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(struct device *dev, struct scatterlist *sg, int nents, 34 enum dma_data_direction dir); 35 int pci_p2pdma_enable_store(const char *page, struct pci_dev **p2p_dev, 36 bool *use_p2pdma); 37 ssize_t pci_p2pdma_enable_show(char *page, struct pci_dev *p2p_dev, 38 bool use_p2pdma); 39 #else /* CONFIG_PCI_P2PDMA */ 40 static inline int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, 41 size_t size, u64 offset) 42 { 43 return -EOPNOTSUPP; 44 } 45 static inline int pci_p2pdma_distance_many(struct pci_dev *provider, 46 struct device **clients, int num_clients, bool verbose) 47 { 48 return -1; 49 } 50 static inline bool pci_has_p2pmem(struct pci_dev *pdev) 51 { 52 return false; 53 } 54 static inline struct pci_dev *pci_p2pmem_find_many(struct device **clients, 55 int num_clients) 56 { 57 return NULL; 58 } 59 static inline void *pci_alloc_p2pmem(struct pci_dev *pdev, size_t size) 60 { 61 return NULL; 62 } 63 static inline void pci_free_p2pmem(struct pci_dev *pdev, void *addr, 64 size_t size) 65 { 66 } 67 static inline pci_bus_addr_t pci_p2pmem_virt_to_bus(struct pci_dev *pdev, 68 void *addr) 69 { 70 return 0; 71 } 72 static inline struct scatterlist *pci_p2pmem_alloc_sgl(struct pci_dev *pdev, 73 unsigned int *nents, u32 length) 74 { 75 return NULL; 76 } 77 static inline void pci_p2pmem_free_sgl(struct pci_dev *pdev, 78 struct scatterlist *sgl) 79 { 80 } 81 static inline void pci_p2pmem_publish(struct pci_dev *pdev, bool publish) 82 { 83 } 84 static inline int pci_p2pdma_map_sg(struct device *dev, 85 struct scatterlist *sg, int nents, enum dma_data_direction dir) 86 { 87 return 0; 88 } 89 static inline int pci_p2pdma_enable_store(const char *page, 90 struct pci_dev **p2p_dev, bool *use_p2pdma) 91 { 92 *use_p2pdma = false; 93 return 0; 94 } 95 static inline ssize_t pci_p2pdma_enable_show(char *page, 96 struct pci_dev *p2p_dev, bool use_p2pdma) 97 { 98 return sprintf(page, "none\n"); 99 } 100 #endif /* CONFIG_PCI_P2PDMA */ 101 102 103 static inline int pci_p2pdma_distance(struct pci_dev *provider, 104 struct device *client, bool verbose) 105 { 106 return pci_p2pdma_distance_many(provider, &client, 1, verbose); 107 } 108 109 static inline struct pci_dev *pci_p2pmem_find(struct device *client) 110 { 111 return pci_p2pmem_find_many(&client, 1); 112 } 113 114 #endif /* _LINUX_PCI_P2P_H */ 115