powerpc/kernel: Cleanup machine check function declarations

__machine_check_early_realmode_p*() are currently declared as extern
in cputable.c and because of this when compiled with "C=1" (which
enables semantic checker) produces these warnings.

    CHECK   arch/powerpc/kernel/mce_power.c
  arch/powerpc/kernel/mce_power.c:709:6: warning: symbol '__machine_check_early_realmode_p7' was not declared. Should it be static?
  arch/powerpc/kernel/mce_power.c:717:6: warning: symbol '__machine_check_early_realmode_p8' was not declared. Should it be static?
  arch/powerpc/kernel/mce_power.c:722:6: warning: symbol '__machine_check_early_realmode_p9' was not declared. Should it be static?
  arch/powerpc/kernel/mce_power.c:740:6: warning: symbol '__machine_check_early_realmode_p10' was not declared. Should it be static?

Patch here moves the declaration to asm/mce.h and includes the same in
cputable.c

Fixes: ae744f3 ("powerpc/book3s: Flush SLB/TLBs if we get SLB/TLB machine check errors on power8")
Fixes: 7b9f71f ("powerpc/64s: POWER9 machine check handler")
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200817005618.3305028-1-maddy@linux.ibm.com

Author: maddy-kerneldev

arch/powerpc/include/asm/cputable.h

@@ -9,6 +9,11 @@
 
 #ifndef __ASSEMBLY__
 
+/*
+ * Added to include __machine_check_early_realmode_* functions
+ */
+#include <asm/mce.h>
+
 /* This structure can grow, it's real size is used by head.S code
  * via the mkdefs mechanism.
  */

arch/powerpc/include/asm/mce.h

@@ -210,6 +210,9 @@ struct mce_error_info {
 #define MCE_EVENT_RELEASE	true
 #define MCE_EVENT_DONTRELEASE	false
 
+struct pt_regs;
+struct notifier_block;
+
 extern void save_mce_event(struct pt_regs *regs, long handled,
 			   struct mce_error_info *mce_err, uint64_t nip,
 			   uint64_t addr, uint64_t phys_addr);
@@ -225,5 +228,9 @@ int mce_register_notifier(struct notifier_block *nb);
 int mce_unregister_notifier(struct notifier_block *nb);
 #ifdef CONFIG_PPC_BOOK3S_64
 void flush_and_reload_slb(void);
+long __machine_check_early_realmode_p7(struct pt_regs *regs);
+long __machine_check_early_realmode_p8(struct pt_regs *regs);
+long __machine_check_early_realmode_p9(struct pt_regs *regs);
+long __machine_check_early_realmode_p10(struct pt_regs *regs);
 #endif /* CONFIG_PPC_BOOK3S_64 */
 #endif /* __ASM_PPC64_MCE_H__ */

arch/powerpc/kernel/cputable.c

@@ -72,10 +72,6 @@ extern void __setup_cpu_power9(unsigned long offset, struct cpu_spec* spec);
 extern void __restore_cpu_power9(void);
 extern void __setup_cpu_power10(unsigned long offset, struct cpu_spec* spec);
 extern void __restore_cpu_power10(void);
-extern long __machine_check_early_realmode_p7(struct pt_regs *regs);
-extern long __machine_check_early_realmode_p8(struct pt_regs *regs);
-extern long __machine_check_early_realmode_p9(struct pt_regs *regs);
-extern long __machine_check_early_realmode_p10(struct pt_regs *regs);
 #endif /* CONFIG_PPC64 */
 #if defined(CONFIG_E500)
 extern void __setup_cpu_e5500(unsigned long offset, struct cpu_spec* spec);

arch/powerpc/kernel/dt_cpu_ftrs.c

@@ -64,10 +64,6 @@ struct dt_cpu_feature {
  * Set up the base CPU
  */
 
-extern long __machine_check_early_realmode_p8(struct pt_regs *regs);
-extern long __machine_check_early_realmode_p9(struct pt_regs *regs);
-extern long __machine_check_early_realmode_p10(struct pt_regs *regs);
-
 static int hv_mode;
 
 static struct {