[ck] [patch v1 3/3] PCI: Add ACS quirk for Zhaoxin Root/Downstream Ports

commit 299bd044a6f332b4a6c8f708575c27cad70a35c1 upstream. Many Zhaoxin Root Ports and Switch Downstream Ports do provide ACS-like capability but have no ACS Capability Structure. Peer-to-Peer transactions could be blocked between these ports, so add quirk so devices behind them could be assigned to different IOMMU group. Link: https://lore.kernel.org/r/20200327091148.5190-4-RaymondPang-oc@zhaoxin.com Signed-off-by: Raymond Pang <RaymondPang-oc(a)zhaoxin.com> Signed-off-by: Bjorn Helgaas <bhelgaas(a)google.com> [ LeoLiu-oc: Adapt to current kernel code ] Signed-off-by: LeoLiu-oc <LeoLiu-oc(a)zhaoxin.com> --- drivers/pci/quirks.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 9c82ba1b2156..943b006c15b9 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -4265,6 +4265,31 @@ static int pci_quirk_xgene_acs(struct pci_dev *dev, u16 acs_flags) return acs_flags ? 0 : 1; } + /* + * Many Zhaoxin Root Ports and Switch Downstream Ports have no ACS capability. + * But the implementation could block peer-to-peer transactions between them + * and provide ACS-like functionality. + */ +static int pci_quirk_zhaoxin_pcie_ports_acs(struct pci_dev *dev, u16 acs_flags) +{ + u16 flags = (PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF | PCI_ACS_SV); + int ret = acs_flags & ~flags ? 0 : 1; + + if (!pci_is_pcie(dev) || + ((pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT) && + (pci_pcie_type(dev) != PCI_EXP_TYPE_DOWNSTREAM))) + return -ENOTTY; + + switch (dev->device) { + case 0x0710 ... 0x071e: + case 0x0721: + case 0x0723 ... 0x0732: + return ret; + } + + return false; +} + /* * Many Intel PCH root ports do provide ACS-like features to disable peer * transactions and validate bus numbers in requests, but do not provide an @@ -4542,6 +4567,8 @@ static const struct pci_dev_acs_enabled { { PCI_VENDOR_ID_ZHAOXIN, 0x3038, pci_quirk_mf_endpoint_acs }, { PCI_VENDOR_ID_ZHAOXIN, 0x3104, pci_quirk_mf_endpoint_acs }, { PCI_VENDOR_ID_ZHAOXIN, 0x9083, pci_quirk_mf_endpoint_acs }, + /* Zhaoxin Root/Downstream Ports */ + { PCI_VENDOR_ID_ZHAOXIN, PCI_ANY_ID, pci_quirk_zhaoxin_pcie_ports_acs }, { 0 } }; -- 2.20.1