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Subject[PATCH 4/6] pmem, nd_blk: update I/O paths to use PMEM API
Date
Update the PMEM and ND_BLK I/O paths to use the new PMEM API and to
adhere to the read/write flows outlined in the "NVDIMM Block Window
Driver Writer's Guide":

http://pmem.io/documents/NVDIMM_Driver_Writers_Guide.pdf

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: linux-nvdimm@lists.01.org
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: linux-acpi@vger.kernel.org
---
drivers/acpi/nfit.c | 10 ++++++++--
drivers/block/nd/pmem.c | 15 +++++++++++----
2 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c
index df14652ea13e..22df61968c1c 100644
--- a/drivers/acpi/nfit.c
+++ b/drivers/acpi/nfit.c
@@ -18,6 +18,7 @@
#include <linux/list.h>
#include <linux/acpi.h>
#include <linux/sort.h>
+#include <linux/pmem.h>
#include <linux/io.h>
#include "nfit.h"

@@ -926,7 +927,9 @@ static void write_blk_ctl(struct nfit_blk *nfit_blk, unsigned int bw,
if (mmio->num_lines)
offset = to_interleave_offset(offset, mmio);

+ /* mmio->base must be mapped uncacheable */
writeq(cmd, mmio->base + offset);
+ persistent_sync();
/* FIXME: conditionally perform read-back if mandated by firmware */
}

@@ -940,7 +943,6 @@ static int acpi_nfit_blk_single_io(struct nfit_blk *nfit_blk, void *iobuf,
int rc;

base_offset = nfit_blk->bdw_offset + dpa % L1_CACHE_BYTES + bw * mmio->size;
- /* TODO: non-temporal access, flush hints, cache management etc... */
write_blk_ctl(nfit_blk, bw, dpa, len, write);
while (len) {
unsigned int c;
@@ -959,13 +961,17 @@ static int acpi_nfit_blk_single_io(struct nfit_blk *nfit_blk, void *iobuf,
}

if (write)
- memcpy(mmio->aperture + offset, iobuf + copied, c);
+ persistent_copy(mmio->aperture + offset, iobuf + copied, c);
else
memcpy(iobuf + copied, mmio->aperture + offset, c);

copied += c;
len -= c;
}
+
+ if (write)
+ persistent_sync();
+
rc = read_blk_stat(nfit_blk, bw) ? -EIO : 0;
return rc;
}
diff --git a/drivers/block/nd/pmem.c b/drivers/block/nd/pmem.c
index a8712e41e7f5..1a447c351aef 100644
--- a/drivers/block/nd/pmem.c
+++ b/drivers/block/nd/pmem.c
@@ -15,15 +15,16 @@
* more details.
*/

-#include <asm/cacheflush.h>
#include <linux/blkdev.h>
#include <linux/hdreg.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
+#include <linux/pmem.h>
#include <linux/slab.h>
#include <linux/nd.h>
+#include <asm/cacheflush.h>
#include "nd.h"

struct pmem_device {
@@ -51,7 +52,7 @@ static void pmem_do_bvec(struct pmem_device *pmem, struct page *page,
flush_dcache_page(page);
} else {
flush_dcache_page(page);
- memcpy(pmem->virt_addr + pmem_off, mem + off, len);
+ persistent_copy(pmem->virt_addr + pmem_off, mem + off, len);
}

kunmap_atomic(mem);
@@ -82,6 +83,8 @@ static void pmem_make_request(struct request_queue *q, struct bio *bio)
sector += bvec.bv_len >> 9;
}

+ if (rw & WRITE)
+ persistent_sync();
out:
bio_endio(bio, err);
}
@@ -92,6 +95,8 @@ static int pmem_rw_page(struct block_device *bdev, sector_t sector,
struct pmem_device *pmem = bdev->bd_disk->private_data;

pmem_do_bvec(pmem, page, PAGE_CACHE_SIZE, 0, rw, sector);
+ if (rw & WRITE)
+ persistent_sync();
page_endio(page, rw & WRITE, 0);

return 0;
@@ -111,8 +116,10 @@ static int pmem_rw_bytes(struct nd_io *ndio, void *buf, size_t offset,

if (rw == READ)
memcpy(buf, pmem->virt_addr + offset, n);
- else
- memcpy(pmem->virt_addr + offset, buf, n);
+ else {
+ persistent_copy(pmem->virt_addr + offset, buf, n);
+ persistent_sync();
+ }

return 0;
}
--
1.9.3


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