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>> + >> + if (start >= end) >> + return nr_range; >> + >> + /* get new start/end: */ >> + for (i = 0; i < nr_range; i++) { >> + >> + if (!range[i].end) >> + continue; >> + >> + /* Try to add to the end */ >> + if (range[i].end + 1 == start) { >> + range[i].end = end; >> + return nr_range; >> + } >> + >> + /* Try to add to the start */ >> + if (range[i].start == end + 1) { >> + range[i].start = start; >> + return nr_range; >> + } >> + } >> + >> + /* Need to add it: */ >> + return add_range(range, az, nr_range, start, end); >> +} Should we use bus addresses while programming the ranges? The 32-bit ranges may be remapped (i.e. the range address doesn't match with the bus address). > > I noticed Arto has a good idea that there needs at most 2 blocks no > matter how the mmio layout is for PF/VF/MFD..., one for 32 bit, one for > 64 bit. And the direct connected upstream bridge to the DSM device has > already aggregated the 2 ranges on enumeration. [1] That greatly reduces > the complexity. No need for callers to iterate the devices/resources to > collect the ranges again. > I agree that the implementation feels unnecessarily complex given that the aggregated ranges are already available. For reference, I am using a routine like this for collecting the ranges before programming the address association registers: static int pci_res_to_ide_addr(struct pci_dev *pdev, struct ide_addr_range *ide_addr) { struct pci_dev *bridge = pci_upstream_bridge(pdev); struct pci_bus_region region; struct resource *res; int naddr = 0; res = &bridge->resource[PCI_BRIDGE_MEM_WINDOW]; if (res->flags & IORESOURCE_MEM) { pcibios_resource_to_bus(bridge->bus, ®ion, res); ide_addr[naddr].start = region.start; ide_addr[naddr].end = region.end; naddr++; } res = &bridge->resource[PCI_BRIDGE_PREF_MEM_WINDOW]; if (res->flags & IORESOURCE_PREFETCH) { pcibios_resource_to_bus(bridge->bus, ®ion, res); ide_addr[naddr].start = region.start; ide_addr[naddr].end = region.end; naddr++; } return naddr; } > For TDX, the firmware enforces to setup only one addr block for RP, no > matter how many supported blocks the RP actually has. That means TDX > could only support 64 bit IDE ranges. I'd like to require an input > parameter like "max_nr_mem_rp" for this purpose. I do not think having only a limited number of addr blocks is unique to TDX. Given that the SW needs only a couple of addr blocks when programmed using the information in the type-1 header of the upstream bridge, I would expect hardware implementations to not have more blocks than necessary. - R2