| Oded Gabbay | 19f6d2a | 2014-07-16 23:25:31 +0300 | [diff] [blame^] | 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/slab.h> |
| 24 | #include <linux/types.h> |
| 25 | #include "kfd_priv.h" |
| 26 | |
| 27 | static unsigned long *pasid_bitmap; |
| 28 | static unsigned int pasid_limit; |
| 29 | static DEFINE_MUTEX(pasid_mutex); |
| 30 | |
| 31 | int kfd_pasid_init(void) |
| 32 | { |
| 33 | pasid_limit = max_num_of_processes; |
| 34 | |
| 35 | pasid_bitmap = kzalloc(DIV_ROUND_UP(pasid_limit, BITS_PER_BYTE), |
| 36 | GFP_KERNEL); |
| 37 | if (!pasid_bitmap) |
| 38 | return -ENOMEM; |
| 39 | |
| 40 | set_bit(0, pasid_bitmap); /* PASID 0 is reserved. */ |
| 41 | |
| 42 | return 0; |
| 43 | } |
| 44 | |
| 45 | void kfd_pasid_exit(void) |
| 46 | { |
| 47 | kfree(pasid_bitmap); |
| 48 | } |
| 49 | |
| 50 | bool kfd_set_pasid_limit(unsigned int new_limit) |
| 51 | { |
| 52 | if (new_limit < pasid_limit) { |
| 53 | bool ok; |
| 54 | |
| 55 | mutex_lock(&pasid_mutex); |
| 56 | |
| 57 | /* ensure that no pasids >= new_limit are in-use */ |
| 58 | ok = (find_next_bit(pasid_bitmap, pasid_limit, new_limit) == |
| 59 | pasid_limit); |
| 60 | if (ok) |
| 61 | pasid_limit = new_limit; |
| 62 | |
| 63 | mutex_unlock(&pasid_mutex); |
| 64 | |
| 65 | return ok; |
| 66 | } |
| 67 | |
| 68 | return true; |
| 69 | } |
| 70 | |
| 71 | inline unsigned int kfd_get_pasid_limit(void) |
| 72 | { |
| 73 | return pasid_limit; |
| 74 | } |
| 75 | |
| 76 | unsigned int kfd_pasid_alloc(void) |
| 77 | { |
| 78 | unsigned int found; |
| 79 | |
| 80 | mutex_lock(&pasid_mutex); |
| 81 | |
| 82 | found = find_first_zero_bit(pasid_bitmap, pasid_limit); |
| 83 | if (found == pasid_limit) |
| 84 | found = 0; |
| 85 | else |
| 86 | set_bit(found, pasid_bitmap); |
| 87 | |
| 88 | mutex_unlock(&pasid_mutex); |
| 89 | |
| 90 | return found; |
| 91 | } |
| 92 | |
| 93 | void kfd_pasid_free(unsigned int pasid) |
| 94 | { |
| 95 | BUG_ON(pasid == 0 || pasid >= pasid_limit); |
| 96 | clear_bit(pasid, pasid_bitmap); |
| 97 | } |