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 <[email protected]>
7  *     Wei Huang <[email protected]>
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
pcie_tph_set_st_entry(struct pci_dev * pdev,unsigned int index,u16 tag)32 static inline int pcie_tph_set_st_entry(struct pci_dev *pdev,
33 					unsigned int index, u16 tag)
34 { return -EINVAL; }
pcie_tph_get_cpu_st(struct pci_dev * dev,enum tph_mem_type mem_type,unsigned int cpu_uid,u16 * tag)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; }
pcie_disable_tph(struct pci_dev * pdev)39 static inline void pcie_disable_tph(struct pci_dev *pdev) { }
pcie_enable_tph(struct pci_dev * pdev,int mode)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 */
45