On Tue, Jul 14, 2020 at 9:22 AM David E. Box
<david.e.box@xxxxxxxxxxxxxxx> 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@xxxxxxxxx>
> Signed-off-by: David E. Box <david.e.box@xxxxxxxxxxxxxxx>
> Signed-off-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxx>
> +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
