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. Devices nodes are consequently generic
in naming, e.g. /dev/telem<n> and /dev/smplr<n>. Each capability driver
creates a class to manage the list of devices supporting it. 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 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
David E. Box (3):
PCI: Add defines for Designated Vendor-Specific Extended Capability
mfd: Intel Platform Monitoring Technology support
platform/x86: Intel PMT Telemetry capability driver
.../ABI/testing/sysfs-class-pmt_telemetry | 46 ++
MAINTAINERS | 6 +
drivers/mfd/Kconfig | 10 +
drivers/mfd/Makefile | 1 +
drivers/mfd/intel_pmt.c | 220 +++++++++
drivers/platform/x86/Kconfig | 10 +
drivers/platform/x86/Makefile | 1 +
drivers/platform/x86/intel_pmt_telemetry.c | 448 ++++++++++++++++++
include/uapi/linux/pci_regs.h | 5 +
9 files changed, 747 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-class-pmt_telemetry
create mode 100644 drivers/mfd/intel_pmt.c
create mode 100644 drivers/platform/x86/intel_pmt_telemetry.c
--
2.20.1
Intel Platform Monitoring Technology (PMT) is an architecture for
enumerating and accessing hardware monitoring facilities. PMT supports
multiple types of monitoring capabilities. This driver creates platform
devices for each type so that they may be managed by capability specific
drivers (to be introduced). Capabilities are discovered using PCIe DVSEC
ids. Support is included for the 3 current capability types, Telemetry,
Watcher, and Crashlog. The features are available on new Intel platforms
starting from Tiger Lake for which support is added.
Also add a quirk mechanism for several early hardware differences and bugs.
For Tiger Lake, do not support Watcher and Crashlog capabilities since they
will not be compatible with future product. Also, fix use a quirk to fix
the discovery table offset.
Co-developed-by: Alexander Duyck <[email protected]>
Signed-off-by: Alexander Duyck <[email protected]>
Signed-off-by: David E. Box <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
---
MAINTAINERS | 5 +
drivers/mfd/Kconfig | 10 ++
drivers/mfd/Makefile | 1 +
drivers/mfd/intel_pmt.c | 220 ++++++++++++++++++++++++++++++++++++++++
4 files changed, 236 insertions(+)
create mode 100644 drivers/mfd/intel_pmt.c
diff --git a/MAINTAINERS b/MAINTAINERS
index f0569cf304ca..b69429c70330 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8845,6 +8845,11 @@ F: drivers/mfd/intel_soc_pmic*
F: include/linux/mfd/intel_msic.h
F: include/linux/mfd/intel_soc_pmic*
+INTEL PMT DRIVER
+M: "David E. Box" <[email protected]>
+S: Maintained
+F: drivers/mfd/intel_pmt.c
+
INTEL PRO/WIRELESS 2100, 2200BG, 2915ABG NETWORK CONNECTION SUPPORT
M: Stanislav Yakovlev <[email protected]>
L: [email protected]
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index a37d7d171382..5dd05f1b8ce5 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -670,6 +670,16 @@ config MFD_INTEL_PMC_BXT
Register and P-unit access. In addition this creates devices
for iTCO watchdog and telemetry that are part of the PMC.
+config MFD_INTEL_PMT
+ tristate "Intel Platform Monitoring Technology (PMT) support"
+ depends on PCI
+ select MFD_CORE
+ help
+ The Intel Platform Monitoring Technology (PMT) is an interface that
+ provides access to hardware monitor registers. This driver supports
+ Telemetry, Watcher, and Crashlog PMT capabilities/devices for
+ platforms starting from Tiger Lake.
+
config MFD_IPAQ_MICRO
bool "Atmel Micro ASIC (iPAQ h3100/h3600/h3700) Support"
depends on SA1100_H3100 || SA1100_H3600
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 9367a92f795a..1961b4737985 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -216,6 +216,7 @@ obj-$(CONFIG_MFD_INTEL_LPSS_PCI) += intel-lpss-pci.o
obj-$(CONFIG_MFD_INTEL_LPSS_ACPI) += intel-lpss-acpi.o
obj-$(CONFIG_MFD_INTEL_MSIC) += intel_msic.o
obj-$(CONFIG_MFD_INTEL_PMC_BXT) += intel_pmc_bxt.o
+obj-$(CONFIG_MFD_INTEL_PMT) += intel_pmt.o
obj-$(CONFIG_MFD_PALMAS) += palmas.o
obj-$(CONFIG_MFD_VIPERBOARD) += viperboard.o
obj-$(CONFIG_MFD_RC5T583) += rc5t583.o rc5t583-irq.o
diff --git a/drivers/mfd/intel_pmt.c b/drivers/mfd/intel_pmt.c
new file mode 100644
index 000000000000..0e572b105101
--- /dev/null
+++ b/drivers/mfd/intel_pmt.c
@@ -0,0 +1,220 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Intel Platform Monitoring Technology PMT driver
+ *
+ * Copyright (c) 2020, Intel Corporation.
+ * All Rights Reserved.
+ *
+ * Author: David E. Box <[email protected]>
+ */
+
+#include <linux/bits.h>
+#include <linux/kernel.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/types.h>
+
+/* Intel DVSEC capability vendor space offsets */
+#define INTEL_DVSEC_ENTRIES 0xA
+#define INTEL_DVSEC_SIZE 0xB
+#define INTEL_DVSEC_TABLE 0xC
+#define INTEL_DVSEC_TABLE_BAR(x) ((x) & GENMASK(2, 0))
+#define INTEL_DVSEC_TABLE_OFFSET(x) ((x) & GENMASK(31, 3))
+#define INTEL_DVSEC_ENTRY_SIZE 4
+
+/* PMT capabilities */
+#define DVSEC_INTEL_ID_TELEMETRY 2
+#define DVSEC_INTEL_ID_WATCHER 3
+#define DVSEC_INTEL_ID_CRASHLOG 4
+
+struct intel_dvsec_header {
+ u16 length;
+ u16 id;
+ u8 num_entries;
+ u8 entry_size;
+ u8 tbir;
+ u32 offset;
+};
+
+enum pmt_quirks {
+ /* Watcher capability not supported */
+ PMT_QUIRK_NO_WATCHER = BIT(0),
+
+ /* Crashlog capability not supported */
+ PMT_QUIRK_NO_CRASHLOG = BIT(1),
+
+ /* Use shift instead of mask to read discovery table offset */
+ PMT_QUIRK_TABLE_SHIFT = BIT(2),
+};
+
+struct pmt_platform_info {
+ unsigned long quirks;
+};
+
+static const struct pmt_platform_info tgl_info = {
+ .quirks = PMT_QUIRK_NO_WATCHER | PMT_QUIRK_NO_CRASHLOG |
+ PMT_QUIRK_TABLE_SHIFT,
+};
+
+static int pmt_add_dev(struct pci_dev *pdev, struct intel_dvsec_header *header,
+ struct pmt_platform_info *info)
+{
+ struct device *dev = &pdev->dev;
+ struct resource *res, *tmp;
+ struct mfd_cell *cell;
+ const char *name;
+ int count = header->num_entries;
+ int size = header->entry_size;
+ int id = header->id;
+ int i;
+
+ switch (id) {
+ case DVSEC_INTEL_ID_TELEMETRY:
+ name = "pmt_telemetry";
+ break;
+ case DVSEC_INTEL_ID_WATCHER:
+ if (info->quirks & PMT_QUIRK_NO_WATCHER) {
+ dev_info(dev, "Watcher not supported\n");
+ return 0;
+ }
+ name = "pmt_watcher";
+ break;
+ case DVSEC_INTEL_ID_CRASHLOG:
+ if (info->quirks & PMT_QUIRK_NO_CRASHLOG) {
+ dev_info(dev, "Crashlog not supported\n");
+ return 0;
+ }
+ name = "pmt_crashlog";
+ break;
+ default:
+ dev_err(dev, "Unrecognized PMT capability: %d\n", id);
+ return -EINVAL;
+ }
+
+ if (!header->num_entries || !header->entry_size) {
+ dev_err(dev, "Invalid count or size for %s header\n", name);
+ return -EINVAL;
+ }
+
+ cell = devm_kzalloc(dev, sizeof(*cell), GFP_KERNEL);
+ if (!cell)
+ return -ENOMEM;
+
+ res = devm_kcalloc(dev, count, sizeof(*res), GFP_KERNEL);
+ if (!res)
+ return -ENOMEM;
+
+ if (info->quirks & PMT_QUIRK_TABLE_SHIFT)
+ header->offset >>= 3;
+
+ /*
+ * The PMT DVSEC contains the starting offset and count for a block of
+ * discovery tables, each providing access to monitoring facilities for
+ * a section of the device. Create a resource list of these tables to
+ * provide to the driver.
+ */
+ for (i = 0, tmp = res; i < count; i++, tmp++) {
+ tmp->start = pdev->resource[header->tbir].start +
+ header->offset + i * (size << 2);
+ tmp->end = tmp->start + (size << 2) - 1;
+ tmp->flags = IORESOURCE_MEM;
+ }
+
+ cell->resources = res;
+ cell->num_resources = count;
+ cell->name = name;
+
+ return devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO, cell, 1, NULL, 0,
+ NULL);
+}
+
+static int pmt_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+ struct pmt_platform_info *info;
+ bool found_devices = false;
+ int ret, pos = 0;
+
+ ret = pcim_enable_device(pdev);
+ if (ret)
+ return ret;
+
+ info = devm_kmemdup(&pdev->dev, (void *)id->driver_data, sizeof(*info),
+ GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+
+ do {
+ struct intel_dvsec_header header;
+ u32 table;
+ u16 vid;
+
+ pos = pci_find_next_ext_capability(pdev, pos, PCI_EXT_CAP_ID_DVSEC);
+ if (!pos)
+ break;
+
+ pci_read_config_word(pdev, pos + PCI_DVSEC_HEADER1, &vid);
+ if (vid != PCI_VENDOR_ID_INTEL)
+ continue;
+
+ pci_read_config_word(pdev, pos + PCI_DVSEC_HEADER2,
+ &header.id);
+ pci_read_config_byte(pdev, pos + INTEL_DVSEC_ENTRIES,
+ &header.num_entries);
+ pci_read_config_byte(pdev, pos + INTEL_DVSEC_SIZE,
+ &header.entry_size);
+ pci_read_config_dword(pdev, pos + INTEL_DVSEC_TABLE,
+ &table);
+
+ header.tbir = INTEL_DVSEC_TABLE_BAR(table);
+ header.offset = INTEL_DVSEC_TABLE_OFFSET(table);
+
+ ret = pmt_add_dev(pdev, &header, info);
+ if (ret) {
+ dev_warn(&pdev->dev,
+ "Failed to add device for DVSEC id %d\n",
+ header.id);
+ continue;
+ }
+
+ found_devices = true;
+ } while (true);
+
+ if (!found_devices) {
+ dev_err(&pdev->dev, "No supported PMT capabilities found.\n");
+ return -ENODEV;
+ }
+
+ pm_runtime_put(&pdev->dev);
+ pm_runtime_allow(&pdev->dev);
+
+ return 0;
+}
+
+static void pmt_pci_remove(struct pci_dev *pdev)
+{
+ pm_runtime_forbid(&pdev->dev);
+ pm_runtime_get_sync(&pdev->dev);
+}
+
+#define PCI_DEVICE_ID_INTEL_PMT_TGL 0x9a0d
+static const struct pci_device_id pmt_pci_ids[] = {
+ { PCI_DEVICE_DATA(INTEL, PMT_TGL, &tgl_info) },
+ { }
+};
+MODULE_DEVICE_TABLE(pci, pmt_pci_ids);
+
+static struct pci_driver pmt_pci_driver = {
+ .name = "intel-pmt",
+ .id_table = pmt_pci_ids,
+ .probe = pmt_pci_probe,
+ .remove = pmt_pci_remove,
+};
+module_pci_driver(pmt_pci_driver);
+
+MODULE_AUTHOR("David E. Box <[email protected]>");
+MODULE_DESCRIPTION("Intel Platform Monitoring Technology PMT driver");
+MODULE_LICENSE("GPL v2");
--
2.20.1
On Wed, 19 Aug 2020, David E. Box wrote:
> Intel Platform Monitoring Technology (PMT) is an architecture for
> enumerating and accessing hardware monitoring facilities. PMT supports
> multiple types of monitoring capabilities. This driver creates platform
> devices for each type so that they may be managed by capability specific
> drivers (to be introduced). Capabilities are discovered using PCIe DVSEC
> ids. Support is included for the 3 current capability types, Telemetry,
> Watcher, and Crashlog. The features are available on new Intel platforms
> starting from Tiger Lake for which support is added.
>
> Also add a quirk mechanism for several early hardware differences and bugs.
> For Tiger Lake, do not support Watcher and Crashlog capabilities since they
> will not be compatible with future product. Also, fix use a quirk to fix
> the discovery table offset.
>
> Co-developed-by: Alexander Duyck <[email protected]>
> Signed-off-by: Alexander Duyck <[email protected]>
> Signed-off-by: David E. Box <[email protected]>
> Reviewed-by: Andy Shevchenko <[email protected]>
> ---
> MAINTAINERS | 5 +
> drivers/mfd/Kconfig | 10 ++
> drivers/mfd/Makefile | 1 +
> drivers/mfd/intel_pmt.c | 220 ++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 236 insertions(+)
> create mode 100644 drivers/mfd/intel_pmt.c
For my own reference (apply this as-is to your sign-off block):
Acked-for-MFD-by: Lee Jones <[email protected]>
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
On Wed, 19 Aug 2020, David E. Box wrote:
[...]
> David E. Box (3):
> PCI: Add defines for Designated Vendor-Specific Extended Capability
> mfd: Intel Platform Monitoring Technology support
> platform/x86: Intel PMT Telemetry capability driver
>
> .../ABI/testing/sysfs-class-pmt_telemetry | 46 ++
> MAINTAINERS | 6 +
> drivers/mfd/Kconfig | 10 +
> drivers/mfd/Makefile | 1 +
> drivers/mfd/intel_pmt.c | 220 +++++++++
> drivers/platform/x86/Kconfig | 10 +
> drivers/platform/x86/Makefile | 1 +
> drivers/platform/x86/intel_pmt_telemetry.c | 448 ++++++++++++++++++
> include/uapi/linux/pci_regs.h | 5 +
> 9 files changed, 747 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-class-pmt_telemetry
> create mode 100644 drivers/mfd/intel_pmt.c
> create mode 100644 drivers/platform/x86/intel_pmt_telemetry.c
What's the plan for this set?
I'm happy to pick it up and take it through MFD if required.
If that's the route of choice, I'll pick it up in just over a week.
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
On Fri, Aug 28, 2020 at 1:57 PM Lee Jones <[email protected]> wrote:
> On Wed, 19 Aug 2020, David E. Box wrote:
>
> [...]
>
> > David E. Box (3):
> > PCI: Add defines for Designated Vendor-Specific Extended Capability
> > mfd: Intel Platform Monitoring Technology support
> > platform/x86: Intel PMT Telemetry capability driver
> >
> > .../ABI/testing/sysfs-class-pmt_telemetry | 46 ++
> > MAINTAINERS | 6 +
> > drivers/mfd/Kconfig | 10 +
> > drivers/mfd/Makefile | 1 +
> > drivers/mfd/intel_pmt.c | 220 +++++++++
> > drivers/platform/x86/Kconfig | 10 +
> > drivers/platform/x86/Makefile | 1 +
> > drivers/platform/x86/intel_pmt_telemetry.c | 448 ++++++++++++++++++
> > include/uapi/linux/pci_regs.h | 5 +
> > 9 files changed, 747 insertions(+)
> > create mode 100644 Documentation/ABI/testing/sysfs-class-pmt_telemetry
> > create mode 100644 drivers/mfd/intel_pmt.c
> > create mode 100644 drivers/platform/x86/intel_pmt_telemetry.c
>
> What's the plan for this set?
>
> I'm happy to pick it up and take it through MFD if required.
I guess that was already agreed like this and you were in Cc list of
that discussion.
>
> If that's the route of choice, I'll pick it up in just over a week.
>
> --
> Lee Jones [李琼斯]
> Senior Technical Lead - Developer Services
> Linaro.org │ Open source software for Arm SoCs
> Follow Linaro: Facebook | Twitter | Blog
--
With Best Regards,
Andy Shevchenko
On Fri, 28 Aug 2020, Andy Shevchenko wrote:
> On Fri, Aug 28, 2020 at 1:57 PM Lee Jones <[email protected]> wrote:
> > On Wed, 19 Aug 2020, David E. Box wrote:
> >
> > [...]
> >
> > > David E. Box (3):
> > > PCI: Add defines for Designated Vendor-Specific Extended Capability
> > > mfd: Intel Platform Monitoring Technology support
> > > platform/x86: Intel PMT Telemetry capability driver
> > >
> > > .../ABI/testing/sysfs-class-pmt_telemetry | 46 ++
> > > MAINTAINERS | 6 +
> > > drivers/mfd/Kconfig | 10 +
> > > drivers/mfd/Makefile | 1 +
> > > drivers/mfd/intel_pmt.c | 220 +++++++++
> > > drivers/platform/x86/Kconfig | 10 +
> > > drivers/platform/x86/Makefile | 1 +
> > > drivers/platform/x86/intel_pmt_telemetry.c | 448 ++++++++++++++++++
> > > include/uapi/linux/pci_regs.h | 5 +
> > > 9 files changed, 747 insertions(+)
> > > create mode 100644 Documentation/ABI/testing/sysfs-class-pmt_telemetry
> > > create mode 100644 drivers/mfd/intel_pmt.c
> > > create mode 100644 drivers/platform/x86/intel_pmt_telemetry.c
> >
> > What's the plan for this set?
> >
> > I'm happy to pick it up and take it through MFD if required.
>
> I guess that was already agreed like this and you were in Cc list of
> that discussion.
I have many submissions on the go at the moment.
Keeping full status for each of them in my head would be impossible.
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog