arch: add do_page_fault prototypes

do_page_fault() is missing a declaration on a couple of architectures:

arch/alpha/mm/fault.c:85:1: error: no previous prototype for 'do_page_fault' [-Werror=missing-prototypes]
arch/csky/mm/fault.c:187:17: error: no previous prototype for 'do_page_fault' [-Werror=missing-prototypes]
arch/mips/mm/fault.c:323:17: error: no previous prototype for 'do_page_fault' [-Werror=missing-prototypes]
arch/nios2/mm/fault.c:43:17: error: no previous prototype for 'do_page_fault' [-Werror=missing-prototypes]
arch/sh/mm/fault.c:389:27: error: no previous prototype for 'do_page_fault' [-Werror=missing-prototypes]

Since the calling conventions are architecture specific here,
add separate prototypes for each one.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch: include linux/cpu.h for trap_init() prototype

some architectures run into a -Wmissing-prototypes warning
for trap_init()

arch/microblaze/kernel/traps.c:21:6: warning: no previous prototype for 'trap_init' [-Wmissing-prototypes]

Include the right header to avoid this consistently, removing
the extra declarations on m68k and x86 that were added as local
workarounds already.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

csky: Fixup compile error

Add header file for asmlinkage macro.

Error log:
In file included from arch/csky/include/asm/ptrace.h:7,
from arch/csky/include/asm/elf.h:6,
from include/linux/elf.h:6,
from kernel/extable.c:6:
arch/csky/include/asm/traps.h:43:11: error: expected ';' before 'void'
43 | asmlinkage void do_trap_unknown(struct pt_regs *regs);
| ^~~~~

Fixes: c8171a86b274 ("csky: Fixup -Wmissing-prototypes warning")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>

csky: Fixup -Wmissing-prototypes warning

Cleanup the warnings:

arch/csky/kernel/ptrace.c:320:16: error: no previous prototype for 'syscall_trace_enter' [-Werror=missing-prototypes]
arch/csky/kernel/ptrace.c:336:17: error: no previous prototype for 'syscall_trace_exit' [-Werror=missing-prototypes]
arch/csky/kernel/setup.c:116:34: error: no previous prototype for 'csky_start' [-Werror=missing-prototypes]
arch/csky/kernel/signal.c:255:17: error: no previous prototype for 'do_notify_resume' [-Werror=missing-prototypes]
arch/csky/kernel/traps.c:150:15: error: no previous prototype for 'do_trap_unknown' [-Werror=missing-prototypes]
arch/csky/kernel/traps.c:152:15: error: no previous prototype for 'do_trap_zdiv' [-Werror=missing-prototypes]
arch/csky/kernel/traps.c:154:15: error: no previous prototype for 'do_trap_buserr' [-Werror=missing-prototypes]
arch/csky/kernel/traps.c:157:17: error: no previous prototype for 'do_trap_misaligned' [-Werror=missing-prototypes]
arch/csky/kernel/traps.c:168:17: error: no previous prototype for 'do_trap_bkpt' [-Werror=missing-prototypes]
arch/csky/kernel/traps.c:187:17: error: no previous prototype for 'do_trap_illinsn' [-Werror=missing-prototypes]
arch/csky/kernel/traps.c:210:17: error: no previous prototype for 'do_trap_fpe' [-Werror=missing-prototypes]
arch/csky/kernel/traps.c:220:17: error: no previous prototype for 'do_trap_priv' [-Werror=missing-prototypes]
arch/csky/kernel/traps.c:230:17: error: no previous prototype for 'trap_c' [-Werror=missing-prototypes]
arch/csky/kernel/traps.c:57:13: error: no previous prototype for 'trap_init' [-Werror=missing-prototypes]
arch/csky/kernel/vdso/vgettimeofday.c:12:5: error: no previous prototype for '__vdso_clock_gettime64' [-Werror=missing-prototypes]
arch/csky/kernel/vdso/vgettimeofday.c:18:5: error: no previous prototype for '__vdso_gettimeofday' [-Werror=missing-prototypes]
arch/csky/kernel/vdso/vgettimeofday.c:24:5: error: no previous prototype for '__vdso_clock_getres' [-Werror=missing-prototypes]
arch/csky/kernel/vdso/vgettimeofday.c:6:5: error: no previous prototype for '__vdso_clock_gettime' [-Werror=missing-prototypes]
arch/csky/mm/fault.c:187:17: error: no previous prototype for 'do_page_fault' [-Werror=missing-prototypes]

Link: https://lore.kernel.org/lkml/20230810141947.1236730-17-arnd@kernel.org/
Reported-by: Arnd Bergmann <arnd@kernel.org>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>

csky: Fixup compile error

: error: C++ style comments are not allowed in ISO C90
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
^
error: (this will be reported only once per input file)

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

csky: Exception handling and mm-fault

This patch adds exception handling code, cpuinfo and mm-fault code.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>