linux-next/include/linux/pci-tph.h
Wei Huang d2e8a34876 PCI/TPH: Add Steering Tag support
Add pcie_tph_get_cpu_st() to allow a caller to retrieve Steering Tags for a
target memory associated with a specific CPU. The ST tag is retrieved by
invoking PCI ACPI "_DSM to Query Cache Locality TPH Features" method
(rev=0x7, func=0xF) of the device's Root Port device.

Add pcie_tph_set_st_entry() to update the device's Steering Tags. The tags
will be written into the device's MSI-X table or the ST table located in
the TPH Extended Capability space.

Co-developed-by: Eric Van Tassell <Eric.VanTassell@amd.com>
Link: https://lore.kernel.org/r/20241002165954.128085-3-wei.huang2@amd.com
Signed-off-by: Eric Van Tassell <Eric.VanTassell@amd.com>
Signed-off-by: Wei Huang <wei.huang2@amd.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
2024-10-02 16:23:10 -05:00

45 lines
1.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* TPH (TLP Processing Hints)
*
* Copyright (C) 2024 Advanced Micro Devices, Inc.
* Eric Van Tassell <Eric.VanTassell@amd.com>
* Wei Huang <wei.huang2@amd.com>
*/
#ifndef LINUX_PCI_TPH_H
#define LINUX_PCI_TPH_H
/*
* According to the ECN for PCI Firmware Spec, Steering Tag can be different
* depending on the memory type: Volatile Memory or Persistent Memory. When a
* caller query about a target's Steering Tag, it must provide the target's
* tph_mem_type. ECN link: https://members.pcisig.com/wg/PCI-SIG/document/15470.
*/
enum tph_mem_type {
TPH_MEM_TYPE_VM, /* volatile memory */
TPH_MEM_TYPE_PM /* persistent memory */
};
#ifdef CONFIG_PCIE_TPH
int pcie_tph_set_st_entry(struct pci_dev *pdev,
unsigned int index, u16 tag);
int pcie_tph_get_cpu_st(struct pci_dev *dev,
enum tph_mem_type mem_type,
unsigned int cpu_uid, u16 *tag);
void pcie_disable_tph(struct pci_dev *pdev);
int pcie_enable_tph(struct pci_dev *pdev, int mode);
#else
static inline int pcie_tph_set_st_entry(struct pci_dev *pdev,
unsigned int index, u16 tag)
{ return -EINVAL; }
static inline int pcie_tph_get_cpu_st(struct pci_dev *dev,
enum tph_mem_type mem_type,
unsigned int cpu_uid, u16 *tag)
{ return -EINVAL; }
static inline void pcie_disable_tph(struct pci_dev *pdev) { }
static inline int pcie_enable_tph(struct pci_dev *pdev, int mode)
{ return -EINVAL; }
#endif
#endif /* LINUX_PCI_TPH_H */