| | 1 | /* |
| | 2 | * Copyright (c) 2020 Apple Inc. All rights reserved. |
| | 3 | * |
| | 4 | * @APPLE_LICENSE_HEADER_START@ |
| | 5 | * |
| | 6 | * This file contains Original Code and/or Modifications of Original Code |
| | 7 | * as defined in and that are subject to the Apple Public Source License |
| | 8 | * Version 2.0 (the 'License'). You may not use this file except in |
| | 9 | * compliance with the License. Please obtain a copy of the License at |
| | 10 | * http://www.opensource.apple.com/apsl/ and read it before using this |
| | 11 | * file. |
| | 12 | * |
| | 13 | * The Original Code and all software distributed under the License are |
| | 14 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER |
| | 15 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
| | 16 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, |
| | 17 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. |
| | 18 | * Please see the License for the specific language governing rights and |
| | 19 | * limitations under the License. |
| | 20 | * |
| | 21 | * @APPLE_LICENSE_HEADER_END@ |
| | 22 | */ |
| | 23 | |
| | 24 | #ifndef log_mem_h |
| | 25 | #define log_mem_h |
| | 26 | |
| | 27 | #include <stddef.h> |
| | 28 | #include <stdint.h> |
| | 29 | |
| | 30 | /* |
| | 31 | * A simple allocator on a top of a plain byte array. Primarily intended to |
| | 32 | * support OS kernel logging in order to avoid dependency to VM. |
| | 33 | */ |
| | 34 | typedef struct logmem_s { |
| | 35 | lck_spin_t *lm_lock; |
| | 36 | uint8_t *lm_mem; |
| | 37 | uint8_t *lm_mem_map; |
| | 38 | size_t lm_cap_order; |
| | 39 | size_t lm_min_order; |
| | 40 | size_t lm_max_order; |
| | 41 | uint32_t lm_cnt_allocations; |
| | 42 | uint32_t lm_cnt_failed_size; |
| | 43 | uint32_t lm_cnt_failed_full; |
| | 44 | uint32_t lm_cnt_free; |
| | 45 | } logmem_t; |
| | 46 | |
| | 47 | /* |
| | 48 | * Static initializer for global instances of logmem. Size order defines the |
| | 49 | * total amount of logmem memory, the min and max order set the minimum and the |
| | 50 | * maximum size respectively of the memory allocatable by the given logmem. |
| | 51 | * Local or dynamically allocated instances of logmem should not be initialized |
| | 52 | * by this macro. |
| | 53 | */ |
| | 54 | #define LOGMEM_STATIC_INIT(name, size_order, min_order, max_order) \ |
| | 55 | SIMPLE_LOCK_DECLARE(name##_lck, 0); \ |
| | 56 | logmem_t name = { \ |
| | 57 | .lm_lock = (lck_spin_t *)&name##_lck, \ |
| | 58 | .lm_mem = (uint8_t[(1 << (size_order))]){ 0 }, \ |
| | 59 | .lm_mem_map = (uint8_t[MAX(1, (1 << ((size_order) - (min_order) + 1)) / 8)]){ 0 }, \ |
| | 60 | .lm_cap_order = (size_order), \ |
| | 61 | .lm_max_order = (max_order), \ |
| | 62 | .lm_min_order = (min_order), \ |
| | 63 | .lm_cnt_free = (1 << (size_order)) \ |
| | 64 | }; |
| | 65 | |
| | 66 | /* |
| | 67 | * Allocates memory from a respective logmem. Returns a pointer to the beginning |
| | 68 | * of the allocated block. The resulting size of the allocated block is equal or |
| | 69 | * bigger than the size passed in during the call. |
| | 70 | */ |
| | 71 | void *logmem_alloc(logmem_t *, size_t *); |
| | 72 | |
| | 73 | /* |
| | 74 | * Frees memory previously allocated by logmem_alloc(). The caller must call |
| | 75 | * logmem_free() with exact pointer and size value returned by logmem_alloc(). |
| | 76 | */ |
| | 77 | void logmem_free(logmem_t *, void *, size_t); |
| | 78 | |
| | 79 | /* |
| | 80 | * Returns the maximum memory size allocatable by the logmem. |
| | 81 | */ |
| | 82 | size_t logmem_max_size(const logmem_t *); |
| | 83 | |
| | 84 | #endif /* log_mem_h */ |
projects / apple / xnu.git / blame_incremental