Re: [PATCH v3 07/13] drm/xe/configfs: Allow to enable PSMI

[Riana Tauro <riana.tauro@intel.com>]

On 8/8/2025 10:59 PM, Lucas De Marchi wrote:
> Now that additional WAs are in place and it's possible to allocate
> buffers through debugfs, add the configfs attribute to turn PSMI on.
> 
> Cc: Matt Roper <matthew.d.roper@intel.com>
> Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
> Cc: John Harrison <John.C.Harrison@Intel.com>
> Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
> ---
>   drivers/gpu/drm/xe/xe_configfs.c | 66 +++++++++++++++++++++++++++++++++++++---
>   drivers/gpu/drm/xe/xe_configfs.h |  2 +-
>   2 files changed, 63 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_configfs.c b/drivers/gpu/drm/xe/xe_configfs.c
> index 17b1d6ae1ff6a..8cf6b1375b7d4 100644
> --- a/drivers/gpu/drm/xe/xe_configfs.c
> +++ b/drivers/gpu/drm/xe/xe_configfs.c
> @@ -77,6 +77,16 @@
>    * available for migrations, but it's disabled. This is intended for debugging
>    * purposes only.
>    *
> + * PSMI
> + * ----
> + *
> + * Enable extra debugging capabilities to trace engine execution. Only useful
> + * during early platform enabling and requiring additional hardware connected.

%s/requiring/requires

> + * Once it's enabled, additionals WAs are added and runtime configuration is
> + * done via debugfs. Example to enable it::
> + *
> + *	# echo 1 > /sys/kernel/config/xe/0000:03:00.0/enable_psmi
> + *
>    * Remove devices
>    * ==============
>    *
> @@ -89,8 +99,9 @@ struct xe_config_group_device {
>   	struct config_group group;
>   
>   	struct xe_config_device {
> -		bool survivability_mode;
>   		u64 engines_allowed;
> +		bool survivability_mode;
> +		bool enable_psmi;
>   	} config;
>   
>   	/* protects attributes */
> @@ -98,8 +109,9 @@ struct xe_config_group_device {
>   };
>   
>   static const struct xe_config_device device_defaults = {
> -	.survivability_mode = false,
>   	.engines_allowed = U64_MAX,
> +	.survivability_mode = false,
> +	.enable_psmi = false,
>   };
>   
>   static void set_device_defaults(struct xe_config_device *config)
> @@ -243,12 +255,38 @@ static ssize_t engines_allowed_store(struct config_item *item, const char *page,
>   	return len;
>   }
>   
> -CONFIGFS_ATTR(, survivability_mode);
> +static ssize_t enable_psmi_show(struct config_item *item, char *page)
> +{
> +	struct xe_config_group_device *dev = to_xe_config_group_device(item);

To have consistency with other functions, we can use

struct xe_config_device *dev = to_xe_config_device(item);

> +
> +	return sprintf(page, "%d\n", dev->config.enable_psmi);
> +}
> +
> +static ssize_t enable_psmi_store(struct config_item *item, const char *page, size_t len)
> +{
> +	struct xe_config_group_device *dev = to_xe_config_group_device(item);
> +	bool val;
> +	int ret;
> +
> +	ret = kstrtobool(page, &val);
> +	if (ret)
> +		return ret;
> +
> +	mutex_lock(&dev->lock);
> +	dev->config.enable_psmi = val;
> +	mutex_unlock(&dev->lock);
> +
> +	return len;
> +}
> +
>   CONFIGFS_ATTR(, engines_allowed);
> +CONFIGFS_ATTR(, survivability_mode);
> +CONFIGFS_ATTR(, enable_psmi);

alphabetical?

Thanks
Riana

>   
>   static struct configfs_attribute *xe_config_device_attrs[] = {
> -	&attr_survivability_mode,
>   	&attr_engines_allowed,
> +	&attr_survivability_mode,
> +	&attr_enable_psmi,
>   	NULL,
>   };
>   
> @@ -443,6 +481,26 @@ u64 xe_configfs_get_engines_allowed(struct pci_dev *pdev)
>   	return engines_allowed;
>   }
>   
> +/**
> + * xe_configfs_get_psmi_enabled - get configfs enable_psmi setting
> + * @pdev: pci device
> + *
> + * Return: enable_psmi setting in configfs
> + */
> +bool xe_configfs_get_psmi_enabled(struct pci_dev *pdev)
> +{
> +	struct xe_config_group_device *dev = find_xe_config_group_device(pdev);
> +	bool ret;
> +
> +	if (!dev)
> +		return false;
> +
> +	ret = dev->config.enable_psmi;
> +	config_item_put(&dev->group.cg_item);
> +
> +	return ret;
> +}
> +
>   int __init xe_configfs_init(void)
>   {
>   	int ret;
> diff --git a/drivers/gpu/drm/xe/xe_configfs.h b/drivers/gpu/drm/xe/xe_configfs.h
> index c14588b86e833..603dd7796c8b2 100644
> --- a/drivers/gpu/drm/xe/xe_configfs.h
> +++ b/drivers/gpu/drm/xe/xe_configfs.h
> @@ -16,7 +16,7 @@ void xe_configfs_exit(void);
>   bool xe_configfs_get_survivability_mode(struct pci_dev *pdev);
>   void xe_configfs_clear_survivability_mode(struct pci_dev *pdev);
>   u64 xe_configfs_get_engines_allowed(struct pci_dev *pdev);
> -static inline bool xe_configfs_get_psmi_enabled(struct pci_dev *pdev) { return false; }
> +bool xe_configfs_get_psmi_enabled(struct pci_dev *pdev);
>   #else
>   static inline int xe_configfs_init(void) { return 0; }
>   static inline void xe_configfs_exit(void) { }
>