diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index 80657bf83b05..1920d52653b4 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -343,6 +343,7 @@ config NR_CPUS
 
 config NUMA
 	bool "NUMA Support"
+	select SMP
 	select ACPI_NUMA if ACPI
 	help
 	  Say Y to compile the kernel with NUMA (Non-Uniform Memory Access)
diff --git a/arch/loongarch/include/asm/hardirq.h b/arch/loongarch/include/asm/hardirq.h
index befe8184aa08..0ef3b18f8980 100644
--- a/arch/loongarch/include/asm/hardirq.h
+++ b/arch/loongarch/include/asm/hardirq.h
@@ -19,7 +19,7 @@ typedef struct {
 	unsigned int __softirq_pending;
 } ____cacheline_aligned irq_cpustat_t;
 
-DECLARE_PER_CPU_ALIGNED(irq_cpustat_t, irq_stat);
+DECLARE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
 
 #define __ARCH_IRQ_STAT
 
diff --git a/arch/loongarch/include/asm/percpu.h b/arch/loongarch/include/asm/percpu.h
index 34f15a6fb1e7..e6569f18c6dd 100644
--- a/arch/loongarch/include/asm/percpu.h
+++ b/arch/loongarch/include/asm/percpu.h
@@ -6,6 +6,7 @@
 #define __ASM_PERCPU_H
 
 #include <asm/cmpxchg.h>
+#include <asm/loongarch.h>
 
 /* Use r21 for fast access */
 register unsigned long __my_cpu_offset __asm__("$r21");
diff --git a/arch/loongarch/include/asm/smp.h b/arch/loongarch/include/asm/smp.h
index 551e1f37c705..71189b28bfb2 100644
--- a/arch/loongarch/include/asm/smp.h
+++ b/arch/loongarch/include/asm/smp.h
@@ -9,10 +9,16 @@
 #include <linux/atomic.h>
 #include <linux/bitops.h>
 #include <linux/linkage.h>
-#include <linux/smp.h>
 #include <linux/threads.h>
 #include <linux/cpumask.h>
 
+extern int smp_num_siblings;
+extern int num_processors;
+extern int disabled_cpus;
+extern cpumask_t cpu_sibling_map[];
+extern cpumask_t cpu_core_map[];
+extern cpumask_t cpu_foreign_map[];
+
 void loongson3_smp_setup(void);
 void loongson3_prepare_cpus(unsigned int max_cpus);
 void loongson3_boot_secondary(int cpu, struct task_struct *idle);
@@ -25,26 +31,11 @@ int loongson3_cpu_disable(void);
 void loongson3_cpu_die(unsigned int cpu);
 #endif
 
-#ifdef CONFIG_SMP
-
 static inline void plat_smp_setup(void)
 {
 	loongson3_smp_setup();
 }
 
-#else /* !CONFIG_SMP */
-
-static inline void plat_smp_setup(void) { }
-
-#endif /* !CONFIG_SMP */
-
-extern int smp_num_siblings;
-extern int num_processors;
-extern int disabled_cpus;
-extern cpumask_t cpu_sibling_map[];
-extern cpumask_t cpu_core_map[];
-extern cpumask_t cpu_foreign_map[];
-
 static inline int raw_smp_processor_id(void)
 {
 #if defined(__VDSO__)
diff --git a/arch/loongarch/include/asm/timex.h b/arch/loongarch/include/asm/timex.h
index d3ed99a4fdbd..fb41e9e7a222 100644
--- a/arch/loongarch/include/asm/timex.h
+++ b/arch/loongarch/include/asm/timex.h
@@ -12,13 +12,6 @@
 #include <asm/cpu.h>
 #include <asm/cpu-features.h>
 
-/*
- * Standard way to access the cycle counter.
- * Currently only used on SMP for scheduling.
- *
- * We know that all SMP capable CPUs have cycle counters.
- */
-
 typedef unsigned long cycles_t;
 
 #define get_cycles get_cycles
diff --git a/arch/loongarch/kernel/acpi.c b/arch/loongarch/kernel/acpi.c
index b16c3dea5eeb..bb729ee8a237 100644
--- a/arch/loongarch/kernel/acpi.c
+++ b/arch/loongarch/kernel/acpi.c
@@ -138,6 +138,7 @@ void __init acpi_boot_table_init(void)
 	}
 }
 
+#ifdef CONFIG_SMP
 static int set_processor_mask(u32 id, u32 flags)
 {
 
@@ -166,15 +167,18 @@ static int set_processor_mask(u32 id, u32 flags)
 
 	return cpu;
 }
+#endif
 
 static void __init acpi_process_madt(void)
 {
+#ifdef CONFIG_SMP
 	int i;
 
 	for (i = 0; i < NR_CPUS; i++) {
 		__cpu_number_map[i] = -1;
 		__cpu_logical_map[i] = -1;
 	}
+#endif
 
 	loongson_sysconf.nr_cpus = num_processors;
 }
diff --git a/arch/loongarch/kernel/cacheinfo.c b/arch/loongarch/kernel/cacheinfo.c
index 8c9fe29e98f0..b38f5489d094 100644
--- a/arch/loongarch/kernel/cacheinfo.c
+++ b/arch/loongarch/kernel/cacheinfo.c
@@ -4,6 +4,7 @@
  *
  * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
  */
+#include <asm/cpu-info.h>
 #include <linux/cacheinfo.h>
 
 /* Populates leaf and increments to next leaf */
diff --git a/arch/loongarch/kernel/irq.c b/arch/loongarch/kernel/irq.c
index 4b671d305ede..b34b8d792aa4 100644
--- a/arch/loongarch/kernel/irq.c
+++ b/arch/loongarch/kernel/irq.c
@@ -22,6 +22,8 @@
 #include <asm/setup.h>
 
 DEFINE_PER_CPU(unsigned long, irq_stack);
+DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
+EXPORT_PER_CPU_SYMBOL(irq_stat);
 
 struct irq_domain *cpu_domain;
 struct irq_domain *liointc_domain;
@@ -56,8 +58,11 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 
 void __init init_IRQ(void)
 {
-	int i, r, ipi_irq;
+	int i;
+#ifdef CONFIG_SMP
+	int r, ipi_irq;
 	static int ipi_dummy_dev;
+#endif
 	unsigned int order = get_order(IRQ_STACK_SIZE);
 	struct page *page;
 
diff --git a/arch/loongarch/kernel/process.c b/arch/loongarch/kernel/process.c
index 6d944d65f600..bfa0dfe8b7d7 100644
--- a/arch/loongarch/kernel/process.c
+++ b/arch/loongarch/kernel/process.c
@@ -120,10 +120,12 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 /*
  * Copy architecture-specific thread state
  */
-int copy_thread(unsigned long clone_flags, unsigned long usp,
-	unsigned long kthread_arg, struct task_struct *p, unsigned long tls)
+int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 {
 	unsigned long childksp;
+	unsigned long tls = args->tls;
+	unsigned long usp = args->stack;
+	unsigned long clone_flags = args->flags;
 	struct pt_regs *childregs, *regs = current_pt_regs();
 
 	childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE - 32;
@@ -136,12 +138,12 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 	p->thread.csr_crmd = csr_read32(LOONGARCH_CSR_CRMD);
 	p->thread.csr_prmd = csr_read32(LOONGARCH_CSR_PRMD);
 	p->thread.csr_ecfg = csr_read32(LOONGARCH_CSR_ECFG);
-	if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
+	if (unlikely(args->fn)) {
 		/* kernel thread */
-		p->thread.reg23 = usp; /* fn */
-		p->thread.reg24 = kthread_arg;
 		p->thread.reg03 = childksp;
-		p->thread.reg01 = (unsigned long) ret_from_kernel_thread;
+		p->thread.reg23 = (unsigned long)args->fn;
+		p->thread.reg24 = (unsigned long)args->fn_arg;
+		p->thread.reg01 = (unsigned long)ret_from_kernel_thread;
 		memset(childregs, 0, sizeof(struct pt_regs));
 		childregs->csr_euen = p->thread.csr_euen;
 		childregs->csr_crmd = p->thread.csr_crmd;
diff --git a/arch/loongarch/kernel/setup.c b/arch/loongarch/kernel/setup.c
index 185e4035811a..c74860b53375 100644
--- a/arch/loongarch/kernel/setup.c
+++ b/arch/loongarch/kernel/setup.c
@@ -39,7 +39,6 @@
 #include <asm/pgalloc.h>
 #include <asm/sections.h>
 #include <asm/setup.h>
-#include <asm/smp.h>
 #include <asm/time.h>
 
 #define SMBIOS_BIOSSIZE_OFFSET		0x09
@@ -349,8 +348,6 @@ static void __init prefill_possible_map(void)
 
 	nr_cpu_ids = possible;
 }
-#else
-static inline void prefill_possible_map(void) {}
 #endif
 
 void __init setup_arch(char **cmdline_p)
@@ -367,8 +364,10 @@ void __init setup_arch(char **cmdline_p)
 	arch_mem_init(cmdline_p);
 
 	resource_init();
+#ifdef CONFIG_SMP
 	plat_smp_setup();
 	prefill_possible_map();
+#endif
 
 	paging_init();
 }
diff --git a/arch/loongarch/kernel/smp.c b/arch/loongarch/kernel/smp.c
index b8c53b755a25..73cec62504fb 100644
--- a/arch/loongarch/kernel/smp.c
+++ b/arch/loongarch/kernel/smp.c
@@ -66,8 +66,6 @@ static cpumask_t cpu_core_setup_map;
 
 struct secondary_data cpuboot_data;
 static DEFINE_PER_CPU(int, cpu_state);
-DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
-EXPORT_PER_CPU_SYMBOL(irq_stat);
 
 enum ipi_msg_type {
 	IPI_RESCHEDULE,