Dan Williams wrote: > Ilpo Järvinen wrote: > > On Thu, 5 Dec 2024, Dan Williams wrote: > > > > > PCIe 6.2 Section 7.7.9 Device 3 Extended Capability Structure, > > > enumerates new link capabilities and status added for Gen 6 devices. One > > > of the link details enumerated in that register block is the "Segment > > > Captured" status in the Device Status 3 register. That status is > > > relevant for enabling IDE (Integrity & Data Encryption) whereby > > > Selective IDE streams can be limited to a given requester id range > > > within a given segment. > > > > > > If a device has captured its Segment value then it knows that PCIe Flit > > > Mode is enabled via all links in the path that a configuration write > > > traversed. IDE establishment requires that "Segment Base" in > > > IDE RID Association Register 2 (PCIe 6.2 Section 7.9.26.5.4.2) be > > > programmed if the RID association mechanism is in effect. > > > > > > When / if IDE + Flit Mode capable devices arrive, the PCI core needs to > > > setup the segment base when using the RID association facility, but no > > > known deployments today depend on this. > > > > > > Cc: Lukas Wunner <lukas@xxxxxxxxx> > > > Cc: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> > > > Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > > > Cc: Samuel Ortiz <sameo@xxxxxxxxxxxx> > > > Cc: Alexey Kardashevskiy <aik@xxxxxxx> > > > Cc: Xu Yilun <yilun.xu@xxxxxxxxxxxxxxx> > > > Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> > [..] > > > @@ -1210,6 +1211,12 @@ > > > #define PCI_DOE_DATA_OBJECT_DISC_RSP_3_PROTOCOL 0x00ff0000 > > > #define PCI_DOE_DATA_OBJECT_DISC_RSP_3_NEXT_INDEX 0xff000000 > > > > > > +/* Device 3 Extended Capability */ > > > +#define PCI_DEV3_CAP 0x4 /* Device 3 Capabilities Register */ > > > +#define PCI_DEV3_CTL 0x8 /* Device 3 Control Register */ > > > > Should save/restore too be added for DEV3_CTL? > > Good point, yes it should. ...although only when the kernel adds a use case to write to DEV3_CTL, for now the use case is read-only for DEV3_CAP.
