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    SubjectRe: [PATCH V3 3/3] platform/x86: Intel PMT Telemetry capability driver
    On Tue, Jul 14, 2020 at 9:22 AM David E. Box
    <david.e.box@linux.intel.com> wrote:
    >
    > PMT Telemetry is a capability of the Intel Platform Monitoring Technology.
    > The Telemetry capability provides access to device telemetry metrics that
    > provide hardware performance data to users from continuous, memory mapped,
    > read-only register spaces.
    >
    > Register mappings are not provided by the driver. Instead, a GUID is read
    > from a header for each endpoint. The GUID identifies the device and is to
    > be used with an XML, provided by the vendor, to discover the available set
    > of metrics and their register mapping. This allows firmware updates to
    > modify the register space without needing to update the driver every time
    > with new mappings. Firmware writes a new GUID in this case to specify the
    > new mapping. Software tools with access to the associated XML file can
    > then interpret the changes.
    >
    > This module manages access to all PMT Telemetry endpoints on a system,
    > independent of the device exporting them. It creates a pmt_telemetry class
    > to manage the devices. For each telemetry endpoint, sysfs files provide
    > GUID and size information as well as a pointer to the parent device the
    > telemetry came from. Software may discover the association between
    > endpoints and devices by iterating through the list in sysfs, or by looking
    > for the existence of the class folder under the device of interest. A
    > device node of the same name allows software to then map the telemetry
    > space for direct access.
    >
    > This patch also creates an pci device id list for early telemetry hardware
    > that requires workarounds for known issues.

    Some more style issues, after addressing feel free to add
    Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

    > Signed-off-by: David E. Box <david.e.box@linux.intel.com>
    > Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>

    Since you are submitting this the order of the above SoB chain is a
    bit strange. I think something like

    SoB: Alexander
    Co-developed-by: Alexander
    SoB: David

    is expected (same for patch 2).

    ...

    > +Contact: David Box <david.e.box@linux.intel.com>
    > +Description:
    > + The telem<x> directory contains files describing an instance of
    > + a PMT telemetry device that exposes hardware telemetry. Each
    > + telem<x> directory has an associated /dev/telem<x> node. This
    > + node may be opened and mapped to access the telemetry space of
    > + the device. The register layout of the telemetry space is
    > + determined from an XML file that matches the pci device id and

    PCI

    > + guid for the device.

    GUID

    Same for all code where it appears.

    ...

    > + psize = (PFN_UP(entry->base_addr + entry->header.size) - pfn) *
    > + PAGE_SIZE;

    I wouldn't mind having this on one line.

    ...

    > +static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
    > + char *buf)

    Ditto.

    ...

    > +static ssize_t offset_show(struct device *dev, struct device_attribute *attr,
    > + char *buf)

    Ditto.

    ...

    > +static bool pmt_telem_is_early_client_hw(struct device *dev)
    > +{

    > + struct pci_dev *parent;
    > +
    > + parent = to_pci_dev(dev->parent);

    Can be one line.

    > + return !!pci_match_id(pmt_telem_early_client_pci_ids, parent);
    > +}

    ...

    > + entry->header_res = platform_get_resource(pdev, IORESOURCE_MEM,
    > + i);

    One line, please.

    --
    With Best Regards,
    Andy Shevchenko

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