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: warnin

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>

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LoongArch: Put the body of play_dead() into arch_cpu_idle_dead()

The initial aim is to silence the following objtool warning:

arch/loongarch/kernel/process.o: warning: objtool: arch_cpu_idle_dead()

LoongArch: Put the body of play_dead() into arch_cpu_idle_dead()

The initial aim is to silence the following objtool warning:

arch/loongarch/kernel/process.o: warning: objtool: arch_cpu_idle_dead() falls through to next function start_thread()

According to tools/objtool/Documentation/objtool.txt, this is because
the last instruction of arch_cpu_idle_dead() is a call to a noreturn
function play_dead(). In order to silence the warning, one simple way
is to add the noreturn function play_dead() to objtool's hard-coded
global_noreturns array, that is to say, just put "NORETURN(play_dead)"
into tools/objtool/noreturns.h, it works well.

But I noticed that play_dead() is only defined once and only called by
arch_cpu_idle_dead(), so put the body of play_dead() into the caller
arch_cpu_idle_dead(), then remove the noreturn function play_dead() is
an alternative way which can reduce the overhead of the function call
at the same time.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

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loongarch/cpu: Mark play_dead() __noreturn

play_dead() doesn't return. Annotate it as such. By extension this
also makes arch_cpu_idle_dead() noreturn.

Reviewed-by: Philippe Mathieu-Daudé <philmd

loongarch/cpu: Mark play_dead() __noreturn

play_dead() doesn't return. Annotate it as such. By extension this
also makes arch_cpu_idle_dead() noreturn.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/r/4da55acfdec8a9132c4e21ffb7edb1f846841193.1676358308.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

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LoongArch: Export symbol for function smp_send_reschedule()

Function smp_send_reschedule() is standard kernel API, which is defined
in header file include/linux/smp.h. However, on LoongArch it is de

LoongArch: Export symbol for function smp_send_reschedule()

Function smp_send_reschedule() is standard kernel API, which is defined
in header file include/linux/smp.h. However, on LoongArch it is defined
as an inline function, this is confusing and kernel modules can not use
this function.

Now we define smp_send_reschedule() as a general function, and add a
EXPORT_SYMBOL_GPL on this function, so that kernel modules can use it.

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

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LoongArch: SMP: Change prefix from loongson3 to loongson

SMP operations can be shared by Loongson-2 series and Loongson-3 series,
so we change the prefix from loongson3 to loongson for all functions

LoongArch: SMP: Change prefix from loongson3 to loongson

SMP operations can be shared by Loongson-2 series and Loongson-3 series,
so we change the prefix from loongson3 to loongson for all functions and
data structures.

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

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LoongArch: Fix the !CONFIG_SMP build

1, We assume arch/loongarch/include/asm/smp.h be included in include/
linux/smp.h is valid and the reverse inclusion isn't. So remove the
<linux/smp.h> in

LoongArch: Fix the !CONFIG_SMP build

1, We assume arch/loongarch/include/asm/smp.h be included in include/
linux/smp.h is valid and the reverse inclusion isn't. So remove the
<linux/smp.h> in arch/loongarch/include/asm/smp.h.
2, arch/loongarch/include/asm/smp.h is only needed when CONFIG_SMP,
and setup.c include it only because it need plat_smp_setup(). So,
reorganize setup.c & smp.h, and then remove <asm/smp.h> in setup.c.
3, Fix cacheinfo.c and percpu.h build error by adding the missing header
files when !CONFIG_SMP.
4, Fix acpi.c build error by adding CONFIG_SMP guards.
5, Move irq_stat definition from smp.c to irq.c and fix its declaration.
6, Select CONFIG_SMP for CONFIG_NUMA, similar as other architectures do.

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

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LoongArch: Add multi-processor (SMP) support

LoongArch-based procesors have 4, 8 or 16 cores per package. This patch
adds multi-processor (SMP) support for LoongArch.

Reviewed-by: WANG Xuerui <git@

LoongArch: Add multi-processor (SMP) support

LoongArch-based procesors have 4, 8 or 16 cores per package. This patch
adds multi-processor (SMP) support for LoongArch.

Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

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