drivers/misc/habanalabs/asid.c

// SPDX-License-Identifier: GPL-2.0

/*
 * Copyright 2016-2019 HabanaLabs, Ltd.
 * All Rights Reserved.
 */

#include "habanalabs.h"

#include <linux/slab.h>

int hl_asid_init(struct hl_device *hdev)
{
	hdev->asid_bitmap = kcalloc(BITS_TO_LONGS(hdev->asic_prop.max_asid),
					sizeof(*hdev->asid_bitmap), GFP_KERNEL);
	if (!hdev->asid_bitmap)
		return -ENOMEM;

	mutex_init(&hdev->asid_mutex);

	/* ASID 0 is reserved for the kernel driver and device CPU */
	set_bit(0, hdev->asid_bitmap);

	return 0;
}

void hl_asid_fini(struct hl_device *hdev)
{
	mutex_destroy(&hdev->asid_mutex);
	kfree(hdev->asid_bitmap);
}

unsigned long hl_asid_alloc(struct hl_device *hdev)
{
	unsigned long found;

	mutex_lock(&hdev->asid_mutex);

	found = find_first_zero_bit(hdev->asid_bitmap,
					hdev->asic_prop.max_asid);
	if (found == hdev->asic_prop.max_asid)
		found = 0;
	else
		set_bit(found, hdev->asid_bitmap);

	mutex_unlock(&hdev->asid_mutex);

	return found;
}

void hl_asid_free(struct hl_device *hdev, unsigned long asid)
{
	if (WARN((asid == 0 || asid >= hdev->asic_prop.max_asid),
						"Invalid ASID %lu", asid))
		return;
	clear_bit(asid, hdev->asid_bitmap);
}