From d2e8a34876ce69b27f450eebfc550ab8e316f752 Mon Sep 17 00:00:00 2001 From: Wei Huang Date: Wed, 2 Oct 2024 11:59:51 -0500 Subject: 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 Link: https://lore.kernel.org/r/20241002165954.128085-3-wei.huang2@amd.com Signed-off-by: Eric Van Tassell Signed-off-by: Wei Huang Signed-off-by: Bjorn Helgaas Reviewed-by: Ajit Khaparde Reviewed-by: Somnath Kotur Reviewed-by: Andy Gospodarek --- include/linux/pci-tph.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'include/linux') diff --git a/include/linux/pci-tph.h b/include/linux/pci-tph.h index 58654a334ffb..c3e806c13d64 100644 --- a/include/linux/pci-tph.h +++ b/include/linux/pci-tph.h @@ -9,10 +9,33 @@ #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; } -- cgit v1.2.3