Re: [PATCH v6 2/3] drm/xe: Enable Boot Survivability mode

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

Hi Satyanarayana

Thanks for the review comments

On 1/29/2025 12:57 PM, K V P, Satyanarayana wrote:
>> From: Intel-xe <intel-xe-bounces@lists.freedesktop.org> On Behalf Of Riana
>> Tauro
>> Sent: Tuesday, January 28, 2025 3:27 PM
>> To: intel-xe@lists.freedesktop.org
>> Cc: Tauro, Riana <riana.tauro@intel.com>; Gupta, Anshuman
>> <anshuman.gupta@intel.com>; Vivi, Rodrigo <rodrigo.vivi@intel.com>
>> Subject: [PATCH v6 2/3] drm/xe: Enable Boot Survivability mode
>>
>> Enable boot survivability mode if pcode initialization fails and
>> if boot status indicates a failure. In this mode, drm card is not
>> exposed and driver probe returns success after loading the bare minimum
>> to allow firmware to be flashed via mei.
>>
>> v2: abstract survivability mode variable
>>      add BMG check inside function (Jani, Rodrigo)
>>
>> v3: return -EBUSY during system suspend (Anshuman)
>>      check survivability mode in pci probe only
>>      on error
>>
>> Signed-off-by: Riana Tauro <riana.tauro@intel.com>
>> Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
>> ---
>>   drivers/gpu/drm/xe/xe_device.c             |  7 ++++++-
>>   drivers/gpu/drm/xe/xe_pci.c                | 23 ++++++++++++++++++++--
>>   drivers/gpu/drm/xe/xe_survivability_mode.c | 16 +++++++++++++++
>>   drivers/gpu/drm/xe/xe_survivability_mode.h |  1 +
>>   4 files changed, 44 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
>> index f3f754beb812..8fedc72e9db4 100644
>> --- a/drivers/gpu/drm/xe/xe_device.c
>> +++ b/drivers/gpu/drm/xe/xe_device.c
>> @@ -52,6 +52,7 @@
>>   #include "xe_pmu.h"
>>   #include "xe_query.h"
>>   #include "xe_sriov.h"
>> +#include "xe_survivability_mode.h"
>>   #include "xe_tile.h"
>>   #include "xe_ttm_stolen_mgr.h"
>>   #include "xe_ttm_sys_mgr.h"
>> @@ -693,8 +694,12 @@ int xe_device_probe_early(struct xe_device *xe)
>>   	update_device_info(xe);
>>
>>   	err = xe_pcode_probe_early(xe);
>> -	if (err)
>> +	if (err) {
>> +		if (xe_survivability_mode_required(xe))
>> +			xe_survivability_mode_init(xe);
>> +
>>   		return err;
>> +	}
>>
>>   	err = wait_for_lmem_ready(xe);
>>   	if (err)
>> diff --git a/drivers/gpu/drm/xe/xe_pci.c b/drivers/gpu/drm/xe/xe_pci.c
>> index e6ad189294c1..b483c5c90132 100644
>> --- a/drivers/gpu/drm/xe/xe_pci.c
>> +++ b/drivers/gpu/drm/xe/xe_pci.c
>> @@ -30,6 +30,7 @@
>>   #include "xe_pm.h"
>>   #include "xe_sriov.h"
>>   #include "xe_step.h"
>> +#include "xe_survivability_mode.h"
>>   #include "xe_tile.h"
>>
>>   enum toggle_d3cold {
>> @@ -766,6 +767,9 @@ static void xe_pci_remove(struct pci_dev *pdev)
>>   	if (IS_SRIOV_PF(xe))
>>   		xe_pci_sriov_configure(pdev, 0);
>>
>> +	if (xe_survivability_mode_enabled(xe))
>> +		return xe_survivability_mode_remove(xe);
>> +
>>   	xe_device_remove(xe);
>>   	xe_pm_runtime_fini(xe);
>>   	pci_set_drvdata(pdev, NULL);
>> @@ -838,8 +842,19 @@ static int xe_pci_probe(struct pci_dev *pdev, const
>> struct pci_device_id *ent)
>>   		return err;
>>
>>   	err = xe_device_probe_early(xe);
>> -	if (err)
>> +
>> +	/*
>> +	 * In Boot Survivability mode, no drm card is exposed
>> +	 * and driver is loaded with bare minimum to allow
>> +	 * for firmware to be flashed through mei. Return
>> +	 * success if survivability mode is enabled.
>> +	 */
>> +	if (err) {
>> +		if (xe_survivability_mode_enabled(xe))
>> +			return 0;
>> +
>>   		return err;
>> +	}
>>
>>   	err = xe_info_init(xe, desc->graphics, desc->media);
>>   	if (err)
>> @@ -926,9 +941,13 @@ static void d3cold_toggle(struct pci_dev *pdev,
>> enum toggle_d3cold toggle)
>>   static int xe_pci_suspend(struct device *dev)
>>   {
>>   	struct pci_dev *pdev = to_pci_dev(dev);
>> +	struct xe_device *xe = pdev_to_xe_device(pdev);
>>   	int err;
>>
>> -	err = xe_pm_suspend(pdev_to_xe_device(pdev));
>> +	if (xe_survivability_mode_enabled(xe))
>> +		return -EBUSY;
>> +
>> +	err = xe_pm_suspend(xe);
>>   	if (err)
>>   		return err;
>>
>> diff --git a/drivers/gpu/drm/xe/xe_survivability_mode.c
>> b/drivers/gpu/drm/xe/xe_survivability_mode.c
>> index 9911e9f6b99b..633f5effa349 100644
>> --- a/drivers/gpu/drm/xe/xe_survivability_mode.c
>> +++ b/drivers/gpu/drm/xe/xe_survivability_mode.c
>> @@ -144,6 +144,19 @@ static void enable_survivability_mode(struct pci_dev
>> *pdev)
>>   	}
>>   }
>>
>> +/**
>> + * xe_survivability_mode_enabled - check if survivability mode is enabled
>> + * @xe: xe device instance
>> + *
>> + * Returns true if in survivability mode, false otherwise
>> + */
>> +bool xe_survivability_mode_enabled(struct xe_device *xe)
>> +{
>> +	struct xe_survivability *survivability = &xe->survivability;
>> +
>> +	return survivability->mode;
>> +}
>> +
>>   /**
>>    * xe_survivability_mode_required - checks if survivability mode is required
>>    * @xe: xe device instance
>> @@ -158,6 +171,9 @@ bool xe_survivability_mode_required(struct
>> xe_device *xe)
>>   	struct xe_mmio *mmio = xe_root_tile_mmio(xe);
>>   	u32 data;
>>
>> +	if (!IS_DGFX(xe) || xe->info.platform < XE_BATTLEMAGE)
>> +		return false;
>> +
> 
> The survivability mode is not needed in case VF. Make sure to return false in case of VF as well.
> if (!IS_DGFX(xe) || xe->info.platform < XE_BATTLEMAGE || IS_SRIOV_VF(xe))
> 	return false;

As discussed offline, survivability mode is set only when pcode 
initialization fails. So if it fails for PF, it will not continue with 
sriov_init.

Thanks
Riana
> 
>>   	data = xe_mmio_read32(mmio, PCODE_SCRATCH(0));
>>   	survivability->boot_status = REG_FIELD_GET(BOOT_STATUS, data);
>>
>> diff --git a/drivers/gpu/drm/xe/xe_survivability_mode.h
>> b/drivers/gpu/drm/xe/xe_survivability_mode.h
>> index 410e3ee5f5d1..f530507a22c6 100644
>> --- a/drivers/gpu/drm/xe/xe_survivability_mode.h
>> +++ b/drivers/gpu/drm/xe/xe_survivability_mode.h
>> @@ -12,6 +12,7 @@ struct xe_device;
>>
>>   void xe_survivability_mode_init(struct xe_device *xe);
>>   void xe_survivability_mode_remove(struct xe_device *xe);
>> +bool xe_survivability_mode_enabled(struct xe_device *xe);
>>   bool xe_survivability_mode_required(struct xe_device *xe);
>>
>>   #endif /* _XE_SURVIVABILITY_MODE_H_ */
>> --
>> 2.47.1
>