Commit 595c7307 authored by Dan Williams's avatar Dan Williams
Browse files

libnvdimm, region: fix flush hint table thinko 



The definition of the flush hint table as:

	void __iomem *flush_wpq[0][0];

...passed the unit test, but is broken as flush_wpq[0][1] and
flush_wpq[1][0] refer to the same entry.  Fix this to use a helper that
calculates a slot in the table based on the geometry of flush hints in
the region.  This is important to get right since virtualization
solutions use this mechanism to trigger hypervisor flushes to platform
persistence.

Reported-by: default avatarDave Jiang <dave.jiang@intel.com>
Tested-by: default avatarDave Jiang <dave.jiang@intel.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 11294d63

drivers/nvdimm/nd.h

+20 −2
Original line number Diff line number Diff line
@@ -52,10 +52,28 @@ struct nvdimm_drvdata { 
struct nd_region_data {

	int ns_count;

	int ns_active;

	unsigned int flush_mask;

	void __iomem *flush_wpq[0][0];

	unsigned int hints_shift;

	void __iomem *flush_wpq[0];

};



static inline void __iomem *ndrd_get_flush_wpq(struct nd_region_data *ndrd,

		int dimm, int hint)

{

	unsigned int num = 1 << ndrd->hints_shift;

	unsigned int mask = num - 1;



	return ndrd->flush_wpq[dimm * num + (hint & mask)];

}



static inline void ndrd_set_flush_wpq(struct nd_region_data *ndrd, int dimm,

		int hint, void __iomem *flush)

{

	unsigned int num = 1 << ndrd->hints_shift;

	unsigned int mask = num - 1;



	ndrd->flush_wpq[dimm * num + (hint & mask)] = flush;

}



static inline struct nd_namespace_index *to_namespace_index(

		struct nvdimm_drvdata *ndd, int i)

{

drivers/nvdimm/region_devs.c

+12 −8
Original line number Diff line number Diff line
@@ -38,7 +38,7 @@ static int nvdimm_map_flush(struct device *dev, struct nvdimm *nvdimm, int dimm, 


	dev_dbg(dev, "%s: map %d flush address%s\n", nvdimm_name(nvdimm),

			nvdimm->num_flush, nvdimm->num_flush == 1 ? "" : "es");

	for (i = 0; i < nvdimm->num_flush; i++) {

	for (i = 0; i < (1 << ndrd->hints_shift); i++) {

		struct resource *res = &nvdimm->flush_wpq[i];

		unsigned long pfn = PHYS_PFN(res->start);

		void __iomem *flush_page;
@@ -54,14 +54,15 @@ static int nvdimm_map_flush(struct device *dev, struct nvdimm *nvdimm, int dimm, 


		if (j < i)

			flush_page = (void __iomem *) ((unsigned long)

					ndrd->flush_wpq[dimm][j] & PAGE_MASK);

					ndrd_get_flush_wpq(ndrd, dimm, j)

					& PAGE_MASK);

		else

			flush_page = devm_nvdimm_ioremap(dev,

					PFN_PHYS(pfn), PAGE_SIZE);

		if (!flush_page)

			return -ENXIO;

		ndrd->flush_wpq[dimm][i] = flush_page

			+ (res->start & ~PAGE_MASK);

		ndrd_set_flush_wpq(ndrd, dimm, i, flush_page

				+ (res->start & ~PAGE_MASK));

	}



	return 0;
@@ -93,7 +94,10 @@ int nd_region_activate(struct nd_region *nd_region) 
		return -ENOMEM;

	dev_set_drvdata(dev, ndrd);



	ndrd->flush_mask = (1 << ilog2(num_flush)) - 1;

	if (!num_flush)

		return 0;



	ndrd->hints_shift = ilog2(num_flush);

	for (i = 0; i < nd_region->ndr_mappings; i++) {

		struct nd_mapping *nd_mapping = &nd_region->mapping[i];

		struct nvdimm *nvdimm = nd_mapping->nvdimm;
@@ -900,8 +904,8 @@ void nvdimm_flush(struct nd_region *nd_region) 
	 */

	wmb();

	for (i = 0; i < nd_region->ndr_mappings; i++)

		if (ndrd->flush_wpq[i][0])

			writeq(1, ndrd->flush_wpq[i][idx & ndrd->flush_mask]);

		if (ndrd_get_flush_wpq(ndrd, i, 0))

			writeq(1, ndrd_get_flush_wpq(ndrd, i, idx));

	wmb();

}

EXPORT_SYMBOL_GPL(nvdimm_flush);
@@ -925,7 +929,7 @@ int nvdimm_has_flush(struct nd_region *nd_region) 


	for (i = 0; i < nd_region->ndr_mappings; i++)

		/* flush hints present, flushing required */

		if (ndrd->flush_wpq[i][0])

		if (ndrd_get_flush_wpq(ndrd, i, 0))

			return 1;



	/*

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