On Mon, Jun 03, 2024 at 12:11:49PM -0500, Bjorn Helgaas wrote: > On Fri, May 31, 2024 at 12:14:18PM -0400, Frank Li wrote: > > On Thu, May 30, 2024 at 06:08:32PM -0500, Bjorn Helgaas wrote: > > > On Tue, May 28, 2024 at 03:39:21PM -0400, Frank Li wrote: > > > > For the i.MX95, configuration of a LUT is necessary to convert Bus Device > > > > Function (BDF) to stream IDs, which are utilized by both IOMMU and ITS. > > > > This involves examining the msi-map and smmu-map to ensure consistent > > > > mapping of PCI BDF to the same stream IDs. Subsequently, LUT-related > > > > registers are configured. In the absence of an msi-map, the built-in MSI > > > > controller is utilized as a fallback. > > > > > > > > Additionally, register a PCI bus notifier to trigger imx_pcie_add_device() > > > > upon the appearance of a new PCI device and when the bus is an iMX6 PCI > > > > controller. This function configures the correct LUT based on Device Tree > > > > Settings (DTS). > > > > > > This scheme is pretty similar to apple_pcie_bus_notifier(). If we > > > have to do this, I wish it were *more* similar, i.e., copy the > > > function names, bitmap tracking, code structure, etc. > > > > Actually, I refer apple_pcie_bus_notifier(). I can't direct use apple's > > implement because in imx95 have difference PCI host controller, another one > > is PCI ECAM netc controller. At lease function name should be similar with > > apple. > > I know it's different hardware, so obviously it can't be exactly the > same. These are the differences that looked possibly unnecessary: > > - registering from initcall instead of .probe(): > > apple_pcie_probe # .probe() method > bus_register_notifier(&pci_bus_type, &apple_pcie_nb) > > imx_pcie_init # device_initcall() > bus_register_notifier(&pci_bus_type, &imx_pcie_nb) Maybe apple only one PCIe controller with multi ports. One nb just register once. If there are multi PCIe controller instance, second bus_register_notifier() report error. Of course, if you like, I can use global reference counter to handle this. > > - naming BUS_NOTIFY_DEL_DEVICE function: > > apple_pcie_release_device() > imx_pcie_del_device() Okay, I can change to release_device(). > > - tracking entries in use via bitmap vs scanning hardware for > invalid entries: > > bitmap_find_free_region # apple > > imx_pcie_config_lut # imx > for (i = 0; i < IMX95_MAX_LUT; i++) > regmap_read(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_DATA1, &data1) > if (data1 & IMX95_PE0_LUT_VLD) > continue Okay, I can change to use bitmap. > > When we fix a bug in one driver, it's easier to check whether other > drivers also need the fix if they use the same structure and names. > > Bjorn
