[tip:x86/mm] drivers/block/pmem: Map NVDIMM in Write-Through mode

[tip-bot for Toshi Kani]

Commit-ID:  957561ec0fa8a701f60ca6a0f40cc46f5c554920
Gitweb:     http://git.kernel.org/tip/957561ec0fa8a701f60ca6a0f40cc46f5c554920
Author:     Toshi Kani <toshi.kani@xxxxxx>
AuthorDate: Thu, 4 Jun 2015 18:55:21 +0200
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Sun, 7 Jun 2015 15:29:01 +0200

drivers/block/pmem: Map NVDIMM in Write-Through mode

The pmem driver maps NVDIMM uncacheable so that we don't lose
data which hasn't reached non-volatile storage in the case of a
crash. Change this to Write-Through mode which provides uncached
writes but cached reads, thus improving read performance.

Signed-off-by: Toshi Kani <toshi.kani@xxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Acked-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Elliott@xxxxxx
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Luis R. Rodriguez <mcgrof@xxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: arnd@xxxxxxxx
Cc: hch@xxxxxx
Cc: hmh@xxxxxxxxxx
Cc: jgross@xxxxxxxx
Cc: konrad.wilk@xxxxxxxxxx
Cc: linux-mm <linux-mm@xxxxxxxxx>
Cc: linux-nvdimm@xxxxxxxxxxxx
Cc: stefan.bader@xxxxxxxxxxxxx
Cc: yigal@xxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/1433436928-31903-14-git-send-email-bp@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 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;
 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/