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