1 // SPDX-License-Identifier: BSD-2-Clause 2 /* 3 * Copyright (c) 2014, STMicroelectronics International N.V. 4 * Copyright (c) 2018-2019, Linaro Limited 5 */ 6 7 8 #include <assert.h> 9 #include <compiler.h> 10 #include <malloc.h> 11 #include <mempool.h> 12 #include <pta_stats.h> 13 #include <string.h> 14 #include <util.h> 15 16 #if defined(__KERNEL__) 17 #include <kernel/mutex.h> 18 #include <kernel/panic.h> 19 #endif 20 21 /* 22 * Allocation of temporary memory buffers which are used in a stack like 23 * fashion. One exmaple is when a Big Number is needed for a temporary 24 * variable in a Big Number computation: Big Number operations (add,...), 25 * crypto algorithms (rsa, ecc,,...). 26 * 27 * The allocation algorithm takes memory buffers from a pool, 28 * characterized by (cf. struct mempool): 29 * - the total size (in bytes) of the pool 30 * - the offset of the last item allocated in the pool (struct 31 * mempool_item). This offset is -1 is nothing is allocated yet. 32 * 33 * Each item consists of (struct mempool_item) 34 * - the size of the item 35 * - the offsets, in the pool, of the previous and next items 36 * 37 * The allocation allocates an item for a given size. 38 * The allocation is performed in the pool after the last 39 * allocated items. This means: 40 * - the heap is never used. 41 * - there is no assumption on the size of the allocated memory buffers. Only 42 * the size of the pool will limit the allocation. 43 * - a constant time allocation and free as there is no list scan 44 * - but a potentially fragmented memory as the allocation does not take into 45 * account "holes" in the pool (allocation is performed after the last 46 * allocated variable). Indeed, this interface is supposed to be used 47 * with stack like allocations to avoid this issue. This means that 48 * allocated items: 49 * - should have a short life cycle 50 * - if an item A is allocated before another item B, then A should be 51 * released after B. 52 * So the potential fragmentation is mitigated. 53 */ 54 55 56 struct mempool { 57 size_t size; /* size of the memory pool, in bytes */ 58 vaddr_t data; 59 struct malloc_ctx *mctx; 60 #ifdef CFG_MEMPOOL_REPORT_LAST_OFFSET 61 size_t max_allocated; 62 #endif 63 #if defined(__KERNEL__) 64 void (*release_mem)(void *ptr, size_t size); 65 struct recursive_mutex mu; 66 #endif 67 }; 68 69 #if defined(__KERNEL__) 70 struct mempool *mempool_default; 71 #endif 72 73 static void init_mpool(struct mempool *pool) 74 { 75 size_t sz = pool->size - raw_malloc_get_ctx_size(); 76 vaddr_t v = ROUNDDOWN(pool->data + sz, sizeof(long) * 2); 77 78 /* 79 * v is the placed as close to the end of the data pool as possible 80 * where the struct malloc_ctx can be placed. This location is selected 81 * as an optimization for the pager case to get better data 82 * locality since raw_malloc() starts to allocate from the end of 83 * the supplied data pool. 84 */ 85 assert(v > pool->data); 86 pool->mctx = (struct malloc_ctx *)v; 87 raw_malloc_init_ctx(pool->mctx); 88 raw_malloc_add_pool(pool->mctx, (void *)pool->data, v - pool->data); 89 } 90 91 static void get_pool(struct mempool *pool __maybe_unused) 92 { 93 #if defined(__KERNEL__) 94 mutex_lock_recursive(&pool->mu); 95 if (!pool->mctx) 96 init_mpool(pool); 97 98 #endif 99 } 100 101 static void put_pool(struct mempool *pool __maybe_unused) 102 { 103 #if defined(__KERNEL__) 104 if (mutex_get_recursive_lock_depth(&pool->mu) == 1) { 105 /* 106 * As the refcount is about to become 0 there should be no items 107 * left 108 */ 109 if (pool->release_mem) { 110 pool->mctx = NULL; 111 pool->release_mem((void *)pool->data, pool->size); 112 } 113 } 114 mutex_unlock_recursive(&pool->mu); 115 #endif 116 } 117 118 struct mempool * 119 mempool_alloc_pool(void *data, size_t size, 120 void (*release_mem)(void *ptr, size_t size) __maybe_unused) 121 { 122 struct mempool *pool = calloc(1, sizeof(*pool)); 123 124 COMPILE_TIME_ASSERT(MEMPOOL_ALIGN >= __alignof__(struct mempool_item)); 125 assert(!((vaddr_t)data & (MEMPOOL_ALIGN - 1))); 126 127 if (pool) { 128 pool->size = size; 129 pool->data = (vaddr_t)data; 130 #if defined(__KERNEL__) 131 pool->release_mem = release_mem; 132 mutex_init_recursive(&pool->mu); 133 #else 134 init_mpool(pool); 135 #endif 136 } 137 138 return pool; 139 } 140 141 void *mempool_alloc(struct mempool *pool, size_t size) 142 { 143 void *p = NULL; 144 145 get_pool(pool); 146 147 p = raw_malloc(0, 0, size, pool->mctx); 148 if (p) { 149 #ifdef CFG_MEMPOOL_REPORT_LAST_OFFSET 150 struct pta_stats_alloc stats = { }; 151 152 raw_malloc_get_stats(pool->mctx, &stats); 153 if (stats.max_allocated > pool->max_allocated) { 154 pool->max_allocated = stats.max_allocated; 155 DMSG("Max memory usage increased to %zu", 156 pool->max_allocated); 157 } 158 #endif 159 return p; 160 } 161 162 EMSG("Failed to allocate %zu bytes, please tune the pool size", size); 163 put_pool(pool); 164 return NULL; 165 } 166 167 void *mempool_calloc(struct mempool *pool, size_t nmemb, size_t size) 168 { 169 size_t sz; 170 void *p; 171 172 if (MUL_OVERFLOW(nmemb, size, &sz)) 173 return NULL; 174 175 p = mempool_alloc(pool, sz); 176 if (p) 177 memset(p, 0, sz); 178 179 return p; 180 } 181 182 void mempool_free(struct mempool *pool, void *ptr) 183 { 184 if (ptr) { 185 raw_free(ptr, pool->mctx, false /*!wipe*/); 186 put_pool(pool); 187 } 188 } 189