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parisc/kgdb: add kgdb_roundup() to make kgdb work with idle polling

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[ Upstream commit 66e29fcda1824f0427966fbee2bd2c85bf362c82 ]

With idle polling, IPIs are not sent when a CPU idle, but queued
and run later from do_idle(). The default kgdb_call_nmi_hook()
implementation gets the pointer to struct pt_regs from get_irq_reqs(),
which doesn't work in that case because it was not called from the
IPI interrupt handler. Fix it by defining our own kgdb_roundup()
function which sents an IPI_ENTER_KGDB. When that IPI is received
on the target CPU kgdb_nmicallback() is called.

Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Sven Schnelle 2021-10-15 21:49:23 +02:00 committed by Greg Kroah-Hartman
parent a1ec31a0be
commit 0c5e946794
1 changed files with 17 additions and 2 deletions
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19
arch/parisc/kernel/smp.c
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@ -29,6 +29,7 @@
#include <linux/bitops.h> #include <linux/bitops.h>
#include <linux/ftrace.h> #include <linux/ftrace.h>
#include <linux/cpu.h> #include <linux/cpu.h>
#include <linux/kgdb.h>
#include <linux/atomic.h> #include <linux/atomic.h>
#include <asm/current.h> #include <asm/current.h>
@ -69,7 +70,10 @@ enum ipi_message_type {
IPI_CALL_FUNC, IPI_CALL_FUNC,
IPI_CPU_START, IPI_CPU_START,
IPI_CPU_STOP, IPI_CPU_STOP,
IPI_CPU_TEST IPI_CPU_TEST,
#ifdef CONFIG_KGDB
IPI_ENTER_KGDB,
#endif
}; };
@ -167,7 +171,12 @@ ipi_interrupt(int irq, void *dev_id)
case IPI_CPU_TEST: case IPI_CPU_TEST:
smp_debug(100, KERN_DEBUG "CPU%d is alive!\n", this_cpu); smp_debug(100, KERN_DEBUG "CPU%d is alive!\n", this_cpu);
break; break;
#ifdef CONFIG_KGDB
case IPI_ENTER_KGDB:
smp_debug(100, KERN_DEBUG "CPU%d ENTER_KGDB\n", this_cpu);
kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
break;
#endif
default: default:
printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n", printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n",
this_cpu, which); this_cpu, which);
@ -226,6 +235,12 @@ send_IPI_allbutself(enum ipi_message_type op)
} }
} }
#ifdef CONFIG_KGDB
void kgdb_roundup_cpus(void)
{
send_IPI_allbutself(IPI_ENTER_KGDB);
}
#endif
inline void inline void
smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP); } smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP); }