diff --git a/arch/m32r/kernel/setup_mappi.c b/arch/m32r/kernel/setup_mappi.c
index 67dbbdc9d111bdc89e0b621adf2d9ef438030915..6b2d77da06830c734c01d588881694c115e84c53 100644
--- a/arch/m32r/kernel/setup_mappi.c
+++ b/arch/m32r/kernel/setup_mappi.c
@@ -86,7 +86,7 @@ void __init init_IRQ(void)
 	/* INT0 : LAN controller (RTL8019AS) */
 	irq_desc[M32R_IRQ_INT0].status = IRQ_DISABLED;
 	irq_desc[M32R_IRQ_INT0].chip = &mappi_irq_type;
-	irq_desc[M32R_IRQ_INT0].action = 0;
+	irq_desc[M32R_IRQ_INT0].action = NULL;
 	irq_desc[M32R_IRQ_INT0].depth = 1;
 	icu_data[M32R_IRQ_INT0].icucr = M32R_ICUCR_IEN|M32R_ICUCR_ISMOD10;
 	disable_mappi_irq(M32R_IRQ_INT0);
@@ -95,7 +95,7 @@ void __init init_IRQ(void)
 	/* MFT2 : system timer */
 	irq_desc[M32R_IRQ_MFT2].status = IRQ_DISABLED;
 	irq_desc[M32R_IRQ_MFT2].chip = &mappi_irq_type;
-	irq_desc[M32R_IRQ_MFT2].action = 0;
+	irq_desc[M32R_IRQ_MFT2].action = NULL;
 	irq_desc[M32R_IRQ_MFT2].depth = 1;
 	icu_data[M32R_IRQ_MFT2].icucr = M32R_ICUCR_IEN;
 	disable_mappi_irq(M32R_IRQ_MFT2);
@@ -104,7 +104,7 @@ void __init init_IRQ(void)
 	/* SIO0_R : uart receive data */
 	irq_desc[M32R_IRQ_SIO0_R].status = IRQ_DISABLED;
 	irq_desc[M32R_IRQ_SIO0_R].chip = &mappi_irq_type;
-	irq_desc[M32R_IRQ_SIO0_R].action = 0;
+	irq_desc[M32R_IRQ_SIO0_R].action = NULL;
 	irq_desc[M32R_IRQ_SIO0_R].depth = 1;
 	icu_data[M32R_IRQ_SIO0_R].icucr = 0;
 	disable_mappi_irq(M32R_IRQ_SIO0_R);
@@ -112,7 +112,7 @@ void __init init_IRQ(void)
 	/* SIO0_S : uart send data */
 	irq_desc[M32R_IRQ_SIO0_S].status = IRQ_DISABLED;
 	irq_desc[M32R_IRQ_SIO0_S].chip = &mappi_irq_type;
-	irq_desc[M32R_IRQ_SIO0_S].action = 0;
+	irq_desc[M32R_IRQ_SIO0_S].action = NULL;
 	irq_desc[M32R_IRQ_SIO0_S].depth = 1;
 	icu_data[M32R_IRQ_SIO0_S].icucr = 0;
 	disable_mappi_irq(M32R_IRQ_SIO0_S);
@@ -120,7 +120,7 @@ void __init init_IRQ(void)
 	/* SIO1_R : uart receive data */
 	irq_desc[M32R_IRQ_SIO1_R].status = IRQ_DISABLED;
 	irq_desc[M32R_IRQ_SIO1_R].chip = &mappi_irq_type;
-	irq_desc[M32R_IRQ_SIO1_R].action = 0;
+	irq_desc[M32R_IRQ_SIO1_R].action = NULL;
 	irq_desc[M32R_IRQ_SIO1_R].depth = 1;
 	icu_data[M32R_IRQ_SIO1_R].icucr = 0;
 	disable_mappi_irq(M32R_IRQ_SIO1_R);
@@ -128,7 +128,7 @@ void __init init_IRQ(void)
 	/* SIO1_S : uart send data */
 	irq_desc[M32R_IRQ_SIO1_S].status = IRQ_DISABLED;
 	irq_desc[M32R_IRQ_SIO1_S].chip = &mappi_irq_type;
-	irq_desc[M32R_IRQ_SIO1_S].action = 0;
+	irq_desc[M32R_IRQ_SIO1_S].action = NULL;
 	irq_desc[M32R_IRQ_SIO1_S].depth = 1;
 	icu_data[M32R_IRQ_SIO1_S].icucr = 0;
 	disable_mappi_irq(M32R_IRQ_SIO1_S);
@@ -138,7 +138,7 @@ void __init init_IRQ(void)
 	/* INT1 : pccard0 interrupt */
 	irq_desc[M32R_IRQ_INT1].status = IRQ_DISABLED;
 	irq_desc[M32R_IRQ_INT1].chip = &mappi_irq_type;
-	irq_desc[M32R_IRQ_INT1].action = 0;
+	irq_desc[M32R_IRQ_INT1].action = NULL;
 	irq_desc[M32R_IRQ_INT1].depth = 1;
 	icu_data[M32R_IRQ_INT1].icucr = M32R_ICUCR_IEN | M32R_ICUCR_ISMOD00;
 	disable_mappi_irq(M32R_IRQ_INT1);
@@ -146,7 +146,7 @@ void __init init_IRQ(void)
 	/* INT2 : pccard1 interrupt */
 	irq_desc[M32R_IRQ_INT2].status = IRQ_DISABLED;
 	irq_desc[M32R_IRQ_INT2].chip = &mappi_irq_type;
-	irq_desc[M32R_IRQ_INT2].action = 0;
+	irq_desc[M32R_IRQ_INT2].action = NULL;
 	irq_desc[M32R_IRQ_INT2].depth = 1;
 	icu_data[M32R_IRQ_INT2].icucr = M32R_ICUCR_IEN | M32R_ICUCR_ISMOD00;
 	disable_mappi_irq(M32R_IRQ_INT2);
diff --git a/arch/m32r/kernel/smp.c b/arch/m32r/kernel/smp.c
index 722e21f556dc53701a5c0989b77ea36c5f0ec8a7..360129174b2bd17aaeed1fcc37c91e80a8100d05 100644
--- a/arch/m32r/kernel/smp.c
+++ b/arch/m32r/kernel/smp.c
@@ -231,7 +231,7 @@ void smp_flush_tlb_all(void)
 	local_irq_save(flags);
 	__flush_tlb_all();
 	local_irq_restore(flags);
-	smp_call_function(flush_tlb_all_ipi, 0, 1, 1);
+	smp_call_function(flush_tlb_all_ipi, NULL, 1, 1);
 	preempt_enable();
 }
 
diff --git a/arch/m32r/kernel/traps.c b/arch/m32r/kernel/traps.c
index c1daf2c40c7c4fb05af0f61b503fe9bf20a92bc1..97e0b1c0830e81cf218d4e61c4dbbc0a1de8e0ff 100644
--- a/arch/m32r/kernel/traps.c
+++ b/arch/m32r/kernel/traps.c
@@ -268,7 +268,7 @@ static __inline__ void do_trap(int trapnr, int signr, const char * str,
 #define DO_ERROR(trapnr, signr, str, name) \
 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
 { \
-	do_trap(trapnr, signr, 0, regs, error_code, NULL); \
+	do_trap(trapnr, signr, NULL, regs, error_code, NULL); \
 }
 
 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \