LXR linux/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
  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(struct device *dev, struct scatterlist *sg, int nents,
  34                      enum dma_data_direction dir);
  35int pci_p2pdma_enable_store(const char *page, struct pci_dev **p2p_dev,
  36                            bool *use_p2pdma);
  37ssize_t pci_p2pdma_enable_show(char *page, struct pci_dev *p2p_dev,
  38                               bool use_p2pdma);
  39#else /* CONFIG_PCI_P2PDMA */
  40static inline int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar,
  41                size_t size, u64 offset)
  42{
  43        return -EOPNOTSUPP;
  44}
  45static inline int pci_p2pdma_distance_many(struct pci_dev *provider,
  46        struct device **clients, int num_clients, bool verbose)
  47{
  48        return -1;
  49}
  50static inline bool pci_has_p2pmem(struct pci_dev *pdev)
  51{
  52        return false;
  53}
  54static inline struct pci_dev *pci_p2pmem_find_many(struct device **clients,
  55                                                   int num_clients)
  56{
  57        return NULL;
  58}
  59static inline void *pci_alloc_p2pmem(struct pci_dev *pdev, size_t size)
  60{
  61        return NULL;
  62}
  63static inline void pci_free_p2pmem(struct pci_dev *pdev, void *addr,
  64                size_t size)
  65{
  66}
  67static inline pci_bus_addr_t pci_p2pmem_virt_to_bus(struct pci_dev *pdev,
  68                                                    void *addr)
  69{
  70        return 0;
  71}
  72static inline struct scatterlist *pci_p2pmem_alloc_sgl(struct pci_dev *pdev,
  73                unsigned int *nents, u32 length)
  74{
  75        return NULL;
  76}
  77static inline void pci_p2pmem_free_sgl(struct pci_dev *pdev,
  78                struct scatterlist *sgl)
  79{
  80}
  81static inline void pci_p2pmem_publish(struct pci_dev *pdev, bool publish)
  82{
  83}
  84static 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}
  89static 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}
  95static 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
 103static 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
 109static 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