Commit dea2df3c authored by Huacai Chen's avatar Huacai Chen
Browse files

LoongArch: Add SysRq-x (TLB Dump) support 



Add SysRq-x (TLB Dump) support for LoongArch, which is useful for
debugging.

Signed-off-by: default avatarHuacai Chen <chenhuacai@loongson.cn>
parent b37042b2

arch/loongarch/kernel/Makefile

+2 −0
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@@ -23,6 +23,8 @@ obj-$(CONFIG_SMP) += smp.o 


obj-$(CONFIG_NUMA)		+= numa.o



obj-$(CONFIG_MAGIC_SYSRQ)	+= sysrq.o



obj-$(CONFIG_UNWINDER_GUESS)	+= unwind_guess.o

obj-$(CONFIG_UNWINDER_PROLOGUE) += unwind_prologue.o

arch/loongarch/kernel/sysrq.c

0 → 100644
+65 −0
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// SPDX-License-Identifier: GPL-2.0

/*

 * LoongArch specific sysrq operations.

 *

 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited

 */

#include <linux/init.h>

#include <linux/smp.h>

#include <linux/spinlock.h>

#include <linux/sysrq.h>

#include <linux/workqueue.h>



#include <asm/cpu-features.h>

#include <asm/tlb.h>



/*

 * Dump TLB entries on all CPUs.

 */



static DEFINE_SPINLOCK(show_lock);



static void sysrq_tlbdump_single(void *dummy)

{

	unsigned long flags;



	spin_lock_irqsave(&show_lock, flags);



	pr_info("CPU%d:\n", smp_processor_id());

	dump_tlb_regs();

	pr_info("\n");

	dump_tlb_all();

	pr_info("\n");



	spin_unlock_irqrestore(&show_lock, flags);

}



#ifdef CONFIG_SMP

static void sysrq_tlbdump_othercpus(struct work_struct *dummy)

{

	smp_call_function(sysrq_tlbdump_single, NULL, 0);

}



static DECLARE_WORK(sysrq_tlbdump, sysrq_tlbdump_othercpus);

#endif



static void sysrq_handle_tlbdump(int key)

{

	sysrq_tlbdump_single(NULL);

#ifdef CONFIG_SMP

	schedule_work(&sysrq_tlbdump);

#endif

}



static struct sysrq_key_op sysrq_tlbdump_op = {

	.handler        = sysrq_handle_tlbdump,

	.help_msg       = "show-tlbs(x)",

	.action_msg     = "Show TLB entries",

	.enable_mask	= SYSRQ_ENABLE_DUMP,

};



static int __init loongarch_sysrq_init(void)

{

	return register_sysrq_key('x', &sysrq_tlbdump_op);

}

arch_initcall(loongarch_sysrq_init);