Commit 58b51df8 authored by Lucas De Marchi's avatar Lucas De Marchi
Browse files

drm/xe: Allow to disable engines 



Sometimes it's useful to load the driver with a smaller set of engines
to allow more targeted debugging, particularly on early enabling.

Besides checking what is fused off in hardware, add similar logic to
disable engines in software. This will use configfs to allow users
to set what engine to disable, so already add prepare for that. The
exact configfs interface will be added later.

Reviewed-by: default avatarMatt Roper <matthew.d.roper@intel.com>
Link: https://lore.kernel.org/r/20250528-engine-mask-v4-3-f4636d2a890a@intel.com


Signed-off-by: default avatarLucas De Marchi <lucas.demarchi@intel.com>
parent 2b0ef1f7

drivers/gpu/drm/xe/xe_configfs.c

+15 −0
Original line number Diff line number Diff line
@@ -226,6 +226,21 @@ void xe_configfs_clear_survivability_mode(struct pci_dev *pdev) 
	config_item_put(&dev->group.cg_item);

}



/**

 * xe_configfs_get_engines_allowed - get engine allowed mask from configfs

 * @pdev: pci device

 *

 * Find the configfs group that belongs to the pci device and return

 * the mask of engines allowed to be used.

 *

 * Return: engine mask with allowed engines

 */

u64 xe_configfs_get_engines_allowed(struct pci_dev *pdev)

{

	/* dummy implementation */

	return U64_MAX;

}



int __init xe_configfs_init(void)

{

	struct config_group *root = &xe_configfs.su_group;

drivers/gpu/drm/xe/xe_configfs.h

+3 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
#ifndef _XE_CONFIGFS_H_

#define _XE_CONFIGFS_H_



#include <linux/limits.h>

#include <linux/types.h>



struct pci_dev;
@@ -14,11 +15,13 @@ int xe_configfs_init(void); 
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);

#else

static inline int xe_configfs_init(void) { return 0; }

static inline void xe_configfs_exit(void) { }

static inline bool xe_configfs_get_survivability_mode(struct pci_dev *pdev) { return false; }

static inline void xe_configfs_clear_survivability_mode(struct pci_dev *pdev) { }

static inline u64 xe_configfs_get_engines_allowed(struct pci_dev *pdev) { return U64_MAX; }

#endif



#endif

drivers/gpu/drm/xe/xe_hw_engine.c

+20 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include "regs/xe_irq_regs.h"

#include "xe_assert.h"

#include "xe_bo.h"

#include "xe_configfs.h"

#include "xe_device.h"

#include "xe_execlist.h"

#include "xe_force_wake.h"
@@ -805,6 +806,24 @@ static void check_gsc_availability(struct xe_gt *gt) 
	}

}



static void check_sw_disable(struct xe_gt *gt)

{

	struct xe_device *xe = gt_to_xe(gt);

	u64 sw_allowed = xe_configfs_get_engines_allowed(to_pci_dev(xe->drm.dev));

	enum xe_hw_engine_id id;



	for (id = 0; id < XE_NUM_HW_ENGINES; ++id) {

		if (!(gt->info.engine_mask & BIT(id)))

			continue;



		if (!(sw_allowed & BIT(id))) {

			gt->info.engine_mask &= ~BIT(id);

			xe_gt_info(gt, "%s disabled via configfs\n",

				   engine_infos[id].name);

		}

	}

}



int xe_hw_engines_init_early(struct xe_gt *gt)

{

	int i;
@@ -813,6 +832,7 @@ int xe_hw_engines_init_early(struct xe_gt *gt) 
	read_copy_fuses(gt);

	read_compute_fuses(gt);

	check_gsc_availability(gt);

	check_sw_disable(gt);



	BUILD_BUG_ON(XE_HW_ENGINE_PREEMPT_TIMEOUT < XE_HW_ENGINE_PREEMPT_TIMEOUT_MIN);

	BUILD_BUG_ON(XE_HW_ENGINE_PREEMPT_TIMEOUT > XE_HW_ENGINE_PREEMPT_TIMEOUT_MAX);