LoongArch: Fix some build warnings with W=1

There are some building warnings when building LoongArch kernel with W=1
as following, this patch fixes them.

arch/loongarch/kernel/acpi.c:284:13: warning: no previous prototype for ‘acpi_numa_arch_fixup’ [-Wmissing-prototypes]
  284 | void __init acpi_numa_arch_fixup(void) {}
      |             ^~~~~~~~~~~~~~~~~~~~
arch/loongarch/kernel/time.c:32:13: warning: no previous prototype for ‘constant_timer_interrupt’ [-Wmissing-prototypes]
   32 | irqreturn_t constant_timer_interrupt(int irq, void *data)
      |             ^~~~~~~~~~~~~~~~~~~~~~~~
arch/loongarch/kernel/traps.c:496:25: warning: no previous prototype for 'do_fpe' [-Wmissing-prototypes]
  496 | asmlinkage void noinstr do_fpe(struct pt_regs *regs
      |                         ^~~~~~
arch/loongarch/kernel/traps.c:813:22: warning: variable ‘opcode’ set but not used [-Wunused-but-set-variable]
  813 |         unsigned int opcode;
      |                      ^~~~~~
arch/loongarch/kernel/signal.c:895:14: warning: no previous prototype for ‘get_sigframe’ [-Wmissing-prototypes]
  895 | void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
      |              ^~~~~~~~~~~~
arch/loongarch/kernel/syscall.c:21:40: warning: initialized field overwritten [-Woverride-init]
   21 | #define __SYSCALL(nr, call)     [nr] = (call),
      |                                        ^
arch/loongarch/kernel/syscall.c:40:14: warning: no previous prototype for ‘do_syscall’ [-Wmissing-prototypes]
   40 | void noinstr do_syscall(struct pt_regs *regs)
      |              ^~~~~~~~~~
arch/loongarch/kernel/smp.c:502:17: warning: no previous prototype for ‘start_secondary’ [-Wmissing-prototypes]
  502 | asmlinkage void start_secondary(void)
      |                 ^~~~~~~~~~~~~~~
arch/loongarch/kernel/process.c:309:15: warning: no previous prototype for ‘arch_align_stack’ [-Wmissing-prototypes]
  309 | unsigned long arch_align_stack(unsigned long sp)
      |               ^~~~~~~~~~~~~~~~
arch/loongarch/kernel/topology.c:13:5: warning: no previous prototype for ‘arch_register_cpu’ [-Wmissing-prototypes]
   13 | int arch_register_cpu(int cpu)
      |     ^~~~~~~~~~~~~~~~~
arch/loongarch/kernel/topology.c:27:6: warning: no previous prototype for ‘arch_unregister_cpu’ [-Wmissing-prototypes]
   27 | void arch_unregister_cpu(int cpu)
      |      ^~~~~~~~~~~~~~~~~~~
arch/loongarch/kernel/module-sections.c:103:5: warning: no previous prototype for ‘module_frob_arch_sections’ [-Wmissing-prototypes]
  103 | int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~
arch/loongarch/mm/hugetlbpage.c:56:5: warning: no previous prototype for ‘is_aligned_hugepage_range’ [-Wmissing-prototypes]
   56 | int is_aligned_hugepage_range(unsigned long addr, unsigned long len)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

2 files changed, 46 insertions, 0 deletions

diff --git a/arch/loongarch/include/asm/exception.h b/arch/loongarch/include/asm/exception.h
new file mode 100644
index 000000000000..af74a3fdcad1
--- /dev/null
+++ b/arch/loongarch/include/asm/exception.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __ASM_EXCEPTION_H
+#define __ASM_EXCEPTION_H
+
+#include <asm/ptrace.h>
+#include <linux/kprobes.h>
+
+void show_registers(struct pt_regs *regs);
+
+asmlinkage void cache_parity_error(void);
+asmlinkage void noinstr do_ade(struct pt_regs *regs);
+asmlinkage void noinstr do_ale(struct pt_regs *regs);
+asmlinkage void noinstr do_bce(struct pt_regs *regs);
+asmlinkage void noinstr do_bp(struct pt_regs *regs);
+asmlinkage void noinstr do_ri(struct pt_regs *regs);
+asmlinkage void noinstr do_fpu(struct pt_regs *regs);
+asmlinkage void noinstr do_fpe(struct pt_regs *regs, unsigned long fcsr);
+asmlinkage void noinstr do_lsx(struct pt_regs *regs);
+asmlinkage void noinstr do_lasx(struct pt_regs *regs);
+asmlinkage void noinstr do_lbt(struct pt_regs *regs);
+asmlinkage void noinstr do_watch(struct pt_regs *regs);
+asmlinkage void noinstr do_syscall(struct pt_regs *regs);
+asmlinkage void noinstr do_reserved(struct pt_regs *regs);
+asmlinkage void noinstr do_vint(struct pt_regs *regs, unsigned long sp);
+asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
+				unsigned long write, unsigned long address);
+
+asmlinkage void handle_ade(void);
+asmlinkage void handle_ale(void);
+asmlinkage void handle_bce(void);
+asmlinkage void handle_sys(void);
+asmlinkage void handle_bp(void);
+asmlinkage void handle_ri(void);
+asmlinkage void handle_fpu(void);
+asmlinkage void handle_fpe(void);
+asmlinkage void handle_lsx(void);
+asmlinkage void handle_lasx(void);
+asmlinkage void handle_lbt(void);
+asmlinkage void handle_watch(void);
+asmlinkage void handle_reserved(void);
+asmlinkage void handle_vint(void);
+asmlinkage void noinstr handle_loongarch_irq(struct pt_regs *regs);
+
+#endif	/* __ASM_EXCEPTION_H */
diff --git a/arch/loongarch/include/asm/smp.h b/arch/loongarch/include/asm/smp.h
index 66ecb480c894..f81e5f01d619 100644
--- a/arch/loongarch/include/asm/smp.h
+++ b/arch/loongarch/include/asm/smp.h
@@ -70,6 +70,7 @@ struct secondary_data {
 extern struct secondary_data cpuboot_data;
 
 extern asmlinkage void smpboot_entry(void);
+extern asmlinkage void start_secondary(void);
 
 extern void calculate_cpu_foreign_map(void);