| Message ID | 20190131185656.17972-2-logang@deltatee.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Support using MSI interrupts in ntb_transport | expand |
On Thu, Jan 31, 2019 at 11:56:48AM -0700, Logan Gunthorpe wrote: > @@ -394,6 +402,10 @@ static int set_msi_sid(struct irte *irte, struct pci_dev *dev) > set_irte_sid(irte, SVT_VERIFY_BUS, SQ_ALL_16, > PCI_DEVID(PCI_BUS_NUM(data.alias), > dev->bus->number)); > + else if (data.count >= 2 && data.busmatch_count == data.count) > + set_irte_sid(irte, SVT_VERIFY_BUS, SQ_ALL_16, > + PCI_DEVID(dev->bus->number, > + dev->bus->number)); The dev->bus->number argument for the devfn parameter of PCI_DEVID is not needed, right? Also, this requires at least a comment to document that special case. Joerg
On 2019-02-01 9:44 a.m., Joerg Roedel wrote: > On Thu, Jan 31, 2019 at 11:56:48AM -0700, Logan Gunthorpe wrote: >> @@ -394,6 +402,10 @@ static int set_msi_sid(struct irte *irte, struct pci_dev *dev) >> set_irte_sid(irte, SVT_VERIFY_BUS, SQ_ALL_16, >> PCI_DEVID(PCI_BUS_NUM(data.alias), >> dev->bus->number)); >> + else if (data.count >= 2 && data.busmatch_count == data.count) >> + set_irte_sid(irte, SVT_VERIFY_BUS, SQ_ALL_16, >> + PCI_DEVID(dev->bus->number, >> + dev->bus->number)); > > The dev->bus->number argument for the devfn parameter of PCI_DEVID is > not needed, right? Oh, yes. I think you are right. > Also, this requires at least a comment to document that special case. I'll add a comment for v2. Thanks for the review! Logan
On Fri, 1 Feb 2019 10:27:29 -0700 Logan Gunthorpe <logang@deltatee.com> wrote: > On 2019-02-01 9:44 a.m., Joerg Roedel wrote: > > On Thu, Jan 31, 2019 at 11:56:48AM -0700, Logan Gunthorpe wrote: > >> @@ -394,6 +402,10 @@ static int set_msi_sid(struct irte *irte, > >> struct pci_dev *dev) set_irte_sid(irte, SVT_VERIFY_BUS, SQ_ALL_16, > >> PCI_DEVID(PCI_BUS_NUM(data.alias), > >> dev->bus->number)); I guess devfn can be removed also. but that is separate cleanup. > >> + else if (data.count >= 2 && data.busmatch_count == > >> data.count) > >> + set_irte_sid(irte, SVT_VERIFY_BUS, SQ_ALL_16, > >> + PCI_DEVID(dev->bus->number, > >> + dev->bus->number)); > > > > The dev->bus->number argument for the devfn parameter of PCI_DEVID > > is not needed, right? > > Oh, yes. I think you are right. > > > Also, this requires at least a comment to document that special > > case. > > I'll add a comment for v2. > > Thanks for the review! > > Logan > _______________________________________________ > iommu mailing list > iommu@lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/iommu [Jacob Pan]
On 2019-02-05 12:19 p.m., Jacob Pan wrote: > On Fri, 1 Feb 2019 10:27:29 -0700 > Logan Gunthorpe <logang@deltatee.com> wrote: > >> On 2019-02-01 9:44 a.m., Joerg Roedel wrote: >>> On Thu, Jan 31, 2019 at 11:56:48AM -0700, Logan Gunthorpe wrote: >>>> @@ -394,6 +402,10 @@ static int set_msi_sid(struct irte *irte, >>>> struct pci_dev *dev) set_irte_sid(irte, SVT_VERIFY_BUS, SQ_ALL_16, >>>> PCI_DEVID(PCI_BUS_NUM(data.alias), >>>> dev->bus->number)); > I guess devfn can be removed also. but that is separate cleanup. Actually, no, I've dug into this and we *do* need the devfn here but it's needlessly confusing. We should not be using PCI_DEVID() as we aren't actually representing a DEVID in this case... According to the Intel VT-D spec, when using SVT_VERIFY_BUS, the MSB of the SID field represents the starting bus number and the LSB represents the end bus number. The requester id's bus number must then be within that range. The PCI_DEVID macro matches these semantics if you assume the devfn is the end bus, but doesn't really make sense here and just confuses the issue. So the code was correct, I'll just try to clean it up to make it less confusing. Thanks, Logan
On Tue, 5 Feb 2019 13:40:36 -0700 Logan Gunthorpe <logang@deltatee.com> wrote: > On 2019-02-05 12:19 p.m., Jacob Pan wrote: > > On Fri, 1 Feb 2019 10:27:29 -0700 > > Logan Gunthorpe <logang@deltatee.com> wrote: > > > >> On 2019-02-01 9:44 a.m., Joerg Roedel wrote: > >>> On Thu, Jan 31, 2019 at 11:56:48AM -0700, Logan Gunthorpe > >>> wrote: > >>>> @@ -394,6 +402,10 @@ static int set_msi_sid(struct irte *irte, > >>>> struct pci_dev *dev) set_irte_sid(irte, SVT_VERIFY_BUS, > >>>> SQ_ALL_16, PCI_DEVID(PCI_BUS_NUM(data.alias), > >>>> dev->bus->number)); > > I guess devfn can be removed also. but that is separate cleanup. > > Actually, no, I've dug into this and we *do* need the devfn here but > it's needlessly confusing. We should not be using PCI_DEVID() as we > aren't actually representing a DEVID in this case... > > According to the Intel VT-D spec, when using SVT_VERIFY_BUS, the MSB > of the SID field represents the starting bus number and the LSB > represents the end bus number. The requester id's bus number must > then be within that range. The PCI_DEVID macro matches these > semantics if you assume the devfn is the end bus, but doesn't really > make sense here and just confuses the issue. > > So the code was correct, I'll just try to clean it up to make it less > confusing. > you are right, thanks for explaining. > Thanks, > > Logan
diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c index 24d45b07f425..8d3107a6b2b4 100644 --- a/drivers/iommu/intel_irq_remapping.c +++ b/drivers/iommu/intel_irq_remapping.c @@ -356,6 +356,8 @@ static int set_hpet_sid(struct irte *irte, u8 id) struct set_msi_sid_data { struct pci_dev *pdev; u16 alias; + int count; + int busmatch_count; }; static int set_msi_sid_cb(struct pci_dev *pdev, u16 alias, void *opaque) @@ -364,6 +366,10 @@ static int set_msi_sid_cb(struct pci_dev *pdev, u16 alias, void *opaque) data->pdev = pdev; data->alias = alias; + data->count++; + + if (PCI_BUS_NUM(alias) == pdev->bus->number) + data->busmatch_count++; return 0; } @@ -375,6 +381,8 @@ static int set_msi_sid(struct irte *irte, struct pci_dev *dev) if (!irte || !dev) return -1; + data.count = 0; + data.busmatch_count = 0; pci_for_each_dma_alias(dev, set_msi_sid_cb, &data); /* @@ -394,6 +402,10 @@ static int set_msi_sid(struct irte *irte, struct pci_dev *dev) set_irte_sid(irte, SVT_VERIFY_BUS, SQ_ALL_16, PCI_DEVID(PCI_BUS_NUM(data.alias), dev->bus->number)); + else if (data.count >= 2 && data.busmatch_count == data.count) + set_irte_sid(irte, SVT_VERIFY_BUS, SQ_ALL_16, + PCI_DEVID(dev->bus->number, + dev->bus->number)); else if (data.pdev->bus->number != dev->bus->number) set_irte_sid(irte, SVT_VERIFY_SID_SQ, SQ_ALL_16, data.alias); else
When a device has multiple aliases that all are from the same bus, we program the IRTE to accept requests from any matching device on the bus. This is so NTB devices which can have requests from multiple bus-devfns can pass MSI interrupts through across the bridge. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: David Woodhouse <dwmw2@infradead.org> --- drivers/iommu/intel_irq_remapping.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)