On Thu, 26 Mar 2020 16:40:06 +1100 David Gibson <da...@gibson.dropbear.id.au> wrote:
> Currently spapr_phb_nvgpu_populate_pcidev_dt() works a little cryptically. > It steps through all the NVLink2 GPUs and NPUs and if they match the device > we're called for, we generate the relevant device tree information. > > Make this a little more obvious by introducing helpers to determine it a ... to determine if a > given PCI device is an NVLink2 GPU or NPU, returning the NVLink2 slot and > link number information as well. > > Signed-off-by: David Gibson <da...@gibson.dropbear.id.au> > --- LGTM Reviewed-by: Greg Kurz <gr...@kaod.org> > hw/ppc/spapr_pci_nvlink2.c | 115 +++++++++++++++++++++++++------------ > 1 file changed, 79 insertions(+), 36 deletions(-) > > diff --git a/hw/ppc/spapr_pci_nvlink2.c b/hw/ppc/spapr_pci_nvlink2.c > index 8332d5694e..7d3a685421 100644 > --- a/hw/ppc/spapr_pci_nvlink2.c > +++ b/hw/ppc/spapr_pci_nvlink2.c > @@ -390,13 +390,12 @@ void spapr_phb_nvgpu_ram_populate_dt(SpaprPhbState > *sphb, void *fdt) > > } > > -void spapr_phb_nvgpu_populate_pcidev_dt(PCIDevice *dev, void *fdt, int > offset, > - SpaprPhbState *sphb) > +static bool is_nvgpu(PCIDevice *dev, SpaprPhbState *sphb, int *slot) > { > - int i, j; > + int i; > > if (!sphb->nvgpus) { > - return; > + return false; > } > > for (i = 0; i < sphb->nvgpus->num; ++i) { > @@ -406,47 +405,91 @@ void spapr_phb_nvgpu_populate_pcidev_dt(PCIDevice *dev, > void *fdt, int offset, > if (!nvslot->gpdev) { > continue; > } > + > if (dev == nvslot->gpdev) { > - uint32_t npus[nvslot->linknum]; > + if (slot) { > + *slot = i; > + } > + return true; > + } > + } > > - for (j = 0; j < nvslot->linknum; ++j) { > - PCIDevice *npdev = nvslot->links[j].npdev; > + return false; > +} > > - npus[j] = cpu_to_be32(PHANDLE_PCIDEV(sphb, npdev)); > - } > - _FDT(fdt_setprop(fdt, offset, "ibm,npu", npus, > - j * sizeof(npus[0]))); > - _FDT((fdt_setprop_cell(fdt, offset, "phandle", > - PHANDLE_PCIDEV(sphb, dev)))); > +static bool is_nvnpu(PCIDevice *dev, SpaprPhbState *sphb, int *slot, int > *link) > +{ > + int i, j; > + > + if (!sphb->nvgpus) { > + return false; > + } > + > + for (i = 0; i < sphb->nvgpus->num; ++i) { > + SpaprPhbPciNvGpuSlot *nvslot = &sphb->nvgpus->slots[i]; > + > + /* Skip "slot" without attached GPU */ > + if (!nvslot->gpdev) { > continue; > } > > for (j = 0; j < nvslot->linknum; ++j) { > - if (dev != nvslot->links[j].npdev) { > - continue; > + if (dev == nvslot->links[j].npdev) { > + if (slot) { > + *slot = i; > + } > + if (link) { > + *link = j; > + } > + return true; > } > + } > + } > > - _FDT((fdt_setprop_cell(fdt, offset, "phandle", > - PHANDLE_PCIDEV(sphb, dev)))); > - _FDT(fdt_setprop_cell(fdt, offset, "ibm,gpu", > - PHANDLE_PCIDEV(sphb, nvslot->gpdev))); > - _FDT((fdt_setprop_cell(fdt, offset, "ibm,nvlink", > - PHANDLE_NVLINK(sphb, i, j)))); > - /* > - * If we ever want to emulate GPU RAM at the same location as on > - * the host - here is the encoding GPA->TGT: > - * > - * gta = ((sphb->nv2_gpa >> 42) & 0x1) << 42; > - * gta |= ((sphb->nv2_gpa >> 45) & 0x3) << 43; > - * gta |= ((sphb->nv2_gpa >> 49) & 0x3) << 45; > - * gta |= sphb->nv2_gpa & ((1UL << 43) - 1); > - */ > - _FDT(fdt_setprop_cell(fdt, offset, "memory-region", > - PHANDLE_GPURAM(sphb, i))); > - _FDT(fdt_setprop_u64(fdt, offset, "ibm,device-tgt-addr", > - nvslot->tgt)); > - _FDT(fdt_setprop_cell(fdt, offset, "ibm,nvlink-speed", > - nvslot->links[j].link_speed)); > + return false; > +} > + > +void spapr_phb_nvgpu_populate_pcidev_dt(PCIDevice *dev, void *fdt, int > offset, > + SpaprPhbState *sphb) > +{ > + int slot, link; > + > + if (is_nvgpu(dev, sphb, &slot)) { > + SpaprPhbPciNvGpuSlot *nvslot = &sphb->nvgpus->slots[slot]; > + uint32_t npus[nvslot->linknum]; > + > + for (link = 0; link < nvslot->linknum; ++link) { > + PCIDevice *npdev = nvslot->links[link].npdev; > + > + npus[link] = cpu_to_be32(PHANDLE_PCIDEV(sphb, npdev)); > } > + _FDT(fdt_setprop(fdt, offset, "ibm,npu", npus, > + link * sizeof(npus[0]))); > + _FDT((fdt_setprop_cell(fdt, offset, "phandle", > + PHANDLE_PCIDEV(sphb, dev)))); > + } else if (is_nvnpu(dev, sphb, &slot, &link)) { > + SpaprPhbPciNvGpuSlot *nvslot = &sphb->nvgpus->slots[slot]; > + > + _FDT((fdt_setprop_cell(fdt, offset, "phandle", > + PHANDLE_PCIDEV(sphb, dev)))); > + _FDT(fdt_setprop_cell(fdt, offset, "ibm,gpu", > + PHANDLE_PCIDEV(sphb, nvslot->gpdev))); > + _FDT((fdt_setprop_cell(fdt, offset, "ibm,nvlink", > + PHANDLE_NVLINK(sphb, slot, link)))); > + /* > + * If we ever want to emulate GPU RAM at the same location as > + * on the host - here is the encoding GPA->TGT: > + * > + * gta = ((sphb->nv2_gpa >> 42) & 0x1) << 42; > + * gta |= ((sphb->nv2_gpa >> 45) & 0x3) << 43; > + * gta |= ((sphb->nv2_gpa >> 49) & 0x3) << 45; > + * gta |= sphb->nv2_gpa & ((1UL << 43) - 1); > + */ > + _FDT(fdt_setprop_cell(fdt, offset, "memory-region", > + PHANDLE_GPURAM(sphb, slot))); > + _FDT(fdt_setprop_u64(fdt, offset, "ibm,device-tgt-addr", > + nvslot->tgt)); > + _FDT(fdt_setprop_cell(fdt, offset, "ibm,nvlink-speed", > + nvslot->links[link].link_speed)); > } > }