[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <CADvopvY5_RO62h2FE5f-F3f4r+LgOVVeNm6mWAuioFwzwsZyDA@mail.gmail.com>
Date: Thu, 17 Jul 2025 09:33:18 -0700
From: Matthew Wood <thepacketgeek@...il.com>
To: Mario Limonciello <superm1@...nel.org>
Cc: Bjorn Helgaas <bhelgaas@...gle.com>, Jonathan Cameron <Jonathan.Cameron@...wei.com>,
Thomas Weißschuh <thomas.weissschuh@...utronix.de>,
linux-kernel@...r.kernel.org, linux-pci@...r.kernel.org
Subject: Re: [PATCH v4 1/1] PCI/sysfs: Expose PCIe device serial number
On Thu, Jul 17, 2025 at 9:29 AM Mario Limonciello <superm1@...nel.org> wrote:
>
> On 7/17/25 11:22 AM, Matthew Wood wrote:
> > Add a single sysfs read-only interface for reading PCIe device serial
> > numbers from userspace in a programmatic way. This device attribute
> > uses the same hexadecimal 1-byte dashed formatting as lspci serial number
> > capability output. If a device doesn't support the serial number
> > capability, the device_serial_number sysfs attribute will not be visible.
>
> You didn't update the commit message here for 'serial_number'.
>
> >
> > Signed-off-by: Matthew Wood <thepacketgeek@...il.com>
>
> With the commit and below comment fixed you can add this to your next spin.
Thank you Mario, I'll send out another v5 soon with these changes.
>
> Reviewed-by: Mario Limonciello <superm1@...nel.org>
>
> > ---
> > Documentation/ABI/testing/sysfs-bus-pci | 9 +++++++++
> > drivers/pci/pci-sysfs.c | 26 ++++++++++++++++++++++---
> > 2 files changed, 32 insertions(+), 3 deletions(-)
> >
> > diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
> > index 69f952fffec7..4da41471cc6b 100644
> > --- a/Documentation/ABI/testing/sysfs-bus-pci
> > +++ b/Documentation/ABI/testing/sysfs-bus-pci
> > @@ -612,3 +612,12 @@ Description:
> >
> > # ls doe_features
> > 0001:01 0001:02 doe_discovery
> > +
> > +What: /sys/bus/pci/devices/.../serial_number
> > +Date: July 2025
> IIRC this should be the date that this is first introduced into the
> kernel. So if this is 6.17 material it should be October 2025 and if
> it's 6.18 material it should be December 2025.
>
> It's getting close to the merge window so I'm not sure right now which
> Bjorn would prefer.
>
> I would say make it October 2025 and if it slips it just gets updated
> for the next spin.
>
> > +Contact: Matthew Wood <thepacketgeek@...il.com>
> > +Description:
> > + This is visible only for PCIe devices that support the serial
> > + number extended capability. The file is read only and due to
> > + the possible sensitivity of accessible serial numbers, admin
> > + only.
> > diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
> > index 268c69daa4d5..bc0e0add15d1 100644
> > --- a/drivers/pci/pci-sysfs.c
> > +++ b/drivers/pci/pci-sysfs.c
> > @@ -239,6 +239,22 @@ static ssize_t current_link_width_show(struct device *dev,
> > }
> > static DEVICE_ATTR_RO(current_link_width);
> >
> > +static ssize_t serial_number_show(struct device *dev,
> > + struct device_attribute *attr, char *buf)
> > +{
> > + struct pci_dev *pci_dev = to_pci_dev(dev);
> > + u64 dsn;
> > +
> > + dsn = pci_get_dsn(pci_dev);
> > + if (!dsn)
> > + return -EIO;
> > +
> > + return sysfs_emit(buf, "%02llx-%02llx-%02llx-%02llx-%02llx-%02llx-%02llx-%02llx\n",
> > + dsn >> 56, (dsn >> 48) & 0xff, (dsn >> 40) & 0xff, (dsn >> 32) & 0xff,
> > + (dsn >> 24) & 0xff, (dsn >> 16) & 0xff, (dsn >> 8) & 0xff, dsn & 0xff);
> > +}
> > +static DEVICE_ATTR_ADMIN_RO(serial_number);
> > +
> > static ssize_t secondary_bus_number_show(struct device *dev,
> > struct device_attribute *attr,
> > char *buf)
> > @@ -660,6 +676,7 @@ static struct attribute *pcie_dev_attrs[] = {
> > &dev_attr_current_link_width.attr,
> > &dev_attr_max_link_width.attr,
> > &dev_attr_max_link_speed.attr,
> > + &dev_attr_serial_number.attr,
> > NULL,
> > };
> >
> > @@ -1749,10 +1766,13 @@ static umode_t pcie_dev_attrs_are_visible(struct kobject *kobj,
> > struct device *dev = kobj_to_dev(kobj);
> > struct pci_dev *pdev = to_pci_dev(dev);
> >
> > - if (pci_is_pcie(pdev))
> > - return a->mode;
> > + if (!pci_is_pcie(pdev))
> > + return 0;
> >
> > - return 0;
> > + if (a == &dev_attr_serial_number.attr && !pci_get_dsn(pdev))
> > + return 0;
> > +
> > + return a->mode;
> > }
> >
> > static const struct attribute_group pci_dev_group = {
>
Powered by blists - more mailing lists