Re: [PATCH RESEND 1/2] powerpc/mce: Add MCE notification chain

[Santosh Sivaraj <santosh@fossix.org>]

Christophe Leroy <christophe.leroy@csgroup.eu> writes:

> Le 09/07/2020 à 09:56, Santosh Sivaraj a écrit :
>> Introduce notification chain which lets know about uncorrected memory
>> errors(UE). This would help prospective users in pmem or nvdimm subsystem
>> to track bad blocks for better handling of persistent memory allocations.
>> 
>> Signed-off-by: Santosh S <santosh@fossix.org>
>> Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
>> ---
>>   arch/powerpc/include/asm/mce.h |  2 ++
>>   arch/powerpc/kernel/mce.c      | 15 +++++++++++++++
>>   2 files changed, 17 insertions(+)
>> 
>> Send the two patches together, so the dependencies are clear. The earlier patch reviews are
>> here: https://lore.kernel.org/linuxppc-dev/20200330071219.12284-1-ganeshgr@linux.ibm.com/
>> 
>> Rebase the patches on top on 5.8-rc4
>> 
>> diff --git a/arch/powerpc/include/asm/mce.h b/arch/powerpc/include/asm/mce.h
>> index 376a395daf329..a57b0772702a9 100644
>> --- a/arch/powerpc/include/asm/mce.h
>> +++ b/arch/powerpc/include/asm/mce.h
>> @@ -220,6 +220,8 @@ extern void machine_check_print_event_info(struct machine_check_event *evt,
>>   unsigned long addr_to_pfn(struct pt_regs *regs, unsigned long addr);
>>   extern void mce_common_process_ue(struct pt_regs *regs,
>>   				  struct mce_error_info *mce_err);
>> +extern int mce_register_notifier(struct notifier_block *nb);
>> +extern int mce_unregister_notifier(struct notifier_block *nb);
>
> Using the 'extern' keyword on function declaration is pointless and 
> should be avoided in new patches. (checkpatch.pl --strict usually 
> complains about it).

I will remove that in the v2 which I will be sending for your comments for
the other patch.

Thanks,
Santosh

>
>>   #ifdef CONFIG_PPC_BOOK3S_64
>>   void flush_and_reload_slb(void);
>>   #endif /* CONFIG_PPC_BOOK3S_64 */
>> diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c
>> index fd90c0eda2290..b7b3ed4e61937 100644
>> --- a/arch/powerpc/kernel/mce.c
>> +++ b/arch/powerpc/kernel/mce.c
>> @@ -49,6 +49,20 @@ static struct irq_work mce_ue_event_irq_work = {
>>   
>>   DECLARE_WORK(mce_ue_event_work, machine_process_ue_event);
>>   
>> +static BLOCKING_NOTIFIER_HEAD(mce_notifier_list);
>> +
>> +int mce_register_notifier(struct notifier_block *nb)
>> +{
>> +	return blocking_notifier_chain_register(&mce_notifier_list, nb);
>> +}
>> +EXPORT_SYMBOL_GPL(mce_register_notifier);
>> +
>> +int mce_unregister_notifier(struct notifier_block *nb)
>> +{
>> +	return blocking_notifier_chain_unregister(&mce_notifier_list, nb);
>> +}
>> +EXPORT_SYMBOL_GPL(mce_unregister_notifier);
>> +
>>   static void mce_set_error_info(struct machine_check_event *mce,
>>   			       struct mce_error_info *mce_err)
>>   {
>> @@ -278,6 +292,7 @@ static void machine_process_ue_event(struct work_struct *work)
>>   	while (__this_cpu_read(mce_ue_count) > 0) {
>>   		index = __this_cpu_read(mce_ue_count) - 1;
>>   		evt = this_cpu_ptr(&mce_ue_event_queue[index]);
>> +		blocking_notifier_call_chain(&mce_notifier_list, 0, evt);
>>   #ifdef CONFIG_MEMORY_FAILURE
>>   		/*
>>   		 * This should probably queued elsewhere, but
>> 
>
> Christophe