MIPS: Add SysRq operation to dump TLBs on all CPUs

Add a MIPS specific SysRq operation to dump the TLB entries on all CPUs,
using the 'x' trigger key.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10072/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
James Hogan 2015-05-19 09:50:29 +01:00 committed by Ralf Baechle
parent 37dd3818d1
commit d1e9a4f547
3 changed files with 79 additions and 0 deletions

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@ -77,6 +77,7 @@ obj-$(CONFIG_MIPS32_O32) += binfmt_elfo32.o scall64-o32.o
obj-$(CONFIG_KGDB) += kgdb.o
obj-$(CONFIG_PROC_FS) += proc.o
obj-$(CONFIG_MAGIC_SYSRQ) += sysrq.o
obj-$(CONFIG_64BIT) += cpu-bugs64.o

77
arch/mips/kernel/sysrq.c Normal file
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@ -0,0 +1,77 @@
/*
* MIPS specific sysrq operations.
*
* Copyright (C) 2015 Imagination Technologies Ltd.
*/
#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/mipsregs.h>
#include <asm/tlbdebug.h>
/*
* Dump TLB entries on all CPUs.
*/
static DEFINE_SPINLOCK(show_lock);
static void sysrq_tlbdump_single(void *dummy)
{
const int field = 2 * sizeof(unsigned long);
unsigned long flags;
spin_lock_irqsave(&show_lock, flags);
pr_info("CPU%d:\n", smp_processor_id());
pr_info("Index : %0x\n", read_c0_index());
pr_info("Pagemask: %0x\n", read_c0_pagemask());
pr_info("EntryHi : %0*lx\n", field, read_c0_entryhi());
pr_info("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
pr_info("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
pr_info("Wired : %0x\n", read_c0_wired());
pr_info("Pagegrain: %0x\n", read_c0_pagegrain());
if (cpu_has_htw) {
pr_info("PWField : %0*lx\n", field, read_c0_pwfield());
pr_info("PWSize : %0*lx\n", field, read_c0_pwsize());
pr_info("PWCtl : %0x\n", read_c0_pwctl());
}
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 mips_sysrq_init(void)
{
return register_sysrq_key('x', &sysrq_tlbdump_op);
}
arch_initcall(mips_sysrq_init);

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@ -463,6 +463,7 @@ static struct sysrq_key_op *sysrq_key_table[36] = {
/* v: May be registered for frame buffer console restore */
NULL, /* v */
&sysrq_showstate_blocked_op, /* w */
/* x: May be registered on mips for TLB dump */
/* x: May be registered on ppc/powerpc for xmon */
/* x: May be registered on sparc64 for global PMU dump */
NULL, /* x */