From abdd2a86535b59c76d14da2547160bc83e059c03 Mon Sep 17 00:00:00 2001 From: Chengwen Feng Date: Wed, 1 Apr 2026 16:16:40 +0800 Subject: PCI/TPH: Pass ACPI Processor UID to Cache Locality _DSM pcie_tph_get_cpu_st() uses the Query Cache Locality Features _DSM [1] to retrieve the TPH Steering Tag for memory associated with the CPU identified by its "cpu_uid" parameter, a Linux logical CPU ID. The _DSM requires an ACPI Processor UID, which pcie_tph_get_cpu_st() previously assumed was the same as the Linux logical CPU ID. This is true on x86 but not on arm64, so pcie_tph_get_cpu_st() returned the wrong Steering Tag, resulting in incorrect TPH functionality on arm64. Convert the Linux logical CPU ID to the ACPI Processor UID with acpi_get_cpu_uid() before passing it to the _DSM. Additionally, rename the pcie_tph_get_cpu_st() parameter from "cpu_uid" to "cpu" to reflect that it represents a logical CPU ID (not an ACPI Processor UID). [1] According to ECN_TPH-ST_Revision_20200924 (https://members.pcisig.com/wg/PCI-SIG/document/15470), the input is defined as: "If the target is a processor, then this field represents the ACPI Processor UID of the processor as specified in the MADT. If the target is a processor container, then this field represents the ACPI Processor UID of the processor container as specified in the PPTT." Fixes: d2e8a34876ce ("PCI/TPH: Add Steering Tag support") Signed-off-by: Chengwen Feng Reviewed-by: Jonathan Cameron Reviewed-by: Bjorn Helgaas Link: https://patch.msgid.link/20260401081640.26875-9-fengchengwen@huawei.com Signed-off-by: Rafael J. Wysocki --- include/linux/pci-tph.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/pci-tph.h b/include/linux/pci-tph.h index ba28140ce670..be68cd17f2f8 100644 --- a/include/linux/pci-tph.h +++ b/include/linux/pci-tph.h @@ -25,7 +25,7 @@ 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); + unsigned int cpu, u16 *tag); void pcie_disable_tph(struct pci_dev *pdev); int pcie_enable_tph(struct pci_dev *pdev, int mode); u16 pcie_tph_get_st_table_size(struct pci_dev *pdev); @@ -36,7 +36,7 @@ static inline int pcie_tph_set_st_entry(struct pci_dev *pdev, { 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) + unsigned int cpu, 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) -- cgit v1.2.3