[v3,4/5] drivers/acpi: Introduce Platform Firmware Runtime Update Telemetry

Commit Message

Chen Yu Sept. 16, 2021, 4:03 p.m. UTC

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.

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 <[e-mail]>
---
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/Kconfig          |  14 +
 drivers/acpi/pfru/Makefile         |   1 +
 drivers/acpi/pfru/pfru_telemetry.c | 412 +++++++++++++++++++++++++++++
 include/uapi/linux/pfru.h          |  43 +++
 4 files changed, 470 insertions(+)
 create mode 100644 drivers/acpi/pfru/pfru_telemetry.c

Comments

Rafael J. Wysocki Sept. 28, 2021, 12:40 p.m. UTC | #1

On Thu, Sep 16, 2021 at 5:58 PM Chen Yu <[e-mail]> wrote:
>
> 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.
>
> 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 <[e-mail]>
> ---
> 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/Kconfig          |  14 +
>  drivers/acpi/pfru/Makefile         |   1 +
>  drivers/acpi/pfru/pfru_telemetry.c | 412 +++++++++++++++++++++++++++++
>  include/uapi/linux/pfru.h          |  43 +++
>  4 files changed, 470 insertions(+)
>  create mode 100644 drivers/acpi/pfru/pfru_telemetry.c
>
> diff --git a/drivers/acpi/pfru/Kconfig b/drivers/acpi/pfru/Kconfig
> index 3f31b7d95f3b..e2934058884e 100644
> --- a/drivers/acpi/pfru/Kconfig
> +++ b/drivers/acpi/pfru/Kconfig
> @@ -13,3 +13,17 @@ config ACPI_PFRU
>
>           To compile this driver as a module, choose M here:
>           the module will be called pfru_update.
> +
> +config ACPI_PFRU_TELEMETRY

Why does this need a separate Kconfig option?

> +       tristate "ACPI Platform Firmware Runtime Update Telemetry Service"
> +       depends on ACPI_PFRU
> +       help
> +         PFRU(Platform Firmware Runtime Update) Telemetry Service is part of
> +         RoT(Root of Trust), which allows Platform Firmware Runtime Update handler
> +         and other PFRU drivers to produce telemetry data to upper layer OS consumer
> +         at runtime.
> +
> +         For more information, see:
> +         <file:Documentation/x86/pfru_update.rst>
> +
> +         If unsure, please say N.
> diff --git a/drivers/acpi/pfru/Makefile b/drivers/acpi/pfru/Makefile
> index 098cbe80cf3d..30060ba320ea 100644
> --- a/drivers/acpi/pfru/Makefile
> +++ b/drivers/acpi/pfru/Makefile
> @@ -1,2 +1,3 @@
>  # SPDX-License-Identifier: GPL-2.0-only
>  obj-$(CONFIG_ACPI_PFRU) += pfru_update.o
> +obj-$(CONFIG_ACPI_PFRU_TELEMETRY) += pfru_telemetry.o

I'm not sure about this ...

> diff --git a/drivers/acpi/pfru/pfru_telemetry.c b/drivers/acpi/pfru/pfru_telemetry.c
> new file mode 100644
> index 000000000000..96dc9e69edc0
> --- /dev/null
> +++ b/drivers/acpi/pfru/pfru_telemetry.c
> @@ -0,0 +1,412 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * ACPI Platform Firmware Runtime Update
> + * Telemetry Service Device Driver
> + *
> + * Copyright (C) 2021 Intel Corporation
> + * Author: Chen Yu <[e-mail]>
> + */
> +#include <linux/acpi.h>
> +#include <linux/errno.h>
> +#include <linux/fs.h>
> +#include <linux/file.h>
> +#include <linux/minmax.h>
> +#include <linux/miscdevice.h>
> +#include <linux/module.h>
> +#include <linux/mm.h>
> +#include <linux/platform_device.h>
> +#include <linux/uuid.h>
> +#include <linux/uaccess.h>
> +#include <uapi/linux/pfru.h>
> +
> +enum update_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,
> +};
> +
> +struct pfru_telem_device {
> +       struct device *dev;
> +       guid_t uuid;
> +       struct pfru_telem_info info;
> +};
> +
> +/*
> + * There would be only one instance of pfru_telem_device.
> + */
> +static struct pfru_telem_device *telem_dev;
> +
> +static int get_pfru_data_info(struct pfru_telem_data_info *data_info,
> +                             int log_type)
> +{
> +       union acpi_object *out_obj, in_obj, in_buf;
> +       acpi_handle handle;
> +       int i, ret = -EINVAL;
> +
> +       handle = ACPI_HANDLE(telem_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, &telem_dev->uuid,
> +                                         telem_dev->info.log_revid, FUNC_GET_DATA,
> +                                         &in_obj, ACPI_TYPE_PACKAGE);
> +       if (!out_obj) {
> +               pr_err("Failed to invoke _DSM\n");
> +               return -EINVAL;
> +       }
> +
> +       for (i = 0; i < out_obj->package.count; i++) {

Is the loop really necessary?

> +               union acpi_object *obj = &out_obj->package.elements[i];
> +
> +               if (obj->type != ACPI_TYPE_INTEGER)
> +                       goto free_acpi_buffer;
> +
> +               switch (i) {
> +               case LOG_STATUS_IDX:
> +                       data_info->status = obj->integer.value;
> +                       break;
> +               case LOG_EXT_STATUS_IDX:
> +                       data_info->ext_status = obj->integer.value;
> +                       break;
> +               case LOG_MAX_SZ_IDX:
> +                       data_info->max_data_size = obj->integer.value;
> +                       break;
> +               case LOG_CHUNK1_LO_IDX:
> +                       data_info->chunk1_addr_lo = obj->integer.value;
> +                       break;
> +               case LOG_CHUNK1_HI_IDX:
> +                       data_info->chunk1_addr_hi = obj->integer.value;
> +                       break;
> +               case LOG_CHUNK1_SZ_IDX:
> +                       data_info->chunk1_size = obj->integer.value;
> +                       break;
> +               case LOG_CHUNK2_LO_IDX:
> +                       data_info->chunk2_addr_lo = obj->integer.value;
> +                       break;
> +               case LOG_CHUNK2_HI_IDX:
> +                       data_info->chunk2_addr_hi = obj->integer.value;
> +                       break;
> +               case LOG_CHUNK2_SZ_IDX:
> +                       data_info->chunk2_size = obj->integer.value;
> +                       break;
> +               case LOG_ROLLOVER_CNT_IDX:
> +                       data_info->rollover_cnt = obj->integer.value;
> +                       break;
> +               case LOG_RESET_CNT_IDX:
> +                       data_info->reset_cnt = obj->integer.value;
> +                       break;
> +               default:
> +                       pr_err("Incorrect format of Telemetry info.\n");

dev_dbg()?  And likewise below.

> +                       goto free_acpi_buffer;
> +               }
> +       }
> +       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(telem_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, &telem_dev->uuid,
> +                                         telem_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) {
> +               pr_err("get MM telemetry level error status %d\n",
> +                      status);
> +               goto free_acpi_buffer;
> +       }
> +
> +       obj = &out_obj->package.elements[1];
> +       status = obj->integer.value;
> +       if (status) {
> +               pr_err("get MM telemetry level error extend status %d\n",
> +                      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(telem_dev->dev);
> +       out_obj = acpi_evaluate_dsm_typed(handle, &telem_dev->uuid,
> +                                         telem_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) {
> +               pr_err("get MM telemetry level error status %d\n",
> +                      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) {
> +               pr_err("get MM telemetry level error status %d\n",
> +                      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);

The parens are redundant AFAICS.

> +}
> +
> +static int valid_log_type(int type)
> +{
> +       return (type == LOG_EXEC_IDX) || (type == LOG_HISTORY_IDX);

And here too.

> +}
> +
> +static long pfru_telemetry_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
> +
> +{
> +       struct pfru_telem_data_info data_info;
> +       struct pfru_telem_info info;
> +       void __user *p;
> +       int ret = 0;
> +
> +       p = (void __user *)arg;
> +
> +       switch (cmd) {
> +       case PFRU_LOG_IOC_SET_INFO:
> +               if (copy_from_user(&info, p, sizeof(info)))
> +                       return -EFAULT;

Empty line, please.

> +               if (pfru_valid_revid(info.log_revid))
> +                       telem_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;

And here.

> +                       telem_dev->info.log_level = info.log_level;
> +               }
> +               if (valid_log_type(info.log_type))
> +                       telem_dev->info.log_type = info.log_type;

And here.  And analogously below.

Generally speaking, I tend to prefer putting empty code lines after an
if () statement that is not followed by a block.

> +               break;
> +       case PFRU_LOG_IOC_GET_INFO:
> +               ret = get_pfru_log_level(&info.log_level);
> +               if (ret)
> +                       return ret;
> +               info.log_type = telem_dev->info.log_type;
> +               info.log_revid = telem_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_data_info(&data_info, telem_dev->info.log_type);
> +               if (ret)
> +                       return ret;
> +               if (copy_to_user(p, &data_info, sizeof(struct pfru_telem_data_info)))
> +                       ret = -EFAULT;
> +               break;
> +       default:
> +               ret = -ENOIOCTLCMD;
> +               break;
> +       }
> +       return ret;
> +}
> +
> +static ssize_t pfru_telemetry_read(struct file *filp, char __user *ubuf,
> +                                  size_t size, loff_t *off)
> +{
> +       struct pfru_telem_data_info info;
> +       phys_addr_t base_addr;
> +       int buf_size, ret;
> +       char *buf_ptr;
> +
> +       if (*off < 0)
> +               return -EINVAL;
> +
> +       ret = get_pfru_data_info(&info, telem_dev->info.log_type);
> +       if (ret) {
> +               pr_err("Could not get telemetry data info %d\n", ret);
> +               return ret;
> +       }
> +
> +       base_addr = (phys_addr_t)(info.chunk2_addr_lo |
> +                       (info.chunk2_addr_hi << 32));

This line doesn't need to be broken as far as I'm concerned.

> +       if (!base_addr) {
> +               pr_err("Telemetry data not ready\n");
> +               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);
> +
> +       size = min_t(size_t, size, buf_size - *off);
> +
> +       ret = -EFAULT;
> +       if (copy_to_user(ubuf, buf_ptr + *off, size))
> +               goto out;
> +       ret = 0;

So this would be far more readable in the following form IMO:

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

And it looks like you won't need the "out" label any more then.

> +out:
> +       memunmap(buf_ptr);
> +
> +       return ret ? ret : size;
> +}
> +
> +#ifdef CONFIG_COMPAT
> +static long compat_pfru_telemetry_ioctl(struct file *filep, unsigned int cmd,
> +                                       unsigned long arg)
> +{
> +       return pfru_telemetry_ioctl(filep, cmd, arg);
> +}
> +#endif
> +
> +static const struct file_operations acpi_pfru_telemetry_fops = {
> +       .owner          = THIS_MODULE,
> +       .read           = pfru_telemetry_read,
> +       .unlocked_ioctl = pfru_telemetry_ioctl,
> +#ifdef CONFIG_COMPAT
> +       .compat_ioctl   = compat_pfru_telemetry_ioctl,
> +#endif
> +       .llseek         = noop_llseek,
> +};

And I would consider combining this with the update interface so that
the write() updates the firmware code and the read() gets telemetry
data from it.

> +
> +static struct miscdevice pfru_telemetry_misc_dev = {
> +       .minor = MISC_DYNAMIC_MINOR,
> +       .name = "pfru_telemetry",
> +       .nodename = "pfru/telemetry",
> +       .fops = &acpi_pfru_telemetry_fops,
> +};
> +
> +static int acpi_pfru_telemetry_remove(struct platform_device *pdev)
> +{
> +       misc_deregister(&pfru_telemetry_misc_dev);
> +       kfree(telem_dev);
> +       telem_dev = NULL;
> +
> +       return 0;
> +}
> +
> +static int acpi_pfru_telemetry_probe(struct platform_device *pdev)
> +{
> +       acpi_handle handle;
> +       int ret;
> +
> +       if (telem_dev) {
> +               pr_err("Duplicated PFRU Telemetry INTC1081 detected, skip...\n");
> +               return 0;
> +       }
> +
> +       telem_dev = kzalloc(sizeof(*telem_dev), GFP_KERNEL);
> +       if (!telem_dev)
> +               return -ENOMEM;
> +
> +       ret = guid_parse(PFRU_TELEMETRY_UUID, &telem_dev->uuid);
> +       if (ret)
> +               goto out;
> +
> +       telem_dev->info.log_revid = 1;
> +       telem_dev->dev = &pdev->dev;
> +       handle = ACPI_HANDLE(telem_dev->dev);
> +       if (!acpi_has_method(handle, "_DSM")) {
> +               pr_err("Missing _DSM\n");
> +               ret = -ENODEV;
> +               goto out;
> +       }
> +
> +       ret = misc_register(&pfru_telemetry_misc_dev);
> +       if (ret)
> +               goto out;
> +
> +       return 0;
> +out:
> +       kfree(telem_dev);
> +       telem_dev = NULL;
> +
> +       return ret;
> +}
> +
> +static const struct acpi_device_id acpi_pfru_telemetry_ids[] = {
> +       {"INTC1081", 0},
> +       {}
> +};
> +MODULE_DEVICE_TABLE(acpi, acpi_pfru_telemetry_ids);
> +
> +static struct platform_driver acpi_pfru_telemetry_driver = {
> +       .driver = {
> +               .name = "pfru_telemetry",
> +               .acpi_match_table = acpi_pfru_telemetry_ids,
> +       },
> +       .probe = acpi_pfru_telemetry_probe,
> +       .remove = acpi_pfru_telemetry_remove,
> +};
> +module_platform_driver(acpi_pfru_telemetry_driver);
> +
> +MODULE_DESCRIPTION("Platform Firmware Runtime Update Telemetry Service device driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/uapi/linux/pfru.h b/include/uapi/linux/pfru.h
> index ca0b7433f79f..b04852602133 100644
> --- a/include/uapi/linux/pfru.h
> +++ b/include/uapi/linux/pfru.h
> @@ -98,4 +98,47 @@ struct pfru_updated_result {
>         __u64 high_exec_time;
>  };
>
> +#define PFRU_TELEMETRY_UUID    "75191659-8178-4D9D-B88F-AC5E5E93E8BF"
> +
> +/* Telemetry structures. */
> +struct pfru_telem_data_info {
> +       enum pfru_dsm_status status;
> +       enum pfru_dsm_status 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 pfru_telem_info {
> +       __u32 log_level;
> +       __u32 log_type;
> +       __u32 log_revid;
> +};
> +
> +/* Two logs: history and execution log */
> +#define LOG_EXEC_IDX   0
> +#define LOG_HISTORY_IDX        1
> +#define NR_LOG_TYPE    2
> +
> +#define LOG_ERR                0
> +#define LOG_WARN       1
> +#define LOG_INFO       2
> +#define LOG_VERB       4
> +
> +#define FUNC_SET_LEV           1
> +#define FUNC_GET_LEV           2
> +#define FUNC_GET_DATA          3
> +
> +#define LOG_NAME_SIZE          10
> +
> +#define PFRU_LOG_IOC_SET_INFO _IOW(PFRU_MAGIC, 0x05, struct pfru_telem_info)
> +#define PFRU_LOG_IOC_GET_INFO _IOR(PFRU_MAGIC, 0x06, struct pfru_telem_info)
> +#define PFRU_LOG_IOC_GET_DATA_INFO _IOR(PFRU_MAGIC, 0x07, struct pfru_telem_data_info)
> +
>  #endif /* __PFRU_H__ */
> --

Patch

diff --git a/drivers/acpi/pfru/Kconfig b/drivers/acpi/pfru/Kconfig
index 3f31b7d95f3b..e2934058884e 100644
--- a/drivers/acpi/pfru/Kconfig
+++ b/drivers/acpi/pfru/Kconfig
@@ -13,3 +13,17 @@  config ACPI_PFRU
 
 	  To compile this driver as a module, choose M here:
 	  the module will be called pfru_update.
+
+config ACPI_PFRU_TELEMETRY
+	tristate "ACPI Platform Firmware Runtime Update Telemetry Service"
+	depends on ACPI_PFRU
+	help
+	  PFRU(Platform Firmware Runtime Update) Telemetry Service is part of
+	  RoT(Root of Trust), which allows Platform Firmware Runtime Update handler
+	  and other PFRU drivers to produce telemetry data to upper layer OS consumer
+	  at runtime.
+
+	  For more information, see:
+	  <file:Documentation/x86/pfru_update.rst>
+
+	  If unsure, please say N.
diff --git a/drivers/acpi/pfru/Makefile b/drivers/acpi/pfru/Makefile
index 098cbe80cf3d..30060ba320ea 100644
--- a/drivers/acpi/pfru/Makefile
+++ b/drivers/acpi/pfru/Makefile
@@ -1,2 +1,3 @@ 
 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_ACPI_PFRU) += pfru_update.o
+obj-$(CONFIG_ACPI_PFRU_TELEMETRY) += pfru_telemetry.o
diff --git a/drivers/acpi/pfru/pfru_telemetry.c b/drivers/acpi/pfru/pfru_telemetry.c
new file mode 100644
index 000000000000..96dc9e69edc0
--- /dev/null
+++ b/drivers/acpi/pfru/pfru_telemetry.c
@@ -0,0 +1,412 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ACPI Platform Firmware Runtime Update
+ * Telemetry Service Device Driver
+ *
+ * Copyright (C) 2021 Intel Corporation
+ * Author: Chen Yu <[e-mail]>
+ */
+#include <linux/acpi.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/minmax.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/platform_device.h>
+#include <linux/uuid.h>
+#include <linux/uaccess.h>
+#include <uapi/linux/pfru.h>
+
+enum update_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,
+};
+
+struct pfru_telem_device {
+	struct device *dev;
+	guid_t uuid;
+	struct pfru_telem_info info;
+};
+
+/*
+ * There would be only one instance of pfru_telem_device.
+ */
+static struct pfru_telem_device *telem_dev;
+
+static int get_pfru_data_info(struct pfru_telem_data_info *data_info,
+			      int log_type)
+{
+	union acpi_object *out_obj, in_obj, in_buf;
+	acpi_handle handle;
+	int i, ret = -EINVAL;
+
+	handle = ACPI_HANDLE(telem_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, &telem_dev->uuid,
+					  telem_dev->info.log_revid, FUNC_GET_DATA,
+					  &in_obj, ACPI_TYPE_PACKAGE);
+	if (!out_obj) {
+		pr_err("Failed to invoke _DSM\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < out_obj->package.count; i++) {
+		union acpi_object *obj = &out_obj->package.elements[i];
+
+		if (obj->type != ACPI_TYPE_INTEGER)
+			goto free_acpi_buffer;
+
+		switch (i) {
+		case LOG_STATUS_IDX:
+			data_info->status = obj->integer.value;
+			break;
+		case LOG_EXT_STATUS_IDX:
+			data_info->ext_status = obj->integer.value;
+			break;
+		case LOG_MAX_SZ_IDX:
+			data_info->max_data_size = obj->integer.value;
+			break;
+		case LOG_CHUNK1_LO_IDX:
+			data_info->chunk1_addr_lo = obj->integer.value;
+			break;
+		case LOG_CHUNK1_HI_IDX:
+			data_info->chunk1_addr_hi = obj->integer.value;
+			break;
+		case LOG_CHUNK1_SZ_IDX:
+			data_info->chunk1_size = obj->integer.value;
+			break;
+		case LOG_CHUNK2_LO_IDX:
+			data_info->chunk2_addr_lo = obj->integer.value;
+			break;
+		case LOG_CHUNK2_HI_IDX:
+			data_info->chunk2_addr_hi = obj->integer.value;
+			break;
+		case LOG_CHUNK2_SZ_IDX:
+			data_info->chunk2_size = obj->integer.value;
+			break;
+		case LOG_ROLLOVER_CNT_IDX:
+			data_info->rollover_cnt = obj->integer.value;
+			break;
+		case LOG_RESET_CNT_IDX:
+			data_info->reset_cnt = obj->integer.value;
+			break;
+		default:
+			pr_err("Incorrect format of Telemetry info.\n");
+			goto free_acpi_buffer;
+		}
+	}
+	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(telem_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, &telem_dev->uuid,
+					  telem_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) {
+		pr_err("get MM telemetry level error status %d\n",
+		       status);
+		goto free_acpi_buffer;
+	}
+
+	obj = &out_obj->package.elements[1];
+	status = obj->integer.value;
+	if (status) {
+		pr_err("get MM telemetry level error extend status %d\n",
+		       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(telem_dev->dev);
+	out_obj = acpi_evaluate_dsm_typed(handle, &telem_dev->uuid,
+					  telem_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) {
+		pr_err("get MM telemetry level error status %d\n",
+		       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) {
+		pr_err("get MM telemetry level error status %d\n",
+		       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);
+}
+
+static long pfru_telemetry_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+
+{
+	struct pfru_telem_data_info data_info;
+	struct pfru_telem_info info;
+	void __user *p;
+	int ret = 0;
+
+	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))
+			telem_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;
+			telem_dev->info.log_level = info.log_level;
+		}
+		if (valid_log_type(info.log_type))
+			telem_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 = telem_dev->info.log_type;
+		info.log_revid = telem_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_data_info(&data_info, telem_dev->info.log_type);
+		if (ret)
+			return ret;
+		if (copy_to_user(p, &data_info, sizeof(struct pfru_telem_data_info)))
+			ret = -EFAULT;
+		break;
+	default:
+		ret = -ENOIOCTLCMD;
+		break;
+	}
+	return ret;
+}
+
+static ssize_t pfru_telemetry_read(struct file *filp, char __user *ubuf,
+				   size_t size, loff_t *off)
+{
+	struct pfru_telem_data_info info;
+	phys_addr_t base_addr;
+	int buf_size, ret;
+	char *buf_ptr;
+
+	if (*off < 0)
+		return -EINVAL;
+
+	ret = get_pfru_data_info(&info, telem_dev->info.log_type);
+	if (ret) {
+		pr_err("Could not get telemetry data info %d\n", ret);
+		return ret;
+	}
+
+	base_addr = (phys_addr_t)(info.chunk2_addr_lo |
+			(info.chunk2_addr_hi << 32));
+	if (!base_addr) {
+		pr_err("Telemetry data not ready\n");
+		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);
+
+	size = min_t(size_t, size, buf_size - *off);
+
+	ret = -EFAULT;
+	if (copy_to_user(ubuf, buf_ptr + *off, size))
+		goto out;
+	ret = 0;
+out:
+	memunmap(buf_ptr);
+
+	return ret ? ret : size;
+}
+
+#ifdef CONFIG_COMPAT
+static long compat_pfru_telemetry_ioctl(struct file *filep, unsigned int cmd,
+					unsigned long arg)
+{
+	return pfru_telemetry_ioctl(filep, cmd, arg);
+}
+#endif
+
+static const struct file_operations acpi_pfru_telemetry_fops = {
+	.owner		= THIS_MODULE,
+	.read		= pfru_telemetry_read,
+	.unlocked_ioctl = pfru_telemetry_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= compat_pfru_telemetry_ioctl,
+#endif
+	.llseek		= noop_llseek,
+};
+
+static struct miscdevice pfru_telemetry_misc_dev = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = "pfru_telemetry",
+	.nodename = "pfru/telemetry",
+	.fops = &acpi_pfru_telemetry_fops,
+};
+
+static int acpi_pfru_telemetry_remove(struct platform_device *pdev)
+{
+	misc_deregister(&pfru_telemetry_misc_dev);
+	kfree(telem_dev);
+	telem_dev = NULL;
+
+	return 0;
+}
+
+static int acpi_pfru_telemetry_probe(struct platform_device *pdev)
+{
+	acpi_handle handle;
+	int ret;
+
+	if (telem_dev) {
+		pr_err("Duplicated PFRU Telemetry INTC1081 detected, skip...\n");
+		return 0;
+	}
+
+	telem_dev = kzalloc(sizeof(*telem_dev), GFP_KERNEL);
+	if (!telem_dev)
+		return -ENOMEM;
+
+	ret = guid_parse(PFRU_TELEMETRY_UUID, &telem_dev->uuid);
+	if (ret)
+		goto out;
+
+	telem_dev->info.log_revid = 1;
+	telem_dev->dev = &pdev->dev;
+	handle = ACPI_HANDLE(telem_dev->dev);
+	if (!acpi_has_method(handle, "_DSM")) {
+		pr_err("Missing _DSM\n");
+		ret = -ENODEV;
+		goto out;
+	}
+
+	ret = misc_register(&pfru_telemetry_misc_dev);
+	if (ret)
+		goto out;
+
+	return 0;
+out:
+	kfree(telem_dev);
+	telem_dev = NULL;
+
+	return ret;
+}
+
+static const struct acpi_device_id acpi_pfru_telemetry_ids[] = {
+	{"INTC1081", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, acpi_pfru_telemetry_ids);
+
+static struct platform_driver acpi_pfru_telemetry_driver = {
+	.driver = {
+		.name = "pfru_telemetry",
+		.acpi_match_table = acpi_pfru_telemetry_ids,
+	},
+	.probe = acpi_pfru_telemetry_probe,
+	.remove = acpi_pfru_telemetry_remove,
+};
+module_platform_driver(acpi_pfru_telemetry_driver);
+
+MODULE_DESCRIPTION("Platform Firmware Runtime Update Telemetry Service device driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/uapi/linux/pfru.h b/include/uapi/linux/pfru.h
index ca0b7433f79f..b04852602133 100644
--- a/include/uapi/linux/pfru.h
+++ b/include/uapi/linux/pfru.h
@@ -98,4 +98,47 @@  struct pfru_updated_result {
 	__u64 high_exec_time;
 };
 
+#define PFRU_TELEMETRY_UUID	"75191659-8178-4D9D-B88F-AC5E5E93E8BF"
+
+/* Telemetry structures. */
+struct pfru_telem_data_info {
+	enum pfru_dsm_status status;
+	enum pfru_dsm_status 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 pfru_telem_info {
+	__u32 log_level;
+	__u32 log_type;
+	__u32 log_revid;
+};
+
+/* Two logs: history and execution log */
+#define LOG_EXEC_IDX	0
+#define LOG_HISTORY_IDX	1
+#define NR_LOG_TYPE	2
+
+#define LOG_ERR		0
+#define LOG_WARN	1
+#define LOG_INFO	2
+#define LOG_VERB	4
+
+#define FUNC_SET_LEV		1
+#define FUNC_GET_LEV		2
+#define FUNC_GET_DATA		3
+
+#define LOG_NAME_SIZE		10
+
+#define PFRU_LOG_IOC_SET_INFO _IOW(PFRU_MAGIC, 0x05, struct pfru_telem_info)
+#define PFRU_LOG_IOC_GET_INFO _IOR(PFRU_MAGIC, 0x06, struct pfru_telem_info)
+#define PFRU_LOG_IOC_GET_DATA_INFO _IOR(PFRU_MAGIC, 0x07, struct pfru_telem_data_info)
+
 #endif /* __PFRU_H__ */