lkml.org 
[lkml]   [2021]   [Nov]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.10 259/575] parisc/kgdb: add kgdb_roundup() to make kgdb work with idle polling
    Date
    From: Sven Schnelle <svens@stackframe.org>

    [ 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>
    ---
    arch/parisc/kernel/smp.c | 19 +++++++++++++++++--
    1 file changed, 17 insertions(+), 2 deletions(-)

    diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c
    index 1405b603b91b6..cf92ece20b757 100644
    --- a/arch/parisc/kernel/smp.c
    +++ b/arch/parisc/kernel/smp.c
    @@ -29,6 +29,7 @@
    #include <linux/bitops.h>
    #include <linux/ftrace.h>
    #include <linux/cpu.h>
    +#include <linux/kgdb.h>

    #include <linux/atomic.h>
    #include <asm/current.h>
    @@ -69,7 +70,10 @@ enum ipi_message_type {
    IPI_CALL_FUNC,
    IPI_CPU_START,
    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:
    smp_debug(100, KERN_DEBUG "CPU%d is alive!\n", this_cpu);
    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:
    printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n",
    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
    smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP); }
    --
    2.33.0


    \
     
     \ /
      Last update: 2021-11-16 03:03    [W:2.286 / U:0.160 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site