Introduce Platform Firmware Runtime Update and Telemetry drivers

Platform Firmware Runtime Update(PFRU) Telemetry Service is part of RoT (Root of Trust), which allows PFRU handler and other PFRU drivers to produce telemetry data to upper layer OS consumer at runtime.

The linux provides interfaces for the user to query the parameters of telemetry data, and the user could read out the telemetry data accordingly.

Also add the ABI documentation.

Typical log looks like:
[SmmRuntimeUpdateHandler.ProcessSmmRuntimeUpdate] ProcessSmmRuntimeUpdate = START, Action = 2 [SmmRuntimeUpdateHandler.ProcessSmmRuntimeUpdate]
FwVersion = 0, CodeInjectionVersion = 1 [ShadowSmmRuntimeUpdateImage]
Image = 0x74D9B000, ImageSize = 0x1172 [ProcessSmmRuntimeUpdate]
ShadowSmmRuntimeUpdateImage.Status = Success [ValidateSmmRuntimeUpdateImage]
CapsuleHeader.CapsuleGuid = 6DCBD5ED-E82D-4C44-BDA1-7194199AD92A [ValidateSmmRuntimeUpdateImage]
FmpCapHeader.Version = 1
[ValidateSmmRuntimeUpdateImage] FmpCapImageHeader.UpdateImageTypeId = B2F84B79-7B6E-4E45-885F-3FB9BB185402 [ValidateSmmRuntimeUpdateImage] SmmRuntimeUpdateVerifyImageWithDenylist.Status = Success [ValidateSmmRuntimeUpdateImage] SmmRuntimeUpdateVerifyImageWithAllowlist.Status = Success [SmmCodeInjectionVerifyPayloadHeader]
PayloadHeader.Signature = 0x31494353 [SmmCodeInjectionVerifyPayloadHeader]
PayloadHeader.PlatformId = 63462139-A8B1-AA4E-9024-F2BB53EA4723 [SmmCodeInjectionVerifyPayloadHeader] PayloadHeader.SupportedSmmFirmwareVersion = 0,

PayloadHeader.SmmCodeInjectionRuntimeVersion = 1 [ProcessSmmRuntimeUpdate] ValidateSmmRuntimeUpdateImage.Status = Success
CPU CSR[0B102D28] Before = 7FBF830E
CPU CSR[0B102D28] After = 7FBF8310 [ProcessSmmRuntimeUpdate] ProcessSmmCodeInjection.Status = Success [SmmRuntimeUpdateHandler.ProcessSmmRuntimeUpdate] ProcessSmmRuntimeUpdate = End, Status = Success

Signed-off-by Chen Yu <[email protected]>

---
v4: Remove the telemetry kernel Kconfig and combine it with pfru
(Rafael J. Wysocki)
Remove redundant parens. (Rafael J. Wysocki)
v3: Use __u32 instead of int and __64 instead of unsigned long
in include/uapi/linux/pfru.h (Greg Kroah-Hartman) Rename the structure in uapi to start with a prefix pfru so as to avoid confusing in the global namespace. (Greg Kroah-Hartman)
v2: Do similar clean up as pfru_update driver:
Add sanity check for duplicated instance of ACPI device. Update the driver to work with allocated telem_device objects. (Mike Rapoport)
For each switch case pair, get rid of the magic case numbers and add a default clause with the error handling. (Mike Rapoport)

---
 drivers/acpi/pfru/pfru_update.c | 380 +++++++++++++++++++++++++++++++-
 include/uapi/linux/pfru.h       |  43 ++++
 2 files changed, 421 insertions(+), 2 deletions(-)

drivers/acpi/pfru/pfru_update.c +299 -0

index f57a39e79808..fe5b1bf0aeb3 100644
@@ -55,6 +55,27 @@ enum update_index {
 	UPDATE_NR_IDX,
 };
 
+enum log_index {
+	LOG_STATUS_IDX,
+	LOG_EXT_STATUS_IDX,
+	LOG_MAX_SZ_IDX,
+	LOG_CHUNK1_LO_IDX,
+	LOG_CHUNK1_HI_IDX,
+	LOG_CHUNK1_SZ_IDX,
+	LOG_CHUNK2_LO_IDX,
+	LOG_CHUNK2_HI_IDX,
+	LOG_CHUNK2_SZ_IDX,
+	LOG_ROLLOVER_CNT_IDX,
+	LOG_RESET_CNT_IDX,
+	LOG_NR_IDX,
+};
+
+struct pfru_log_device {
+	struct device *dev;
+	guid_t uuid;
+	struct pfru_log_info info;
+};
+
 struct pfru_device {
 	guid_t uuid, code_uuid, drv_uuid;
 	int rev_id;

@@ -62,6 +83,299 @@ struct pfru_device {
 };
 
 static struct pfru_device *pfru_dev;
+static struct pfru_log_device *pfru_log_dev;
+
+static int get_pfru_log_data_info(struct pfru_log_data_info *data_info,
+				  int log_type)
+{
+	union acpi_object *out_obj, in_obj, in_buf;
+	acpi_handle handle;
+	int ret = -EINVAL;
+
+	handle = ACPI_HANDLE(pfru_log_dev->dev);
+
+	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 = log_type;
+
+	out_obj = acpi_evaluate_dsm_typed(handle, &pfru_log_dev->uuid,
+					  pfru_log_dev->info.log_revid, FUNC_GET_DATA,
+					  &in_obj, ACPI_TYPE_PACKAGE);
+	if (!out_obj)
+		return ret;
+
+	if (out_obj->package.count < LOG_NR_IDX)
+		goto free_acpi_buffer;
+
+	if (out_obj->package.elements[LOG_STATUS_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	data_info->status = out_obj->package.elements[LOG_STATUS_IDX].integer.value;
+
+	if (out_obj->package.elements[LOG_EXT_STATUS_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	data_info->ext_status =
+		out_obj->package.elements[LOG_EXT_STATUS_IDX].integer.value;
+
+	if (out_obj->package.elements[LOG_MAX_SZ_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	data_info->max_data_size =
+		out_obj->package.elements[LOG_MAX_SZ_IDX].integer.value;
+
+	if (out_obj->package.elements[LOG_CHUNK1_LO_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	data_info->chunk1_addr_lo =
+		out_obj->package.elements[LOG_CHUNK1_LO_IDX].integer.value;
+
+	if (out_obj->package.elements[LOG_CHUNK1_HI_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	data_info->chunk1_addr_hi =
+		out_obj->package.elements[LOG_CHUNK1_HI_IDX].integer.value;
+
+	if (out_obj->package.elements[LOG_CHUNK1_SZ_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	data_info->chunk1_size =
+		out_obj->package.elements[LOG_CHUNK1_SZ_IDX].integer.value;
+
+	if (out_obj->package.elements[LOG_CHUNK2_LO_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	data_info->chunk2_addr_lo =
+		out_obj->package.elements[LOG_CHUNK2_LO_IDX].integer.value;
+
+	if (out_obj->package.elements[LOG_CHUNK2_HI_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	data_info->chunk2_addr_hi =
+		out_obj->package.elements[LOG_CHUNK2_HI_IDX].integer.value;
+
+	if (out_obj->package.elements[LOG_CHUNK2_SZ_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	data_info->chunk2_size =
+		out_obj->package.elements[LOG_CHUNK2_SZ_IDX].integer.value;
+
+	if (out_obj->package.elements[LOG_ROLLOVER_CNT_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	data_info->rollover_cnt =
+		out_obj->package.elements[LOG_ROLLOVER_CNT_IDX].integer.value;
+
+	if (out_obj->package.elements[LOG_RESET_CNT_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	data_info->reset_cnt =
+		out_obj->package.elements[LOG_RESET_CNT_IDX].integer.value;
+
+	ret = 0;
+free_acpi_buffer:
+	ACPI_FREE(out_obj);
+
+	return ret;
+}
+
+static int set_pfru_log_level(int level)
+{
+	union acpi_object *out_obj, *obj, in_obj, in_buf;
+	enum pfru_dsm_status status;
+	acpi_handle handle;
+	int ret = -EINVAL;
+
+	handle = ACPI_HANDLE(pfru_log_dev->dev);
+
+	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, &pfru_log_dev->uuid,
+					  pfru_log_dev->info.log_revid, 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)
+		goto free_acpi_buffer;
+
+	obj = &out_obj->package.elements[1];
+	status = obj->integer.value;
+	if (status)
+		goto free_acpi_buffer;
+
+	ret = 0;
+
+free_acpi_buffer:
+	ACPI_FREE(out_obj);
+
+	return ret;
+}
+
+static int get_pfru_log_level(int *level)
+{
+	union acpi_object *out_obj, *obj;
+	enum pfru_dsm_status status;
+	acpi_handle handle;
+	int ret = -EINVAL;
+
+	handle = ACPI_HANDLE(pfru_log_dev->dev);
+	out_obj = acpi_evaluate_dsm_typed(handle, &pfru_log_dev->uuid,
+					  pfru_log_dev->info.log_revid, 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)
+		goto free_acpi_buffer;
+
+	obj = &out_obj->package.elements[1];
+	if (obj->type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	status = obj->integer.value;
+	if (status)
+		goto free_acpi_buffer;
+
+	obj = &out_obj->package.elements[2];
+	if (obj->type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	*level = obj->integer.value;
+	ret = 0;
+free_acpi_buffer:
+	ACPI_FREE(out_obj);
+
+	return ret;
+}
+
+static int valid_log_level(int level)
+{
+	return level == LOG_ERR || level == LOG_WARN ||
+		level == LOG_INFO || level == LOG_VERB;
+}
+
+static int valid_log_type(int type)
+{
+	return type == LOG_EXEC_IDX || type == LOG_HISTORY_IDX;
+}
+
+long pfru_log_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct pfru_log_data_info data_info;
+	struct pfru_log_info info;
+	void __user *p;
+	int ret = 0;
+
+	if (!pfru_log_dev)
+		return -ENODEV;
+
+	p = (void __user *)arg;
+
+	switch (cmd) {
+	case PFRU_LOG_IOC_SET_INFO:
+		if (copy_from_user(&info, p, sizeof(info)))
+			return -EFAULT;
+
+		if (pfru_valid_revid(info.log_revid))
+			pfru_log_dev->info.log_revid = info.log_revid;
+
+		if (valid_log_level(info.log_level)) {
+			ret = set_pfru_log_level(info.log_level);
+			if (ret)
+				return ret;
+			pfru_log_dev->info.log_level = info.log_level;
+		}
+
+		if (valid_log_type(info.log_type))
+			pfru_log_dev->info.log_type = info.log_type;
+
+		break;
+	case PFRU_LOG_IOC_GET_INFO:
+		ret = get_pfru_log_level(&info.log_level);
+		if (ret)
+			return ret;
+
+		info.log_type = pfru_log_dev->info.log_type;
+		info.log_revid = pfru_log_dev->info.log_revid;
+		if (copy_to_user(p, &info, sizeof(info)))
+			ret = -EFAULT;
+
+		break;
+	case PFRU_LOG_IOC_GET_DATA_INFO:
+		ret = get_pfru_log_data_info(&data_info, pfru_log_dev->info.log_type);
+		if (ret)
+			return ret;
+
+		if (copy_to_user(p, &data_info, sizeof(struct pfru_log_data_info)))
+			ret = -EFAULT;
+
+		break;
+	default:
+		ret = -ENOTTY;
+		break;
+	}
+	return ret;
+}
+
+ssize_t pfru_log_read(struct file *filp, char __user *ubuf,
+		      size_t size, loff_t *off)
+{
+	struct pfru_log_data_info info;
+	phys_addr_t base_addr;
+	int buf_size, ret;
+	char *buf_ptr;
+
+	if (!pfru_log_dev)
+		return -ENODEV;
+
+	if (*off < 0)
+		return -EINVAL;
+
+	ret = get_pfru_log_data_info(&info, pfru_log_dev->info.log_type);
+	if (ret)
+		return ret;
+
+	base_addr = (phys_addr_t)(info.chunk2_addr_lo | (info.chunk2_addr_hi << 32));
+	/* pfru update has not been launched yet.*/
+	if (!base_addr)
+		return -EBUSY;
+
+	buf_size = info.max_data_size;
+	if (*off >= buf_size)
+		return 0;

Introduce the pfru_update driver which can be used for Platform Firmware Runtime code injection and driver update[1]. The user is expected to provide the update firmware in the form of capsule file, and pass it to the driver via ioctl. Then the driver would hand this capsule file to the Platform Firmware Runtime Update via the ACPI device _DSM method. At last the low level Management Mode would do the firmware update.

[1] https://uefi.org/sites/default/files/resources/Intel_MM_OS_Interface_Spec_Rev100.pdf

Signed-off-by Chen Yu <[email protected]>

---
v4: Add Documentation/ABI/testing/pfru (Rafael J. Wysocki)
Change all pr_debug() to dev_dbg() (Greg Kroah-Hartman, Rafael J. Wysocki)
Change the error code ENOIOCTLCMD to ENOTTY in ioctl. (Greg Kroah-Hartman)
Remove compat ioctl. (Greg Kroah-Hartman)
Change /dev/pfru/update to /dev/acpi_pfru (Greg Kroah-Hartman) Remove valid_cap_type() and do sanity check in query_capability(). (Rafael J. Wysocki)
Remove the loop in query_capability().
(Rafael J. Wysocki)
Do not fail if the package has more elements than expected, and return error if the number of package elements is too small. (Rafael J. Wysocki)
Return the type or a negative error code in get_image_type() (Rafael J. Wysocki)
Put the comment inside the function rather than outside. (Rafael J. Wysocki)
Return the size or a negative error code adjust_efi_size() (Rafael J. Wysocki)
Return -EINVAL rather than -EFAULT if revison id is incorrect. (Rafael J. Wysocki)
Move the an read() of pfru into ioctl(), and using read() for the telemetry retrieval. So as to avoid the telemetry device file, the write() will be the code injection/update, the read() will be telemetry retrieval and all of the rest can be ioctl()s under one special device file.
(Rafael J. Wysocki)
v3: Use __u32 instead of int and __64 instead of unsigned long
in include/uapi/linux/pfru.h (Greg Kroah-Hartman)
Rename the structure in uapi to start with a prefix pfru so as to avoid confusing in the global namespace. (Greg Kroah-Hartman)
v2: Add sanity check for duplicated instance of ACPI device.
Update the driver to work with allocated pfru_device objects. (Mike Rapoport)
For each switch case pair, get rid of the magic case numbers and add a default clause with the error handling.
(Mike Rapoport)
Move the obj->type checks outside the switch to reduce redundancy. (Mike Rapoport)
Parse the code_inj_id and drv_update_id at driver initialization time to reduce the re-parsing at runtime.(Mike Rapoport) Explain in detail how the size needs to be adjusted when doing version check.(Mike Rapoport)
Rename parse_update_result() to dump_update_result()(Mike Rapoport) Remove redundant return.(Mike Rapoport)
Do not expose struct capsulate_buf_info to uapi, since it is not needed in userspace.(Mike Rapoport)

---
 Documentation/ABI/testing/pfru                |  41 ++
 .../userspace-api/ioctl/ioctl-number.rst      |   1 +
 drivers/acpi/Kconfig                          |   1 +
 drivers/acpi/Makefile                         |   1 +
 drivers/acpi/pfru/Kconfig                     |  16 +
 drivers/acpi/pfru/Makefile                    |   2 +
 drivers/acpi/pfru/pfru_update.c               | 567 ++++++++++++++++++
 include/uapi/linux/pfru.h                     | 102 ++++
 8 files changed, 731 insertions(+)
 create mode 100644 Documentation/ABI/testing/pfru
 create mode 100644 drivers/acpi/pfru/Kconfig
 create mode 100644 drivers/acpi/pfru/Makefile
 create mode 100644 drivers/acpi/pfru/pfru_update.c
 create mode 100644 include/uapi/linux/pfru.h

Documentation/ABI/testing/pfru new file +31 -0

new file mode 100644
index 000000000000..b8bc81703f46
@@ -0,0 +1,41 @@
+What:		/dev/acpi_pfru
+Date:		October 2021
+KernelVersion:	5.15
+Contact:	Chen Yu <[email protected]>
+Description:
+		The ioctl interface to drivers for platform firmware runtime
+		update(PFRU). Following actions are supported:
+
+		* PFRU_IOC_QUERY_CAP: Read the PFRU Runtime Update capability.
+		  The value is a structure of pfru_update_cap_info.
+		  See include/uapi/linux/pfru.h for definition.
+
+		* PFRU_SET_REV: Set the Revision ID for PFRU Runtime Update.
+		  It could be either 1 or 2.
+
+		* PFRU_IOC_STAGE: Stage a capsule image from communication
+		  buffer and perform authentication.
+
+		* PFRU_IOC_ACTIVATE: Activate a previous staged capsule image.
+
+		* PFRU_IOC_STAGE_ACTIVATE: Perform both stage and activation
+		  actions.
+
+		* PFRU_LOG_IOC_SET_INFO: set log information in Telemetry
+		  Service. The input is a structure of pfru_log_info.
+		  This structure includes log revision id(1 or 2),
+		  log level(0 : Error Message, 1 : Warning Message,
+		  2 : Informational Message, 4 : Verbose), log data type
+		  (0 : Execution Log, 1 : History Information).
+		  See include/uapi/linux/pfru.h for definition.
+

Documentation/userspace-api/ioctl/ioctl-number.rst +0 -0

 0xF3  00-3F  drivers/usb/misc/sisusbvga/sisusb.h                     sisfb (in development)
                                                                      <mailto:[email protected]>
 0xF6  all                                                            LTTng Linux Trace Toolkit Next Generation

drivers/acpi/Kconfig +1 -0

index 1da360c51d66..1d8d2e2cefac 100644
@@ -482,6 +482,7 @@ source "drivers/acpi/nfit/Kconfig"
 source "drivers/acpi/numa/Kconfig"
 source "drivers/acpi/apei/Kconfig"
 source "drivers/acpi/dptf/Kconfig"
+source "drivers/acpi/pfru/Kconfig"
 
 config ACPI_WATCHDOG
 	bool

drivers/acpi/Makefile +1 -0

index 3018714e87d9..9c2c5ddff6ec 100644
@@ -102,6 +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_PFRU)		+= pfru/
 
 # processor has its own "processor." module_param namespace
 processor-y			:= processor_driver.o

drivers/acpi/pfru/Kconfig new file +16 -0

new file mode 100644
index 000000000000..87388a46e760
@@ -0,0 +1,16 @@
+# SPDX-License-Identifier: GPL-2.0
+config ACPI_PFRU
+	tristate "ACPI Platform Firmware Runtime Update (PFRU)"
+	depends on 64BIT
+	help
+	  In order to reduce the system reboot times and update the platform firmware
+	  in time, Platform Firmware Runtime Update is leveraged to patch the system
+	  without reboot. This driver supports Platform Firmware Runtime Update,
+	  which is composed of two parts: code injection and driver update. It also
+	  allows telemetry data to be retrieved from the platform firmware.
+
+	  For more information, see:
+	  <file:Documentation/ABI/testing/pfru>
+
+	  To compile this driver as a module, choose M here:
+	  the module will be called pfru_update.

drivers/acpi/pfru/Makefile new file +2 -0

new file mode 100644
index 000000000000..098cbe80cf3d
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_ACPI_PFRU) += pfru_update.o

drivers/acpi/pfru/pfru_update.c new file +54 -0

new file mode 100644
index 000000000000..f57a39e79808
@@ -0,0 +1,567 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ACPI Platform Firmware Runtime Update Device Driver
+ *
+ * Copyright (C) 2021 Intel Corporation
+ * Author: Chen Yu <[email protected]>
+ */
+#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/efi.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/platform_device.h>
+#include <linux/string.h>
+#include <linux/uaccess.h>
+#include <linux/uio.h>
+#include <linux/uuid.h>
+#include <uapi/linux/pfru.h>
+
+enum cap_index {
+	CAP_STATUS_IDX,
+	CAP_UPDATE_IDX,
+	CAP_CODE_TYPE_IDX,
+	CAP_FW_VER_IDX,
+	CAP_CODE_RT_VER_IDX,
+	CAP_DRV_TYPE_IDX,
+	CAP_DRV_RT_VER_IDX,
+	CAP_DRV_SVN_IDX,
+	CAP_PLAT_ID_IDX,
+	CAP_OEM_ID_IDX,
+	CAP_OEM_INFO_IDX,
+	CAP_NR_IDX,
+};
+
+enum buf_index {
+	BUF_STATUS_IDX,
+	BUF_EXT_STATUS_IDX,
+	BUF_ADDR_LOW_IDX,
+	BUF_ADDR_HI_IDX,
+	BUF_SIZE_IDX,
+	BUF_NR_IDX,
+};
+
+enum update_index {
+	UPDATE_STATUS_IDX,
+	UPDATE_EXT_STATUS_IDX,
+	UPDATE_AUTH_TIME_LOW_IDX,
+	UPDATE_AUTH_TIME_HI_IDX,
+	UPDATE_EXEC_TIME_LOW_IDX,
+	UPDATE_EXEC_TIME_HI_IDX,

drivers/acpi/pfru/pfru_update.c new file +410 -0

+
+static int query_capability(struct pfru_update_cap_info *cap)
+{
+	union acpi_object *out_obj;
+	acpi_handle handle;
+	int ret = -EINVAL;
+
+	handle = ACPI_HANDLE(pfru_dev->dev);
+	out_obj = acpi_evaluate_dsm_typed(handle, &pfru_dev->uuid,
+					  pfru_dev->rev_id,
+					  FUNC_QUERY_UPDATE_CAP,
+					  NULL, ACPI_TYPE_PACKAGE);
+	if (!out_obj)
+		return ret;
+
+	if (out_obj->package.count < CAP_NR_IDX)
+		goto free_acpi_buffer;
+
+	if (out_obj->package.elements[CAP_STATUS_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	cap->status = out_obj->package.elements[CAP_STATUS_IDX].integer.value;
+
+	if (out_obj->package.elements[CAP_UPDATE_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	cap->update_cap = out_obj->package.elements[CAP_UPDATE_IDX].integer.value;
+
+	if (out_obj->package.elements[CAP_CODE_TYPE_IDX].type != ACPI_TYPE_BUFFER)
+		goto free_acpi_buffer;
+
+	memcpy(&cap->code_type,
+	       out_obj->package.elements[CAP_CODE_TYPE_IDX].buffer.pointer,
+	       out_obj->package.elements[CAP_CODE_TYPE_IDX].buffer.length);
+
+	if (out_obj->package.elements[CAP_FW_VER_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	cap->fw_version =
+		out_obj->package.elements[CAP_FW_VER_IDX].integer.value;
+
+	if (out_obj->package.elements[CAP_CODE_RT_VER_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	cap->code_rt_version =
+		out_obj->package.elements[CAP_CODE_RT_VER_IDX].integer.value;
+
+	if (out_obj->package.elements[CAP_DRV_TYPE_IDX].type != ACPI_TYPE_BUFFER)
+		goto free_acpi_buffer;
+
+	memcpy(&cap->drv_type,
+	       out_obj->package.elements[CAP_DRV_TYPE_IDX].buffer.pointer,
+	       out_obj->package.elements[CAP_DRV_TYPE_IDX].buffer.length);
+
+	if (out_obj->package.elements[CAP_DRV_RT_VER_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	cap->drv_rt_version =
+		out_obj->package.elements[CAP_DRV_RT_VER_IDX].integer.value;
+
+	if (out_obj->package.elements[CAP_DRV_SVN_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	cap->drv_svn =
+		out_obj->package.elements[CAP_DRV_SVN_IDX].integer.value;
+
+	if (out_obj->package.elements[CAP_PLAT_ID_IDX].type != ACPI_TYPE_BUFFER)
+		goto free_acpi_buffer;
+
+	memcpy(&cap->platform_id,
+	       out_obj->package.elements[CAP_PLAT_ID_IDX].buffer.pointer,
+	       out_obj->package.elements[CAP_PLAT_ID_IDX].buffer.length);
+
+	if (out_obj->package.elements[CAP_OEM_ID_IDX].type != ACPI_TYPE_BUFFER)
+		goto free_acpi_buffer;
+
+	memcpy(&cap->oem_id,
+	       out_obj->package.elements[CAP_OEM_ID_IDX].buffer.pointer,
+	       out_obj->package.elements[CAP_OEM_ID_IDX].buffer.length);
+	ret = 0;
+free_acpi_buffer:
+	ACPI_FREE(out_obj);
+
+	return ret;
+}
+
+static int query_buffer(struct pfru_com_buf_info *info)
+{
+	union acpi_object *out_obj;
+	acpi_handle handle;
+	int ret = -EINVAL;
+
+	handle = ACPI_HANDLE(pfru_dev->dev);
+	out_obj = acpi_evaluate_dsm_typed(handle, &pfru_dev->uuid,
+					  pfru_dev->rev_id, FUNC_QUERY_BUF,
+					  NULL, ACPI_TYPE_PACKAGE);
+	if (!out_obj)
+		return ret;
+
+	if (out_obj->package.count < BUF_NR_IDX)
+		goto free_acpi_buffer;
+
+	if (out_obj->package.elements[BUF_STATUS_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	info->status = out_obj->package.elements[BUF_STATUS_IDX].integer.value;
+
+	if (out_obj->package.elements[BUF_EXT_STATUS_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	info->ext_status =
+		out_obj->package.elements[BUF_EXT_STATUS_IDX].integer.value;
+
+	if (out_obj->package.elements[BUF_ADDR_LOW_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	info->addr_lo =
+		out_obj->package.elements[BUF_ADDR_LOW_IDX].integer.value;
+
+	if (out_obj->package.elements[BUF_ADDR_HI_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	info->addr_hi =
+		out_obj->package.elements[BUF_ADDR_HI_IDX].integer.value;
+
+	if (out_obj->package.elements[BUF_SIZE_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	info->buf_size = out_obj->package.elements[BUF_SIZE_IDX].integer.value;
+
+	ret = 0;
+free_acpi_buffer:
+	ACPI_FREE(out_obj);
+
+	return ret;
+}
+
+static int get_image_type(efi_manage_capsule_image_header_t *img_hdr)
+{
+	guid_t *image_type_id = &img_hdr->image_type_id;
+
+	/* check whether this is a code injection or driver update */
+	if (guid_equal(image_type_id, &pfru_dev->code_uuid))
+		return CODE_INJECT_TYPE;
+	else if (guid_equal(image_type_id, &pfru_dev->drv_uuid))
+		return DRIVER_UPDATE_TYPE;
+	else
+		return -EINVAL;
+}
+
+static int adjust_efi_size(efi_manage_capsule_image_header_t *img_hdr,
+			   int size)
+{
+	/*
+	 * The (u64 hw_ins) was introduced in UEFI spec version 2,
+	 * and (u64 capsule_support) was introduced in version 3.
+	 * The size needs to be adjusted accordingly. That is to
+	 * say, version 1 should subtract the size of hw_ins+capsule_support,
+	 * and version 2 should sbstract the size of capsule_support.
+	 */
+	size += sizeof(efi_manage_capsule_image_header_t);
+	switch (img_hdr->ver) {
+	case 1:
+		size -= 2 * sizeof(u64);
+		break;
+	case 2:
+		size -= sizeof(u64);
+		break;
+	default:
+		/* only support version 1 and 2 */
+		return -EINVAL;
+	}
+
+	return size;
+}
+
+static bool valid_version(const void *data, struct pfru_update_cap_info *cap)
+{
+	struct pfru_payload_hdr *payload_hdr;
+	efi_capsule_header_t *cap_hdr;
+	efi_manage_capsule_header_t *m_hdr;
+	efi_manage_capsule_image_header_t *m_img_hdr;
+	efi_image_auth_t *auth;
+	int type, size;
+
+	/*
+	 * Sanity check if the capsule image has a newer version
+	 * than current one.
+	 */
+	cap_hdr = (efi_capsule_header_t *)data;
+	size = cap_hdr->headersize;
+	m_hdr = (efi_manage_capsule_header_t *)(data + size);
+	/*
+	 * Current data structure size plus variable array indicated
+	 * by number of (emb_drv_cnt + payload_cnt)
+	 */
+	size += sizeof(efi_manage_capsule_header_t) +
+		      (m_hdr->emb_drv_cnt + m_hdr->payload_cnt) * sizeof(u64);
+	m_img_hdr = (efi_manage_capsule_image_header_t *)(data + size);
+
+	type = get_image_type(m_img_hdr);
+	if (type < 0)
+		return false;
+
+	size = adjust_efi_size(m_img_hdr, size);
+	if (size < 0)
+		return false;
+
+	auth = (efi_image_auth_t *)(data + size);
+	size += sizeof(u64) + auth->auth_info.hdr.len;
+	payload_hdr = (struct pfru_payload_hdr *)(data + size);
+
+	/* Finally, compare the version. */
+	if (type == CODE_INJECT_TYPE)
+		return payload_hdr->rt_ver >= cap->code_rt_version;
+	else
+		return payload_hdr->rt_ver >= cap->drv_rt_version;
+}
+
+static void dump_update_result(struct pfru_updated_result *result)
+{
+	dev_dbg(pfru_dev->dev, "Update result:\n");
+	dev_dbg(pfru_dev->dev, "Status:%d\n", result->status);
+	dev_dbg(pfru_dev->dev, "Extended Status:%d\n", result->ext_status);
+	dev_dbg(pfru_dev->dev, "Authentication Time Low:%lld\n",
+		result->low_auth_time);
+	dev_dbg(pfru_dev->dev, "Authentication Time High:%lld\n",
+		result->high_auth_time);
+	dev_dbg(pfru_dev->dev, "Execution Time Low:%lld\n",
+		result->low_exec_time);
+	dev_dbg(pfru_dev->dev, "Execution Time High:%lld\n",
+		result->high_exec_time);
+}
+
+static int start_acpi_update(int action)
+{
+	union acpi_object *out_obj, in_obj, in_buf;
+	struct pfru_updated_result update_result;
+	acpi_handle handle;
+	int ret = -EINVAL;
+
+	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 = action;
+
+	handle = ACPI_HANDLE(pfru_dev->dev);
+	out_obj = acpi_evaluate_dsm_typed(handle, &pfru_dev->uuid,
+					  pfru_dev->rev_id, FUNC_START,
+					  &in_obj, ACPI_TYPE_PACKAGE);
+	if (!out_obj)
+		return ret;
+
+	if (out_obj->package.count < UPDATE_NR_IDX)
+		goto free_acpi_buffer;
+
+	if (out_obj->package.elements[UPDATE_STATUS_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	update_result.status =
+		out_obj->package.elements[UPDATE_STATUS_IDX].integer.value;
+
+	if (out_obj->package.elements[UPDATE_EXT_STATUS_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	update_result.ext_status =
+		out_obj->package.elements[UPDATE_EXT_STATUS_IDX].integer.value;
+
+	if (out_obj->package.elements[UPDATE_AUTH_TIME_LOW_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	update_result.low_auth_time =
+		out_obj->package.elements[UPDATE_AUTH_TIME_LOW_IDX].integer.value;
+
+	if (out_obj->package.elements[UPDATE_AUTH_TIME_HI_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	update_result.high_auth_time =
+		out_obj->package.elements[UPDATE_AUTH_TIME_HI_IDX].integer.value;
+
+	if (out_obj->package.elements[UPDATE_EXEC_TIME_LOW_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	update_result.low_exec_time =
+		out_obj->package.elements[UPDATE_EXEC_TIME_LOW_IDX].integer.value;
+
+	if (out_obj->package.elements[UPDATE_EXEC_TIME_HI_IDX].type != ACPI_TYPE_INTEGER)
+		goto free_acpi_buffer;
+
+	update_result.high_exec_time =
+		out_obj->package.elements[UPDATE_EXEC_TIME_HI_IDX].integer.value;
+
+	dump_update_result(&update_result);
+	ret = 0;
+
+free_acpi_buffer:
+	ACPI_FREE(out_obj);
+
+	return ret;
+}
+
+static long pfru_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct pfru_update_cap_info cap;
+	void __user *p;
+	int ret = 0, rev;
+
+	if (!pfru_dev)
+		return -ENODEV;
+
+	p = (void __user *)arg;
+
+	switch (cmd) {
+	case PFRU_IOC_QUERY_CAP:
+		ret = query_capability(&cap);
+		if (ret)
+			return ret;
+
+		if (copy_to_user(p, &cap, sizeof(cap)))
+			return -EFAULT;
+
+		break;
+	case PFRU_IOC_SET_REV:
+		if (copy_from_user(&rev, p, sizeof(unsigned int)))
+			return -EFAULT;
+
+		if (!pfru_valid_revid(rev))
+			return -EINVAL;
+
+		pfru_dev->rev_id = rev;
+		break;
+	case PFRU_IOC_STAGE:
+		ret = start_acpi_update(START_STAGE);
+		break;
+	case PFRU_IOC_ACTIVATE:
+		ret = start_acpi_update(START_ACTIVATE);
+		break;
+	case PFRU_IOC_STAGE_ACTIVATE:
+		ret = start_acpi_update(START_STAGE_ACTIVATE);
+		break;
+	default:
+		ret = -ENOTTY;
+		break;
+	}
+
+	return ret;
+}
+
+static ssize_t pfru_write(struct file *file, const char __user *buf,
+			  size_t len, loff_t *ppos)
+{
+	struct pfru_update_cap_info cap;
+	struct pfru_com_buf_info info;
+	phys_addr_t phy_addr;
+	struct iov_iter iter;
+	struct iovec iov;
+	char *buf_ptr;
+	int ret;
+
+	if (!pfru_dev)
+		return -ENODEV;
+
+	ret = query_buffer(&info);
+	if (ret)
+		return ret;
+
+	if (len > info.buf_size)
+		return -EINVAL;
+
+	iov.iov_base = (void __user *)buf;
+	iov.iov_len = len;
+	iov_iter_init(&iter, WRITE, &iov, 1, len);
+
+	/* map the communication buffer */
+	phy_addr = (phys_addr_t)(info.addr_lo | (info.addr_hi << 32));
+	buf_ptr = memremap(phy_addr, info.buf_size, MEMREMAP_WB);
+	if (IS_ERR(buf_ptr))
+		return PTR_ERR(buf_ptr);
+
+	if (!copy_from_iter_full(buf_ptr, len, &iter)) {
+		ret = -EINVAL;
+		goto unmap;
+	}
+
+	/* Check if the capsule header has a valid version number. */
+	ret = query_capability(&cap);
+	if (ret)
+		goto unmap;
+
+	if (cap.status != DSM_SUCCEED)
+		ret = -EBUSY;
+	else if (!valid_version(buf_ptr, &cap))
+		ret = -EINVAL;
+unmap:
+	memunmap(buf_ptr);
+
+	return ret ?: len;
+}
+
+static const struct file_operations acpi_pfru_fops = {
+	.owner		= THIS_MODULE,
+	.write		= pfru_write,
+	.unlocked_ioctl = pfru_ioctl,
+	.llseek		= noop_llseek,
+};
+
+static struct miscdevice pfru_misc_dev = {

drivers/acpi/pfru/pfru_update.c new file +47 -0

+	pfru_dev = kzalloc(sizeof(*pfru_dev), GFP_KERNEL);
+	if (!pfru_dev)
+		return -ENOMEM;
+
+	ret = guid_parse(PFRU_UUID, &pfru_dev->uuid);
+	if (ret)
+		goto out;
+
+	ret = guid_parse(PFRU_CODE_INJ_UUID, &pfru_dev->code_uuid);
+	if (ret)
+		goto out;
+
+	ret = guid_parse(PFRU_DRV_UPDATE_UUID, &pfru_dev->drv_uuid);
+	if (ret)
+		goto out;
+
+	/* default rev id is 1 */
+	pfru_dev->rev_id = 1;
+	pfru_dev->dev = &pdev->dev;
+	handle = ACPI_HANDLE(pfru_dev->dev);
+	if (!acpi_has_method(handle, "_DSM")) {
+		dev_dbg(&pdev->dev, "Missing _DSM\n");
+		ret = -ENODEV;
+		goto out;
+	}
+
+	return 0;
+out:
+	kfree(pfru_dev);
+	pfru_dev = NULL;
+
+	return ret;
+}
+
+static const struct acpi_device_id acpi_pfru_ids[] = {
+	{"INTC1080", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, acpi_pfru_ids);
+
+static struct platform_driver acpi_pfru_driver = {
+	.driver = {
+		.name = "pfru_update",
+		.acpi_match_table = acpi_pfru_ids,
+	},
+	.probe = acpi_pfru_probe,
+	.remove = acpi_pfru_remove,

Quoted 118 lines · Chen Yu

Introduce the pfru_update driver which can be used for Platform Firmware Runtime code injection and driver update[1]. The user is expected to provide the update firmware in the form of capsule file, and pass it to the driver via ioctl. Then the driver would hand this capsule file to the Platform Firmware Runtime Update via the ACPI device _DSM method. At last the low level Management Mode would do the firmware update.

[1] https://uefi.org/sites/default/files/resources/Intel_MM_OS_Interface_Spec_Rev100.pdf

Signed-off-by Chen Yu <[email protected]>

---
v4: Add Documentation/ABI/testing/pfru (Rafael J. Wysocki)
Change all pr_debug() to dev_dbg() (Greg Kroah-Hartman, Rafael J. Wysocki)
Change the error code ENOIOCTLCMD to ENOTTY in ioctl. (Greg Kroah-Hartman)
Remove compat ioctl. (Greg Kroah-Hartman)
Change /dev/pfru/update to /dev/acpi_pfru (Greg Kroah-Hartman) Remove valid_cap_type() and do sanity check in query_capability(). (Rafael J. Wysocki)
Remove the loop in query_capability().
(Rafael J. Wysocki)
Do not fail if the package has more elements than expected, and return error if the number of package elements is too small. (Rafael J. Wysocki)
Return the type or a negative error code in get_image_type() (Rafael J. Wysocki)
Put the comment inside the function rather than outside. (Rafael J. Wysocki)
Return the size or a negative error code adjust_efi_size() (Rafael J. Wysocki)
Return -EINVAL rather than -EFAULT if revison id is incorrect. (Rafael J. Wysocki)
Move the an read() of pfru into ioctl(), and using read() for the telemetry retrieval. So as to avoid the telemetry device file, the write() will be the code injection/update, the read() will be telemetry retrieval and all of the rest can be ioctl()s under one special device file.
(Rafael J. Wysocki)
v3: Use __u32 instead of int and __64 instead of unsigned long
in include/uapi/linux/pfru.h (Greg Kroah-Hartman)
Rename the structure in uapi to start with a prefix pfru so as to avoid confusing in the global namespace. (Greg Kroah-Hartman)
v2: Add sanity check for duplicated instance of ACPI device.
Update the driver to work with allocated pfru_device objects. (Mike Rapoport)
For each switch case pair, get rid of the magic case numbers and add a default clause with the error handling.
(Mike Rapoport)
Move the obj->type checks outside the switch to reduce redundancy. (Mike Rapoport)
Parse the code_inj_id and drv_update_id at driver initialization time to reduce the re-parsing at runtime.(Mike Rapoport) Explain in detail how the size needs to be adjusted when doing version check.(Mike Rapoport)
Rename parse_update_result() to dump_update_result()(Mike Rapoport) Remove redundant return.(Mike Rapoport)
Do not expose struct capsulate_buf_info to uapi, since it is not needed in userspace.(Mike Rapoport)

---
 Documentation/ABI/testing/pfru                |  41 ++
 .../userspace-api/ioctl/ioctl-number.rst      |   1 +
 drivers/acpi/Kconfig                          |   1 +
 drivers/acpi/Makefile                         |   1 +
 drivers/acpi/pfru/Kconfig                     |  16 +
 drivers/acpi/pfru/Makefile                    |   2 +
 drivers/acpi/pfru/pfru_update.c               | 567 ++++++++++++++++++
 include/uapi/linux/pfru.h                     | 102 ++++
 8 files changed, 731 insertions(+)
 create mode 100644 Documentation/ABI/testing/pfru
 create mode 100644 drivers/acpi/pfru/Kconfig
 create mode 100644 drivers/acpi/pfru/Makefile
 create mode 100644 drivers/acpi/pfru/pfru_update.c
 create mode 100644 include/uapi/linux/pfru.h

Documentation/ABI/testing/pfru new file +37 -0

new file mode 100644
index 000000000000..b8bc81703f46
@@ -0,0 +1,41 @@
+What:                /dev/acpi_pfru
+Date:                October 2021
+KernelVersion:       5.15
+Contact:     Chen Yu <[email protected]>
+Description:
+             The ioctl interface to drivers for platform firmware runtime
+             update(PFRU). Following actions are supported:
+
+             * PFRU_IOC_QUERY_CAP: Read the PFRU Runtime Update capability.
+               The value is a structure of pfru_update_cap_info.
+               See include/uapi/linux/pfru.h for definition.
+
+             * PFRU_SET_REV: Set the Revision ID for PFRU Runtime Update.
+               It could be either 1 or 2.
+
+             * PFRU_IOC_STAGE: Stage a capsule image from communication
+               buffer and perform authentication.
+
+             * PFRU_IOC_ACTIVATE: Activate a previous staged capsule image.
+
+             * PFRU_IOC_STAGE_ACTIVATE: Perform both stage and activation
+               actions.
+
+             * PFRU_LOG_IOC_SET_INFO: set log information in Telemetry
+               Service. The input is a structure of pfru_log_info.
+               This structure includes log revision id(1 or 2),
+               log level(0 : Error Message, 1 : Warning Message,
+               2 : Informational Message, 4 : Verbose), log data type
+               (0 : Execution Log, 1 : History Information).
+               See include/uapi/linux/pfru.h for definition.
+
+             * PFRU_LOG_IOC_GET_INFO: get log information in Telemetry.
+               The output is a structure of pfru_log_info.
+
+             * PFRU_LOG_IOC_GET_DATA_INFO: get log data information in
+               Telemetry. The output is a structure of pfru_log_data_info.
+               See include/uapi/linux/pfru.h for definition.

Documentation/ABI/testing/pfru line 41

Quoted 4 lines

Documentation/ABI/testing/pfru new file +4 -0

+
+             Besides ioctl interface, write() and read() are supported on
+             /dev/acpi_pfru. The write() will be the code injection/update,
+             and the read() will be telemetry retrieval.

Do we normally describe ioctl interfaces in Documentation/ABI/? Why not just add this to the kernel doc with the structures you are creating? Wouldn't that be easier?

Or are other acpi ioctl interfaces documented here already?

Quoted 9 lines · Chen Yu

Introduce the pfru_update driver which can be used for Platform Firmware Runtime code injection and driver update[1]. The user is expected to provide the update firmware in the form of capsule file, and pass it to the driver via ioctl. Then the driver would hand this capsule file to the Platform Firmware Runtime Update via the ACPI device _DSM method. At last the low level Management Mode would do the firmware update.

[1] https://uefi.org/sites/default/files/resources/Intel_MM_OS_Interface_Spec_Rev100.pdf

Do we normally describe ioctl interfaces in Documentation/ABI/? Why not just add this to the kernel doc with the structures you are creating? Wouldn't that be easier?

Or are other acpi ioctl interfaces documented here already?

Documentation/userspace-api/ioctl/ioctl-number.rst Code Seq# Include File Comments · line 368

Quoted 9 lines

Documentation/userspace-api/ioctl/ioctl-number.rst +1 -0

index 2e8134059c87..6e5a82fff408 100644
@@ -365,6 +365,7 @@ Code  Seq#    Include File                                           Comments
                                                                      <mailto:[email protected]>
 0xE5  00-3F  linux/fuse.h
 0xEC  00-01  drivers/platform/chrome/cros_ec_dev.h                   ChromeOS EC driver
+0xEE  00-1F  uapi/linux/pfru.h                                       Platform Firmware Runtime Update and Telemetry

You are not using all of those values, right?

Documentation/userspace-api/ioctl/ioctl-number.rst Code Seq# Include File Comments · line 370

Quoted 2 lines

Documentation/userspace-api/ioctl/ioctl-number.rst +0 -0

 0xF3  00-3F  drivers/usb/misc/sisusbvga/sisusb.h                     sisfb (in development)
 

Documentation/userspace-api/ioctl/ioctl-number.rst Code Seq# Include File Comments

Quoted 8 lines

Documentation/userspace-api/ioctl/ioctl-number.rst +8 -0

+
+struct pfru_device {
+	guid_t uuid, code_uuid, drv_uuid;
+	int rev_id;
+	struct device *dev;
+};
+
+static struct pfru_device *pfru_dev;

Why is this a single variable? Shouldn't this be per-device as the bus provides it to you?

Documentation/userspace-api/ioctl/ioctl-number.rst

Quoted 9 lines

Documentation/userspace-api/ioctl/ioctl-number.rst +9 -0

+
+static int acpi_pfru_probe(struct platform_device *pdev)
+{
+	acpi_handle handle;
+	int ret;
+
+	/* Only one instance is allowed. */
+	if (pfru_dev)
+		return 0;

Why is only one instance allowed? Why add extra work to do this when it really is not needed at all? It is simpler and less code to make it so that there is no restriction like this at all.

Also, the return value is incorrect, so your implementaion of trying to keep only one instance does not work properly :(

Quoted 2 lines

Documentation/userspace-api/ioctl/ioctl-number.rst +2 -0

+};
+

Documentation/userspace-api/ioctl/ioctl-number.rst

Quoted 8 lines

Documentation/userspace-api/ioctl/ioctl-number.rst +8 -0

+static int __init pfru_init(void)
+{
+	int ret;
+
+	ret = misc_register(&pfru_misc_dev);
+	if (ret)
+		return ret;
+

Why register this here, BEFORE you have a real device? That looks like a big race condition here :(

Register it per device you have in the system please.

thanks,

greg k-h

Quoted 7 lines · Chen Yu

Platform Firmware Runtime Update(PFRU) Telemetry Service is part of RoT (Root of Trust), which allows PFRU handler and other PFRU drivers to produce telemetry data to upper layer OS consumer at runtime.

The linux provides interfaces for the user to query the parameters of telemetry data, and the user could read out the telemetry data accordingly.

What type of interface is this? How does userspace interact with it?

Quoted 2 lines

Also add the ABI documentation.

Add it where?

Quoted 26 lines

Typical log looks like:
[SmmRuntimeUpdateHandler.ProcessSmmRuntimeUpdate] ProcessSmmRuntimeUpdate = START, Action = 2 [SmmRuntimeUpdateHandler.ProcessSmmRuntimeUpdate]
FwVersion = 0, CodeInjectionVersion = 1 [ShadowSmmRuntimeUpdateImage]
Image = 0x74D9B000, ImageSize = 0x1172 [ProcessSmmRuntimeUpdate]
ShadowSmmRuntimeUpdateImage.Status = Success [ValidateSmmRuntimeUpdateImage]
CapsuleHeader.CapsuleGuid = 6DCBD5ED-E82D-4C44-BDA1-7194199AD92A [ValidateSmmRuntimeUpdateImage]
FmpCapHeader.Version = 1
[ValidateSmmRuntimeUpdateImage] FmpCapImageHeader.UpdateImageTypeId = B2F84B79-7B6E-4E45-885F-3FB9BB185402 [ValidateSmmRuntimeUpdateImage] SmmRuntimeUpdateVerifyImageWithDenylist.Status = Success [ValidateSmmRuntimeUpdateImage] SmmRuntimeUpdateVerifyImageWithAllowlist.Status = Success [SmmCodeInjectionVerifyPayloadHeader]
PayloadHeader.Signature = 0x31494353 [SmmCodeInjectionVerifyPayloadHeader]
PayloadHeader.PlatformId = 63462139-A8B1-AA4E-9024-F2BB53EA4723 [SmmCodeInjectionVerifyPayloadHeader] PayloadHeader.SupportedSmmFirmwareVersion = 0,

Quoted 8 lines

PayloadHeader.SmmCodeInjectionRuntimeVersion = 1 [ProcessSmmRuntimeUpdate] ValidateSmmRuntimeUpdateImage.Status = Success
CPU CSR[0B102D28] Before = 7FBF830E
CPU CSR[0B102D28] After = 7FBF8310 [ProcessSmmRuntimeUpdate] ProcessSmmCodeInjection.Status = Success [SmmRuntimeUpdateHandler.ProcessSmmRuntimeUpdate] ProcessSmmRuntimeUpdate = End, Status = Success

This log does not make any sense to me, where is it from? Why the odd line-wrapping?

Quoted 3 lines

drivers/acpi/pfru/pfru_update.c +3 -0

+};
+
+

Quoted 31 lines

drivers/acpi/pfru/pfru_update.c +31 -0

+ssize_t pfru_log_read(struct file *filp, char __user *ubuf,
+		      size_t size, loff_t *off)
+{
+	struct pfru_log_data_info info;
+	phys_addr_t base_addr;
+	int buf_size, ret;
+	char *buf_ptr;
+
+	if (!pfru_log_dev)
+		return -ENODEV;
+
+	if (*off < 0)
+		return -EINVAL;
+
+	ret = get_pfru_log_data_info(&info, pfru_log_dev->info.log_type);
+	if (ret)
+		return ret;
+
+	base_addr = (phys_addr_t)(info.chunk2_addr_lo | (info.chunk2_addr_hi << 32));
+	/* pfru update has not been launched yet.*/
+	if (!base_addr)
+		return -EBUSY;
+
+	buf_size = info.max_data_size;
+	if (*off >= buf_size)
+		return 0;
+
+	buf_ptr = memremap(base_addr, buf_size, MEMREMAP_WB);
+	if (IS_ERR(buf_ptr))
+		return PTR_ERR(buf_ptr);
+

drivers/acpi/pfru/pfru_update.c struct pfru_device { · line 373

Quoted 5 lines

drivers/acpi/pfru/pfru_update.c +5 -0

+	size = min_t(size_t, size, buf_size - *off);
+	if (copy_to_user(ubuf, buf_ptr + *off, size))
+		ret = -EFAULT;
+	else
+		ret = 0;

As all you are doing is mapping some memory and reading from it, why do you need a read() file operation at all? Why not just use mmap?

thanks,

greg k-h

Quoted 31 lines

Quoted 31 lines

drivers/acpi/pfru/pfru_update.c +31 -0

+ssize_t pfru_log_read(struct file *filp, char __user *ubuf,
+		      size_t size, loff_t *off)
+{
+	struct pfru_log_data_info info;
+	phys_addr_t base_addr;
+	int buf_size, ret;
+	char *buf_ptr;
+
+	if (!pfru_log_dev)
+		return -ENODEV;
+
+	if (*off < 0)
+		return -EINVAL;
+
+	ret = get_pfru_log_data_info(&info, pfru_log_dev->info.log_type);
+	if (ret)
+		return ret;
+
+	base_addr = (phys_addr_t)(info.chunk2_addr_lo | (info.chunk2_addr_hi << 32));
+	/* pfru update has not been launched yet.*/
+	if (!base_addr)
+		return -EBUSY;
+
+	buf_size = info.max_data_size;
+	if (*off >= buf_size)
+		return 0;
+
+	buf_ptr = memremap(base_addr, buf_size, MEMREMAP_WB);
+	if (IS_ERR(buf_ptr))
+		return PTR_ERR(buf_ptr);
+

Quoted 9 lines

drivers/acpi/pfru/pfru_update.c struct pfru_device { · line 373

Quoted 5 lines

drivers/acpi/pfru/pfru_update.c +5 -0

+	size = min_t(size_t, size, buf_size - *off);
+	if (copy_to_user(ubuf, buf_ptr + *off, size))
+		ret = -EFAULT;
+	else
+		ret = 0;

As all you are doing is mapping some memory and reading from it, why do you need a read() file operation at all? Why not just use mmap?

In the beginning mmap() interface was provided to the user. Then it was realized that there is no guarantee in the spec that, the physical address provided by the BIOS would remain unchanged. So instead of asking the user to mmap the file each time before reading the log, the read() is leveraged here to always memremap() the latest address.

Quoted 40 lines · Chen Yu

Quoted 31 lines

Quoted 31 lines

drivers/acpi/pfru/pfru_update.c +31 -0

+ssize_t pfru_log_read(struct file *filp, char __user *ubuf,
+		      size_t size, loff_t *off)
+{
+	struct pfru_log_data_info info;
+	phys_addr_t base_addr;
+	int buf_size, ret;
+	char *buf_ptr;
+
+	if (!pfru_log_dev)
+		return -ENODEV;
+
+	if (*off < 0)
+		return -EINVAL;
+
+	ret = get_pfru_log_data_info(&info, pfru_log_dev->info.log_type);
+	if (ret)
+		return ret;
+
+	base_addr = (phys_addr_t)(info.chunk2_addr_lo | (info.chunk2_addr_hi << 32));
+	/* pfru update has not been launched yet.*/
+	if (!base_addr)
+		return -EBUSY;
+
+	buf_size = info.max_data_size;
+	if (*off >= buf_size)
+		return 0;
+
+	buf_ptr = memremap(base_addr, buf_size, MEMREMAP_WB);
+	if (IS_ERR(buf_ptr))
+		return PTR_ERR(buf_ptr);
+

Quoted 9 lines

drivers/acpi/pfru/pfru_update.c struct pfru_device { · line 373

Quoted 5 lines

drivers/acpi/pfru/pfru_update.c +5 -0

+	size = min_t(size_t, size, buf_size - *off);
+	if (copy_to_user(ubuf, buf_ptr + *off, size))
+		ret = -EFAULT;
+	else
+		ret = 0;

As all you are doing is mapping some memory and reading from it, why do you need a read() file operation at all? Why not just use mmap?

Quoted 5 lines

In the beginning mmap() interface was provided to the user. Then it was realized that there is no guarantee in the spec that, the physical address provided by the BIOS would remain unchanged. So instead of asking the user to mmap the file each time before reading the log, the read() is leveraged here to always memremap() the latest address.

So you are forced to memremap on _EVERY_ read call because the BIOS can change things underneath us without the kernel knowing about it? How does the chunk2_addr_lo and _hi values change while the system is running? Where does that happen, and isn't this going to be a very slow and expensive read call all the time?

Quoted 40 lines · Chen Yu

Quoted 31 lines

Quoted 31 lines

drivers/acpi/pfru/pfru_update.c +31 -0

+ssize_t pfru_log_read(struct file *filp, char __user *ubuf,
+		      size_t size, loff_t *off)
+{
+	struct pfru_log_data_info info;
+	phys_addr_t base_addr;
+	int buf_size, ret;
+	char *buf_ptr;
+
+	if (!pfru_log_dev)
+		return -ENODEV;
+
+	if (*off < 0)
+		return -EINVAL;
+
+	ret = get_pfru_log_data_info(&info, pfru_log_dev->info.log_type);
+	if (ret)
+		return ret;
+
+	base_addr = (phys_addr_t)(info.chunk2_addr_lo | (info.chunk2_addr_hi << 32));
+	/* pfru update has not been launched yet.*/
+	if (!base_addr)
+		return -EBUSY;
+
+	buf_size = info.max_data_size;
+	if (*off >= buf_size)
+		return 0;
+
+	buf_ptr = memremap(base_addr, buf_size, MEMREMAP_WB);
+	if (IS_ERR(buf_ptr))
+		return PTR_ERR(buf_ptr);
+

Quoted 9 lines

drivers/acpi/pfru/pfru_update.c struct pfru_device { · line 373

Quoted 5 lines

drivers/acpi/pfru/pfru_update.c +5 -0

+	size = min_t(size_t, size, buf_size - *off);
+	if (copy_to_user(ubuf, buf_ptr + *off, size))
+		ret = -EFAULT;
+	else
+		ret = 0;

As all you are doing is mapping some memory and reading from it, why do you need a read() file operation at all? Why not just use mmap?

Quoted 5 lines

In the beginning mmap() interface was provided to the user. Then it was realized that there is no guarantee in the spec that, the physical address provided by the BIOS would remain unchanged. So instead of asking the user to mmap the file each time before reading the log, the read() is leveraged here to always memremap() the latest address.

So you are forced to memremap on _EVERY_ read call because the BIOS can change things underneath us without the kernel knowing about it? How does the chunk2_addr_lo and _hi values change while the system is running? Where does that happen, and isn't this going to be a very slow and expensive read call all the time?

thanks,

greg k-h