
-extern int tau_interrupts(int);
+u32 tau_interrupts(unsigned long cpu);
 #endif
 #endif /* CONFIG_PPC32 */
 

arch/powerpc/kernel/setup-common.c

@@ -192,12 +192,6 @@ void machine_halt(void)
 	machine_hang();
 }
 
-
-#ifdef CONFIG_TAU
-extern u32 cpu_temp(unsigned long cpu);
-extern u32 cpu_temp_both(unsigned long cpu);
-#endif /* CONFIG_TAU */
-
 #ifdef CONFIG_SMP
 DEFINE_PER_CPU(unsigned int, cpu_pvr);
 #endif

arch/powerpc/kernel/setup.h

@@ -62,4 +62,10 @@ void kvm_cma_reserve(void);
 static inline void kvm_cma_reserve(void) { };
 #endif
 
+#ifdef CONFIG_TAU
+u32 cpu_temp(unsigned long cpu);
+u32 cpu_temp_both(unsigned long cpu);
+u32 tau_interrupts(unsigned long cpu);
+#endif /* CONFIG_TAU */
+
 #endif /* __ARCH_POWERPC_KERNEL_SETUP_H */

arch/powerpc/kernel/tau_6xx.c

@@ -27,6 +27,9 @@
 #include <asm/cache.h>
 #include <asm/8xx_immap.h>
 #include <asm/machdep.h>
+#include <asm/asm-prototypes.h>
+
+#include "setup.h"
 
 static struct tau_temp
 {
@@ -259,12 +262,12 @@ u32 cpu_temp_both(unsigned long cpu)
 	return ((tau[cpu].high << 16) | tau[cpu].low);
 }
 
-int cpu_temp(unsigned long cpu)
+u32 cpu_temp(unsigned long cpu)
 {
 	return ((tau[cpu].high + tau[cpu].low) / 2);
 }
 
-int tau_interrupts(unsigned long cpu)
+u32 tau_interrupts(unsigned long cpu)
 {
 	return (tau[cpu].interrupts);
 }