nvme: add helper nvme_map_len()
The helper returns the number of bytes that need to be mapped
using PRPs/SGL entries.
Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index f846da4..6376cd7 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -173,6 +173,14 @@
return (sector >> (ns->lba_shift - 9));
}
+static inline unsigned nvme_map_len(struct request *rq)
+{
+ if (rq->cmd_flags & REQ_DISCARD)
+ return sizeof(struct nvme_dsm_range);
+ else
+ return blk_rq_bytes(rq);
+}
+
static inline void nvme_setup_flush(struct nvme_ns *ns,
struct nvme_command *cmnd)
{
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 154194e..d23ede7 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -334,16 +334,11 @@
return (__le64 **)(iod->sg + req->nr_phys_segments);
}
-static int nvme_init_iod(struct request *rq, struct nvme_dev *dev)
+static int nvme_init_iod(struct request *rq, unsigned size,
+ struct nvme_dev *dev)
{
struct nvme_iod *iod = blk_mq_rq_to_pdu(rq);
int nseg = rq->nr_phys_segments;
- unsigned size;
-
- if (rq->cmd_flags & REQ_DISCARD)
- size = sizeof(struct nvme_dsm_range);
- else
- size = blk_rq_bytes(rq);
if (nseg > NVME_INT_PAGES || size > NVME_INT_BYTES(dev)) {
iod->sg = kmalloc(nvme_iod_alloc_size(dev, size, nseg), GFP_ATOMIC);
@@ -637,6 +632,7 @@
struct nvme_dev *dev = nvmeq->dev;
struct request *req = bd->rq;
struct nvme_command cmnd;
+ unsigned map_len;
int ret = BLK_MQ_RQ_QUEUE_OK;
/*
@@ -652,7 +648,8 @@
}
}
- ret = nvme_init_iod(req, dev);
+ map_len = nvme_map_len(req);
+ ret = nvme_init_iod(req, map_len, dev);
if (ret)
return ret;