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 bool pasids_allocated; /* = false */
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 (pasids_allocated)
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 u32 kfd_pasid_alloc(void)
55 {
56 	int r = amdgpu_pasid_alloc(pasid_bits);
57 
58 	if (r > 0) {
59 		pasids_allocated = true;
60 		return r;
61 	}
62 
63 	return 0;
64 }
65 
66 void kfd_pasid_free(u32 pasid)
67 {
68 	amdgpu_pasid_free(pasid);
69 }
70