From: Xi Wang wangxi11@huawei.com
driver inclusion category: bugfix bugzilla: NA CVE: NA
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 Signed-off-by: Xi Wang wangxi11@huawei.com Signed-off-by: Shunfeng Yang yangshunfeng2@huawei.com Reviewed-by: chunzhi hu huchunzhi@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/infiniband/core/verbs.c | 34 ++++++++++++++++++++++++ include/rdma/ib_verbs.h | 47 +++++++++++++++++++++++++++++++++ 2 files changed, 81 insertions(+)
diff --git a/drivers/infiniband/core/verbs.c b/drivers/infiniband/core/verbs.c index e1ecd4682c096..6467645c84d09 100644 --- a/drivers/infiniband/core/verbs.c +++ b/drivers/infiniband/core/verbs.c @@ -2628,3 +2628,37 @@ void ib_drain_qp(struct ib_qp *qp) ib_drain_rq(qp); } EXPORT_SYMBOL(ib_drain_qp); + +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); diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h index c1c1a61d81f6e..43a7426b43a15 100644 --- a/include/rdma/ib_verbs.h +++ b/include/rdma/ib_verbs.h @@ -2629,6 +2629,21 @@ struct ib_client { struct list_head list; };
+/* + * IB block DMA iterator + * + * Iterates the DMA-mapped SGL in contiguous memory blocks aligned + * to a HW supported page size. + */ +struct ib_block_iter { + /* internal states */ + struct scatterlist *__sg; /* sg holding the current aligned block */ + dma_addr_t __dma_addr; /* unaligned DMA address of this block */ + unsigned int __sg_nents; /* number of SG entries */ + unsigned int __sg_advance; /* number of bytes to advance in sg in next step */ + unsigned int __pg_bit; /* alignment of current block */ +}; + struct ib_device *ib_alloc_device(size_t size); void ib_dealloc_device(struct ib_device *device);
@@ -2642,6 +2657,38 @@ void ib_unregister_device(struct ib_device *device); int ib_register_client (struct ib_client *client); void ib_unregister_client(struct ib_client *client);
+void __rdma_block_iter_start(struct ib_block_iter *biter, + struct scatterlist *sglist, + unsigned int nents, + unsigned long pgsz); +bool __rdma_block_iter_next(struct ib_block_iter *biter); + +/** + * rdma_block_iter_dma_address - get the aligned dma address of the current + * block held by the block iterator. + * @biter: block iterator holding the memory block + */ +static inline dma_addr_t +rdma_block_iter_dma_address(struct ib_block_iter *biter) +{ + return biter->__dma_addr & ~(BIT_ULL(biter->__pg_bit) - 1); +} + +/** + * rdma_for_each_block - iterate over contiguous memory blocks of the sg list + * @sglist: sglist to iterate over + * @biter: block iterator holding the memory block + * @nents: maximum number of sg entries to iterate over + * @pgsz: best HW supported page size to use + * + * Callers may use rdma_block_iter_dma_address() to get each + * blocks aligned DMA address. + */ +#define rdma_for_each_block(sglist, biter, nents, pgsz) \ + for (__rdma_block_iter_start(biter, sglist, nents, \ + pgsz); \ + __rdma_block_iter_next(biter);) + void *ib_get_client_data(struct ib_device *device, struct ib_client *client); void ib_set_client_data(struct ib_device *device, struct ib_client *client, void *data);