Unverified Commit 62cac480 authored by Dengcheng Zhu's avatar Dengcheng Zhu Committed by Paul Burton
Browse files

MIPS: kexec: Make a framework for both jumping and halting on nonboot CPUs 



The existing implementation lets machine_kexec() CPU jump to reboot code
buffer, whereas other CPUs to relocated_kexec_smp_wait. The natural way to
bring up an SMP new kernel would be to let CPU0 do it while others being
halted. For those failing to do so, fall back to the jumping method.

Signed-off-by: default avatarDengcheng Zhu <dzhu@wavecomp.com>
[paul.burton@mips.com: Guard kexec_nonboot_cpu_jump with CONFIG_SMP]
Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/20570/
Cc: pburton@wavecomp.com
Cc: ralf@linux-mips.org
Cc: linux-mips@linux-mips.org
Cc: rachel.mozes@intel.com
parent dc57aaf9

arch/mips/cavium-octeon/smp.c

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

#include <linux/init.h>

#include <linux/export.h>

#include <linux/kexec.h>



#include <asm/mmu_context.h>

#include <asm/time.h>
@@ -424,6 +425,9 @@ const struct plat_smp_ops octeon_smp_ops = { 
	.cpu_disable		= octeon_cpu_disable,

	.cpu_die		= octeon_cpu_die,

#endif

#ifdef CONFIG_KEXEC

	.kexec_nonboot_cpu	= kexec_nonboot_cpu_jump,

#endif

};



static irqreturn_t octeon_78xx_reched_interrupt(int irq, void *dev_id)
@@ -501,6 +505,9 @@ static const struct plat_smp_ops octeon_78xx_smp_ops = { 
	.cpu_disable		= octeon_cpu_disable,

	.cpu_die		= octeon_cpu_die,

#endif

#ifdef CONFIG_KEXEC

	.kexec_nonboot_cpu	= kexec_nonboot_cpu_jump,

#endif

};



void __init octeon_setup_smp(void)

arch/mips/include/asm/kexec.h

+3 −2
Original line number Diff line number Diff line
@@ -39,11 +39,12 @@ extern unsigned long kexec_args[4]; 
extern int (*_machine_kexec_prepare)(struct kimage *);

extern void (*_machine_kexec_shutdown)(void);

extern void (*_machine_crash_shutdown)(struct pt_regs *regs);

extern void default_machine_crash_shutdown(struct pt_regs *regs);

void default_machine_crash_shutdown(struct pt_regs *regs);

void kexec_nonboot_cpu_jump(void);

void kexec_reboot(void);

#ifdef CONFIG_SMP

extern const unsigned char kexec_smp_wait[];

extern unsigned long secondary_kexec_args[4];

extern void (*relocated_kexec_smp_wait) (void *);

extern atomic_t kexec_ready_to_reboot;

extern void (*_crash_smp_send_stop)(void);

#endif

arch/mips/include/asm/smp-ops.h

+3 −0
Original line number Diff line number Diff line
@@ -33,6 +33,9 @@ struct plat_smp_ops { 
	int (*cpu_disable)(void);

	void (*cpu_die)(unsigned int cpu);

#endif

#ifdef CONFIG_KEXEC

	void (*kexec_nonboot_cpu)(void);

#endif

};



extern void register_smp_ops(const struct plat_smp_ops *ops);

arch/mips/include/asm/smp.h

+16 −0
Original line number Diff line number Diff line
@@ -91,6 +91,22 @@ static inline void __cpu_die(unsigned int cpu) 
extern void play_dead(void);

#endif



#ifdef CONFIG_KEXEC

static inline void kexec_nonboot_cpu(void)

{

	extern const struct plat_smp_ops *mp_ops;	/* private */



	return mp_ops->kexec_nonboot_cpu();

}



static inline void *kexec_nonboot_cpu_func(void)

{

	extern const struct plat_smp_ops *mp_ops;	/* private */



	return mp_ops->kexec_nonboot_cpu;

}

#endif



/*

 * This function will set up the necessary IPIs for Linux to communicate

 * with the CPUs in mask.

arch/mips/kernel/crash.c

+3 −1
Original line number Diff line number Diff line
@@ -46,7 +46,9 @@ static void crash_shutdown_secondary(void *passed_regs) 


	while (!atomic_read(&kexec_ready_to_reboot))

		cpu_relax();

	relocated_kexec_smp_wait(NULL);



	kexec_reboot();



	/* NOTREACHED */

}

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