From: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
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 read-only register spaces.
With this driver present the intel_pmt directory can be populated with
telem<x> devices. These devices will contain the standard intel_pmt sysfs
data and a "telem" binary sysfs attribute which can be used to access the
telemetry data.
Co-developed-by: David E. Box <david.e.box@xxxxxxxxxxxxxxx>
Signed-off-by: David E. Box <david.e.box@xxxxxxxxxxxxxxx>
Signed-off-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
---
drivers/platform/x86/Kconfig | 8 ++
drivers/platform/x86/Makefile | 1 +
drivers/platform/x86/intel_pmt_telemetry.c | 158 +++++++++++++++++++++
3 files changed, 167 insertions(+)
create mode 100644 drivers/platform/x86/intel_pmt_telemetry.c
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 093c43b63f48..02cb2db11417 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -1369,6 +1369,14 @@ config INTEL_PMT_CLASS
For more information, see
<file:Documentation/ABI/testing/sysfs-class-intel_pmt>
+config INTEL_PMT_TELEMETRY
+ tristate "Intel Platform Monitoring Technology (PMT) Telemetry driver"
+ select INTEL_PMT_CLASS
+ help
+ The Intel Platform Monitory Technology (PMT) Telemetry driver provides
+ access to hardware telemetry metrics on devices that support the
+ feature.
+
config INTEL_PUNIT_IPC
tristate "Intel P-Unit IPC Driver"
help
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index f4b1f87f2401..6a7b61f59ea8 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -141,6 +141,7 @@ obj-$(CONFIG_INTEL_MID_POWER_BUTTON) += intel_mid_powerbtn.o
obj-$(CONFIG_INTEL_MRFLD_PWRBTN) += intel_mrfld_pwrbtn.o
obj-$(CONFIG_INTEL_PMC_CORE) += intel_pmc_core.o intel_pmc_core_pltdrv.o
obj-$(CONFIG_INTEL_PMT_CLASS) += intel_pmt_class.o
+obj-$(CONFIG_INTEL_PMT_TELEMETRY) += intel_pmt_telemetry.o
obj-$(CONFIG_INTEL_PUNIT_IPC) += intel_punit_ipc.o
obj-$(CONFIG_INTEL_SCU_IPC) += intel_scu_ipc.o
obj-$(CONFIG_INTEL_SCU_PCI) += intel_scu_pcidrv.o
diff --git a/drivers/platform/x86/intel_pmt_telemetry.c b/drivers/platform/x86/intel_pmt_telemetry.c
new file mode 100644
index 000000000000..d4819aefdd65
--- /dev/null
+++ b/drivers/platform/x86/intel_pmt_telemetry.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Intel Platform Monitory Technology Telemetry driver
+ *
+ * Copyright (c) 2020, Intel Corporation.
+ * All Rights Reserved.
+ *
+ * Author: "David E. Box" <david.e.box@xxxxxxxxxxxxxxx>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+#include "intel_pmt_class.h"
+
+#define TELEM_DEV_NAME "pmt_telemetry"
+
+#define TELEM_SIZE_OFFSET 0x0
+#define TELEM_GUID_OFFSET 0x4
+#define TELEM_BASE_OFFSET 0x8
+#define TELEM_ACCESS(v) ((v) & GENMASK(3, 0))
+/* size is in bytes */
+#define TELEM_SIZE(v) (((v) & GENMASK(27, 12)) >> 10)
+
+/* Used by client hardware to identify a fixed telemetry entry*/
+#define TELEM_CLIENT_FIXED_BLOCK_GUID 0x10000000
+
+struct pmt_telem_priv {
+ int num_entries;
+ struct intel_pmt_entry entry[];
+};
+
+static DEFINE_XARRAY_ALLOC(telem_array);
+static struct intel_pmt_namespace pmt_telem_ns = {
+ .name = "telem",
+ .xa = &telem_array
+};
+
+/*
+ * driver initialization
+ */
+static int pmt_telem_add_entry(struct intel_pmt_entry *entry,
+ struct device *parent,
+ struct resource *disc_res)
+{
+ void __iomem *disc_table = entry->disc_table;
+ struct intel_pmt_header header;
+ int ret;
+
+ header.access_type = TELEM_ACCESS(readl(disc_table));
+ header.guid = readl(disc_table + TELEM_GUID_OFFSET);
+ header.base_offset = readl(disc_table + TELEM_BASE_OFFSET);
+
+ /* Size is measured in DWORDS, but accessor returns bytes */
+ header.size = TELEM_SIZE(readl(disc_table));
+
+ ret = intel_pmt_populate_entry(entry, &header, parent, disc_res);
+ if (ret)
+ return ret;
+
+ return intel_pmt_dev_create(entry, &pmt_telem_ns, parent);
+}
+
+static bool pmt_telem_region_overlaps(struct intel_pmt_entry *entry)
+{
+ u32 guid;
+
+ guid = readl(entry->disc_table + TELEM_GUID_OFFSET);
+
+ return guid == TELEM_CLIENT_FIXED_BLOCK_GUID;
+}
+
+static int pmt_telem_remove(struct platform_device *pdev)
+{
+ struct pmt_telem_priv *priv = platform_get_drvdata(pdev);
+ int i;
+
+ for (i = 0; i < priv->num_entries; i++)
+ intel_pmt_dev_destroy(&priv->entry[i], &pmt_telem_ns);
+
+ return 0;
+}
+
+static int pmt_telem_probe(struct platform_device *pdev)
+{
+ struct pmt_telem_priv *priv;
+ bool early_hw;
+ size_t size;
+ int i, ret;
+
+ size = offsetof(struct pmt_telem_priv, entry[pdev->num_resources]);
+ priv = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, priv);
+
+ if (intel_pmt_is_early_client_hw(&pdev->dev))
+ early_hw = true;
+
+ for (i = 0; i < pdev->num_resources; i++) {
+ struct intel_pmt_entry *entry = &priv->entry[i];
+ struct resource *disc_res;
+
+ ret = -ENODEV;
+
+ disc_res = platform_get_resource(pdev, IORESOURCE_MEM, i);
+ if (!disc_res)
+ goto abort_probe;
+
+ ret = intel_pmt_ioremap_discovery_table(entry, pdev, i);
+ if (ret)
+ goto abort_probe;
+
+ if (pmt_telem_region_overlaps(entry) && early_hw)
+ continue;
+
+ ret = pmt_telem_add_entry(entry, &pdev->dev, disc_res);
+ if (ret)
+ goto abort_probe;
+
+ priv->num_entries++;
+ }
+
+ return 0;
+abort_probe:
+ pmt_telem_remove(pdev);
+ return ret;
+}
+
+static struct platform_driver pmt_telem_driver = {
+ .driver = {
+ .name = TELEM_DEV_NAME,
+ },
+ .remove = pmt_telem_remove,
+ .probe = pmt_telem_probe,
+};
+
+static int __init pmt_telem_init(void)
+{
+ return platform_driver_register(&pmt_telem_driver);
+}
+module_init(pmt_telem_init);
+
+static void __exit pmt_telem_exit(void)
+{
+ platform_driver_unregister(&pmt_telem_driver);
+ xa_destroy(&telem_array);
+}
+module_exit(pmt_telem_exit);
+
+MODULE_AUTHOR("David E. Box <david.e.box@xxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Intel PMT Telemetry driver");
+MODULE_ALIAS("platform:" TELEM_DEV_NAME);
+MODULE_LICENSE("GPL v2");
--
2.20.1
