Re: [PATCH 2/2] drm/xe/xe_survivability: Add support for survivability mode v2

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

On Wed, Nov 12, 2025 at 04:03:39PM +0530, Riana Tauro wrote:
> v2 survivability breadcrumbs introduces a new mode called
> SPI Flash Descriptor Override mode (FDO). This is enabled by
> PCODE when MEI itself fails and firmware cannot be updated via
> MEI using igsc. This mode provides the ability to update
> the firmware directly via SPI driver.
> 
> Xe KMD initializes the nvm aux driver if FDO mode is enabled.
> 
> Userspace should check FDO mode entry in survivability info sysfs before
> using the SPI driver to update firmware.
> 
> 	/sys/bus/pci/devices/<device>/survivability_info/fdo_mode
> 
> v2 also supports survivability mode for critical boot errors.
> 
> Signed-off-by: Riana Tauro <riana.tauro@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_pcode_api.h             |  2 +
>  drivers/gpu/drm/xe/xe_survivability_mode.c    | 41 +++++++++++++++++--
>  .../gpu/drm/xe/xe_survivability_mode_types.h  |  6 +++
>  3 files changed, 46 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_pcode_api.h b/drivers/gpu/drm/xe/xe_pcode_api.h
> index 92bfcba51e19..d41f07f9194d 100644
> --- a/drivers/gpu/drm/xe/xe_pcode_api.h
> +++ b/drivers/gpu/drm/xe/xe_pcode_api.h
> @@ -77,11 +77,13 @@
>  
>  #define PCODE_SCRATCH(x)		XE_REG(0x138320 + ((x) * 4))
>  /* PCODE_SCRATCH0 */
> +#define   BREADCRUMB_VERSION		REG_GENMASK(31, 29)
>  #define   AUXINFO_REG_OFFSET		REG_GENMASK(17, 15)
>  #define   OVERFLOW_REG_OFFSET		REG_GENMASK(14, 12)
>  #define   HISTORY_TRACKING		REG_BIT(11)
>  #define   OVERFLOW_SUPPORT		REG_BIT(10)
>  #define   AUXINFO_SUPPORT		REG_BIT(9)
> +#define   FDO_MODE			REG_BIT(4)
>  #define   BOOT_STATUS			REG_GENMASK(3, 1)
>  #define      CRITICAL_FAILURE		4
>  #define      NON_CRITICAL_FAILURE	7
> diff --git a/drivers/gpu/drm/xe/xe_survivability_mode.c b/drivers/gpu/drm/xe/xe_survivability_mode.c
> index 3d9417911c33..d22fdd08d227 100644
> --- a/drivers/gpu/drm/xe/xe_survivability_mode.c
> +++ b/drivers/gpu/drm/xe/xe_survivability_mode.c
> @@ -16,6 +16,7 @@
>  #include "xe_heci_gsc.h"
>  #include "xe_i2c.h"
>  #include "xe_mmio.h"
> +#include "xe_nvm.h"
>  #include "xe_pcode_api.h"
>  #include "xe_vsec.h"
>  
> @@ -66,6 +67,11 @@
>   *
>   * - ``aux_info<n>`` : Some failures have additional debug information
>   *
> + * - ``fdo_mode`` : To allow recovery in scenarios where MEI itself fails, a new SPI Flash
> + *   Descriptor Override (FDO) mode is added in v2 survivability breadcrumbs. This mode is enabled
> + *   by PCODE and provides the ability to directly update the firmware via SPI Driver without
> + *   any dependency on MEI. Xe KMD initializes the nvm aux driver if FDO mode is enabled.
> + *
>   * Runtime Survivability
>   * =====================
>   *
> @@ -95,6 +101,8 @@ enum scratch_reg {
>  	MAX_SCRATCH_REG,
>  };
>  
> +#define FDO_INFO	(MAX_SCRATCH_REG + 1)
> +
>  struct xe_survivability_attribute {
>  	struct device_attribute attr;
>  	u8 index;
> @@ -131,6 +139,11 @@ static void populate_survivability_info(struct xe_device *xe)
>  	set_survivability_info(mmio, info, CAPABILITY_INFO, "Capability Info");
>  	reg_value = info[CAPABILITY_INFO].value;
>  
> +	survivability->version = REG_FIELD_GET(BREADCRUMB_VERSION, reg_value);
> +	/* FDO mode is exposed only from version 2 */
> +	if (survivability->version >= 2)
> +		survivability->fdo_mode = REG_FIELD_GET(FDO_MODE, reg_value);
> +
>  	if (reg_value & HISTORY_TRACKING) {
>  		set_survivability_info(mmio, info, POSTCODE_TRACE, "Postcode Trace");
>  
> @@ -193,6 +206,9 @@ static ssize_t survivability_info_show(struct device *dev,
>  	struct xe_survivability_info *info = survivability->info;
>  	struct xe_survivability_attribute *sa = dev_attr_to_survivability_attr(attr);
>  
> +	if (sa->index == FDO_INFO)
> +		return sysfs_emit(buff, "%s\n", str_enabled_disabled(survivability->fdo_mode));
> +
>  	return sysfs_emit(buff, "0x%x\n", info[sa->index].value);
>  }
>  
> @@ -210,13 +226,18 @@ SURVIVABILITY_ATTR_RO(aux_info1, AUX_INFO1);
>  SURVIVABILITY_ATTR_RO(aux_info2, AUX_INFO2);
>  SURVIVABILITY_ATTR_RO(aux_info3, AUX_INFO3);
>  SURVIVABILITY_ATTR_RO(aux_info4, AUX_INFO4);
> +SURVIVABILITY_ATTR_RO(fdo_mode, FDO_INFO);
>  
>  static void xe_survivability_mode_fini(void *arg)
>  {
>  	struct xe_device *xe = arg;
> +	struct xe_survivability *survivability = &xe->survivability;
>  	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
>  	struct device *dev = &pdev->dev;
>  
> +	if (survivability->fdo_mode)
> +		xe_nvm_fini(xe);
> +
>  	device_remove_file(dev, &dev_attr_survivability_mode);
>  }
>  
> @@ -227,12 +248,16 @@ static umode_t survivability_info_attrs_visible(struct kobject *kobj, struct att
>  	struct xe_survivability *survivability = &xe->survivability;
>  	struct xe_survivability_info *info = survivability->info;
>  
> -	if (info[idx].value)
> +	/* FDO mode is visible only when supported */
> +	if (idx >= MAX_SCRATCH_REG && survivability->version >= 2)

should we also make the version a file inside survivability_info?
for explicit check instead of implicit?

> +		return 0400;
> +	else if (info[idx].value)
>  		return 0400;
>  
>  	return 0;
>  }
>  
> +/* Attributes are ordered according to enum scratch_reg */
>  static struct attribute *survivability_info_attrs[] = {
>  	&attr_capability_info.attr.attr,
>  	&attr_postcode_trace.attr.attr,
> @@ -242,6 +267,7 @@ static struct attribute *survivability_info_attrs[] = {
>  	&attr_aux_info2.attr.attr,
>  	&attr_aux_info3.attr.attr,
>  	&attr_aux_info4.attr.attr,
> +	&attr_fdo_mode.attr.attr,
>  	NULL,
>  };
>  
> @@ -301,11 +327,18 @@ static int enable_boot_survivability_mode(struct pci_dev *pdev)
>  	if (ret)
>  		goto err;
>  
> +	if (survivability->fdo_mode) {
> +		ret = xe_nvm_init(xe);
> +		if (ret)
> +			goto err;

should we really fail the survivability mode here?
Or keep the survivability mode with some indication that fdo/nvm has failed?

> +	}
> +
>  	dev_err(dev, "In Survivability Mode\n");
>  
>  	return 0;
>  
>  err:
> +	dev_err(dev, "Failed to enable Survivability Mode\n");
>  	survivability->mode = false;
>  	return ret;
>  }
> @@ -436,8 +469,10 @@ int xe_survivability_mode_boot_enable(struct xe_device *xe)
>  	if (ret)
>  		return ret;
>  
> -	/* Log breadcrumbs but do not enter survivability mode for Critical boot errors */
> -	if (survivability->boot_status == CRITICAL_FAILURE) {
> +	/*
> +	 * v2 supports survivability mode for critical errors
> +	 */
> +	if (survivability->version < 2  && survivability->boot_status == CRITICAL_FAILURE) {
>  		log_survivability_info(pdev);
>  		return -ENXIO;
>  	}
> diff --git a/drivers/gpu/drm/xe/xe_survivability_mode_types.h b/drivers/gpu/drm/xe/xe_survivability_mode_types.h
> index 1ed122cf62f2..d887b443b397 100644
> --- a/drivers/gpu/drm/xe/xe_survivability_mode_types.h
> +++ b/drivers/gpu/drm/xe/xe_survivability_mode_types.h
> @@ -37,6 +37,12 @@ struct xe_survivability {
>  
>  	/** @type: survivability type */
>  	enum xe_survivability_type type;
> +
> +	/** @fdo_mode: indicates if FDO mode is enabled */
> +	bool fdo_mode;
> +
> +	/** @version: breadcrumb version of survivability mode  */
> +	u8 version;
>  };
>  
>  #endif /* _XE_SURVIVABILITY_MODE_TYPES_H_ */
> -- 
> 2.47.1
>