From f69767a1ada3ac74be2e1ac0795a05e1d1384eff Mon Sep 17 00:00:00 2001 From: Wei Huang Date: Wed, 2 Oct 2024 11:59:50 -0500 Subject: PCI: Add TLP Processing Hints (TPH) support Add support for PCIe TLP Processing Hints (TPH) support (see PCIe r6.2, sec 6.17). Add TPH register definitions in pci_regs.h, including the TPH Requester capability register, TPH Requester control register, TPH Completer capability, and the ST fields of MSI-X entry. Introduce pcie_enable_tph() and pcie_disable_tph(), enabling drivers to toggle TPH support and configure specific ST mode as needed. Also add a new kernel parameter, "pci=notph", allowing users to disable TPH support across the entire system. Link: https://lore.kernel.org/r/20241002165954.128085-2-wei.huang2@amd.com Co-developed-by: Jing Liu Co-developed-by: Paul Luse Co-developed-by: Eric Van Tassell Signed-off-by: Jing Liu Signed-off-by: Paul Luse 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 Reviewed-by: Jonathan Cameron Reviewed-by: Lukas Wunner --- Documentation/admin-guide/kernel-parameters.txt | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'Documentation/admin-guide/kernel-parameters.txt') diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 1518343bbe22..178995b07451 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -4678,6 +4678,10 @@ nomio [S390] Do not use MIO instructions. norid [S390] ignore the RID field and force use of one PCI domain per PCI function + notph [PCIE] If the PCIE_TPH kernel config parameter + is enabled, this kernel boot option can be used + to disable PCIe TLP Processing Hints support + system-wide. pcie_aspm= [PCIE] Forcibly enable or ignore PCIe Active State Power Management. -- cgit