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

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

On Tue, Dec 02, 2025 at 08:37:09AM +0530, Riana Tauro wrote:
> 
> 
> On 12/1/2025 11:13 PM, Rodrigo Vivi wrote:
> > On Mon, Dec 01, 2025 at 08:04:23PM +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>
> > > ---
> > > v2: do not exit survivability mode in case of mei init failure (Rodrigo)
> > 
> > I still see the goto err there, what am I missing?
> > I mean, no strong feeling about what is right or wrong to do here,
> > I just want to make sure the code matches the doc and expectations...
> 
> PCODE enables FDO mode when mei has some failure and firmware flashing
> cannot be done using igsc. In FDO mode, XE KMD initializes the SPI driver.
> 
> If initialization of SPI driver fails, then user cannot update through igsc
> or using spi driver. In this case, there wouldn't be any reason to
> stay in survivability mode. The goto err is to fail probe.
> 
> I have mentioned in documentation that 'FDO is enabled only when MEI fails'.
> Is there something else i am missing?

Nevermind. I have mixed things up.
Thanks for the explanation.

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

> 
> Thanks
> Riana
> 
> > 
> > > ---
> > >   drivers/gpu/drm/xe/xe_pcode_api.h             |  2 +
> > >   drivers/gpu/drm/xe/xe_survivability_mode.c    | 44 ++++++++++++++++---
> > >   .../gpu/drm/xe/xe_survivability_mode_types.h  |  6 +++
> > >   3 files changed, 46 insertions(+), 6 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/xe/xe_pcode_api.h b/drivers/gpu/drm/xe/xe_pcode_api.h
> > > index 70dcd6625680..975892d6b230 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 b5b582442637..8d409bc9c14b 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
> > >    * =====================
> > >    *
> > > @@ -94,6 +100,8 @@ static const char * const reg_map[] = {
> > >   	[AUX_INFO4]               = "Auxiliary Info 4",
> > >   };
> > > +#define FDO_INFO	(MAX_SCRATCH_REG + 1)
> > > +
> > >   struct xe_survivability_attribute {
> > >   	struct device_attribute attr;
> > >   	u8 index;
> > > @@ -127,6 +135,11 @@ static void populate_survivability_info(struct xe_device *xe)
> > >   	set_survivability_info(mmio, info, CAPABILITY_INFO);
> > >   	reg_value = info[CAPABILITY_INFO];
> > > +	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);
> > > @@ -188,6 +201,9 @@ static ssize_t survivability_info_show(struct device *dev,
> > >   	struct xe_survivability *survivability = &xe->survivability;
> > >   	u32 *info = survivability->info;
> > > +	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]);
> > >   }
> > > @@ -205,13 +221,18 @@ 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);
> > >   }
> > > @@ -222,7 +243,10 @@ static umode_t survivability_info_attrs_visible(struct kobject *kobj, struct att
> > >   	struct xe_survivability *survivability = &xe->survivability;
> > >   	u32 *info = survivability->info;
> > > -	if (info[idx])
> > > +	/* FDO mode is visible only when supported */
> > > +	if (idx >= MAX_SCRATCH_REG && survivability->version >= 2)
> > > +		return 0400;
> > > +	else if (info[idx])
> > >   		return 0400;
> > >   	return 0;
> > > @@ -238,6 +262,7 @@ 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,
> > >   };
> > > @@ -287,12 +312,16 @@ static int enable_boot_survivability_mode(struct pci_dev *pdev)
> > >   	/* Make sure xe_heci_gsc_init() knows about survivability mode */
> > >   	survivability->mode = true;
> > > -	ret = xe_heci_gsc_init(xe);
> > > -	if (ret)
> > > -		goto err;
> > > +	xe_heci_gsc_init(xe);
> > >   	xe_vsec_init(xe);
> > > +	if (survivability->fdo_mode) {
> > > +		ret = xe_nvm_init(xe);
> > > +		if (ret)
> > > +			goto err;
> > > +	}
> > > +
> > >   	ret = xe_i2c_probe(xe);
> > >   	if (ret)
> > >   		goto err;
> > > @@ -302,6 +331,7 @@ static int enable_boot_survivability_mode(struct pci_dev *pdev)
> > >   	return 0;
> > >   err:
> > > +	dev_err(dev, "Failed to enable Survivability Mode\n");
> > >   	survivability->mode = false;
> > >   	return ret;
> > >   }
> > > @@ -408,8 +438,10 @@ int xe_survivability_mode_boot_enable(struct xe_device *xe)
> > >   	populate_survivability_info(xe);
> > > -	/* 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 f31b3907d933..bd5dc1c955ff 100644
> > > --- a/drivers/gpu/drm/xe/xe_survivability_mode_types.h
> > > +++ b/drivers/gpu/drm/xe/xe_survivability_mode_types.h
> > > @@ -44,6 +44,12 @@ 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
> > > 
>