From 5ef9998c96b0c99c49c202054586967e609286d2 Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Wed, 28 Oct 2020 18:55:36 -0700 Subject: [PATCH] platform/x86: Intel PMT Crashlog capability driver Add support for the Intel Platform Monitoring Technology crashlog interface. This interface provides a few sysfs values to allow for controlling the crashlog telemetry interface as well as a character driver to allow for mapping the crashlog memory region so that it can be accessed after a crashlog has been recorded. This driver is meant to only support the server version of the crashlog which is identified as crash_type 1 with a version of zero. Currently no other types are supported. Signed-off-by: Alexander Duyck Signed-off-by: David E. Box Reviewed-by: Hans de Goede Signed-off-by: Lee Jones --- Documentation/ABI/testing/sysfs-class-intel_pmt | 65 +++++ drivers/platform/x86/Kconfig | 11 + drivers/platform/x86/Makefile | 1 + drivers/platform/x86/intel_pmt_crashlog.c | 328 ++++++++++++++++++++++++ 4 files changed, 405 insertions(+) create mode 100644 drivers/platform/x86/intel_pmt_crashlog.c diff --git a/Documentation/ABI/testing/sysfs-class-intel_pmt b/Documentation/ABI/testing/sysfs-class-intel_pmt index 926b5cf..ed4c886 100644 --- a/Documentation/ABI/testing/sysfs-class-intel_pmt +++ b/Documentation/ABI/testing/sysfs-class-intel_pmt @@ -52,3 +52,68 @@ Contact: David Box Description: (RO) The offset of telemetry region in bytes that corresponds to the mapping for the telem file. + +What: /sys/class/intel_pmt/crashlog +Date: October 2020 +KernelVersion: 5.10 +Contact: Alexander Duyck +Description: + The crashlog directory contains files for configuring an + instance of a PMT crashlog device that can perform crash data + recording. Each crashlog device has an associated crashlog + file. This file can be opened and mapped or read to access the + resulting crashlog buffer. The register layout for the buffer + can be determined from an XML file of specified GUID for the + parent device. + +What: /sys/class/intel_pmt/crashlog/crashlog +Date: October 2020 +KernelVersion: 5.10 +Contact: David Box +Description: + (RO) The crashlog buffer for this crashlog device. This file + may be mapped or read to obtain the data. + +What: /sys/class/intel_pmt/crashlog/guid +Date: October 2020 +KernelVersion: 5.10 +Contact: Alexander Duyck +Description: + (RO) The GUID for this crashlog device. The GUID identifies the + version of the XML file for the parent device that should be + used to determine the register layout. + +What: /sys/class/intel_pmt/crashlog/size +Date: October 2020 +KernelVersion: 5.10 +Contact: Alexander Duyck +Description: + (RO) The length of the result buffer in bytes that corresponds + to the size for the crashlog buffer. + +What: /sys/class/intel_pmt/crashlog/offset +Date: October 2020 +KernelVersion: 5.10 +Contact: Alexander Duyck +Description: + (RO) The offset of the buffer in bytes that corresponds + to the mapping for the crashlog device. + +What: /sys/class/intel_pmt/crashlog/enable +Date: October 2020 +KernelVersion: 5.10 +Contact: Alexander Duyck +Description: + (RW) Boolean value controlling if the crashlog functionality + is enabled for the crashlog device. + +What: /sys/class/intel_pmt/crashlog/trigger +Date: October 2020 +KernelVersion: 5.10 +Contact: Alexander Duyck +Description: + (RW) Boolean value controlling the triggering of the crashlog + device node. When read it provides data on if the crashlog has + been triggered. When written to it can be used to either clear + the current trigger by writing false, or to trigger a new + event if the trigger is not currently set. diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig index 6982c56..971d1cd 100644 --- a/drivers/platform/x86/Kconfig +++ b/drivers/platform/x86/Kconfig @@ -1385,6 +1385,17 @@ config INTEL_PMT_TELEMETRY To compile this driver as a module, choose M here: the module will be called intel_pmt_telemetry. +config INTEL_PMT_CRASHLOG + tristate "Intel Platform Monitoring Technology (PMT) Crashlog driver" + select INTEL_PMT_CLASS + help + The Intel Platform Monitoring Technology (PMT) crashlog driver provides + access to hardware crashlog capabilities on devices that support the + feature. + + To compile this driver as a module, choose M here: the module + will be called intel_pmt_crashlog. + config INTEL_PUNIT_IPC tristate "Intel P-Unit IPC Driver" help diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile index 6a7b61f..ca82c13 100644 --- a/drivers/platform/x86/Makefile +++ b/drivers/platform/x86/Makefile @@ -142,6 +142,7 @@ 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-$(CONFIG_INTEL_PMT_CRASHLOG) += intel_pmt_crashlog.o obj-$(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_crashlog.c b/drivers/platform/x86/intel_pmt_crashlog.c new file mode 100644 index 0000000..97dd749 --- /dev/null +++ b/drivers/platform/x86/intel_pmt_crashlog.c @@ -0,0 +1,328 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Intel Platform Monitoring Technology Crashlog driver + * + * Copyright (c) 2020, Intel Corporation. + * All Rights Reserved. + * + * Author: "Alexander Duyck" + */ + +#include +#include +#include +#include +#include +#include + +#include "intel_pmt_class.h" + +#define DRV_NAME "pmt_crashlog" + +/* Crashlog discovery header types */ +#define CRASH_TYPE_OOBMSM 1 + +/* Control Flags */ +#define CRASHLOG_FLAG_DISABLE BIT(27) + +/* + * Bits 28 and 29 control the state of bit 31. + * + * Bit 28 will clear bit 31, if set, allowing a new crashlog to be captured. + * Bit 29 will immediately trigger a crashlog to be generated, setting bit 31. + * Bit 30 is read-only and reserved as 0. + * Bit 31 is the read-only status with a 1 indicating log is complete. + */ +#define CRASHLOG_FLAG_TRIGGER_CLEAR BIT(28) +#define CRASHLOG_FLAG_TRIGGER_EXECUTE BIT(29) +#define CRASHLOG_FLAG_TRIGGER_COMPLETE BIT(31) +#define CRASHLOG_FLAG_TRIGGER_MASK GENMASK(31, 28) + +/* Crashlog Discovery Header */ +#define CONTROL_OFFSET 0x0 +#define GUID_OFFSET 0x4 +#define BASE_OFFSET 0x8 +#define SIZE_OFFSET 0xC +#define GET_ACCESS(v) ((v) & GENMASK(3, 0)) +#define GET_TYPE(v) (((v) & GENMASK(7, 4)) >> 4) +#define GET_VERSION(v) (((v) & GENMASK(19, 16)) >> 16) +/* size is in bytes */ +#define GET_SIZE(v) ((v) * sizeof(u32)) + +struct crashlog_entry { + /* entry must be first member of struct */ + struct intel_pmt_entry entry; + struct mutex control_mutex; +}; + +struct pmt_crashlog_priv { + int num_entries; + struct crashlog_entry entry[]; +}; + +/* + * I/O + */ +static bool pmt_crashlog_complete(struct intel_pmt_entry *entry) +{ + u32 control = readl(entry->disc_table + CONTROL_OFFSET); + + /* return current value of the crashlog complete flag */ + return !!(control & CRASHLOG_FLAG_TRIGGER_COMPLETE); +} + +static bool pmt_crashlog_disabled(struct intel_pmt_entry *entry) +{ + u32 control = readl(entry->disc_table + CONTROL_OFFSET); + + /* return current value of the crashlog disabled flag */ + return !!(control & CRASHLOG_FLAG_DISABLE); +} + +static bool pmt_crashlog_supported(struct intel_pmt_entry *entry) +{ + u32 discovery_header = readl(entry->disc_table + CONTROL_OFFSET); + u32 crash_type, version; + + crash_type = GET_TYPE(discovery_header); + version = GET_VERSION(discovery_header); + + /* + * Currently we only recognize OOBMSM version 0 devices. + * We can ignore all other crashlog devices in the system. + */ + return crash_type == CRASH_TYPE_OOBMSM && version == 0; +} + +static void pmt_crashlog_set_disable(struct intel_pmt_entry *entry, + bool disable) +{ + u32 control = readl(entry->disc_table + CONTROL_OFFSET); + + /* clear trigger bits so we are only modifying disable flag */ + control &= ~CRASHLOG_FLAG_TRIGGER_MASK; + + if (disable) + control |= CRASHLOG_FLAG_DISABLE; + else + control &= ~CRASHLOG_FLAG_DISABLE; + + writel(control, entry->disc_table + CONTROL_OFFSET); +} + +static void pmt_crashlog_set_clear(struct intel_pmt_entry *entry) +{ + u32 control = readl(entry->disc_table + CONTROL_OFFSET); + + control &= ~CRASHLOG_FLAG_TRIGGER_MASK; + control |= CRASHLOG_FLAG_TRIGGER_CLEAR; + + writel(control, entry->disc_table + CONTROL_OFFSET); +} + +static void pmt_crashlog_set_execute(struct intel_pmt_entry *entry) +{ + u32 control = readl(entry->disc_table + CONTROL_OFFSET); + + control &= ~CRASHLOG_FLAG_TRIGGER_MASK; + control |= CRASHLOG_FLAG_TRIGGER_EXECUTE; + + writel(control, entry->disc_table + CONTROL_OFFSET); +} + +/* + * sysfs + */ +static ssize_t +enable_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct intel_pmt_entry *entry = dev_get_drvdata(dev); + int enabled = !pmt_crashlog_disabled(entry); + + return sprintf(buf, "%d\n", enabled); +} + +static ssize_t +enable_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct crashlog_entry *entry; + bool enabled; + int result; + + entry = dev_get_drvdata(dev); + + result = kstrtobool(buf, &enabled); + if (result) + return result; + + mutex_lock(&entry->control_mutex); + pmt_crashlog_set_disable(&entry->entry, !enabled); + mutex_unlock(&entry->control_mutex); + + return count; +} +static DEVICE_ATTR_RW(enable); + +static ssize_t +trigger_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct intel_pmt_entry *entry; + int trigger; + + entry = dev_get_drvdata(dev); + trigger = pmt_crashlog_complete(entry); + + return sprintf(buf, "%d\n", trigger); +} + +static ssize_t +trigger_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct crashlog_entry *entry; + bool trigger; + int result; + + entry = dev_get_drvdata(dev); + + result = kstrtobool(buf, &trigger); + if (result) + return result; + + mutex_lock(&entry->control_mutex); + + if (!trigger) { + pmt_crashlog_set_clear(&entry->entry); + } else if (pmt_crashlog_complete(&entry->entry)) { + /* we cannot trigger a new crash if one is still pending */ + result = -EEXIST; + goto err; + } else if (pmt_crashlog_disabled(&entry->entry)) { + /* if device is currently disabled, return busy */ + result = -EBUSY; + goto err; + } else { + pmt_crashlog_set_execute(&entry->entry); + } + + result = count; +err: + mutex_unlock(&entry->control_mutex); + return result; +} +static DEVICE_ATTR_RW(trigger); + +static struct attribute *pmt_crashlog_attrs[] = { + &dev_attr_enable.attr, + &dev_attr_trigger.attr, + NULL +}; + +static struct attribute_group pmt_crashlog_group = { + .attrs = pmt_crashlog_attrs, +}; + +static int pmt_crashlog_header_decode(struct intel_pmt_entry *entry, + struct intel_pmt_header *header, + struct device *dev) +{ + void __iomem *disc_table = entry->disc_table; + struct crashlog_entry *crashlog; + + if (!pmt_crashlog_supported(entry)) + return 1; + + /* initialize control mutex */ + crashlog = container_of(entry, struct crashlog_entry, entry); + mutex_init(&crashlog->control_mutex); + + header->access_type = GET_ACCESS(readl(disc_table)); + header->guid = readl(disc_table + GUID_OFFSET); + header->base_offset = readl(disc_table + BASE_OFFSET); + + /* Size is measured in DWORDS, but accessor returns bytes */ + header->size = GET_SIZE(readl(disc_table + SIZE_OFFSET)); + + return 0; +} + +static DEFINE_XARRAY_ALLOC(crashlog_array); +static struct intel_pmt_namespace pmt_crashlog_ns = { + .name = "crashlog", + .xa = &crashlog_array, + .attr_grp = &pmt_crashlog_group, + .pmt_header_decode = pmt_crashlog_header_decode, +}; + +/* + * initialization + */ +static int pmt_crashlog_remove(struct platform_device *pdev) +{ + struct pmt_crashlog_priv *priv = platform_get_drvdata(pdev); + int i; + + for (i = 0; i < priv->num_entries; i++) + intel_pmt_dev_destroy(&priv->entry[i].entry, &pmt_crashlog_ns); + + return 0; +} + +static int pmt_crashlog_probe(struct platform_device *pdev) +{ + struct pmt_crashlog_priv *priv; + size_t size; + int i, ret; + + size = struct_size(priv, entry, pdev->num_resources); + priv = devm_kzalloc(&pdev->dev, size, GFP_KERNEL); + if (!priv) + return -ENOMEM; + + platform_set_drvdata(pdev, priv); + + for (i = 0; i < pdev->num_resources; i++) { + struct intel_pmt_entry *entry = &priv->entry[i].entry; + + ret = intel_pmt_dev_create(entry, &pmt_crashlog_ns, pdev, i); + if (ret < 0) + goto abort_probe; + if (ret) + continue; + + priv->num_entries++; + } + + return 0; +abort_probe: + pmt_crashlog_remove(pdev); + return ret; +} + +static struct platform_driver pmt_crashlog_driver = { + .driver = { + .name = DRV_NAME, + }, + .remove = pmt_crashlog_remove, + .probe = pmt_crashlog_probe, +}; + +static int __init pmt_crashlog_init(void) +{ + return platform_driver_register(&pmt_crashlog_driver); +} + +static void __exit pmt_crashlog_exit(void) +{ + platform_driver_unregister(&pmt_crashlog_driver); + xa_destroy(&crashlog_array); +} + +module_init(pmt_crashlog_init); +module_exit(pmt_crashlog_exit); + +MODULE_AUTHOR("Alexander Duyck "); +MODULE_DESCRIPTION("Intel PMT Crashlog driver"); +MODULE_ALIAS("platform:" DRV_NAME); +MODULE_LICENSE("GPL v2"); -- 2.7.4