On 21.12.2015 12:47, Gabriele Paoloni wrote:
- In the quirk mechanism you proposed, I see that the callback function allows to do some preparation work for the host bridge. For example in Hisilicon hip05 case we would need to read some values from the ACPI table (see acpi_pci_root_hisi_add() function in https://lkml.org/lkml/2015/12/3/426). I am quite new to ACPI and I wonder if it is OK to add such "Packages" to the PCI host bridge ACPI device...or maybe we need to declare a new one...?
I may miss sth so please correct me in that case.
https://lkml.org/lkml/2015/12/3/426 shows that you need special handling for root->secondary.start bus number only, right? So how about creating special MCFG region rc-base:rc-base+rc-size only for <segment,bus>. Like that:
[0008] Base Address : <rc-base> [0002] Segment Group Number : <segment> [0001] Start Bus Number : <root->secondary.start> [0001] End Bus Number : <root->secondary.start> [0004] Reserved : 00000000
static const struct dmi_system_id hisi_quirk[] = { { .ident = "HiSi...", .matches = { DMI_MATCH(<whatever you need to match your platform>), }, }, { } };
static struct pci_ops hisi_ecam_pci_ops = { .map_bus = pci_mcfg_dev_base, .read = hisi_pcie_cfg_read, .write = hisi_pcie_cfg_write, };
DECLARE_ACPI_MCFG_FIXUP(hisi_quirk, &hisi_ecam_pci_ops, <segment>, <bus>);
With above code you can use your custom PCI config accessor only for that region.
Let me know if that is not enough for you.
Tomasz