> -----Original Message----- > From: Will Deacon [mailto:will.deacon@xxxxxxx] > Sent: Friday, October 13, 2017 8:22 PM > To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@xxxxxxxxxx> > Cc: lorenzo.pieralisi@xxxxxxx; marc.zyngier@xxxxxxx; > sudeep.holla@xxxxxxx; robin.murphy@xxxxxxx; joro@xxxxxxxxxx; > bhelgaas@xxxxxxxxxx; Gabriele Paoloni <gabriele.paoloni@xxxxxxxxxx>; > John Garry <john.garry@xxxxxxxxxx>; iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx; > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-acpi@xxxxxxxxxxxxxxx; linux- > pci@xxxxxxxxxxxxxxx; devel@xxxxxxxxxx; Linuxarm <linuxarm@xxxxxxxxxx>; > Wangzhou (B) <wangzhou1@xxxxxxxxxxxxx>; Guohanjun (Hanjun Guo) > <guohanjun@xxxxxxxxxx> > Subject: Re: [PATCH v9 4/4] PCI: hisi: blacklist hip06/hip07 controllers behind > SMMUv3 > > On Fri, Oct 06, 2017 at 03:04:50PM +0100, Shameer Kolothum wrote: > > The HiSilicon erratum 161010801 describes the limitation of HiSilicon > > platforms hip06/hip07 to support the SMMUv3 mappings for MSI > > transactions. > > > > PCIe controller on these platforms has to differentiate the MSI > > payload against other DMA payload and has to modify the MSI payload. > > This basically makes it difficult for this platforms to have a SMMU > > translation for MSI. In order to workaround this, ARM > > SMMUv3 driver requires a quirk to treat the MSI regions separately. > > Such a quirk is currently missing for DT based systems and therefore > > we need to blacklist the hip06/hip07 PCIe controllers. > > > > Signed-off-by: Shameer Kolothum > <shameerali.kolothum.thodi@xxxxxxxxxx> > > --- > > drivers/pci/dwc/pcie-hisi.c | 12 ++++++++++++ > > 1 file changed, 12 insertions(+) > > > > diff --git a/drivers/pci/dwc/pcie-hisi.c b/drivers/pci/dwc/pcie-hisi.c > > index a201791..6800747 100644 > > --- a/drivers/pci/dwc/pcie-hisi.c > > +++ b/drivers/pci/dwc/pcie-hisi.c > > @@ -270,6 +270,12 @@ static int hisi_pcie_probe(struct platform_device > *pdev) > > struct resource *reg; > > int ret; > > > > + if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) && > > + of_property_read_bool(dev->of_node, "iommu- > map")) { > > + dev_warn(dev, "HiSilicon erratum 161010801: blacklisting > PCIe controllers behind SMMUv3\n"); > > + return -ENODEV; > > + } > > + > > hisi_pcie = devm_kzalloc(dev, sizeof(*hisi_pcie), GFP_KERNEL); > > if (!hisi_pcie) > > return -ENOMEM; > > @@ -340,6 +346,12 @@ static int hisi_pcie_almost_ecam_probe(struct > platform_device *pdev) > > struct device *dev = &pdev->dev; > > struct pci_ecam_ops *ops; > > > > + if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) && > > + of_property_read_bool(dev->of_node, "iommu- > map")) { > > + dev_warn(dev, "HiSilicon erratum 161010801: blacklisting > PCIe controllers behind SMMUv3\n"); > > + return -ENODEV; > > + } > > This isn't the right way to solve this problem. I was really hoping you'd come > up with a solution for DT, and I know you've been trying, so I suppose for > now we'll just have to go with the ACPI workaround you have and leave DT in > the balance. I'm not at all happy with that, but I don't think this patch really > improves things. Yes Will, this is to get the ACPI support enabled for now. > What I think you should do is remove the relevant smmu/iommu-map > entries from the .dts files that are available for these platforms (i.e. > comment them out with a description as to why). We don't have any smmu/iommu-map entries for these platforms in the .dts files [1][2]. We are not aiming for any official DT support for these platforms. This patch is to enforce the non-support. Thanks, Shameer 1. http://elixir.free-electrons.com/linux/v4.14-rc4/source/arch/arm64/boot/dts/hisilicon/hip07.dtsi 2. http://elixir.free-electrons.com/linux/v4.14-rc4/source/arch/arm64/boot/dts/hisilicon/hip06.dtsi
