ACPI: Introduce Platform Firmware Runtime Telemetry driver

This driver allows user space to fetch telemetry data from the
firmware with the help of the Platform Firmware Runtime Telemetry
interface.

Both PFRU and PFRT are based on ACPI _DSM interfaces located under
special device objects in the ACPI Namespace, but these interfaces
are different from each other, so it is better to provide a separate
driver from each of them, even though they share some common
definitions and naming conventions.

Tested-by: Hongyu Ning <hongyu.ning@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

4 files changed, 529 insertions, 3 deletions

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index d0b3ca9d4a97..91f1da16934d 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -532,8 +532,12 @@ config ACPI_PFRUT
 	  The existing firmware code can be modified (driver update) or
 	  extended by adding new code to the firmware (code injection).
 
-	  To compile this driver as module, choose M here:
-	  the module will be called pfr_update.
+	  Besides, the telemetry driver allows user space to fetch telemetry
+	  data from the firmware with the help of the Platform Firmware Runtime
+	  Telemetry interface.
+
+	  To compile the drivers as modules, choose M here:
+	  the modules will be called pfr_update and pfr_telemetry.
 
 if ARM64
 source "drivers/acpi/arm64/Kconfig"
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 2ad2e821cc08..d3dc79298ce3 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -102,7 +102,7 @@ obj-$(CONFIG_ACPI_CPPC_LIB)	+= cppc_acpi.o
 obj-$(CONFIG_ACPI_SPCR_TABLE)	+= spcr.o
 obj-$(CONFIG_ACPI_DEBUGGER_USER) += acpi_dbg.o
 obj-$(CONFIG_ACPI_PPTT) 	+= pptt.o
-obj-$(CONFIG_ACPI_PFRUT)	+= pfr_update.o
+obj-$(CONFIG_ACPI_PFRUT)	+= pfr_update.o pfr_telemetry.o
 
 # processor has its own "processor." module_param namespace
 processor-y			:= processor_driver.o
diff --git a/drivers/acpi/pfr_telemetry.c b/drivers/acpi/pfr_telemetry.c
new file mode 100644
index 000000000000..da50dd80192c
--- /dev/null
+++ b/drivers/acpi/pfr_telemetry.c
@@ -0,0 +1,434 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ACPI Platform Firmware Runtime Telemetry driver
+ *
+ * Copyright (C) 2021 Intel Corporation
+ * Author: Chen Yu <yu.c.chen@intel.com>
+ *
+ * This driver allows user space to fetch telemetry data from the
+ * firmware with the help of the Platform Firmware Runtime Telemetry
+ * interface.
+ */
+#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/platform_device.h>
+#include <linux/string.h>
+#include <linux/uaccess.h>
+#include <linux/uio.h>
+#include <linux/uuid.h>
+
+#include <uapi/linux/pfrut.h>
+
+#define PFRT_LOG_EXEC_IDX	0
+#define PFRT_LOG_HISTORY_IDX	1
+
+#define PFRT_LOG_ERR		0
+#define PFRT_LOG_WARN	1
+#define PFRT_LOG_INFO	2
+#define PFRT_LOG_VERB	4
+
+#define PFRT_FUNC_SET_LEV		1
+#define PFRT_FUNC_GET_LEV		2
+#define PFRT_FUNC_GET_DATA		3
+
+#define PFRT_REVID_1		1
+#define PFRT_REVID_2		2
+#define PFRT_DEFAULT_REV_ID	PFRT_REVID_1
+
+enum log_index {
+	LOG_STATUS_IDX = 0,
+	LOG_EXT_STATUS_IDX = 1,
+	LOG_MAX_SZ_IDX = 2,
+	LOG_CHUNK1_LO_IDX = 3,
+	LOG_CHUNK1_HI_IDX = 4,
+	LOG_CHUNK1_SZ_IDX = 5,
+	LOG_CHUNK2_LO_IDX = 6,
+	LOG_CHUNK2_HI_IDX = 7,
+	LOG_CHUNK2_SZ_IDX = 8,
+	LOG_ROLLOVER_CNT_IDX = 9,
+	LOG_RESET_CNT_IDX = 10,
+	LOG_NR_IDX
+};
+
+struct pfrt_log_device {
+	int index;
+	struct pfrt_log_info info;
+	struct device *parent_dev;
+	struct miscdevice miscdev;
+};
+
+/* pfrt_guid is the parameter for _DSM method */
+static const guid_t pfrt_log_guid =
+	GUID_INIT(0x75191659, 0x8178, 0x4D9D, 0xB8, 0x8F, 0xAC, 0x5E,
+		  0x5E, 0x93, 0xE8, 0xBF);
+
+static DEFINE_IDA(pfrt_log_ida);
+
+static inline struct pfrt_log_device *to_pfrt_log_dev(struct file *file)
+{
+	return container_of(file->private_data, struct pfrt_log_device, miscdev);
+}
+
+static int get_pfrt_log_data_info(struct pfrt_log_data_info *data_info,
+				  struct pfrt_log_device *pfrt_log_dev)
+{
+	acpi_handle handle = ACPI_HANDLE(pfrt_log_dev->parent_dev);
+	union acpi_object *out_obj, in_obj, in_buf;
+	int ret = -EBUSY;
+
+	memset(&in_obj, 0, sizeof(in_obj));
+	memset(&in_buf, 0, sizeof(in_buf));
+	in_obj.type = ACPI_TYPE_PACKAGE;
+	in_obj.package.count = 1;
+	in_obj.package.elements = &in_buf;
+	in_buf.type = ACPI_TYPE_INTEGER;
+	in_buf.integer.value = pfrt_log_dev->info.log_type;
+
+	out_obj = acpi_evaluate_dsm_typed(handle, &pfrt_log_guid,
+					  pfrt_log_dev->info.log_revid, PFRT_FUNC_GET_DATA,
+					  &in_obj, ACPI_TYPE_PACKAGE);
+	if (!out_obj)
+		return -EINVAL;
+
+	if (out_obj->package.count < LOG_NR_IDX ||
+	    out_obj->package.elements[LOG_STATUS_IDX].type != ACPI_TYPE_INTEGER ||
+	    out_obj->package.elements[LOG_EXT_STATUS_IDX].type != ACPI_TYPE_INTEGER ||
+	    out_obj->package.elements[LOG_MAX_SZ_IDX].type != ACPI_TYPE_INTEGER ||
+	    out_obj->package.elements[LOG_CHUNK1_LO_IDX].type != ACPI_TYPE_INTEGER ||
+	    out_obj->package.elements[LOG_CHUNK1_HI_IDX].type != ACPI_TYPE_INTEGER ||
+	    out_obj->package.elements[LOG_CHUNK1_SZ_IDX].type != ACPI_TYPE_INTEGER ||
+	    out_obj->package.elements[LOG_CHUNK2_LO_IDX].type != ACPI_TYPE_INTEGER ||
+	    out_obj->package.elements[LOG_CHUNK2_HI_IDX].type != ACPI_TYPE_INTEGER ||
+	    out_obj->package.elements[LOG_CHUNK2_SZ_IDX].type != ACPI_TYPE_INTEGER ||
+	    out_obj->package.elements[LOG_ROLLOVER_CNT_IDX].type != ACPI_TYPE_INTEGER ||
+	    out_obj->package.elements[LOG_RESET_CNT_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	data_info->status = out_obj->package.elements[LOG_STATUS_IDX].integer.value;
+	data_info->ext_status =
+		out_obj->package.elements[LOG_EXT_STATUS_IDX].integer.value;
+	if (data_info->status != DSM_SUCCEED) {
+		dev_dbg(pfrt_log_dev->parent_dev, "Error Status:%d\n", data_info->status);
+		dev_dbg(pfrt_log_dev->parent_dev, "Error Extend Status:%d\n",
+			data_info->ext_status);
+		goto free_acpi_buffer;
+	}
+
+	data_info->max_data_size =
+		out_obj->package.elements[LOG_MAX_SZ_IDX].integer.value;
+	data_info->chunk1_addr_lo =
+		out_obj->package.elements[LOG_CHUNK1_LO_IDX].integer.value;
+	data_info->chunk1_addr_hi =
+		out_obj->package.elements[LOG_CHUNK1_HI_IDX].integer.value;
+	data_info->chunk1_size =
+		out_obj->package.elements[LOG_CHUNK1_SZ_IDX].integer.value;
+	data_info->chunk2_addr_lo =
+		out_obj->package.elements[LOG_CHUNK2_LO_IDX].integer.value;
+	data_info->chunk2_addr_hi =
+		out_obj->package.elements[LOG_CHUNK2_HI_IDX].integer.value;
+	data_info->chunk2_size =
+		out_obj->package.elements[LOG_CHUNK2_SZ_IDX].integer.value;
+	data_info->rollover_cnt =
+		out_obj->package.elements[LOG_ROLLOVER_CNT_IDX].integer.value;
+	data_info->reset_cnt =
+		out_obj->package.elements[LOG_RESET_CNT_IDX].integer.value;
+
+	ret = 0;
+
+free_acpi_buffer:
+	kfree(out_obj);
+
+	return ret;
+}
+
+static int set_pfrt_log_level(int level, struct pfrt_log_device *pfrt_log_dev)
+{
+	acpi_handle handle = ACPI_HANDLE(pfrt_log_dev->parent_dev);
+	union acpi_object *out_obj, *obj, in_obj, in_buf;
+	enum pfru_dsm_status status, ext_status;
+	int ret = 0;
+
+	memset(&in_obj, 0, sizeof(in_obj));
+	memset(&in_buf, 0, sizeof(in_buf));
+	in_obj.type = ACPI_TYPE_PACKAGE;
+	in_obj.package.count = 1;
+	in_obj.package.elements = &in_buf;
+	in_buf.type = ACPI_TYPE_INTEGER;
+	in_buf.integer.value = level;
+
+	out_obj = acpi_evaluate_dsm_typed(handle, &pfrt_log_guid,
+					  pfrt_log_dev->info.log_revid, PFRT_FUNC_SET_LEV,
+					  &in_obj, ACPI_TYPE_PACKAGE);
+	if (!out_obj)
+		return -EINVAL;
+
+	obj = &out_obj->package.elements[0];
+	status = obj->integer.value;
+	if (status != DSM_SUCCEED) {
+		obj = &out_obj->package.elements[1];
+		ext_status = obj->integer.value;
+		dev_dbg(pfrt_log_dev->parent_dev, "Error Status:%d\n", status);
+		dev_dbg(pfrt_log_dev->parent_dev, "Error Extend Status:%d\n", ext_status);
+		ret = -EBUSY;
+	}
+
+	kfree(out_obj);
+
+	return ret;
+}
+
+static int get_pfrt_log_level(struct pfrt_log_device *pfrt_log_dev)
+{
+	acpi_handle handle = ACPI_HANDLE(pfrt_log_dev->parent_dev);
+	union acpi_object *out_obj, *obj;
+	enum pfru_dsm_status status, ext_status;
+	int ret = -EBUSY;
+
+	out_obj = acpi_evaluate_dsm_typed(handle, &pfrt_log_guid,
+					  pfrt_log_dev->info.log_revid, PFRT_FUNC_GET_LEV,
+					  NULL, ACPI_TYPE_PACKAGE);
+	if (!out_obj)
+		return -EINVAL;
+
+	obj = &out_obj->package.elements[0];
+	if (obj->type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	status = obj->integer.value;
+	if (status != DSM_SUCCEED) {
+		obj = &out_obj->package.elements[1];
+		ext_status = obj->integer.value;
+		dev_dbg(pfrt_log_dev->parent_dev, "Error Status:%d\n", status);
+		dev_dbg(pfrt_log_dev->parent_dev, "Error Extend Status:%d\n", ext_status);
+		goto free_acpi_buffer;
+	}
+
+	obj = &out_obj->package.elements[2];
+	if (obj->type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	ret = obj->integer.value;
+
+free_acpi_buffer:
+	kfree(out_obj);
+
+	return ret;
+}
+
+static int valid_log_level(u32 level)
+{
+	return level == PFRT_LOG_ERR || level == PFRT_LOG_WARN ||
+	       level == PFRT_LOG_INFO || level == PFRT_LOG_VERB;
+}
+
+static int valid_log_type(u32 type)
+{
+	return type == PFRT_LOG_EXEC_IDX || type == PFRT_LOG_HISTORY_IDX;
+}
+
+static inline int valid_log_revid(u32 id)
+{
+	return id == PFRT_REVID_1 || id == PFRT_REVID_2;
+}
+
+static long pfrt_log_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct pfrt_log_device *pfrt_log_dev = to_pfrt_log_dev(file);
+	struct pfrt_log_data_info data_info;
+	struct pfrt_log_info info;
+	void __user *p;
+	int ret = 0;
+
+	p = (void __user *)arg;
+
+	switch (cmd) {
+	case PFRT_LOG_IOC_SET_INFO:
+		if (copy_from_user(&info, p, sizeof(info)))
+			return -EFAULT;
+
+		if (valid_log_revid(info.log_revid))
+			pfrt_log_dev->info.log_revid = info.log_revid;
+
+		if (valid_log_level(info.log_level)) {
+			ret = set_pfrt_log_level(info.log_level, pfrt_log_dev);
+			if (ret < 0)
+				return ret;
+
+			pfrt_log_dev->info.log_level = info.log_level;
+		}
+
+		if (valid_log_type(info.log_type))
+			pfrt_log_dev->info.log_type = info.log_type;
+
+		return 0;
+
+	case PFRT_LOG_IOC_GET_INFO:
+		info.log_level = get_pfrt_log_level(pfrt_log_dev);
+		if (ret < 0)
+			return ret;
+
+		info.log_type = pfrt_log_dev->info.log_type;
+		info.log_revid = pfrt_log_dev->info.log_revid;
+		if (copy_to_user(p, &info, sizeof(info)))
+			return -EFAULT;
+
+		return 0;
+
+	case PFRT_LOG_IOC_GET_DATA_INFO:
+		ret = get_pfrt_log_data_info(&data_info, pfrt_log_dev);
+		if (ret)
+			return ret;
+
+		if (copy_to_user(p, &data_info, sizeof(struct pfrt_log_data_info)))
+			return -EFAULT;
+
+		return 0;
+
+	default:
+		return -ENOTTY;
+	}
+}
+
+static int
+pfrt_log_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct pfrt_log_device *pfrt_log_dev;
+	struct pfrt_log_data_info info;
+	unsigned long psize, vsize;
+	phys_addr_t base_addr;
+	int ret;
+
+	if (vma->vm_flags & VM_WRITE)
+		return -EROFS;
+
+	/* changing from read to write with mprotect is not allowed */
+	vma->vm_flags &= ~VM_MAYWRITE;
+
+	pfrt_log_dev = to_pfrt_log_dev(file);
+
+	ret = get_pfrt_log_data_info(&info, pfrt_log_dev);
+	if (ret)
+		return ret;
+
+	base_addr = (phys_addr_t)((info.chunk2_addr_hi << 32) | info.chunk2_addr_lo);
+	/* pfrt update has not been launched yet */
+	if (!base_addr)
+		return -ENODEV;
+
+	psize = info.max_data_size;
+	/* base address and total buffer size must be page aligned */
+	if (!PAGE_ALIGNED(base_addr) || !PAGE_ALIGNED(psize))
+		return -ENODEV;
+
+	vsize = vma->vm_end - vma->vm_start;
+	if (vsize > psize)
+		return -EINVAL;
+
+	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+	if (io_remap_pfn_range(vma, vma->vm_start, PFN_DOWN(base_addr),
+			       vsize, vma->vm_page_prot))
+		return -EAGAIN;
+
+	return 0;
+}
+
+static const struct file_operations acpi_pfrt_log_fops = {
+	.owner		= THIS_MODULE,
+	.mmap		= pfrt_log_mmap,
+	.unlocked_ioctl = pfrt_log_ioctl,
+	.llseek		= noop_llseek,
+};
+
+static int acpi_pfrt_log_remove(struct platform_device *pdev)
+{
+	struct pfrt_log_device *pfrt_log_dev = platform_get_drvdata(pdev);
+
+	misc_deregister(&pfrt_log_dev->miscdev);
+
+	return 0;
+}
+
+static void pfrt_log_put_idx(void *data)
+{
+	struct pfrt_log_device *pfrt_log_dev = data;
+
+	ida_free(&pfrt_log_ida, pfrt_log_dev->index);
+}
+
+static int acpi_pfrt_log_probe(struct platform_device *pdev)
+{
+	acpi_handle handle = ACPI_HANDLE(&pdev->dev);
+	struct pfrt_log_device *pfrt_log_dev;
+	int ret;
+
+	if (!acpi_has_method(handle, "_DSM")) {
+		dev_dbg(&pdev->dev, "Missing _DSM\n");
+		return -ENODEV;
+	}
+
+	pfrt_log_dev = devm_kzalloc(&pdev->dev, sizeof(*pfrt_log_dev), GFP_KERNEL);
+	if (!pfrt_log_dev)
+		return -ENOMEM;
+
+	ret = ida_alloc(&pfrt_log_ida, GFP_KERNEL);
+	if (ret < 0)
+		return ret;
+
+	pfrt_log_dev->index = ret;
+	ret = devm_add_action_or_reset(&pdev->dev, pfrt_log_put_idx, pfrt_log_dev);
+	if (ret)
+		return ret;
+
+	pfrt_log_dev->info.log_revid = PFRT_DEFAULT_REV_ID;
+	pfrt_log_dev->parent_dev = &pdev->dev;
+
+	pfrt_log_dev->miscdev.minor = MISC_DYNAMIC_MINOR;
+	pfrt_log_dev->miscdev.name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
+						    "pfrt%d",
+						    pfrt_log_dev->index);
+	if (!pfrt_log_dev->miscdev.name)
+		return -ENOMEM;
+
+	pfrt_log_dev->miscdev.nodename = devm_kasprintf(&pdev->dev, GFP_KERNEL,
+							"acpi_pfr_telemetry%d",
+							pfrt_log_dev->index);
+	if (!pfrt_log_dev->miscdev.nodename)
+		return -ENOMEM;
+
+	pfrt_log_dev->miscdev.fops = &acpi_pfrt_log_fops;
+	pfrt_log_dev->miscdev.parent = &pdev->dev;
+
+	ret = misc_register(&pfrt_log_dev->miscdev);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, pfrt_log_dev);
+
+	return 0;
+}
+
+static const struct acpi_device_id acpi_pfrt_log_ids[] = {
+	{"INTC1081"},
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, acpi_pfrt_log_ids);
+
+static struct platform_driver acpi_pfrt_log_driver = {
+	.driver = {
+		.name = "pfr_telemetry",
+		.acpi_match_table = acpi_pfrt_log_ids,
+	},
+	.probe = acpi_pfrt_log_probe,
+	.remove = acpi_pfrt_log_remove,
+};
+module_platform_driver(acpi_pfrt_log_driver);
+
+MODULE_DESCRIPTION("Platform Firmware Runtime Update Telemetry driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/uapi/linux/pfrut.h b/include/uapi/linux/pfrut.h
index fa97e80a93b7..42fa15f8310d 100644
--- a/include/uapi/linux/pfrut.h
+++ b/include/uapi/linux/pfrut.h
@@ -171,4 +171,92 @@ struct pfru_updated_result {
 	__u64 high_exec_time;
 };
 
+/**
+ * struct pfrt_log_data_info - Log Data from telemetry service.
+ * @status: Indicator of whether this update succeed.
+ * @ext_status: Implementation specific update result.
+ * @chunk1_addr_lo: Low 32bit physical address of the telemetry data chunk1
+ *                  starting address.
+ * @chunk1_addr_hi: High 32bit physical address of the telemetry data chunk1
+ *                  starting address.
+ * @chunk2_addr_lo: Low 32bit physical address of the telemetry data chunk2
+ *                  starting address.
+ * @chunk2_addr_hi: High 32bit physical address of the telemetry data chunk2
+ *                  starting address.
+ * @max_data_size: Maximum supported size of data of all data chunks combined.
+ * @chunk1_size: Data size in bytes of the telemetry data chunk1 buffer.
+ * @chunk2_size: Data size in bytes of the telemetry data chunk2 buffer.
+ * @rollover_cnt: Number of times telemetry data buffer is overwritten
+ *                since telemetry buffer reset.
+ * @reset_cnt: Number of times telemetry services resets that results in
+ *             rollover count and data chunk buffers are reset.
+ */
+struct pfrt_log_data_info {
+	__u32 status;
+	__u32 ext_status;
+	__u64 chunk1_addr_lo;
+	__u64 chunk1_addr_hi;
+	__u64 chunk2_addr_lo;
+	__u64 chunk2_addr_hi;
+	__u32 max_data_size;
+	__u32 chunk1_size;
+	__u32 chunk2_size;
+	__u32 rollover_cnt;
+	__u32 reset_cnt;
+};
+
+/**
+ * struct pfrt_log_info - Telemetry log information.
+ * @log_level: The telemetry log level.
+ * @log_type: The telemetry log type(history and execution).
+ * @log_revid: The telemetry log revision id.
+ */
+struct pfrt_log_info {
+	__u32 log_level;
+	__u32 log_type;
+	__u32 log_revid;
+};
+
+/**
+ * PFRT_LOG_IOC_SET_INFO - _IOW(PFRUT_IOCTL_MAGIC, 0x06,
+ *				struct pfrt_log_info)
+ *
+ * Return:
+ * * 0			- success
+ * * -EFAULT		- fail to get the setting parameter
+ * * -EINVAL		- fail to set the log level
+ *
+ * Set the PFRT log level and log type. The input information is
+ * a struct pfrt_log_info.
+ */
+#define PFRT_LOG_IOC_SET_INFO _IOW(PFRUT_IOCTL_MAGIC, 0x06, struct pfrt_log_info)
+
+/**
+ * PFRT_LOG_IOC_GET_INFO - _IOR(PFRUT_IOCTL_MAGIC, 0x07,
+ *				struct pfrt_log_info)
+ *
+ * Return:
+ * * 0			- success
+ * * -EINVAL		- fail to get the log level
+ * * -EFAULT		- fail to copy the result back to userspace
+ *
+ * Retrieve log level and log type of the telemetry. The information is
+ * a struct pfrt_log_info.
+ */
+#define PFRT_LOG_IOC_GET_INFO _IOR(PFRUT_IOCTL_MAGIC, 0x07, struct pfrt_log_info)
+
+/**
+ * PFRT_LOG_IOC_GET_DATA_INFO - _IOR(PFRUT_IOCTL_MAGIC, 0x08,
+ *				     struct pfrt_log_data_info)
+ *
+ * Return:
+ * * 0			- success
+ * * -EINVAL		- fail to get the log buffer information
+ * * -EFAULT		- fail to copy the log buffer information to userspace
+ *
+ * Retrieve data information about the telemetry. The information
+ * is a struct pfrt_log_data_info.
+ */
+#define PFRT_LOG_IOC_GET_DATA_INFO _IOR(PFRUT_IOCTL_MAGIC, 0x08, struct pfrt_log_data_info)
+
 #endif /* __PFRUT_H__ */