Messages in this thread | | | Date | Tue, 21 Jun 2022 11:29:35 -0700 | From | Ira Weiny <> | Subject | Re: [PATCH V11 4/8] cxl/pci: Create PCI DOE mailbox's for memory devices |
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On Fri, Jun 17, 2022 at 04:44:27PM -0700, Dan Williams wrote: > ira.weiny@ wrote:
[snip]
> > diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h > > index 60d10ee1e7fc..4d2764b865ab 100644 > > --- a/drivers/cxl/cxlmem.h > > +++ b/drivers/cxl/cxlmem.h > > @@ -191,6 +191,8 @@ struct cxl_endpoint_dvsec_info { > > * @component_reg_phys: register base of component registers > > * @info: Cached DVSEC information about the device. > > * @serial: PCIe Device Serial Number > > + * @doe_mbs: PCI DOE mailbox array > > + * @num_mbs: Number of DOE mailboxes > > * @mbox_send: @dev specific transport for transmitting mailbox commands > > * > > * See section 8.2.9.5.2 Capacity Configuration and Label Storage for > > @@ -224,6 +226,10 @@ struct cxl_dev_state { > > resource_size_t component_reg_phys; > > u64 serial; > > > > + bool doe_use_irq; > > Don't pass temporary state through a long lived data structure. Just > pass flag by reference between the functions that want to coordinate > this.
Done.
[snip]
> > + > > +static void cxl_alloc_irq_vectors(struct cxl_dev_state *cxlds) > > +{ > > + struct device *dev = cxlds->dev; > > + struct pci_dev *pdev = to_pci_dev(dev); > > + int max_irqs = 0; > > + int off = 0; > > + int rc; > > + > > + /* Account for all the DOE vectors needed */ > > + pci_doe_for_each_off(pdev, off) { > > + int irq = pci_doe_get_irq_num(pdev, off); > > + > > + if (irq < 0) > > + continue; > > + max_irqs = max(max_irqs, irq + 1); > > This seems to assume that different DOEs will get independent vectors. > The driver needs to be prepared for DOE instances, Event notifications, > and mailbox commands to share a single MSI vector in the worst case. > Lets focus on polled mode DOE, or explicitly only support interrupt > based operation when no vector sharing is detected. >
Ok I see now. I was under the impression they had to be unique.
Do you think it is sufficient to check in this loop for duplicates and bail if any are shared?
Ira
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