blk-mq-dma.h

 1/* SPDX-License-Identifier: GPL-2.0-only */
 2#ifndef BLK_MQ_DMA_H
 3#define BLK_MQ_DMA_H
 4
 5#include <linux/blk-mq.h>
 6#include <linux/pci-p2pdma.h>
 7
 8struct blk_map_iter {
 9	struct bvec_iter		iter;
10	struct bio			*bio;
11	struct bio_vec			*bvecs;
12	bool				is_integrity;
13};
14
15struct blk_dma_iter {
16	/* Output address range for this iteration */
17	dma_addr_t			addr;
18	u32				len;
19	struct pci_p2pdma_map_state	p2pdma;
20
21	/* Status code. Only valid when blk_rq_dma_map_iter_* returned false */
22	blk_status_t			status;
23
24	/* Internal to blk_rq_dma_map_iter_* */
25	struct blk_map_iter		iter;
26};
27
28bool blk_rq_dma_map_iter_start(struct request *req, struct device *dma_dev,
29		struct dma_iova_state *state, struct blk_dma_iter *iter);
30bool blk_rq_dma_map_iter_next(struct request *req, struct device *dma_dev,
31		struct dma_iova_state *state, struct blk_dma_iter *iter);
32
33/**
34 * blk_rq_dma_map_coalesce - were all segments coalesced?
35 * @state: DMA state to check
36 *
37 * Returns true if blk_rq_dma_map_iter_start coalesced all segments into a
38 * single DMA range.
39 */
40static inline bool blk_rq_dma_map_coalesce(struct dma_iova_state *state)
41{
42	return dma_use_iova(state);
43}
44
45/**
46 * blk_rq_dma_unmap - try to DMA unmap a request
47 * @req:	request to unmap
48 * @dma_dev:	device to unmap from
49 * @state:	DMA IOVA state
50 * @mapped_len: number of bytes to unmap
51 * @map:	peer-to-peer mapping type
52 *
53 * Returns %false if the callers need to manually unmap every DMA segment
54 * mapped using @iter or %true if no work is left to be done.
55 */
56static inline bool blk_rq_dma_unmap(struct request *req, struct device *dma_dev,
57		struct dma_iova_state *state, size_t mapped_len,
58		enum pci_p2pdma_map_type map)
59{
60	if (map == PCI_P2PDMA_MAP_BUS_ADDR)
61		return true;
62
63	if (dma_use_iova(state)) {
64		unsigned int attrs = 0;
65
66		if (map == PCI_P2PDMA_MAP_THRU_HOST_BRIDGE)
67			attrs |= DMA_ATTR_MMIO;
68
69		dma_iova_destroy(dma_dev, state, mapped_len, rq_dma_dir(req),
70				 attrs);
71		return true;
72	}
73
74	return !dma_need_unmap(dma_dev);
75}
76#endif /* BLK_MQ_DMA_H */