1// SPDX-License-Identifier: GPL-2.0 OR MIT
2/*
3 * Copyright 2014-2022 Advanced Micro Devices, Inc.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be included in
13 * all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
19 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
20 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
21 * OTHER DEALINGS IN THE SOFTWARE.
22 */
23
24#include <linux/types.h>
25#include "kfd_priv.h"
26#include "amdgpu_ids.h"
27
28static unsigned int pasid_bits = 16;
29static bool pasids_allocated; /* = false */
30
31bool kfd_set_pasid_limit(unsigned int new_limit)
32{
33	if (new_limit < 2)
34		return false;
35
36	if (new_limit < (1U << pasid_bits)) {
37		if (pasids_allocated)
38			/* We've already allocated user PASIDs, too late to
39			 * change the limit
40			 */
41			return false;
42
43		while (new_limit < (1U << pasid_bits))
44			pasid_bits--;
45	}
46
47	return true;
48}
49
50unsigned int kfd_get_pasid_limit(void)
51{
52	return 1U << pasid_bits;
53}
54
55u32 kfd_pasid_alloc(void)
56{
57	int r = amdgpu_pasid_alloc(pasid_bits);
58
59	if (r > 0) {
60		pasids_allocated = true;
61		return r;
62	}
63
64	return 0;
65}
66
67void kfd_pasid_free(u32 pasid)
68{
69	amdgpu_pasid_free(pasid);
70}
71