[PATCH v9 10/10] drivers/block/pmem: Map NVDIMM with ioremap_wt()

[Toshi Kani <toshi.kani@hp.com>]

The pmem driver maps NVDIMM with ioremap_nocache() as we cannot
write back the contents of the CPU caches in case of a crash.

This patch changes to use ioremap_wt(), which provides uncached
writes but cached reads, for improving read performance.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
---
 drivers/block/pmem.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/block/pmem.c b/drivers/block/pmem.c
index eabf4a8..095dfaa 100644
--- a/drivers/block/pmem.c
+++ b/drivers/block/pmem.c
@@ -139,11 +139,11 @@ static struct pmem_device *pmem_alloc(struct device *dev, struct resource *res)
 	}
 
 	/*
-	 * Map the memory as non-cachable, as we can't write back the contents
+	 * Map the memory as write-through, as we can't write back the contents
 	 * of the CPU caches in case of a crash.
 	 */
 	err = -ENOMEM;
-	pmem->virt_addr = ioremap_nocache(pmem->phys_addr, pmem->size);
+	pmem->virt_addr = ioremap_wt(pmem->phys_addr, pmem->size);
 	if (!pmem->virt_addr)
 		goto out_release_region;
 

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