2 * Copyright 2014 Advanced Micro Devices, Inc.
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:
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
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
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19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20 * OTHER DEALINGS IN THE SOFTWARE.
23 #include <linux/slab.h>
24 #include <linux/types.h>
27 static unsigned long *pasid_bitmap;
28 static unsigned int pasid_limit;
29 static DEFINE_MUTEX(pasid_mutex);
31 int kfd_pasid_init(void)
33 pasid_limit = KFD_MAX_NUM_OF_PROCESSES;
35 pasid_bitmap = kcalloc(BITS_TO_LONGS(pasid_limit), sizeof(long),
40 set_bit(0, pasid_bitmap); /* PASID 0 is reserved. */
45 void kfd_pasid_exit(void)
50 bool kfd_set_pasid_limit(unsigned int new_limit)
52 if (new_limit < pasid_limit) {
55 mutex_lock(&pasid_mutex);
57 /* ensure that no pasids >= new_limit are in-use */
58 ok = (find_next_bit(pasid_bitmap, pasid_limit, new_limit) ==
61 pasid_limit = new_limit;
63 mutex_unlock(&pasid_mutex);
71 inline unsigned int kfd_get_pasid_limit(void)
76 unsigned int kfd_pasid_alloc(void)
80 mutex_lock(&pasid_mutex);
82 found = find_first_zero_bit(pasid_bitmap, pasid_limit);
83 if (found == pasid_limit)
86 set_bit(found, pasid_bitmap);
88 mutex_unlock(&pasid_mutex);
93 void kfd_pasid_free(unsigned int pasid)
95 if (!WARN_ON(pasid == 0 || pasid >= pasid_limit))
96 clear_bit(pasid, pasid_bitmap);