[PATCH RESEND 2/2] papr/scm: Add bad memory ranges to nvdimm bad ranges

[Santosh Sivaraj]

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

> Le 09/07/2020 à 09:56, Santosh Sivaraj a écrit :
>> Subscribe to the MCE notification and add the physical address which
>> generated a memory error to nvdimm bad range.
>> 
>> Reviewed-by: Mahesh Salgaonkar <mahesh at linux.ibm.com>
>> Signed-off-by: Santosh Sivaraj <santosh at fossix.org>
>> ---
>>   arch/powerpc/platforms/pseries/papr_scm.c | 98 ++++++++++++++++++++++-
>>   1 file changed, 97 insertions(+), 1 deletion(-)
>> 
>> diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c
>> index 9c569078a09fd..5ebb1c797795d 100644
>> --- a/arch/powerpc/platforms/pseries/papr_scm.c
>> +++ b/arch/powerpc/platforms/pseries/papr_scm.c
>> @@ -13,9 +13,11 @@
>>   #include <linux/platform_device.h>
>>   #include <linux/delay.h>
>>   #include <linux/seq_buf.h>
>> +#include <linux/nd.h>
>>   
>>   #include <asm/plpar_wrappers.h>
>>   #include <asm/papr_pdsm.h>
>> +#include <asm/mce.h>
>>   
>>   #define BIND_ANY_ADDR (~0ul)
>>   
>> @@ -80,6 +82,7 @@ struct papr_scm_priv {
>>   	struct resource res;
>>   	struct nd_region *region;
>>   	struct nd_interleave_set nd_set;
>> +	struct list_head region_list;
>>   
>>   	/* Protect dimm health data from concurrent read/writes */
>>   	struct mutex health_mutex;
>> @@ -91,6 +94,9 @@ struct papr_scm_priv {
>>   	u64 health_bitmap;
>>   };
>>   
>> +LIST_HEAD(papr_nd_regions);
>> +DEFINE_MUTEX(papr_ndr_lock);
>> +
>>   static int drc_pmem_bind(struct papr_scm_priv *p)
>>   {
>>   	unsigned long ret[PLPAR_HCALL_BUFSIZE];
>> @@ -759,6 +765,10 @@ static int papr_scm_nvdimm_init(struct papr_scm_priv *p)
>>   		dev_info(dev, "Region registered with target node %d and online node %d",
>>   			 target_nid, online_nid);
>>   
>> +	mutex_lock(&papr_ndr_lock);
>> +	list_add_tail(&p->region_list, &papr_nd_regions);
>> +	mutex_unlock(&papr_ndr_lock);
>> +
>>   	return 0;
>>   
>>   err:	nvdimm_bus_unregister(p->bus);
>> @@ -766,6 +776,70 @@ err:	nvdimm_bus_unregister(p->bus);
>>   	return -ENXIO;
>>   }
>>   
>> +static void papr_scm_add_badblock(struct nd_region *region,
>> +				  struct nvdimm_bus *bus, u64 phys_addr)
>> +{
>> +	u64 aligned_addr = ALIGN_DOWN(phys_addr, L1_CACHE_BYTES);
>> +
>> +	if (nvdimm_bus_add_badrange(bus, aligned_addr, L1_CACHE_BYTES)) {
>> +		pr_err("Bad block registration for 0x%llx failed\n", phys_addr);
>> +		return;
>> +	}
>> +
>> +	pr_debug("Add memory range (0x%llx - 0x%llx) as bad range\n",
>> +		 aligned_addr, aligned_addr + L1_CACHE_BYTES);
>> +
>> +	nvdimm_region_notify(region, NVDIMM_REVALIDATE_POISON);
>> +}
>> +
>> +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;
>> +
>> +	/*
>> +	 * The physical address obtained here is PAGE_SIZE aligned, so get the
>> +	 * exact address from the effective address
>> +	 */
>> +	phys_addr = evt->u.ue_error.physical_address +
>> +		(evt->u.ue_error.effective_address & ~PAGE_MASK);
>
> Not properly aligned

Will fix it.

>
>> +
>> +	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;
>
> Is this local struct really worth it ? Why not use p->res below directly ?
>

Right, not really needed. I can fix that in v2.

>> +
>> +		if (phys_addr >= res.start && phys_addr <= res.end) {
>> +			found = true;
>> +			break;
>> +		}
>> +	}
>> +
>> +	if (found)
>> +		papr_scm_add_badblock(p->region, p->bus, phys_addr);
>> +
>> +	mutex_unlock(&papr_ndr_lock);
>> +
>> +	return found ? NOTIFY_OK : NOTIFY_DONE;
>> +}
>> +
>> +static struct notifier_block mce_ue_nb = {
>> +	.notifier_call = handle_mce_ue
>> +};
>> +
>>   static int papr_scm_probe(struct platform_device *pdev)
>>   {
>>   	struct device_node *dn = pdev->dev.of_node;
>> @@ -866,6 +940,10 @@ static int papr_scm_remove(struct platform_device *pdev)
>>   {
>>   	struct papr_scm_priv *p = platform_get_drvdata(pdev);
>>   
>> +	mutex_lock(&papr_ndr_lock);
>> +	list_del(&(p->region_list));
>> +	mutex_unlock(&papr_ndr_lock);
>> +
>>   	nvdimm_bus_unregister(p->bus);
>>   	drc_pmem_unbind(p);
>>   	kfree(p->bus_desc.provider_name);
>> @@ -888,7 +966,25 @@ static struct platform_driver papr_scm_driver = {
>>   	},
>>   };
>>   
>> -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;
>
> Not properly aligned.

will fix it.

Thanks for the review!

Thanks,
Santosh
>
>> +}
>> +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);
>> +
>>   MODULE_DEVICE_TABLE(of, papr_scm_match);
>>   MODULE_LICENSE("GPL");
>>   MODULE_AUTHOR("IBM Corporation");
>> 
>
> Christophe