xref: /linux-6.15/include/linux/pci-p2pdma.h (revision bbcee72c) 
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * PCI Peer 2 Peer DMA support.
4  *
5  * Copyright (c) 2016-2018, Logan Gunthorpe
6  * Copyright (c) 2016-2017, Microsemi Corporation
7  * Copyright (c) 2017, Christoph Hellwig
8  * Copyright (c) 2018, Eideticom Inc.
9  */
10 
11 #ifndef _LINUX_PCI_P2PDMA_H
12 #define _LINUX_PCI_P2PDMA_H
13 
14 #include <linux/pci.h>
15 
16 struct block_device;
17 struct scatterlist;
18 
19 #ifdef CONFIG_PCI_P2PDMA
20 int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, size_t size,
21 		u64 offset);
22 int pci_p2pdma_distance_many(struct pci_dev *provider, struct device **clients,
23 			     int num_clients, bool verbose);
24 bool pci_has_p2pmem(struct pci_dev *pdev);
25 struct pci_dev *pci_p2pmem_find_many(struct device **clients, int num_clients);
26 void *pci_alloc_p2pmem(struct pci_dev *pdev, size_t size);
27 void pci_free_p2pmem(struct pci_dev *pdev, void *addr, size_t size);
28 pci_bus_addr_t pci_p2pmem_virt_to_bus(struct pci_dev *pdev, void *addr);
29 struct scatterlist *pci_p2pmem_alloc_sgl(struct pci_dev *pdev,
30 					 unsigned int *nents, u32 length);
31 void pci_p2pmem_free_sgl(struct pci_dev *pdev, struct scatterlist *sgl);
32 void pci_p2pmem_publish(struct pci_dev *pdev, bool publish);
33 int pci_p2pdma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
34 		int nents, enum dma_data_direction dir, unsigned long attrs);
35 void pci_p2pdma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg,
36 		int nents, enum dma_data_direction dir, unsigned long attrs);
37 int pci_p2pdma_enable_store(const char *page, struct pci_dev **p2p_dev,
38 			    bool *use_p2pdma);
39 ssize_t pci_p2pdma_enable_show(char *page, struct pci_dev *p2p_dev,
40 			       bool use_p2pdma);
41 #else /* CONFIG_PCI_P2PDMA */
42 static inline int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar,
43 		size_t size, u64 offset)
44 {
45 	return -EOPNOTSUPP;
46 }
47 static inline int pci_p2pdma_distance_many(struct pci_dev *provider,
48 	struct device **clients, int num_clients, bool verbose)
49 {
50 	return -1;
51 }
52 static inline bool pci_has_p2pmem(struct pci_dev *pdev)
53 {
54 	return false;
55 }
56 static inline struct pci_dev *pci_p2pmem_find_many(struct device **clients,
57 						   int num_clients)
58 {
59 	return NULL;
60 }
61 static inline void *pci_alloc_p2pmem(struct pci_dev *pdev, size_t size)
62 {
63 	return NULL;
64 }
65 static inline void pci_free_p2pmem(struct pci_dev *pdev, void *addr,
66 		size_t size)
67 {
68 }
69 static inline pci_bus_addr_t pci_p2pmem_virt_to_bus(struct pci_dev *pdev,
70 						    void *addr)
71 {
72 	return 0;
73 }
74 static inline struct scatterlist *pci_p2pmem_alloc_sgl(struct pci_dev *pdev,
75 		unsigned int *nents, u32 length)
76 {
77 	return NULL;
78 }
79 static inline void pci_p2pmem_free_sgl(struct pci_dev *pdev,
80 		struct scatterlist *sgl)
81 {
82 }
83 static inline void pci_p2pmem_publish(struct pci_dev *pdev, bool publish)
84 {
85 }
86 static inline int pci_p2pdma_map_sg_attrs(struct device *dev,
87 		struct scatterlist *sg, int nents, enum dma_data_direction dir,
88 		unsigned long attrs)
89 {
90 	return 0;
91 }
92 static inline void pci_p2pdma_unmap_sg_attrs(struct device *dev,
93 		struct scatterlist *sg, int nents, enum dma_data_direction dir,
94 		unsigned long attrs)
95 {
96 }
97 static inline int pci_p2pdma_enable_store(const char *page,
98 		struct pci_dev **p2p_dev, bool *use_p2pdma)
99 {
100 	*use_p2pdma = false;
101 	return 0;
102 }
103 static inline ssize_t pci_p2pdma_enable_show(char *page,
104 		struct pci_dev *p2p_dev, bool use_p2pdma)
105 {
106 	return sprintf(page, "none\n");
107 }
108 #endif /* CONFIG_PCI_P2PDMA */
109 
110 
111 static inline int pci_p2pdma_distance(struct pci_dev *provider,
112 	struct device *client, bool verbose)
113 {
114 	return pci_p2pdma_distance_many(provider, &client, 1, verbose);
115 }
116 
117 static inline struct pci_dev *pci_p2pmem_find(struct device *client)
118 {
119 	return pci_p2pmem_find_many(&client, 1);
120 }
121 
122 static inline int pci_p2pdma_map_sg(struct device *dev, struct scatterlist *sg,
123 				    int nents, enum dma_data_direction dir)
124 {
125 	return pci_p2pdma_map_sg_attrs(dev, sg, nents, dir, 0);
126 }
127 
128 static inline void pci_p2pdma_unmap_sg(struct device *dev,
129 		struct scatterlist *sg, int nents, enum dma_data_direction dir)
130 {
131 	pci_p2pdma_unmap_sg_attrs(dev, sg, nents, dir, 0);
132 }
133 
134 #endif /* _LINUX_PCI_P2P_H */
135