diff options
| author | Shiraz Saleem <shiraz.saleem@intel.com> | 2019-05-06 15:53:33 +0200 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@mellanox.com> | 2019-05-06 18:08:11 +0200 |
| commit | a808273a495c657e33281b181fd7fcc2bb28f662 (patch) | |
| tree | 4da75f55f429a761ae4e0bb9bf3126fbe8f996b2 /drivers/infiniband | |
| parent | RDMA/umem: Add API to find best driver supported page size in an MR (diff) | |
| download | linux-a808273a495c657e33281b181fd7fcc2bb28f662.tar.xz linux-a808273a495c657e33281b181fd7fcc2bb28f662.zip | |
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.c | 34 |
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); |