diff options
Diffstat (limited to 'include/linux/blk-mq-dma.h')
-rw-r--r-- | include/linux/blk-mq-dma.h | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/include/linux/blk-mq-dma.h b/include/linux/blk-mq-dma.h new file mode 100644 index 000000000000..c26a01aeae00 --- /dev/null +++ b/include/linux/blk-mq-dma.h @@ -0,0 +1,63 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef BLK_MQ_DMA_H +#define BLK_MQ_DMA_H + +#include <linux/blk-mq.h> +#include <linux/pci-p2pdma.h> + +struct blk_dma_iter { + /* Output address range for this iteration */ + dma_addr_t addr; + u32 len; + + /* Status code. Only valid when blk_rq_dma_map_iter_* returned false */ + blk_status_t status; + + /* Internal to blk_rq_dma_map_iter_* */ + struct req_iterator iter; + struct pci_p2pdma_map_state p2pdma; +}; + +bool blk_rq_dma_map_iter_start(struct request *req, struct device *dma_dev, + struct dma_iova_state *state, struct blk_dma_iter *iter); +bool blk_rq_dma_map_iter_next(struct request *req, struct device *dma_dev, + struct dma_iova_state *state, struct blk_dma_iter *iter); + +/** + * blk_rq_dma_map_coalesce - were all segments coalesced? + * @state: DMA state to check + * + * Returns true if blk_rq_dma_map_iter_start coalesced all segments into a + * single DMA range. + */ +static inline bool blk_rq_dma_map_coalesce(struct dma_iova_state *state) +{ + return dma_use_iova(state); +} + +/** + * blk_rq_dma_unmap - try to DMA unmap a request + * @req: request to unmap + * @dma_dev: device to unmap from + * @state: DMA IOVA state + * @mapped_len: number of bytes to unmap + * + * Returns %false if the callers need to manually unmap every DMA segment + * mapped using @iter or %true if no work is left to be done. + */ +static inline bool blk_rq_dma_unmap(struct request *req, struct device *dma_dev, + struct dma_iova_state *state, size_t mapped_len) +{ + if (req->cmd_flags & REQ_P2PDMA) + return true; + + if (dma_use_iova(state)) { + dma_iova_destroy(dma_dev, state, mapped_len, rq_dma_dir(req), + 0); + return true; + } + + return !dma_need_unmap(dma_dev); +} + +#endif /* BLK_MQ_DMA_H */ |