Commit 338f6dac authored Mar 24, 2020 by Aneesh Kumar K.V Committed by Dan Williams Mar 31, 2020

libnvdimm: Update persistence domain value for of_pmem and papr_scm device



Currently, kernel shows the below values
	"persistence_domain":"cpu_cache"
	"persistence_domain":"memory_controller"
	"persistence_domain":"unknown"

"cpu_cache" indicates no extra instructions is needed to ensure the persistence
of data in the pmem media on power failure.

"memory_controller" indicates cpu cache flush instructions are required to flush
the data. Platform provides mechanisms to automatically flush outstanding
write data from memory controler to pmem on system power loss.

Based on the above use memory_controller for non volatile regions on ppc64.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/20200324034821.60869-1-aneesh.kumar@linux.ibm.com


Signed-off-by: Dan Williams <dan.j.williams@intel.com>

parent 9106137c

arch/powerpc/platforms/pseries/papr_scm.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -361,8 +361,10 @@ static int papr_scm_nvdimm_init(struct papr_scm_priv *p)

		if (p->is_volatile)
		p->region = nvdimm_volatile_region_create(p->bus, &ndr_desc);
		else
		else {
		set_bit(ND_REGION_PERSIST_MEMCTRL, &ndr_desc.flags);
		p->region = nvdimm_pmem_region_create(p->bus, &ndr_desc);
		}
		if (!p->region) {
		dev_err(dev, "Error registering region %pR from %pOF\n",
		ndr_desc.res, p->dn);

drivers/nvdimm/of_pmem.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -62,8 +62,10 @@ static int of_pmem_region_probe(struct platform_device *pdev)

		if (is_volatile)
		region = nvdimm_volatile_region_create(bus, &ndr_desc);
		else
		else {
		set_bit(ND_REGION_PERSIST_MEMCTRL, &ndr_desc.flags);
		region = nvdimm_pmem_region_create(bus, &ndr_desc);
		}

		if (!region)
		dev_warn(&pdev->dev, "Unable to register region %pR from %pOF\n",

Admin message