| From | "Jonathan Zhang (Infra)" <> | Subject | Re: [PATCH 09/15] cxl/acpi: Determine PCI host bridge's ACPI UID | Date | Thu, 8 Sep 2022 20:47:13 +0000 |
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> On Aug 31, 2022, at 1:15 AM, Robert Richter <rrichter@amd.com> wrote: > > The UID is needed to read the RCH's CEDT entry with the RCRB base > address. Determine the host's UID from its ACPI fw node. > > Signed-off-by: Robert Richter <rrichter@amd.com> > --- > drivers/cxl/acpi.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c > index f9cdf23a91a8..b3146b7ae922 100644 > --- a/drivers/cxl/acpi.c > +++ b/drivers/cxl/acpi.c > @@ -368,8 +368,20 @@ struct pci_host_bridge *cxl_find_next_rch(struct pci_host_bridge *host) > static int __init cxl_restricted_host_probe(struct platform_device *pdev) > { > struct pci_host_bridge *host = NULL; > + struct acpi_device *adev; > + unsigned long long uid = ~0; > > while ((host = cxl_find_next_rch(host)) != NULL) { > + adev = ACPI_COMPANION(&host->dev); > + if (!adev || !adev->pnp.unique_id || > + (kstrtoull(adev->pnp.unique_id, 10, &uid) < 0)) The UID field holds 4 bytes of ASCII characters. kstrtoull() would fail if the UID field has value such as ‘CX03’.
> + continue; > + > + dev_dbg(&adev->dev, "host uid: %llu\n", uid); > + > + if (uid > U32_MAX) > + continue; > + > dev_info(&host->dev, "host supports CXL\n"); > } > > -- > 2.30.2 > >
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