1 files changed, 614 insertions, 0 deletions
diff --git a/drivers/platform/x86/intel/pmt/crashlog.c b/drivers/platform/x86/intel/pmt/crashlog.c
new file mode 100644
index 000000000000..b0393c9c5b4b
--- /dev/null
+++ b/drivers/platform/x86/intel/pmt/crashlog.c
@@ -0,0 +1,614 @@
+// 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/auxiliary_bus.h>
+#include <linux/cleanup.h>
+#include <linux/intel_vsec.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/overflow.h>
+
+#include "class.h"
+
+/* Crashlog discovery header types */
+#define CRASH_TYPE_OOBMSM	1
+
+/* 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))
+
+/*
+ * Type 1 Version 0
+ * status and control registers are combined.
+ *
+ * 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 TYPE1_VER0_STATUS_OFFSET	0x00
+#define TYPE1_VER0_CONTROL_OFFSET	0x00
+
+#define TYPE1_VER0_DISABLE		BIT(28)
+#define TYPE1_VER0_CLEAR		BIT(29)
+#define TYPE1_VER0_EXECUTE		BIT(30)
+#define TYPE1_VER0_COMPLETE		BIT(31)
+#define TYPE1_VER0_TRIGGER_MASK		GENMASK(31, 28)
+
+/*
+ * Type 1 Version 2
+ * status and control are different registers
+ */
+#define TYPE1_VER2_STATUS_OFFSET	0x00
+#define TYPE1_VER2_CONTROL_OFFSET	0x14
+
+/* status register */
+#define TYPE1_VER2_CLEAR_SUPPORT	BIT(20)
+#define TYPE1_VER2_REARMED		BIT(25)
+#define TYPE1_VER2_ERROR		BIT(26)
+#define TYPE1_VER2_CONSUMED		BIT(27)
+#define TYPE1_VER2_DISABLED		BIT(28)
+#define TYPE1_VER2_CLEARED		BIT(29)
+#define TYPE1_VER2_IN_PROGRESS		BIT(30)
+#define TYPE1_VER2_COMPLETE		BIT(31)
+
+/* control register */
+#define TYPE1_VER2_CONSUME		BIT(25)
+#define TYPE1_VER2_REARM		BIT(28)
+#define TYPE1_VER2_EXECUTE		BIT(29)
+#define TYPE1_VER2_CLEAR		BIT(30)
+#define TYPE1_VER2_DISABLE		BIT(31)
+#define TYPE1_VER2_TRIGGER_MASK	\
+	(TYPE1_VER2_EXECUTE | TYPE1_VER2_CLEAR | TYPE1_VER2_DISABLE)
+
+/* After offset, order alphabetically, not bit ordered */
+struct crashlog_status {
+	u32 offset;
+	u32 clear_supported;
+	u32 cleared;
+	u32 complete;
+	u32 consumed;
+	u32 disabled;
+	u32 error;
+	u32 in_progress;
+	u32 rearmed;
+};
+
+struct crashlog_control {
+	u32 offset;
+	u32 trigger_mask;
+	u32 clear;
+	u32 consume;
+	u32 disable;
+	u32 manual;
+	u32 rearm;
+};
+
+struct crashlog_info {
+	const struct crashlog_status status;
+	const struct crashlog_control control;
+	const struct attribute_group *attr_grp;
+};
+
+struct crashlog_entry {
+	/* entry must be first member of struct */
+	struct intel_pmt_entry		entry;
+	struct mutex			control_mutex;
+	const struct crashlog_info	*info;
+};
+
+struct pmt_crashlog_priv {
+	int			num_entries;
+	struct crashlog_entry	entry[];
+};
+
+/*
+ * I/O
+ */
+
+/* Read, modify, write the control register, setting or clearing @bit based on @set */
+static void pmt_crashlog_rmw(struct crashlog_entry *crashlog, u32 bit, bool set)
+{
+	const struct crashlog_control *control = &crashlog->info->control;
+	struct intel_pmt_entry *entry = &crashlog->entry;
+	u32 reg = readl(entry->disc_table + control->offset);
+
+	reg &= ~control->trigger_mask;
+
+	if (set)
+		reg |= bit;
+	else
+		reg &= ~bit;
+
+	writel(reg, entry->disc_table + control->offset);
+}
+
+/* Read the status register and see if the specified @bit is set */
+static bool pmt_crashlog_rc(struct crashlog_entry *crashlog, u32 bit)
+{
+	const struct crashlog_status *status = &crashlog->info->status;
+	u32 reg = readl(crashlog->entry.disc_table + status->offset);
+
+	return !!(reg & bit);
+}
+
+static bool pmt_crashlog_complete(struct crashlog_entry *crashlog)
+{
+	/* return current value of the crashlog complete flag */
+	return pmt_crashlog_rc(crashlog, crashlog->info->status.complete);
+}
+
+static bool pmt_crashlog_disabled(struct crashlog_entry *crashlog)
+{
+	/* return current value of the crashlog disabled flag */
+	return pmt_crashlog_rc(crashlog, crashlog->info->status.disabled);
+}
+
+static bool pmt_crashlog_supported(struct intel_pmt_entry *entry, u32 *crash_type, u32 *version)
+{
+	u32 discovery_header = readl(entry->disc_table + CONTROL_OFFSET);
+
+	*crash_type = GET_TYPE(discovery_header);
+	*version = GET_VERSION(discovery_header);
+
+	/*
+	 * Currently we only recognize OOBMSM (type 1) and version 0 or 2
+	 * devices.
+	 *
+	 * Ignore all other crashlog devices in the system.
+	 */
+	if (*crash_type == CRASH_TYPE_OOBMSM && (*version == 0 || *version == 2))
+		return true;
+
+	return false;
+}
+
+static void pmt_crashlog_set_disable(struct crashlog_entry *crashlog,
+				     bool disable)
+{
+	pmt_crashlog_rmw(crashlog, crashlog->info->control.disable, disable);
+}
+
+static void pmt_crashlog_set_clear(struct crashlog_entry *crashlog)
+{
+	pmt_crashlog_rmw(crashlog, crashlog->info->control.clear, true);
+}
+
+static void pmt_crashlog_set_execute(struct crashlog_entry *crashlog)
+{
+	pmt_crashlog_rmw(crashlog, crashlog->info->control.manual, true);
+}
+
+static bool pmt_crashlog_cleared(struct crashlog_entry *crashlog)
+{
+	return pmt_crashlog_rc(crashlog, crashlog->info->status.cleared);
+}
+
+static bool pmt_crashlog_consumed(struct crashlog_entry *crashlog)
+{
+	return pmt_crashlog_rc(crashlog, crashlog->info->status.consumed);
+}
+
+static void pmt_crashlog_set_consumed(struct crashlog_entry *crashlog)
+{
+	pmt_crashlog_rmw(crashlog, crashlog->info->control.consume, true);
+}
+
+static bool pmt_crashlog_error(struct crashlog_entry *crashlog)
+{
+	return pmt_crashlog_rc(crashlog, crashlog->info->status.error);
+}
+
+static bool pmt_crashlog_rearm(struct crashlog_entry *crashlog)
+{
+	return pmt_crashlog_rc(crashlog, crashlog->info->status.rearmed);
+}
+
+static void pmt_crashlog_set_rearm(struct crashlog_entry *crashlog)
+{
+	pmt_crashlog_rmw(crashlog, crashlog->info->control.rearm, true);
+}
+
+/*
+ * sysfs
+ */
+static ssize_t
+clear_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct crashlog_entry *crashlog = dev_get_drvdata(dev);
+	bool cleared = pmt_crashlog_cleared(crashlog);
+
+	return sysfs_emit(buf, "%d\n", cleared);
+}
+
+static ssize_t
+clear_store(struct device *dev, struct device_attribute *attr,
+	    const char *buf, size_t count)
+{
+	struct crashlog_entry *crashlog;
+	bool clear;
+	int result;
+
+	crashlog = dev_get_drvdata(dev);
+
+	result = kstrtobool(buf, &clear);
+	if (result)
+		return result;
+
+	/* set bit only */
+	if (!clear)
+		return -EINVAL;
+
+	guard(mutex)(&crashlog->control_mutex);
+
+	pmt_crashlog_set_clear(crashlog);
+
+	return count;
+}
+static DEVICE_ATTR_RW(clear);
+
+static ssize_t
+consumed_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct crashlog_entry *crashlog = dev_get_drvdata(dev);
+	bool consumed = pmt_crashlog_consumed(crashlog);
+
+	return sysfs_emit(buf, "%d\n", consumed);
+}
+
+static ssize_t
+consumed_store(struct device *dev, struct device_attribute *attr, const char *buf,
+	       size_t count)
+{
+	struct crashlog_entry *crashlog;
+	bool consumed;
+	int result;
+
+	crashlog = dev_get_drvdata(dev);
+
+	result = kstrtobool(buf, &consumed);
+	if (result)
+		return result;
+
+	/* set bit only */
+	if (!consumed)
+		return -EINVAL;
+
+	guard(mutex)(&crashlog->control_mutex);
+
+	if (pmt_crashlog_disabled(crashlog))
+		return -EBUSY;
+
+	if (!pmt_crashlog_complete(crashlog))
+		return -EEXIST;
+
+	pmt_crashlog_set_consumed(crashlog);
+
+	return count;
+}
+static DEVICE_ATTR_RW(consumed);
+
+static ssize_t
+enable_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct crashlog_entry *crashlog = dev_get_drvdata(dev);
+	bool enabled = !pmt_crashlog_disabled(crashlog);
+
+	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 *crashlog;
+	bool enabled;
+	int result;
+
+	crashlog = dev_get_drvdata(dev);
+
+	result = kstrtobool(buf, &enabled);
+	if (result)
+		return result;
+
+	guard(mutex)(&crashlog->control_mutex);
+
+	pmt_crashlog_set_disable(crashlog, !enabled);
+
+	return count;
+}
+static DEVICE_ATTR_RW(enable);
+
+static ssize_t
+error_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct crashlog_entry *crashlog = dev_get_drvdata(dev);
+	bool error = pmt_crashlog_error(crashlog);
+
+	return sysfs_emit(buf, "%d\n", error);
+}
+static DEVICE_ATTR_RO(error);
+
+static ssize_t
+rearm_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct crashlog_entry *crashlog = dev_get_drvdata(dev);
+	int rearmed = pmt_crashlog_rearm(crashlog);
+
+	return sysfs_emit(buf, "%d\n", rearmed);
+}
+
+static ssize_t
+rearm_store(struct device *dev, struct device_attribute *attr, const char *buf,
+	    size_t count)
+{
+	struct crashlog_entry *crashlog;
+	bool rearm;
+	int result;
+
+	crashlog = dev_get_drvdata(dev);
+
+	result = kstrtobool(buf, &rearm);
+	if (result)
+		return result;
+
+	/* set only */
+	if (!rearm)
+		return -EINVAL;
+
+	guard(mutex)(&crashlog->control_mutex);
+
+	pmt_crashlog_set_rearm(crashlog);
+
+	return count;
+}
+static DEVICE_ATTR_RW(rearm);
+
+static ssize_t
+trigger_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct crashlog_entry *crashlog;
+	bool trigger;
+
+	crashlog = dev_get_drvdata(dev);
+	trigger = pmt_crashlog_complete(crashlog);
+
+	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 *crashlog;
+	bool trigger;
+	int result;
+
+	crashlog = dev_get_drvdata(dev);
+
+	result = kstrtobool(buf, &trigger);
+	if (result)
+		return result;
+
+	guard(mutex)(&crashlog->control_mutex);
+
+	/* if device is currently disabled, return busy */
+	if (pmt_crashlog_disabled(crashlog))
+		return -EBUSY;
+
+	if (!trigger) {
+		pmt_crashlog_set_clear(crashlog);
+		return count;
+	}
+
+	/* we cannot trigger a new crash if one is still pending */
+	if (pmt_crashlog_complete(crashlog))
+		return -EEXIST;
+
+	pmt_crashlog_set_execute(crashlog);
+
+	return count;
+}
+static DEVICE_ATTR_RW(trigger);
+
+static struct attribute *pmt_crashlog_type1_ver0_attrs[] = {
+	&dev_attr_enable.attr,
+	&dev_attr_trigger.attr,
+	NULL
+};
+
+static struct attribute *pmt_crashlog_type1_ver2_attrs[] = {
+	&dev_attr_clear.attr,
+	&dev_attr_consumed.attr,
+	&dev_attr_enable.attr,
+	&dev_attr_error.attr,
+	&dev_attr_rearm.attr,
+	&dev_attr_trigger.attr,
+	NULL
+};
+
+static const struct attribute_group pmt_crashlog_type1_ver0_group = {
+	.attrs	= pmt_crashlog_type1_ver0_attrs,
+};
+
+static const struct attribute_group pmt_crashlog_type1_ver2_group = {
+	.attrs = pmt_crashlog_type1_ver2_attrs,
+};
+
+static const struct crashlog_info crashlog_type1_ver0 = {
+	.status.offset = TYPE1_VER0_STATUS_OFFSET,
+	.status.cleared = TYPE1_VER0_CLEAR,
+	.status.complete = TYPE1_VER0_COMPLETE,
+	.status.disabled = TYPE1_VER0_DISABLE,
+
+	.control.offset = TYPE1_VER0_CONTROL_OFFSET,
+	.control.trigger_mask = TYPE1_VER0_TRIGGER_MASK,
+	.control.clear = TYPE1_VER0_CLEAR,
+	.control.disable = TYPE1_VER0_DISABLE,
+	.control.manual = TYPE1_VER0_EXECUTE,
+	.attr_grp = &pmt_crashlog_type1_ver0_group,
+};
+
+static const struct crashlog_info crashlog_type1_ver2 = {
+	.status.offset = TYPE1_VER2_STATUS_OFFSET,
+	.status.clear_supported = TYPE1_VER2_CLEAR_SUPPORT,
+	.status.cleared = TYPE1_VER2_CLEARED,
+	.status.complete = TYPE1_VER2_COMPLETE,
+	.status.consumed = TYPE1_VER2_CONSUMED,
+	.status.disabled = TYPE1_VER2_DISABLED,
+	.status.error = TYPE1_VER2_ERROR,
+	.status.in_progress = TYPE1_VER2_IN_PROGRESS,
+	.status.rearmed = TYPE1_VER2_REARMED,
+
+	.control.offset = TYPE1_VER2_CONTROL_OFFSET,
+	.control.trigger_mask = TYPE1_VER2_TRIGGER_MASK,
+	.control.clear = TYPE1_VER2_CLEAR,
+	.control.consume = TYPE1_VER2_CONSUME,
+	.control.disable = TYPE1_VER2_DISABLE,
+	.control.manual = TYPE1_VER2_EXECUTE,
+	.control.rearm = TYPE1_VER2_REARM,
+	.attr_grp = &pmt_crashlog_type1_ver2_group,
+};
+
+static const struct crashlog_info *select_crashlog_info(u32 type, u32 version)
+{
+	if (version == 0)
+		return &crashlog_type1_ver0;
+
+	return &crashlog_type1_ver2;
+}
+
+static int pmt_crashlog_header_decode(struct intel_pmt_entry *entry,
+				      struct device *dev)
+{
+	void __iomem *disc_table = entry->disc_table;
+	struct intel_pmt_header *header = &entry->header;
+	struct crashlog_entry *crashlog;
+	u32 version;
+	u32 type;
+
+	if (!pmt_crashlog_supported(entry, &type, &version))
+		return 1;
+
+	/* initialize the crashlog struct */
+	crashlog = container_of(entry, struct crashlog_entry, entry);
+	mutex_init(&crashlog->control_mutex);
+
+	crashlog->info = select_crashlog_info(type, version);
+
+	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));
+
+	entry->attr_grp = crashlog->info->attr_grp;
+
+	return 0;
+}
+
+static DEFINE_XARRAY_ALLOC(crashlog_array);
+static struct intel_pmt_namespace pmt_crashlog_ns = {
+	.name = "crashlog",
+	.xa = &crashlog_array,
+	.pmt_header_decode = pmt_crashlog_header_decode,
+};
+
+/*
+ * initialization
+ */
+static void pmt_crashlog_remove(struct auxiliary_device *auxdev)
+{
+	struct pmt_crashlog_priv *priv = auxiliary_get_drvdata(auxdev);
+	int i;
+
+	for (i = 0; i < priv->num_entries; i++) {
+		struct crashlog_entry *crashlog = &priv->entry[i];
+
+		intel_pmt_dev_destroy(&crashlog->entry, &pmt_crashlog_ns);
+		mutex_destroy(&crashlog->control_mutex);
+	}
+}
+
+static int pmt_crashlog_probe(struct auxiliary_device *auxdev,
+			      const struct auxiliary_device_id *id)
+{
+	struct intel_vsec_device *intel_vsec_dev = auxdev_to_ivdev(auxdev);
+	struct pmt_crashlog_priv *priv;
+	size_t size;
+	int i, ret;
+
+	size = struct_size(priv, entry, intel_vsec_dev->num_resources);
+	priv = devm_kzalloc(&auxdev->dev, size, GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	auxiliary_set_drvdata(auxdev, priv);
+
+	for (i = 0; i < intel_vsec_dev->num_resources; i++) {
+		struct intel_pmt_entry *entry = &priv->entry[priv->num_entries].entry;
+
+		ret = intel_pmt_dev_create(entry, &pmt_crashlog_ns, intel_vsec_dev, i);
+		if (ret < 0)
+			goto abort_probe;
+		if (ret)
+			continue;
+
+		priv->num_entries++;
+	}
+
+	return 0;
+abort_probe:
+	pmt_crashlog_remove(auxdev);
+	return ret;
+}
+
+static const struct auxiliary_device_id pmt_crashlog_id_table[] = {
+	{ .name = "intel_vsec.crashlog" },
+	{}
+};
+MODULE_DEVICE_TABLE(auxiliary, pmt_crashlog_id_table);
+
+static struct auxiliary_driver pmt_crashlog_aux_driver = {
+	.id_table	= pmt_crashlog_id_table,
+	.remove		= pmt_crashlog_remove,
+	.probe		= pmt_crashlog_probe,
+};
+
+static int __init pmt_crashlog_init(void)
+{
+	return auxiliary_driver_register(&pmt_crashlog_aux_driver);
+}
+
+static void __exit pmt_crashlog_exit(void)
+{
+	auxiliary_driver_unregister(&pmt_crashlog_aux_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_LICENSE("GPL v2");
+MODULE_IMPORT_NS("INTEL_PMT");