@@ -275,6 +275,7 @@ static int pmem_attach_disk(struct device *dev,
struct vmem_altmap __altmap, *altmap = NULL;
struct resource *res = &nsio->res;
struct nd_pfn *nd_pfn = NULL;
+ int has_flush, fua = 0, wbc;
struct dax_device *dax_dev;
int nid = dev_to_node(dev);
struct nd_pfn_sb *pfn_sb;
@@ -302,8 +303,12 @@ static int pmem_attach_disk(struct device *dev,
dev_set_drvdata(dev, pmem);
pmem->phys_addr = res->start;
pmem->size = resource_size(res);
- if (nvdimm_has_flush(nd_region) < 0)
+ has_flush = nvdimm_has_flush(nd_region);
+ if (has_flush < 0)
dev_warn(dev, "unable to guarantee persistence of writes\n");
+ else
+ fua = has_flush;
+ wbc = nvdimm_has_cache(nd_region);
if (!devm_request_mem_region(dev, res->start, resource_size(res),
dev_name(&ndns->dev))) {
@@ -344,7 +349,7 @@ static int pmem_attach_disk(struct device *dev,
return PTR_ERR(addr);
pmem->virt_addr = addr;
- blk_queue_write_cache(q, true, true);
+ blk_queue_write_cache(q, wbc, fua);
blk_queue_make_request(q, pmem_make_request);
blk_queue_physical_block_size(q, PAGE_SIZE);
blk_queue_max_hw_sectors(q, UINT_MAX);
@@ -989,6 +989,12 @@ int nvdimm_has_flush(struct nd_region *nd_region)
}
EXPORT_SYMBOL_GPL(nvdimm_has_flush);
+int nvdimm_has_cache(struct nd_region *nd_region)
+{
+ return is_nd_pmem(&nd_region->dev);
+}
+EXPORT_SYMBOL_GPL(nvdimm_has_cache);
+
void __exit nd_region_devs_exit(void)
{
ida_destroy(®ion_ida);
@@ -162,6 +162,7 @@ void nd_region_release_lane(struct nd_region *nd_region, unsigned int lane);
u64 nd_fletcher64(void *addr, size_t len, bool le);
void nvdimm_flush(struct nd_region *nd_region);
int nvdimm_has_flush(struct nd_region *nd_region);
+int nvdimm_has_cache(struct nd_region *nd_region);
#ifdef CONFIG_ARCH_HAS_PMEM_API
void arch_memcpy_to_pmem(void *dst, void *src, unsigned size);
#define ARCH_MEMREMAP_PMEM MEMREMAP_WB
The pmem driver attaches to both persistent and volatile memory ranges advertised by the ACPI NFIT. When the region is volatile it is redundant to spend cycles flushing caches at fsync(). Check if the hosting region is volatile and do not set QUEUE_FLAG_WC if it is. Cc: Jan Kara <jack@suse.cz> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- drivers/nvdimm/pmem.c | 9 +++++++-- drivers/nvdimm/region_devs.c | 6 ++++++ include/linux/libnvdimm.h | 1 + 3 files changed, 14 insertions(+), 2 deletions(-)