Hi Balbir,

Balbir Singh <bsinghar...@gmail.com> writes:

> On 12/8/19 7:22 pm, Santosh Sivaraj wrote:
>> If we take a UE on one of the instructions with a fixup entry, set nip
>> to continue execution at the fixup entry. Stop processing the event
>> further or print it.
>> 
>> Co-developed-by: Reza Arbab <ar...@linux.ibm.com>
>> Signed-off-by: Reza Arbab <ar...@linux.ibm.com>
>> Cc: Mahesh Salgaonkar <mah...@linux.ibm.com>
>> Signed-off-by: Santosh Sivaraj <sant...@fossix.org>
>> ---
>
> Isn't this based on https://patchwork.ozlabs.org/patch/895294/? If so it
> should still have my author tag and signed-off-by

Originally when I received the series for posting, I had Reza's authorship and
signed-off-by, since the patch changed significantly I added co-developed-by as
Reza. I will update in the next spin.

https://lore.kernel.org/linuxppc-dev/20190702051932.511-1-sant...@fossix.org/

Santosh
>
> Balbir Singh
>
>>  arch/powerpc/include/asm/mce.h  |  4 +++-
>>  arch/powerpc/kernel/mce.c       | 16 ++++++++++++++++
>>  arch/powerpc/kernel/mce_power.c | 15 +++++++++++++--
>>  3 files changed, 32 insertions(+), 3 deletions(-)
>> 
>> diff --git a/arch/powerpc/include/asm/mce.h b/arch/powerpc/include/asm/mce.h
>> index f3a6036b6bc0..e1931c8c2743 100644
>> --- a/arch/powerpc/include/asm/mce.h
>> +++ b/arch/powerpc/include/asm/mce.h
>> @@ -122,7 +122,8 @@ struct machine_check_event {
>>                      enum MCE_UeErrorType ue_error_type:8;
>>                      u8              effective_address_provided;
>>                      u8              physical_address_provided;
>> -                    u8              reserved_1[5];
>> +                    u8              ignore_event;
>> +                    u8              reserved_1[4];
>>                      u64             effective_address;
>>                      u64             physical_address;
>>                      u8              reserved_2[8];
>> @@ -193,6 +194,7 @@ struct mce_error_info {
>>      enum MCE_Initiator      initiator:8;
>>      enum MCE_ErrorClass     error_class:8;
>>      bool                    sync_error;
>> +    bool                    ignore_event;
>>  };
>>  
>>  #define MAX_MC_EVT  100
>> diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c
>> index a3b122a685a5..ec4b3e1087be 100644
>> --- a/arch/powerpc/kernel/mce.c
>> +++ b/arch/powerpc/kernel/mce.c
>> @@ -149,6 +149,7 @@ void save_mce_event(struct pt_regs *regs, long handled,
>>              if (phys_addr != ULONG_MAX) {
>>                      mce->u.ue_error.physical_address_provided = true;
>>                      mce->u.ue_error.physical_address = phys_addr;
>> +                    mce->u.ue_error.ignore_event = mce_err->ignore_event;
>>                      machine_check_ue_event(mce);
>>              }
>>      }
>> @@ -266,8 +267,17 @@ static void machine_process_ue_event(struct work_struct 
>> *work)
>>              /*
>>               * This should probably queued elsewhere, but
>>               * oh! well
>> +             *
>> +             * Don't report this machine check because the caller has a
>> +             * asked us to ignore the event, it has a fixup handler which
>> +             * will do the appropriate error handling and reporting.
>>               */
>>              if (evt->error_type == MCE_ERROR_TYPE_UE) {
>> +                    if (evt->u.ue_error.ignore_event) {
>> +                            __this_cpu_dec(mce_ue_count);
>> +                            continue;
>> +                    }
>> +
>>                      if (evt->u.ue_error.physical_address_provided) {
>>                              unsigned long pfn;
>>  
>> @@ -301,6 +311,12 @@ static void machine_check_process_queued_event(struct 
>> irq_work *work)
>>      while (__this_cpu_read(mce_queue_count) > 0) {
>>              index = __this_cpu_read(mce_queue_count) - 1;
>>              evt = this_cpu_ptr(&mce_event_queue[index]);
>> +
>> +            if (evt->error_type == MCE_ERROR_TYPE_UE &&
>> +                evt->u.ue_error.ignore_event) {
>> +                    __this_cpu_dec(mce_queue_count);
>> +                    continue;
>> +            }
>>              machine_check_print_event_info(evt, false, false);
>>              __this_cpu_dec(mce_queue_count);
>>      }
>> diff --git a/arch/powerpc/kernel/mce_power.c 
>> b/arch/powerpc/kernel/mce_power.c
>> index e74816f045f8..1dd87f6f5186 100644
>> --- a/arch/powerpc/kernel/mce_power.c
>> +++ b/arch/powerpc/kernel/mce_power.c
>> @@ -11,6 +11,7 @@
>>  
>>  #include <linux/types.h>
>>  #include <linux/ptrace.h>
>> +#include <linux/extable.h>
>>  #include <asm/mmu.h>
>>  #include <asm/mce.h>
>>  #include <asm/machdep.h>
>> @@ -18,6 +19,7 @@
>>  #include <asm/pte-walk.h>
>>  #include <asm/sstep.h>
>>  #include <asm/exception-64s.h>
>> +#include <asm/extable.h>
>>  
>>  /*
>>   * Convert an address related to an mm to a physical address.
>> @@ -559,9 +561,18 @@ static int mce_handle_derror(struct pt_regs *regs,
>>      return 0;
>>  }
>>  
>> -static long mce_handle_ue_error(struct pt_regs *regs)
>> +static long mce_handle_ue_error(struct pt_regs *regs,
>> +                            struct mce_error_info *mce_err)
>>  {
>>      long handled = 0;
>> +    const struct exception_table_entry *entry;
>> +
>> +    entry = search_kernel_exception_table(regs->nip);
>> +    if (entry) {
>> +            mce_err->ignore_event = true;
>> +            regs->nip = extable_fixup(entry);
>> +            return 1;
>> +    }
>>  
>>      /*
>>       * On specific SCOM read via MMIO we may get a machine check
>> @@ -594,7 +605,7 @@ static long mce_handle_error(struct pt_regs *regs,
>>                              &phys_addr);
>>  
>>      if (!handled && mce_err.error_type == MCE_ERROR_TYPE_UE)
>> -            handled = mce_handle_ue_error(regs);
>> +            handled = mce_handle_ue_error(regs, &mce_err);
>>  
>>      save_mce_event(regs, handled, &mce_err, regs->nip, addr, phys_addr);
>>  
>> 

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