| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Intel Platform Monitoring Technology Crashlog driver |
| * |
| * Copyright (c) 2020, Intel Corporation. |
| * All Rights Reserved. |
| * |
| * Author: "Alexander Duyck" <alexander.h.duyck@linux.intel.com> |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/pci.h> |
| #include <linux/slab.h> |
| #include <linux/uaccess.h> |
| #include <linux/overflow.h> |
| |
| #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(28) |
| |
| /* |
| * Bits 29 and 30 control the state of bit 31. |
| * |
| * Bit 29 will clear bit 31, if set, allowing a new crashlog to be captured. |
| * Bit 30 will immediately trigger a crashlog to be generated, setting bit 31. |
| * Bit 31 is the read-only status with a 1 indicating log is complete. |
| */ |
| #define CRASHLOG_FLAG_TRIGGER_CLEAR BIT(29) |
| #define CRASHLOG_FLAG_TRIGGER_EXECUTE BIT(30) |
| #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 const 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 <alexander.h.duyck@linux.intel.com>"); |
| MODULE_DESCRIPTION("Intel PMT Crashlog driver"); |
| MODULE_ALIAS("platform:" DRV_NAME); |
| MODULE_LICENSE("GPL v2"); |