Re: [PATCH v2] platform/x86/amd: pmc: Add sysfs files for SMU

From: Hans de Goede
Date: Mon Sep 19 2022 - 07:50:28 EST


Hi,

On 9/14/22 15:18, Mario Limonciello wrote:
> The CPU/APU SMU FW version and program is currently discoverable by
> turning on dynamic debugging or examining debugfs for the amdgpu
> driver. To make this more discoverable, create a dedicated sysfs
> file for it that userspace can parse without debugging enabled.
>
> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>

Thank you for your patch, I've applied this patch to my review-hans
branch:
https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans

Note it will show up in my review-hans branch once I've pushed my
local branch there, which might take a while.

Once I've run some tests on this branch the patches there will be
added to the platform-drivers-x86/for-next branch and eventually
will be included in the pdx86 pull-request to Linus for the next
merge-window.

Regards,

Hans


> ---
> v1->v2:
> * Feedback from Barnabás Pőcze
> - Fix documentation EOF missing newline
> - Use ATTRIBUTE_GROUPS macro
> - Add missing NULL at end of attr
>
> Documentation/ABI/testing/sysfs-amd-pmc | 14 +++++++++
> drivers/platform/x86/amd/pmc.c | 39 +++++++++++++++++++++++++
> 2 files changed, 53 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-amd-pmc
>
> diff --git a/Documentation/ABI/testing/sysfs-amd-pmc b/Documentation/ABI/testing/sysfs-amd-pmc
> new file mode 100644
> index 000000000000..5d71c2298f5b
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-amd-pmc
> @@ -0,0 +1,14 @@
> +What: /sys/bus/platform/drivers/amd_pmc/*/smu_fw_version
> +Date: October 2022
> +Contact: Mario Limonciello <mario.limonciello@xxxxxxx>
> +Description: Reading this file reports the version of the firmware loaded to
> + System Management Unit (SMU) contained in AMD CPUs and
> + APUs.
> +
> +What: /sys/bus/platform/drivers/amd_pmc/*/smu_program
> +Date: October 2022
> +Contact: Mario Limonciello <mario.limonciello@xxxxxxx>
> +Description: Reading this file reports the program corresponding to the SMU
> + firmware version. The program field is used to disambiguate two
> + APU/CPU models that can share the same firmware binary.
> +
> diff --git a/drivers/platform/x86/amd/pmc.c b/drivers/platform/x86/amd/pmc.c
> index 700eb19e8450..6373c1bce649 100644
> --- a/drivers/platform/x86/amd/pmc.c
> +++ b/drivers/platform/x86/amd/pmc.c
> @@ -455,6 +455,44 @@ static int amd_pmc_get_smu_version(struct amd_pmc_dev *dev)
> return 0;
> }
>
> +static ssize_t smu_fw_version_show(struct device *d, struct device_attribute *attr,
> + char *buf)
> +{
> + struct amd_pmc_dev *dev = dev_get_drvdata(d);
> +
> + if (!dev->major) {
> + int rc = amd_pmc_get_smu_version(dev);
> +
> + if (rc)
> + return rc;
> + }
> + return sysfs_emit(buf, "%u.%u.%u\n", dev->major, dev->minor, dev->rev);
> +}
> +
> +static ssize_t smu_program_show(struct device *d, struct device_attribute *attr,
> + char *buf)
> +{
> + struct amd_pmc_dev *dev = dev_get_drvdata(d);
> +
> + if (!dev->major) {
> + int rc = amd_pmc_get_smu_version(dev);
> +
> + if (rc)
> + return rc;
> + }
> + return sysfs_emit(buf, "%u\n", dev->smu_program);
> +}
> +
> +static DEVICE_ATTR_RO(smu_fw_version);
> +static DEVICE_ATTR_RO(smu_program);
> +
> +static struct attribute *pmc_attrs[] = {
> + &dev_attr_smu_fw_version.attr,
> + &dev_attr_smu_program.attr,
> + NULL,
> +};
> +ATTRIBUTE_GROUPS(pmc);
> +
> static int amd_pmc_idlemask_show(struct seq_file *s, void *unused)
> {
> struct amd_pmc_dev *dev = s->private;
> @@ -935,6 +973,7 @@ static struct platform_driver amd_pmc_driver = {
> .driver = {
> .name = "amd_pmc",
> .acpi_match_table = amd_pmc_acpi_ids,
> + .dev_groups = pmc_groups,
> },
> .probe = amd_pmc_probe,
> .remove = amd_pmc_remove,