diff options
| author | Chengwen Feng <fengchengwen@huawei.com> | 2026-04-01 16:16:40 +0800 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2026-04-06 16:55:16 +0200 |
| commit | abdd2a86535b59c76d14da2547160bc83e059c03 (patch) | |
| tree | 8c3dfd7261824828c9676c5012d241d128c1eaea /include/linux | |
| parent | a7034e9e4491573d268126a5e6991b83e95db560 (diff) | |
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 <fengchengwen@huawei.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20260401081640.26875-9-fengchengwen@huawei.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/pci-tph.h | 4 |
1 files changed, 2 insertions, 2 deletions
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) |