RISC-V: simplify software interrupt / IPI code

Rename handle_ipi to riscv_software_interrupt, drop the unused return
value and move the prototype to irq.h together with riscv_timer_interupt.
This allows simplifying the upcoming interrupt handling support.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

arch/riscv/include/asm/irq.h

@@ -22,6 +22,7 @@
 #define INTERRUPT_CAUSE_EXTERNAL    9
 
 void riscv_timer_interrupt(void);
+void riscv_software_interrupt(void);
 
 #include <asm-generic/irq.h>
 

arch/riscv/include/asm/smp.h

@@ -44,9 +44,6 @@ void arch_send_call_function_single_ipi(int cpu);
  */
 #define raw_smp_processor_id() (*((int*)((char*)get_current() + TASK_TI_CPU)))
 
-/* Interprocessor interrupt handler */
-irqreturn_t handle_ipi(void);
-
 #endif /* CONFIG_SMP */
 
 #endif /* _ASM_RISCV_SMP_H */

arch/riscv/kernel/smp.c

@@ -45,7 +45,7 @@ int setup_profiling_timer(unsigned int multiplier)
 	return -EINVAL;
 }
 
-irqreturn_t handle_ipi(void)
+void riscv_software_interrupt(void)
 {
 	unsigned long *pending_ipis = &ipi_data[smp_processor_id()].bits;
 
@@ -60,7 +60,7 @@ irqreturn_t handle_ipi(void)
 
 		ops = xchg(pending_ipis, 0);
 		if (ops == 0)
-			return IRQ_HANDLED;
+			return;
 
 		if (ops & (1 << IPI_RESCHEDULE))
 			scheduler_ipi();
@@ -73,8 +73,6 @@ irqreturn_t handle_ipi(void)
 		/* Order data access and bit testing. */
 		mb();
 	}
-
-	return IRQ_HANDLED;
 }
 
 static void