Hi all, I am currently working on a custom AMD Ryzen™ Embedded R2000 (AMD Family 17h) device and have discovered that PCI IO Extended Configuration Space (ECS) access is no longer possible. Consider the following functions: amd_bus_cpu_online() and pci_enable_pci_io_ecs(). These functions are part of the amd_postcore_init() initcall and are responsible for enabling PCI IO ECS. Both functions modify the CoreMasterAccessCtrl (EnableCf8ExtCfg) value via the PCI device function or the MSR register directly (see the "BIOS and Kernel Developer’s Guide (BKDG) for AMD Family 15h", Section 2.7). However, neither the MSR register nor the PCI function at the specified address (D18F3x8C) exists for AMD Family 17h. The CoreMasterAccessCtrl register still exists but is now located at a different address (see the "Processor Programming Reference (PPR) for AMD Family 17h", Section 2.1.8). I would be happy to submit a patch to fix this issue. However, since the most recent change affecting this functionality appears to be 14 years old, I would like to confirm whether this is still relevant or if the kernel should always be built with CONFIG_PCI_MMCONFIG when ECS access is required. Linux Kernel info: root@qt5222:~# uname -a Linux qt5222 6.6.49-2447-qtec-standard--gef032148967a #1 SMP Fri Nov 22 09:25:55 UTC 2024 x86_64 GNU/Linux Best regards, Ros
