Mahesh J Salgaonkar <mah...@linux.ibm.com> writes:
> On 2020-04-01 13:17:41 Wed, Santosh Sivaraj wrote:
>> Subscribe to the MCE notification and add the physical address which
>> generated a memory error to nvdimm bad range.
>>
>> Signed-off-by: Santosh Sivaraj <sant...@fossix.org>
>> ---
>>
>> This patch depends on "powerpc/mce: Add MCE notification chain" [1].
>>
>> Unlike the previous series[2], the patch adds badblock registration only for
>> pseries scm driver. Handling badblocks for baremetal (powernv) PMEM will be
>> done
>> later and if possible get the badblock handling as a common code.
>>
>> [1]
>> https://lore.kernel.org/linuxppc-dev/20200330071219.12284-1-ganes...@linux.ibm.com/
>> [2]
>> https://lore.kernel.org/linuxppc-dev/20190820023030.18232-1-sant...@fossix.org/
>>
>> arch/powerpc/platforms/pseries/papr_scm.c | 96 ++++++++++++++++++++++-
>> 1 file changed, 95 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/powerpc/platforms/pseries/papr_scm.c
>> b/arch/powerpc/platforms/pseries/papr_scm.c
>> index 0b4467e378e5..5012cbf4606e 100644
>> --- a/arch/powerpc/platforms/pseries/papr_scm.c
>> +++ b/arch/powerpc/platforms/pseries/papr_scm.c
> [...]
>> +static int handle_mce_ue(struct notifier_block *nb, unsigned long val,
>> + void *data)
>> +{
>> + struct machine_check_event *evt = data;
>> + struct papr_scm_priv *p;
>> + u64 phys_addr;
>> + bool found = false;
>> +
>> + if (evt->error_type != MCE_ERROR_TYPE_UE)
>> + return NOTIFY_DONE;
>> +
>> + if (list_empty(&papr_nd_regions))
>> + return NOTIFY_DONE;
>
> Do you really need this check ?
Quite harmless I guess, atleast it saves a branch and mutex_lock/unlock.
>
>> +
>> + phys_addr = evt->u.ue_error.physical_address +
>> + (evt->u.ue_error.effective_address & ~PAGE_MASK);
>> +
>> + if (!evt->u.ue_error.physical_address_provided ||
>> + !is_zone_device_page(pfn_to_page(phys_addr >> PAGE_SHIFT)))
>> + return NOTIFY_DONE;
>> +
>> + /* mce notifier is called from a process context, so mutex is safe */
>> + mutex_lock(&papr_ndr_lock);
>> + list_for_each_entry(p, &papr_nd_regions, region_list) {
>> + struct resource res = p->res;
>> +
>> + if (phys_addr >= res.start && phys_addr <= res.end) {
>> + found = true;
>> + break;
>> + }
>> + }
>> +
>> + mutex_unlock(&papr_ndr_lock);
>> +
>> + if (!found)
>> + return NOTIFY_DONE;
>> +
>> + papr_scm_add_badblock(p->region, p->bus, phys_addr);
>> +
>> + return NOTIFY_OK;
>> +}
>> +
>> +static struct notifier_block mce_ue_nb = {
>> + .notifier_call = handle_mce_ue
>> +};
>> +
> [...]
>> -module_platform_driver(papr_scm_driver);
>> +static int __init papr_scm_init(void)
>> +{
>> + int ret;
>> +
>> + ret = platform_driver_register(&papr_scm_driver);
>> + if (!ret)
>> + mce_register_notifier(&mce_ue_nb);
>> +
>> + return ret;
>> +}
>> +module_init(papr_scm_init);
>> +
>> +static void __exit papr_scm_exit(void)
>> +{
>> + mce_unregister_notifier(&mce_ue_nb);
>> + platform_driver_unregister(&papr_scm_driver);
>> +}
>> +module_exit(papr_scm_exit);
>
> Rest Looks good to me.
>
> Reviewed-by: Mahesh Salgaonkar <mah...@linux.ibm.com>
Thanks for the review.
Santosh
>
> Thanks,
> -Mahesh.
>
>> +
>> MODULE_DEVICE_TABLE(of, papr_scm_match);
>> MODULE_LICENSE("GPL");
>> MODULE_AUTHOR("IBM Corporation");
>> --
>> 2.25.1
>>
>
> --
> Mahesh J Salgaonkar
