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
 16struct block_device;
 17struct scatterlist;
 18
 19#ifdef CONFIG_PCI_P2PDMA
 20int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, size_t size,
 21		u64 offset);
 22int pci_p2pdma_distance_many(struct pci_dev *provider, struct device **clients,
 23			     int num_clients, bool verbose);
 24bool pci_has_p2pmem(struct pci_dev *pdev);
 25struct pci_dev *pci_p2pmem_find_many(struct device **clients, int num_clients);
 26void *pci_alloc_p2pmem(struct pci_dev *pdev, size_t size);
 27void pci_free_p2pmem(struct pci_dev *pdev, void *addr, size_t size);
 28pci_bus_addr_t pci_p2pmem_virt_to_bus(struct pci_dev *pdev, void *addr);
 29struct scatterlist *pci_p2pmem_alloc_sgl(struct pci_dev *pdev,
 30					 unsigned int *nents, u32 length);
 31void pci_p2pmem_free_sgl(struct pci_dev *pdev, struct scatterlist *sgl);
 32void pci_p2pmem_publish(struct pci_dev *pdev, bool publish);
 33int pci_p2pdma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
 34		int nents, enum dma_data_direction dir, unsigned long attrs);
 35void pci_p2pdma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg,
 36		int nents, enum dma_data_direction dir, unsigned long attrs);
 37int pci_p2pdma_enable_store(const char *page, struct pci_dev **p2p_dev,
 38			    bool *use_p2pdma);
 39ssize_t pci_p2pdma_enable_show(char *page, struct pci_dev *p2p_dev,
 40			       bool use_p2pdma);
 41#else /* CONFIG_PCI_P2PDMA */
 42static inline int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar,
 43		size_t size, u64 offset)
 44{
 45	return -EOPNOTSUPP;
 46}
 47static inline int pci_p2pdma_distance_many(struct pci_dev *provider,
 48	struct device **clients, int num_clients, bool verbose)
 49{
 50	return -1;
 51}
 52static inline bool pci_has_p2pmem(struct pci_dev *pdev)
 53{
 54	return false;
 55}
 56static inline struct pci_dev *pci_p2pmem_find_many(struct device **clients,
 57						   int num_clients)
 58{
 59	return NULL;
 60}
 61static inline void *pci_alloc_p2pmem(struct pci_dev *pdev, size_t size)
 62{
 63	return NULL;
 64}
 65static inline void pci_free_p2pmem(struct pci_dev *pdev, void *addr,
 66		size_t size)
 67{
 68}
 69static inline pci_bus_addr_t pci_p2pmem_virt_to_bus(struct pci_dev *pdev,
 70						    void *addr)
 71{
 72	return 0;
 73}
 74static inline struct scatterlist *pci_p2pmem_alloc_sgl(struct pci_dev *pdev,
 75		unsigned int *nents, u32 length)
 76{
 77	return NULL;
 78}
 79static inline void pci_p2pmem_free_sgl(struct pci_dev *pdev,
 80		struct scatterlist *sgl)
 81{
 82}
 83static inline void pci_p2pmem_publish(struct pci_dev *pdev, bool publish)
 84{
 85}
 86static 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}
 92static 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}
 97static 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}
103static 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
111static 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
117static inline struct pci_dev *pci_p2pmem_find(struct device *client)
118{
119	return pci_p2pmem_find_many(&client, 1);
120}
121
122static 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
128static 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 */