Commit 78e2701a authored by Niranjana Vishwanathapura's avatar Niranjana Vishwanathapura Committed by Rodrigo Vivi
Browse files

drm/xe: Avoid any races around ccs_mode update 



Ensure that there are no drm clients when changing CCS mode.
Allow exec_queue creation only with enabled CCS engines.

v2: Rebase

Reviewed-by: default avatarAndi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: default avatarNiranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Signed-off-by: default avatarRodrigo Vivi <rodrigo.vivi@intel.com>
parent f3bc5bb4

drivers/gpu/drm/xe/xe_device.c

+9 −0
Original line number Diff line number Diff line
@@ -73,6 +73,10 @@ static int xe_file_open(struct drm_device *dev, struct drm_file *file) 
	mutex_init(&xef->exec_queue.lock);

	xa_init_flags(&xef->exec_queue.xa, XA_FLAGS_ALLOC1);



	spin_lock(&xe->clients.lock);

	xe->clients.count++;

	spin_unlock(&xe->clients.lock);



	file->driver_priv = xef;

	return 0;

}
@@ -105,6 +109,10 @@ static void xe_file_close(struct drm_device *dev, struct drm_file *file) 
	xa_destroy(&xef->vm.xa);

	mutex_destroy(&xef->vm.lock);



	spin_lock(&xe->clients.lock);

	xe->clients.count--;

	spin_unlock(&xe->clients.lock);



	xe_drm_client_put(xef->client);

	kfree(xef);

}
@@ -225,6 +233,7 @@ struct xe_device *xe_device_create(struct pci_dev *pdev, 
	xe->info.force_execlist = xe_modparam.force_execlist;



	spin_lock_init(&xe->irq.lock);

	spin_lock_init(&xe->clients.lock);



	init_waitqueue_head(&xe->ufence_wq);

drivers/gpu/drm/xe/xe_device_types.h

+9 −0
Original line number Diff line number Diff line
@@ -310,6 +310,15 @@ struct xe_device { 
		enum xe_sriov_mode __mode;

	} sriov;



	/** @clients: drm clients info */

	struct {

		/** @lock: Protects drm clients info */

		spinlock_t lock;



		/** @count: number of drm clients */

		u64 count;

	} clients;



	/** @usm: unified memory state */

	struct {

		/** @asid: convert a ASID to VM */

drivers/gpu/drm/xe/xe_gt_ccs_mode.c

+10 −0
Original line number Diff line number Diff line
@@ -105,6 +105,7 @@ ccs_mode_store(struct device *kdev, struct device_attribute *attr, 
	       const char *buff, size_t count)

{

	struct xe_gt *gt = kobj_to_gt(&kdev->kobj);

	struct xe_device *xe = gt_to_xe(gt);

	u32 num_engines, num_slices;

	int ret;
@@ -123,12 +124,21 @@ ccs_mode_store(struct device *kdev, struct device_attribute *attr, 
		return -EINVAL;

	}



	/* CCS mode can only be updated when there are no drm clients */

	spin_lock(&xe->clients.lock);

	if (xe->clients.count) {

		spin_unlock(&xe->clients.lock);

		return -EBUSY;

	}



	if (gt->ccs_mode != num_engines) {

		xe_gt_info(gt, "Setting compute mode to %d\n", num_engines);

		gt->ccs_mode = num_engines;

		xe_gt_reset_async(gt);

	}



	spin_unlock(&xe->clients.lock);



	return count;

}