> -----Original Message----- > From: iommu <iommu-bounces@xxxxxxxxxxxxxxxxxxxxxxxxxx> On Behalf Of Lu > Baolu > Sent: Monday, July 20, 2020 7:17 PM > To: Joerg Roedel > Cc: Ashok Raj; linux-kernel@xxxxxxxxxxxxxxx; stable@xxxxxxxxxxxxxxx; Koba > Ko; iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx > Subject: [PATCH 1/1] iommu/vt-d: Skip TE disabling on quirky gfx dedicated > iommu > > The VT-d spec requires (10.4.4 Global Command Register, TE field) that: > > Hardware implementations supporting DMA draining must drain any in-flight > DMA read/write requests queued within the Root-Complex before completing > the translation enable command and reflecting the status of the command > through the TES field in the Global Status register. > > Unfortunately, some integrated graphic devices fail to do so after some > kind of power state transition. As the result, the system might stuck in > iommu_disable_translation(), waiting for the completion of TE transition. > > This provides a quirk list for those devices and skips TE disabling if > the qurik hits. > > Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=208363 That one is for TGL. I think you also want to add this one for ICL: Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=206571 > Tested-by: Koba Ko <koba.ko@xxxxxxxxxxxxx> > Cc: Ashok Raj <ashok.raj@xxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> > --- > drivers/iommu/intel/dmar.c | 1 + > drivers/iommu/intel/iommu.c | 27 +++++++++++++++++++++++++++ > include/linux/dmar.h | 1 + > include/linux/intel-iommu.h | 2 ++ > 4 files changed, 31 insertions(+) > > diff --git a/drivers/iommu/intel/dmar.c b/drivers/iommu/intel/dmar.c > index 683b812c5c47..16f47041f1bf 100644 > --- a/drivers/iommu/intel/dmar.c > +++ b/drivers/iommu/intel/dmar.c > @@ -1102,6 +1102,7 @@ static int alloc_iommu(struct dmar_drhd_unit *drhd) > } > > drhd->iommu = iommu; > + iommu->drhd = drhd; > > return 0; > > diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c > index 98390a6d8113..11418b14cc3f 100644 > --- a/drivers/iommu/intel/iommu.c > +++ b/drivers/iommu/intel/iommu.c > @@ -356,6 +356,7 @@ static int intel_iommu_strict; > static int intel_iommu_superpage = 1; > static int iommu_identity_mapping; > static int intel_no_bounce; > +static int iommu_skip_te_disable; > > #define IDENTMAP_GFX 2 > #define IDENTMAP_AZALIA 4 > @@ -1633,6 +1634,10 @@ static void iommu_disable_translation(struct > intel_iommu *iommu) > u32 sts; > unsigned long flag; > > + if (iommu_skip_te_disable && iommu->drhd->gfx_dedicated && > + (cap_read_drain(iommu->cap) || cap_write_drain(iommu->cap))) > + return; > + > raw_spin_lock_irqsave(&iommu->register_lock, flag); > iommu->gcmd &= ~DMA_GCMD_TE; > writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG); > @@ -4043,6 +4048,7 @@ static void __init init_no_remapping_devices(void) > > /* This IOMMU has *only* gfx devices. Either bypass it or > set the gfx_mapped flag, as appropriate */ > + drhd->gfx_dedicated = 1; > if (!dmar_map_gfx) { > drhd->ignored = 1; > for_each_active_dev_scope(drhd->devices, > @@ -6160,6 +6166,27 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, > 0x0044, quirk_calpella_no_shadow_g > DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0062, > quirk_calpella_no_shadow_gtt); > DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x006a, > quirk_calpella_no_shadow_gtt); > > +static void quirk_igfx_skip_te_disable(struct pci_dev *dev) > +{ > + unsigned short ver; > + > + if (!IS_GFX_DEVICE(dev)) > + return; > + > + ver = (dev->device >> 8) & 0xff; > + if (ver != 0x45 && ver != 0x46 && ver != 0x4c && > + ver != 0x4e && ver != 0x8a && ver != 0x98 && > + ver != 0x9a) > + return; > + > + if (risky_device(dev)) > + return; > + > + pci_info(dev, "Skip IOMMU disabling for graphics\n"); > + iommu_skip_te_disable = 1; > +} > +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_ANY_ID, > quirk_igfx_skip_te_disable); > + > /* On Tylersburg chipsets, some BIOSes have been known to enable the > ISOCH DMAR unit for the Azalia sound device, but not give it any > TLB entries, which causes it to deadlock. Check for that. We do > diff --git a/include/linux/dmar.h b/include/linux/dmar.h > index d7bf029df737..65565820328a 100644 > --- a/include/linux/dmar.h > +++ b/include/linux/dmar.h > @@ -48,6 +48,7 @@ struct dmar_drhd_unit { > u16 segment; /* PCI domain */ > u8 ignored:1; /* ignore drhd */ > u8 include_all:1; > + u8 gfx_dedicated:1; /* graphic dedicated */ > struct intel_iommu *iommu; > }; > > diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h > index bf6009a344f5..329629e1e9de 100644 > --- a/include/linux/intel-iommu.h > +++ b/include/linux/intel-iommu.h > @@ -600,6 +600,8 @@ struct intel_iommu { > struct iommu_device iommu; /* IOMMU core code handle */ > int node; > u32 flags; /* Software defined flags */ > + > + struct dmar_drhd_unit *drhd; > }; > > /* PCI domain-device relationship */ > -- > 2.17.1 > > _______________________________________________ > iommu mailing list > iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx > https://lists.linuxfoundation.org/mailman/listinfo/iommu
