On Tue, 2014-01-14 at 11:48 -0800, Hugh Dickins wrote:
> On Tue, 14 Jan 2014, Mahesh J Salgaonkar wrote:
> > From: Mahesh Salgaonkar <mah...@linux.vnet.ibm.com>
> >
> > Huge Dickins reported an issue that b5ff4211a829
> > "powerpc/book3s: Queue up and process delayed MCE events" breaks the
> > PowerMac G5 boot. This patch fixes it by moving the mce even processing
> > away from syscall exit, which was wrong to do that in first place, and
> > using irq work framework to delay processing of mce event.
> >
> > Reported-by: Hugh Dickins <hu...@google.com
> > Signed-off-by: Mahesh Salgaonkar <mah...@linux.vnet.ibm.com>
>
> This version also boots and runs fine for me on the G5
> (but of course, I'm probably not testing delayed MCE events at all).
Thanks Hugh !
Cheers,
Ben.
> Hugh
>
> > ---
> > arch/powerpc/include/asm/mce.h | 1 -
> > arch/powerpc/kernel/entry_64.S | 5 -----
> > arch/powerpc/kernel/mce.c | 13 ++++++++++---
> > 3 files changed, 10 insertions(+), 9 deletions(-)
> >
> > diff --git a/arch/powerpc/include/asm/mce.h b/arch/powerpc/include/asm/mce.h
> > index 2257d1e..f97d8cb 100644
> > --- a/arch/powerpc/include/asm/mce.h
> > +++ b/arch/powerpc/include/asm/mce.h
> > @@ -192,7 +192,6 @@ extern void save_mce_event(struct pt_regs *regs, long
> > handled,
> > extern int get_mce_event(struct machine_check_event *mce, bool release);
> > extern void release_mce_event(void);
> > extern void machine_check_queue_event(void);
> > -extern void machine_check_process_queued_event(void);
> > extern void machine_check_print_event_info(struct machine_check_event
> > *evt);
> > extern uint64_t get_mce_fault_addr(struct machine_check_event *evt);
> >
> > diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
> > index 770d6d6..bbfb029 100644
> > --- a/arch/powerpc/kernel/entry_64.S
> > +++ b/arch/powerpc/kernel/entry_64.S
> > @@ -184,11 +184,6 @@ syscall_exit:
> > bl .do_show_syscall_exit
> > ld r3,RESULT(r1)
> > #endif
> > -#ifdef CONFIG_PPC_BOOK3S_64
> > -BEGIN_FTR_SECTION
> > - bl .machine_check_process_queued_event
> > -END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
> > -#endif
> > CURRENT_THREAD_INFO(r12, r1)
> >
> > ld r8,_MSR(r1)
> > diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c
> > index d6edf2b..a7fd4cb 100644
> > --- a/arch/powerpc/kernel/mce.c
> > +++ b/arch/powerpc/kernel/mce.c
> > @@ -26,6 +26,7 @@
> > #include <linux/ptrace.h>
> > #include <linux/percpu.h>
> > #include <linux/export.h>
> > +#include <linux/irq_work.h>
> > #include <asm/mce.h>
> >
> > static DEFINE_PER_CPU(int, mce_nest_count);
> > @@ -35,6 +36,11 @@ static DEFINE_PER_CPU(struct
> > machine_check_event[MAX_MC_EVT], mce_event);
> > static DEFINE_PER_CPU(int, mce_queue_count);
> > static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT],
> > mce_event_queue);
> >
> > +static void machine_check_process_queued_event(struct irq_work *work);
> > +struct irq_work mce_event_process_work = {
> > + .func = machine_check_process_queued_event,
> > +};
> > +
> > static void mce_set_error_info(struct machine_check_event *mce,
> > struct mce_error_info *mce_err)
> > {
> > @@ -185,17 +191,19 @@ void machine_check_queue_event(void)
> > return;
> > }
> > __get_cpu_var(mce_event_queue[index]) = evt;
> > +
> > + /* Queue irq work to process this event later. */
> > + irq_work_queue(&mce_event_process_work);
> > }
> >
> > /*
> > * process pending MCE event from the mce event queue. This function will
> > be
> > * called during syscall exit.
> > */
> > -void machine_check_process_queued_event(void)
> > +static void machine_check_process_queued_event(struct irq_work *work)
> > {
> > int index;
> >
> > - preempt_disable();
> > /*
> > * For now just print it to console.
> > * TODO: log this error event to FSP or nvram.
> > @@ -206,7 +214,6 @@ void machine_check_process_queued_event(void)
> > &__get_cpu_var(mce_event_queue[index]));
> > __get_cpu_var(mce_queue_count)--;
> > }
> > - preempt_enable();
> > }
> >
> > void machine_check_print_event_info(struct machine_check_event *evt)
> >
> >
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