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