1/*	$NetBSD: kfd_pasid.c,v 1.3 2021/12/18 23:44:59 riastradh Exp $	*/
2
3/*
4 * Copyright 2014 Advanced Micro Devices, Inc.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22 * OTHER DEALINGS IN THE SOFTWARE.
23 */
24
25#include <sys/cdefs.h>
26__KERNEL_RCSID(0, "$NetBSD: kfd_pasid.c,v 1.3 2021/12/18 23:44:59 riastradh Exp $");
27
28#include <linux/types.h>
29#include "kfd_priv.h"
30#include "amdgpu_ids.h"
31
32static unsigned int pasid_bits = 16;
33static const struct kfd2kgd_calls *kfd2kgd;
34
35bool kfd_set_pasid_limit(unsigned int new_limit)
36{
37	if (new_limit < 2)
38		return false;
39
40	if (new_limit < (1U << pasid_bits)) {
41		if (kfd2kgd)
42			/* We've already allocated user PASIDs, too late to
43			 * change the limit
44			 */
45			return false;
46
47		while (new_limit < (1U << pasid_bits))
48			pasid_bits--;
49	}
50
51	return true;
52}
53
54unsigned int kfd_get_pasid_limit(void)
55{
56	return 1U << pasid_bits;
57}
58
59unsigned int kfd_pasid_alloc(void)
60{
61	int r;
62
63	/* Find the first best KFD device for calling KGD */
64	if (!kfd2kgd) {
65		struct kfd_dev *dev = NULL;
66		unsigned int i = 0;
67
68		while ((kfd_topology_enum_kfd_devices(i, &dev)) == 0) {
69			if (dev && dev->kfd2kgd) {
70				kfd2kgd = dev->kfd2kgd;
71				break;
72			}
73			i++;
74		}
75
76		if (!kfd2kgd)
77			return false;
78	}
79
80	r = amdgpu_pasid_alloc(pasid_bits);
81
82	return r > 0 ? r : 0;
83}
84
85void kfd_pasid_free(unsigned int pasid)
86{
87	if (kfd2kgd)
88		amdgpu_pasid_free(pasid);
89}
90