include/linux/pci-p2pdma.h

   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 */