Re: [PATCH 05/15] drm/xe: Make survivability_mode configfs attribute a bitmap

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Mon, Oct 05, 2026 at 10:06:41PM +0000, Stuart Summers wrote:
> Survivability mode is likely to grow additional independently selectable
> behaviors, so store it as a u8 bitmap rather than a bool. Only bit 0 is
> defined, so the accepted values are unchanged.
> 
> Signed-off-by: Stuart Summers <stuart.summers@intel.com>

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

> Assisted-by: LLM
> ---
>  drivers/gpu/drm/xe/xe_configfs.c           | 25 +++++++++++++---------
>  drivers/gpu/drm/xe/xe_configfs.h           | 16 ++++++++++++--
>  drivers/gpu/drm/xe/xe_survivability_mode.c |  7 +++---
>  3 files changed, 33 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_configfs.c b/drivers/gpu/drm/xe/xe_configfs.c
> index 0ccf163306fc..a16e2f48b01a 100644
> --- a/drivers/gpu/drm/xe/xe_configfs.c
> +++ b/drivers/gpu/drm/xe/xe_configfs.c
> @@ -78,8 +78,10 @@
>   * Survivability mode:
>   * -------------------
>   *
> - * Enable survivability mode on supported cards. This setting only takes
> - * effect when probing the device. Example to enable it::
> + * Enable survivability mode on supported cards. This is a bitmap; bit 0
> + * enables survivability mode and is currently the only bit defined, so the
> + * only accepted values remain 0 and 1. This setting only takes effect when
> + * probing the device. Example to enable it::
>   *
>   *	# echo 1 > /sys/kernel/config/xe/0000:03:00.0/survivability_mode
>   *
> @@ -301,7 +303,7 @@ struct xe_config_group_device {
>  		u32 migrate_ulls_period_ms;
>  		struct wa_bb ctx_restore_post_bb[XE_ENGINE_CLASS_MAX];
>  		struct wa_bb ctx_restore_mid_bb[XE_ENGINE_CLASS_MAX];
> -		bool survivability_mode;
> +		u8 survivability_mode;
>  		bool enable_psmi;
>  		bool enable_multi_queue;
>  		bool enable_vram_page_offline;
> @@ -323,7 +325,7 @@ static const struct xe_config_device device_defaults = {
>  	.gt_types_allowed = U64_MAX,
>  	.engines_allowed = U64_MAX,
>  	.migrate_ulls_period_ms = 5,
> -	.survivability_mode = false,
> +	.survivability_mode = 0,
>  	.enable_psmi = false,
>  	.enable_multi_queue = true,
>  	.enable_vram_page_offline = true,
> @@ -407,19 +409,22 @@ static ssize_t survivability_mode_show(struct config_item *item, char *page)
>  {
>  	struct xe_config_device *dev = to_xe_config_device(item);
>  
> -	return sprintf(page, "%d\n", dev->survivability_mode);
> +	return sprintf(page, "%u\n", dev->survivability_mode);
>  }
>  
>  static ssize_t survivability_mode_store(struct config_item *item, const char *page, size_t len)
>  {
>  	struct xe_config_group_device *dev = to_xe_config_group_device(item);
> -	bool survivability_mode;
> +	u8 survivability_mode;
>  	int ret;
>  
> -	ret = kstrtobool(page, &survivability_mode);
> +	ret = kstrtou8(page, 0, &survivability_mode);
>  	if (ret)
>  		return ret;
>  
> +	if (survivability_mode & ~XE_CONFIGFS_SURVIVABILITY_MASK)
> +		return -EINVAL;
> +
>  	guard(mutex)(&dev->lock);
>  	if (is_bound(dev))
>  		return -EBUSY;
> @@ -1243,7 +1248,7 @@ static void dump_custom_dev_config(struct pci_dev *pdev,
>  	PRI_CUSTOM_ATTR("%d", enable_multi_queue);
>  	PRI_CUSTOM_ATTR("%d", enable_psmi);
>  	PRI_CUSTOM_ATTR("%d", enable_vram_page_offline);
> -	PRI_CUSTOM_ATTR("%d", survivability_mode);
> +	PRI_CUSTOM_ATTR("%u", survivability_mode);
>  	PRI_CUSTOM_ATTR("%u", sriov.admin_only_pf);
>  
>  #undef PRI_CUSTOM_ATTR
> @@ -1278,10 +1283,10 @@ void xe_configfs_check_device(struct pci_dev *pdev)
>   *
>   * Return: survivability_mode attribute in configfs
>   */
> -bool xe_configfs_get_survivability_mode(struct pci_dev *pdev)
> +u8 xe_configfs_get_survivability_mode(struct pci_dev *pdev)
>  {
>  	struct xe_config_group_device *dev = find_xe_config_group_device(pdev);
> -	bool mode;
> +	u8 mode;
>  
>  	if (!dev)
>  		return device_defaults.survivability_mode;
> diff --git a/drivers/gpu/drm/xe/xe_configfs.h b/drivers/gpu/drm/xe/xe_configfs.h
> index 1d538ce0ed2c..a5c081fc1672 100644
> --- a/drivers/gpu/drm/xe/xe_configfs.h
> +++ b/drivers/gpu/drm/xe/xe_configfs.h
> @@ -5,6 +5,7 @@
>  #ifndef _XE_CONFIGFS_H_
>  #define _XE_CONFIGFS_H_
>  
> +#include <linux/bits.h>
>  #include <linux/limits.h>
>  #include <linux/types.h>
>  
> @@ -14,11 +15,22 @@
>  
>  struct pci_dev;
>  
> +/**
> + * DOC: survivability_mode configfs bits
> + *
> + * The survivability_mode attribute is a bitmap so that additional
> + * survivability behaviors can be requested independently in the future.
> + * %XE_CONFIGFS_SURVIVABILITY_ENABLE is currently the only defined bit, so
> + * the attribute still only accepts 0 and 1.
> + */
> +#define XE_CONFIGFS_SURVIVABILITY_ENABLE	BIT(0)
> +#define XE_CONFIGFS_SURVIVABILITY_MASK		XE_CONFIGFS_SURVIVABILITY_ENABLE
> +
>  #if IS_ENABLED(CONFIG_CONFIGFS_FS)
>  int xe_configfs_init(void);
>  void xe_configfs_exit(void);
>  void xe_configfs_check_device(struct pci_dev *pdev);
> -bool xe_configfs_get_survivability_mode(struct pci_dev *pdev);
> +u8 xe_configfs_get_survivability_mode(struct pci_dev *pdev);
>  bool xe_configfs_primary_gt_allowed(struct pci_dev *pdev);
>  bool xe_configfs_media_gt_allowed(struct pci_dev *pdev);
>  u64 xe_configfs_get_engines_allowed(struct pci_dev *pdev);
> @@ -40,7 +52,7 @@ bool xe_configfs_admin_only_pf(struct pci_dev *pdev);
>  static inline int xe_configfs_init(void) { return 0; }
>  static inline void xe_configfs_exit(void) { }
>  static inline void xe_configfs_check_device(struct pci_dev *pdev) { }
> -static inline bool xe_configfs_get_survivability_mode(struct pci_dev *pdev) { return false; }
> +static inline u8 xe_configfs_get_survivability_mode(struct pci_dev *pdev) { return 0; }
>  static inline bool xe_configfs_primary_gt_allowed(struct pci_dev *pdev) { return true; }
>  static inline bool xe_configfs_media_gt_allowed(struct pci_dev *pdev) { return true; }
>  static inline u64 xe_configfs_get_engines_allowed(struct pci_dev *pdev) { return U64_MAX; }
> diff --git a/drivers/gpu/drm/xe/xe_survivability_mode.c b/drivers/gpu/drm/xe/xe_survivability_mode.c
> index 45d44ebe288b..3b96097f6ee6 100644
> --- a/drivers/gpu/drm/xe/xe_survivability_mode.c
> +++ b/drivers/gpu/drm/xe/xe_survivability_mode.c
> @@ -306,7 +306,8 @@ static const struct attribute_group survivability_info_group = {
>  static int create_survivability_sysfs(struct pci_dev *pdev)
>  {
>  	/* Survivability info is required if not enabled via configfs */
> -	bool needs_info = !xe_configfs_get_survivability_mode(pdev);
> +	bool needs_info = !(xe_configfs_get_survivability_mode(pdev) &
> +			    XE_CONFIGFS_SURVIVABILITY_ENABLE);
>  	struct xe_device *xe = pdev_to_xe_device(pdev);
>  	struct device *dev = &pdev->dev;
>  	int ret;
> @@ -405,14 +406,14 @@ bool xe_survivability_mode_is_requested(struct xe_device *xe)
>  	struct xe_mmio *mmio = xe_root_tile_mmio(xe);
>  	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
>  	u32 data;
> -	bool survivability_mode;
> +	u8 survivability_mode;
>  
>  	if (!IS_DGFX(xe) || IS_SRIOV_VF(xe) || xe->info.platform < XE_BATTLEMAGE)
>  		return false;
>  
>  	survivability_mode = xe_configfs_get_survivability_mode(pdev);
>  	/* Enable survivability mode if set via configfs */
> -	if (survivability_mode)
> +	if (survivability_mode & XE_CONFIGFS_SURVIVABILITY_ENABLE)
>  		return true;
>  
>  	data = xe_mmio_read32(mmio, PCODE_SCRATCH(0));
> -- 
> 2.43.0
>