include/linux/pci-tph.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * TPH (TLP Processing Hints)
   4  *
   5  * Copyright (C) 2024 Advanced Micro Devices, Inc.
   6  *     Eric Van Tassell <Eric.VanTassell@amd.com>
   7  *     Wei Huang <wei.huang2@amd.com>
   8  */
   9 #ifndef LINUX_PCI_TPH_H
  10 #define LINUX_PCI_TPH_H
  11
  12 /*
  13  * According to the ECN for PCI Firmware Spec, Steering Tag can be different
  14  * depending on the memory type: Volatile Memory or Persistent Memory. When a
  15  * caller query about a target's Steering Tag, it must provide the target's
  16  * tph_mem_type. ECN link: https://members.pcisig.com/wg/PCI-SIG/document/15470.
  17  */
  18 enum tph_mem_type {
  19         TPH_MEM_TYPE_VM,        /* volatile memory */
  20         TPH_MEM_TYPE_PM         /* persistent memory */
  21 };
  22
  23 #ifdef CONFIG_PCIE_TPH
  24 int pcie_tph_set_st_entry(struct pci_dev *pdev,
  25                           unsigned int index, u16 tag);
  26 int pcie_tph_get_cpu_st(struct pci_dev *dev,
  27                         enum tph_mem_type mem_type,
  28                         unsigned int cpu_uid, u16 *tag);
  29 void pcie_disable_tph(struct pci_dev *pdev);
  30 int pcie_enable_tph(struct pci_dev *pdev, int mode);
  31 #else
  32 static inline int pcie_tph_set_st_entry(struct pci_dev *pdev,
  33                                         unsigned int index, u16 tag)
  34 { return -EINVAL; }
  35 static inline int pcie_tph_get_cpu_st(struct pci_dev *dev,
  36                                       enum tph_mem_type mem_type,
  37                                       unsigned int cpu_uid, u16 *tag)
  38 { return -EINVAL; }
  39 static inline void pcie_disable_tph(struct pci_dev *pdev) { }
  40 static inline int pcie_enable_tph(struct pci_dev *pdev, int mode)
  41 { return -EINVAL; }
  42 #endif
  43
  44 #endif /* LINUX_PCI_TPH_H */