summaryrefslogtreecommitdiff
path: root/drivers/infiniband
diff options
context:
space:
mode:
authorShiraz Saleem <shiraz.saleem@intel.com>2019-05-06 08:53:33 -0500
committerJason Gunthorpe <jgg@mellanox.com>2019-05-06 13:08:11 -0300
commita808273a495c657e33281b181fd7fcc2bb28f662 (patch)
tree4da75f55f429a761ae4e0bb9bf3126fbe8f996b2 /drivers/infiniband
parent4a35339958f16d42a4ca06a8da9d4b5ab39ee8ea (diff)
RDMA/verbs: Add a DMA iterator to return aligned contiguous memory blocks
This helper iterates over a DMA-mapped SGL and returns contiguous memory blocks aligned to a HW supported page size. Suggested-by: Jason Gunthorpe <jgg@ziepe.ca> Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'drivers/infiniband')
-rw-r--r--drivers/infiniband/core/verbs.c34
1 files changed, 34 insertions, 0 deletions
diff --git a/drivers/infiniband/core/verbs.c b/drivers/infiniband/core/verbs.c
index d607c319ad50..a4e97dd3c4b6 100644
--- a/drivers/infiniband/core/verbs.c
+++ b/drivers/infiniband/core/verbs.c
@@ -2710,3 +2710,37 @@ int rdma_init_netdev(struct ib_device *device, u8 port_num,
netdev, params.param);
}
EXPORT_SYMBOL(rdma_init_netdev);
+
+void __rdma_block_iter_start(struct ib_block_iter *biter,
+ struct scatterlist *sglist, unsigned int nents,
+ unsigned long pgsz)
+{
+ memset(biter, 0, sizeof(struct ib_block_iter));
+ biter->__sg = sglist;
+ biter->__sg_nents = nents;
+
+ /* Driver provides best block size to use */
+ biter->__pg_bit = __fls(pgsz);
+}
+EXPORT_SYMBOL(__rdma_block_iter_start);
+
+bool __rdma_block_iter_next(struct ib_block_iter *biter)
+{
+ unsigned int block_offset;
+
+ if (!biter->__sg_nents || !biter->__sg)
+ return false;
+
+ biter->__dma_addr = sg_dma_address(biter->__sg) + biter->__sg_advance;
+ block_offset = biter->__dma_addr & (BIT_ULL(biter->__pg_bit) - 1);
+ biter->__sg_advance += BIT_ULL(biter->__pg_bit) - block_offset;
+
+ if (biter->__sg_advance >= sg_dma_len(biter->__sg)) {
+ biter->__sg_advance = 0;
+ biter->__sg = sg_next(biter->__sg);
+ biter->__sg_nents--;
+ }
+
+ return true;
+}
+EXPORT_SYMBOL(__rdma_block_iter_next);