Unverified Commit 29844792 authored by Greentime Hu's avatar Greentime Hu Committed by Palmer Dabbelt
Browse files

riscv: Support irq_work via self IPIs 



Support for arch_irq_work_raise() and arch_irq_work_has_interrupt() was
missing from riscv (a prerequisite for FULL_NOHZ).

Signed-off-by: default avatarGreentime Hu <greentime.hu@sifive.com>
Signed-off-by: default avatarPalmer Dabbelt <palmerdabbelt@google.com>
parent 3c469798

arch/riscv/include/asm/irq_work.h

0 → 100644
+10 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

#ifndef _ASM_RISCV_IRQ_WORK_H

#define _ASM_RISCV_IRQ_WORK_H



static inline bool arch_irq_work_has_interrupt(void)

{

	return true;

}

extern void arch_irq_work_raise(void);

#endif /* _ASM_RISCV_IRQ_WORK_H */

arch/riscv/kernel/smp.c

+15 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
#include <linux/sched.h>

#include <linux/seq_file.h>

#include <linux/delay.h>

#include <linux/irq_work.h>



#include <asm/clint.h>

#include <asm/sbi.h>
@@ -26,6 +27,7 @@ enum ipi_message_type { 
	IPI_RESCHEDULE,

	IPI_CALL_FUNC,

	IPI_CPU_STOP,

	IPI_IRQ_WORK,

	IPI_MAX

};
@@ -123,6 +125,13 @@ static inline void clear_ipi(void) 
		clint_clear_ipi(cpuid_to_hartid_map(smp_processor_id()));

}



#ifdef CONFIG_IRQ_WORK

void arch_irq_work_raise(void)

{

	send_ipi_single(smp_processor_id(), IPI_IRQ_WORK);

}

#endif



void handle_IPI(struct pt_regs *regs)

{

	struct pt_regs *old_regs = set_irq_regs(regs);
@@ -158,6 +167,11 @@ void handle_IPI(struct pt_regs *regs) 
			ipi_stop();

		}



		if (ops & (1 << IPI_IRQ_WORK)) {

			stats[IPI_IRQ_WORK]++;

			irq_work_run();

		}



		BUG_ON((ops >> IPI_MAX) != 0);



		/* Order data access and bit testing. */
@@ -173,6 +187,7 @@ static const char * const ipi_names[] = { 
	[IPI_RESCHEDULE]	= "Rescheduling interrupts",

	[IPI_CALL_FUNC]		= "Function call interrupts",

	[IPI_CPU_STOP]		= "CPU stop interrupts",

	[IPI_IRQ_WORK]		= "IRQ work interrupts",

};



void show_ipi_stats(struct seq_file *p, int prec)