When we reenable TPH after changing a Steering Tag value, we need the
actual TPH Requester Enable value, not the ST Mode (which only happens to
work out by chance for non-extended TPH in interrupt vector mode).
Link: https://lore.kernel.org/r/13118098116d7bce07aa20b8c52e28c7d1847246.1738759933.git.robin.murphy@arm.com
Fixes: d2e8a34876 ("PCI/TPH: Add Steering Tag support")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Wei Huang <wei.huang2@amd.com>
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>
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 <jing2.liu@intel.com>
Co-developed-by: Paul Luse <paul.e.luse@linux.intel.com>
Co-developed-by: Eric Van Tassell <Eric.VanTassell@amd.com>
Signed-off-by: Jing Liu <jing2.liu@intel.com>
Signed-off-by: Paul Luse <paul.e.luse@linux.intel.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>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Robin Murphy
Wei Huang