Intel Platform Monitoring Technology (PMT) is an architecture for
enumerating and accessing hardware monitoring capabilities on a device.
With customers increasingly asking for hardware telemetry, engineers not
only have to figure out how to measure and collect data, but also how to
deliver it and make it discoverable. The latter may be through some device
specific method requiring device specific tools to collect the data. This
in turn requires customers to manage a suite of different tools in order to
collect the differing assortment of monitoring data on their systems. Even
when such information can be provided in kernel drivers, they may require
constant maintenance to update register mappings as they change with
firmware updates and new versions of hardware. PMT provides a solution for
discovering and reading telemetry from a device through a hardware agnostic
framework that allows for updates to systems without requiring patches to
the kernel or software tools.
PMT defines several capabilities to support collecting monitoring data from
hardware. All are discoverable as separate instances of the PCIE Designated
Vendor extended capability (DVSEC) with the Intel vendor code. The DVSEC ID
field uniquely identifies the capability. Each DVSEC also provides a BAR
offset to a header that defines capability-specific attributes, including
GUID, feature type, offset and length, as well as configuration settings
where applicable. The GUID uniquely identifies the register space of any
monitor data exposed by the capability. The GUID is associated with an XML
file from the vendor that describes the mapping of the register space along
with properties of the monitor data. This allows vendors to perform
firmware updates that can change the mapping (e.g. add new metrics) without
requiring any changes to drivers or software tools. The new mapping is
confirmed by an updated GUID, read from the hardware, which software uses
with a new XML.
The current capabilities defined by PMT are Telemetry, Watcher, and
Crashlog. The Telemetry capability provides access to a continuous block
of read only data. The Watcher capability provides access to hardware
sampling and tracing features. Crashlog provides access to device crash
dumps. While there is some relationship between capabilities (Watcher can
be configured to sample from the Telemetry data set) each exists as stand
alone features with no dependency on any other. The design therefore splits
them into individual, capability specific drivers. MFD is used to create
platform devices for each capability so that they may be managed by their
own driver. The PMT architecture is (for the most part) agnostic to the
type of device it can collect from. Software can determine which devices
support a PMT feature by searching through each device node entry in the
sysfs class folder. It can additionally determine if a particular device
supports a PMT feature by checking for a PMT class folder in the device
folder.
This patch set provides support for the PMT framework, along with support
for Telemetry on Tiger Lake.
Changes from V8:
- Rebase on 5.10-rc1
- Add missing changes in MFD patch from V7 that were accidentally
dropped in V8
- Remove error message when unsupported capability found. Avoids
unnecessary noise on some systems.
Changes from V7:
Link: https://lore.kernel.org/lkml/[email protected]/
- Refactor to minimize code duplication by putting more setup code
in the common intel_pmt_dev_create().
- Add and use a function pointer to handle capability specific
header decoding.
- Add comment on usage of early_client_pci_ids list and add
Alder Lake PCI ID to the list.
- Remove unneeded check on the count variable in intel_pmt_read().
- Add missing header functions.
- Specify module names in Kconfig.
- Fix spelling errors across patch set.
Changes from V6:
- Use NULL for OOBMSM driver data instead of an empty struct.
Rewrite the code to check for NULL driver_data.
- Fix spelling and formatting in Kconfig.
- Use MKDEV(0,0) to prevent unneeded device node from being
created.
Changes from V5:
- Add Alder Lake and the "Out of Band Management Services
Module (OOBMSM)" ids to the MFD driver. Transferred to this
patch set.
- Use a single class for all PMT capabilities as suggested by
Hans.
- Add binary attribute for telemetry driver to allow read
syscall as suggested by Hans.
- Use the class file to hold attributes and other common code
used by all PMT drivers.
- Add the crashlog driver to the patch set and add a mutex to
protect access to the enable control and trigger files as
suggested by Hans.
Changes from V4:
- Replace MFD with PMT in driver title
- Fix commit tags in chronological order
- Fix includes in alphabetical order
- Use 'raw' string instead of defines for device names
- Add an error message when returning an error code for
unrecognized capability id
- Use dev_err instead of dev_warn for messages when returning
an error
- Change while loop to call pci_find_next_ext_capability once
- Add missing continue in while loop
- Keep PCI platform defines using PCI_DEVICE_DATA magic tied to
the pci_device_id table
- Comment and kernel message cleanup
Changes from V3:
- Write out full acronym for DVSEC in PCI patch commit message and
add 'Designated' to comments
- remove unused variable caught by kernel test robot <[email protected]>
- Add required Co-developed-by signoffs, noted by Andy
- Allow access using new CAP_PERFMON capability as suggested by
Alexey Bundankov
- Fix spacing in Kconfig, noted by Randy
- Other style changes and fixups suggested by Andy
Changes from V2:
- In order to handle certain HW bugs from the telemetry capability
driver, create a single platform device per capability instead of
a device per entry. Add the entry data as device resources and
let the capability driver manage them as a set allowing for
cleaner HW bug resolution.
- Handle discovery table offset bug in intel_pmt.c
- Handle overlapping regions in intel_pmt_telemetry.c
- Add description of sysfs class to testing ABI.
- Don't check size and count until confirming support for the PMT
capability to avoid bailing out when we need to skip it.
- Remove unneeded header file. Move code to the intel_pmt.c, the
only place where it's needed.
- Remove now unused platform data.
- Add missing header files types.h, bits.h.
- Rename file name and build options from telem to telemetry.
- Code cleanup suggested by Andy S.
- x86 mailing list added.
Changes from V1:
- In the telemetry driver, set the device in device_create() to
the parent PCI device (the monitoring device) for clear
association in sysfs. Was set before to the platform device
created by the PCI parent.
- Move telem struct into driver and delete unneeded header file.
- Start telem device numbering from 0 instead of 1. 1 was used
due to anticipated changes, no longer needed.
- Use helper macros suggested by Andy S.
- Rename class to pmt_telemetry, spelling out full name
- Move monitor device name defines to common header
- Coding style, spelling, and Makefile/MAINTAINERS ordering fixes
Alexander Duyck (3):
platform/x86: Intel PMT class driver
platform/x86: Intel PMT Telemetry capability driver
platform/x86: Intel PMT Crashlog capability driver
David E. Box (2):
PCI: Add defines for Designated Vendor-Specific Extended Capability
mfd: Intel Platform Monitoring Technology support
.../ABI/testing/sysfs-class-intel_pmt | 119 +++++++
MAINTAINERS | 6 +
drivers/mfd/Kconfig | 10 +
drivers/mfd/Makefile | 1 +
drivers/mfd/intel_pmt.c | 223 ++++++++++++
drivers/platform/x86/Kconfig | 34 ++
drivers/platform/x86/Makefile | 3 +
drivers/platform/x86/intel_pmt_class.c | 297 ++++++++++++++++
drivers/platform/x86/intel_pmt_class.h | 52 +++
drivers/platform/x86/intel_pmt_crashlog.c | 328 ++++++++++++++++++
drivers/platform/x86/intel_pmt_telemetry.c | 160 +++++++++
include/uapi/linux/pci_regs.h | 5 +
12 files changed, 1238 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-class-intel_pmt
create mode 100644 drivers/mfd/intel_pmt.c
create mode 100644 drivers/platform/x86/intel_pmt_class.c
create mode 100644 drivers/platform/x86/intel_pmt_class.h
create mode 100644 drivers/platform/x86/intel_pmt_crashlog.c
create mode 100644 drivers/platform/x86/intel_pmt_telemetry.c
--
2.20.1
Add PCIe Designated Vendor-Specific Extended Capability (DVSEC) and defines
for the header offsets. Defined in PCIe r5.0, sec 7.9.6.
Signed-off-by: David E. Box <[email protected]>
Acked-by: Bjorn Helgaas <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
---
Changes from V8:
- None
include/uapi/linux/pci_regs.h | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
index a95d55f9f257..8f8bd2318c6c 100644
--- a/include/uapi/linux/pci_regs.h
+++ b/include/uapi/linux/pci_regs.h
@@ -723,6 +723,7 @@
#define PCI_EXT_CAP_ID_DPC 0x1D /* Downstream Port Containment */
#define PCI_EXT_CAP_ID_L1SS 0x1E /* L1 PM Substates */
#define PCI_EXT_CAP_ID_PTM 0x1F /* Precision Time Measurement */
+#define PCI_EXT_CAP_ID_DVSEC 0x23 /* Designated Vendor-Specific */
#define PCI_EXT_CAP_ID_DLF 0x25 /* Data Link Feature */
#define PCI_EXT_CAP_ID_PL_16GT 0x26 /* Physical Layer 16.0 GT/s */
#define PCI_EXT_CAP_ID_MAX PCI_EXT_CAP_ID_PL_16GT
@@ -1066,6 +1067,10 @@
#define PCI_L1SS_CTL1_LTR_L12_TH_SCALE 0xe0000000 /* LTR_L1.2_THRESHOLD_Scale */
#define PCI_L1SS_CTL2 0x0c /* Control 2 Register */
+/* Designated Vendor-Specific (DVSEC, PCI_EXT_CAP_ID_DVSEC) */
+#define PCI_DVSEC_HEADER1 0x4 /* Designated Vendor-Specific Header1 */
+#define PCI_DVSEC_HEADER2 0x8 /* Designated Vendor-Specific Header2 */
+
/* Data Link Feature */
#define PCI_DLF_CAP 0x04 /* Capabilities Register */
#define PCI_DLF_EXCHANGE_ENABLE 0x80000000 /* Data Link Feature Exchange Enable */
--
2.20.1
On Wed, 28 Oct 2020, David E. Box wrote:
> Intel Platform Monitoring Technology (PMT) is an architecture for
> enumerating and accessing hardware monitoring capabilities on a device.
> With customers increasingly asking for hardware telemetry, engineers not
> only have to figure out how to measure and collect data, but also how to
> deliver it and make it discoverable. The latter may be through some device
> specific method requiring device specific tools to collect the data. This
> in turn requires customers to manage a suite of different tools in order to
> collect the differing assortment of monitoring data on their systems. Even
> when such information can be provided in kernel drivers, they may require
> constant maintenance to update register mappings as they change with
> firmware updates and new versions of hardware. PMT provides a solution for
> discovering and reading telemetry from a device through a hardware agnostic
> framework that allows for updates to systems without requiring patches to
> the kernel or software tools.
>
> PMT defines several capabilities to support collecting monitoring data from
> hardware. All are discoverable as separate instances of the PCIE Designated
> Vendor extended capability (DVSEC) with the Intel vendor code. The DVSEC ID
> field uniquely identifies the capability. Each DVSEC also provides a BAR
> offset to a header that defines capability-specific attributes, including
> GUID, feature type, offset and length, as well as configuration settings
> where applicable. The GUID uniquely identifies the register space of any
> monitor data exposed by the capability. The GUID is associated with an XML
> file from the vendor that describes the mapping of the register space along
> with properties of the monitor data. This allows vendors to perform
> firmware updates that can change the mapping (e.g. add new metrics) without
> requiring any changes to drivers or software tools. The new mapping is
> confirmed by an updated GUID, read from the hardware, which software uses
> with a new XML.
>
> The current capabilities defined by PMT are Telemetry, Watcher, and
> Crashlog. The Telemetry capability provides access to a continuous block
> of read only data. The Watcher capability provides access to hardware
> sampling and tracing features. Crashlog provides access to device crash
> dumps. While there is some relationship between capabilities (Watcher can
> be configured to sample from the Telemetry data set) each exists as stand
> alone features with no dependency on any other. The design therefore splits
> them into individual, capability specific drivers. MFD is used to create
> platform devices for each capability so that they may be managed by their
> own driver. The PMT architecture is (for the most part) agnostic to the
> type of device it can collect from. Software can determine which devices
> support a PMT feature by searching through each device node entry in the
> sysfs class folder. It can additionally determine if a particular device
> supports a PMT feature by checking for a PMT class folder in the device
> folder.
>
> This patch set provides support for the PMT framework, along with support
> for Telemetry on Tiger Lake.
>
> Changes from V8:
> - Rebase on 5.10-rc1
> - Add missing changes in MFD patch from V7 that were accidentally
> dropped in V8
Which changes are those?
Do I need to re-review?
> - Remove error message when unsupported capability found. Avoids
> unnecessary noise on some systems.
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
Hi Lee,
On Thu, 2020-10-29 at 15:16 +0000, Lee Jones wrote:
...
> > Changes from V8:
> > - Rebase on 5.10-rc1
> > - Add missing changes in MFD patch from V7 that were
> > accidentally
> > dropped in V8
>
> Which changes are those?
>
> Do I need to re-review?
Should have mentioned here. Patch 2 is the only one that changed. It
was corrected to be the last patch you reviewed (which was accidentally
reverted in V8) plus I dropped this dev_err:
if (!found_devices) {
dev_err(&pdev->dev, "No supported PMT capabilities
found.\n");
return -ENODEV;
}
There are no more changes planned for this series and we're still
looking to merge in 5.11. Thanks.
David
Enjoy!
The following changes since commit 3650b228f83adda7e5ee532e2b90429c03f7b9ec:
Linux 5.10-rc1 (2020-10-25 15:14:11 -0700)
are available in the Git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd.git ib-mfd-x86-v5.11
for you to fetch changes up to 5ef9998c96b0c99c49c202054586967e609286d2:
platform/x86: Intel PMT Crashlog capability driver (2020-11-04 11:14:38 +0000)
----------------------------------------------------------------
Immutable branch between MFD and x86 due for the v5.11 merge window
----------------------------------------------------------------
Alexander Duyck (3):
platform/x86: Intel PMT class driver
platform/x86: Intel PMT Telemetry capability driver
platform/x86: Intel PMT Crashlog capability driver
David E. Box (2):
PCI: Add defines for Designated Vendor-Specific Extended Capability
mfd: Intel Platform Monitoring Technology support
Documentation/ABI/testing/sysfs-class-intel_pmt | 119 +++++++++
MAINTAINERS | 6 +
drivers/mfd/Kconfig | 10 +
drivers/mfd/Makefile | 1 +
drivers/mfd/intel_pmt.c | 223 ++++++++++++++++
drivers/platform/x86/Kconfig | 34 +++
drivers/platform/x86/Makefile | 3 +
drivers/platform/x86/intel_pmt_class.c | 297 +++++++++++++++++++++
drivers/platform/x86/intel_pmt_class.h | 52 ++++
drivers/platform/x86/intel_pmt_crashlog.c | 328 ++++++++++++++++++++++++
drivers/platform/x86/intel_pmt_telemetry.c | 160 ++++++++++++
include/uapi/linux/pci_regs.h | 5 +
12 files changed, 1238 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-class-intel_pmt
create mode 100644 drivers/mfd/intel_pmt.c
create mode 100644 drivers/platform/x86/intel_pmt_class.c
create mode 100644 drivers/platform/x86/intel_pmt_class.h
create mode 100644 drivers/platform/x86/intel_pmt_crashlog.c
create mode 100644 drivers/platform/x86/intel_pmt_telemetry.c
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
Hi,
On 11/4/20 12:17 PM, Lee Jones wrote:
> Enjoy!
>
> The following changes since commit 3650b228f83adda7e5ee532e2b90429c03f7b9ec:
>
> Linux 5.10-rc1 (2020-10-25 15:14:11 -0700)
>
> are available in the Git repository at:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd.git ib-mfd-x86-v5.11
>
> for you to fetch changes up to 5ef9998c96b0c99c49c202054586967e609286d2:
>
> platform/x86: Intel PMT Crashlog capability driver (2020-11-04 11:14:38 +0000)
>
> ----------------------------------------------------------------
> Immutable branch between MFD and x86 due for the v5.11 merge window
Thank you I've merged this into my review-hans (future for-next) branch of:
git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86
Regards,
Hans
>
> ----------------------------------------------------------------
> Alexander Duyck (3):
> platform/x86: Intel PMT class driver
> platform/x86: Intel PMT Telemetry capability driver
> platform/x86: Intel PMT Crashlog capability driver
>
> David E. Box (2):
> PCI: Add defines for Designated Vendor-Specific Extended Capability
> mfd: Intel Platform Monitoring Technology support
>
> Documentation/ABI/testing/sysfs-class-intel_pmt | 119 +++++++++
> MAINTAINERS | 6 +
> drivers/mfd/Kconfig | 10 +
> drivers/mfd/Makefile | 1 +
> drivers/mfd/intel_pmt.c | 223 ++++++++++++++++
> drivers/platform/x86/Kconfig | 34 +++
> drivers/platform/x86/Makefile | 3 +
> drivers/platform/x86/intel_pmt_class.c | 297 +++++++++++++++++++++
> drivers/platform/x86/intel_pmt_class.h | 52 ++++
> drivers/platform/x86/intel_pmt_crashlog.c | 328 ++++++++++++++++++++++++
> drivers/platform/x86/intel_pmt_telemetry.c | 160 ++++++++++++
> include/uapi/linux/pci_regs.h | 5 +
> 12 files changed, 1238 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-class-intel_pmt
> create mode 100644 drivers/mfd/intel_pmt.c
> create mode 100644 drivers/platform/x86/intel_pmt_class.c
> create mode 100644 drivers/platform/x86/intel_pmt_class.h
> create mode 100644 drivers/platform/x86/intel_pmt_crashlog.c
> create mode 100644 drivers/platform/x86/intel_pmt_telemetry.c
>