NanostackMemoryManager.cpp

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2016 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 
00017 #include "nsdynmemLIB.h"
00018 #include <string.h>
00019 #include "mbed_assert.h"
00020 #include "NanostackMemoryManager.h"
00021 
00022 struct ns_stack_mem_t
00023 {
00024     ns_stack_mem_t *next;
00025     void *payload;
00026     uint32_t len;
00027     uint8_t mem[];
00028 };
00029 
00030 emac_mem_buf_t *NanostackMemoryManager::alloc_heap(uint32_t size, uint32_t align)
00031 {
00032     ns_stack_mem_t *buf = static_cast<ns_stack_mem_t *>(ns_dyn_mem_temporary_alloc(sizeof(ns_stack_mem_t) + size + align));
00033     if (buf == NULL) {
00034         return NULL;
00035     }
00036 
00037     buf->next = NULL;
00038     buf->payload = buf->mem;
00039     buf->len = size;
00040 
00041     if (align) {
00042         uint32_t remainder = reinterpret_cast<uint32_t>(buf->payload) % align;
00043         if (remainder) {
00044             uint32_t offset = align - remainder;
00045             if (offset >= align) {
00046                 offset = align;
00047             }
00048 
00049             buf->payload = static_cast<char *>(buf->payload) + offset;
00050         }
00051     }
00052 
00053     return static_cast<emac_mem_buf_t *>(buf);
00054 }
00055 
00056 emac_mem_buf_t *NanostackMemoryManager::alloc_pool(uint32_t size, uint32_t align)
00057 {
00058     return alloc_heap(size, align);
00059 }
00060 
00061 uint32_t NanostackMemoryManager::get_pool_alloc_unit(uint32_t align) const
00062 {
00063     return 1536; // arbitrary nicely-aligned number big enough for Ethernet
00064 }
00065 
00066 void NanostackMemoryManager::free(emac_mem_buf_t *mem)
00067 {
00068     ns_dyn_mem_free(mem);
00069 }
00070 
00071 uint32_t NanostackMemoryManager::get_total_len(const emac_mem_buf_t *buf) const
00072 {
00073     const ns_stack_mem_t *mem = static_cast<const ns_stack_mem_t *>(buf);
00074     uint32_t total = 0;
00075 
00076     while (mem) {
00077         total += mem->len;
00078         mem = mem->next;
00079     }
00080     return total;
00081 }
00082 
00083 void NanostackMemoryManager::copy(emac_mem_buf_t *to, const emac_mem_buf_t *from)
00084 {
00085     ns_stack_mem_t *to_mem = static_cast<ns_stack_mem_t *>(to);
00086     const ns_stack_mem_t *from_mem = static_cast<const ns_stack_mem_t *>(from);
00087     MBED_ASSERT(get_total_len(to) >= get_total_len(from));
00088 
00089     uint32_t to_offset = 0;
00090     uint32_t from_offset = 0;
00091     while (from_mem) {
00092         uint32_t to_avail = to_mem->len - to_offset;
00093         uint32_t from_avail = from_mem->len - from_offset;
00094         uint32_t chunk = to_avail < from_avail ? to_avail : from_avail;
00095         uint8_t *to_ptr = static_cast<uint8_t *>(to_mem->payload) + to_offset;
00096         const uint8_t *from_ptr = static_cast<const uint8_t *>(from_mem->payload) + from_offset;
00097         memcpy(to_ptr, from_ptr, chunk);
00098         to_offset += chunk;
00099         if (to_offset == to_mem->len) {
00100             to_mem = to_mem->next;
00101             to_offset = 0;
00102         }
00103         from_offset += chunk;
00104         if (from_offset == from_mem->len) {
00105             from_mem = from_mem->next;
00106             from_offset = 0;
00107         }
00108     }
00109 }
00110 
00111 void NanostackMemoryManager::cat(emac_mem_buf_t *to_buf, emac_mem_buf_t *cat_buf)
00112 {
00113     ns_stack_mem_t *to_mem = static_cast<ns_stack_mem_t *>(to_buf);
00114     ns_stack_mem_t *cat_mem = static_cast<ns_stack_mem_t *>(cat_buf);
00115 
00116     while (to_mem->next) {
00117         to_mem = to_mem->next;
00118     }
00119 
00120     to_mem->next = cat_mem;
00121 }
00122 
00123 emac_mem_buf_t *NanostackMemoryManager::get_next(const emac_mem_buf_t *buf) const
00124 {
00125     return static_cast<const ns_stack_mem_t *>(buf)->next;
00126 }
00127 
00128 void *NanostackMemoryManager::get_ptr(const emac_mem_buf_t *buf) const
00129 {
00130     return static_cast<const ns_stack_mem_t *>(buf)->payload;
00131 }
00132 
00133 uint32_t NanostackMemoryManager::get_len(const emac_mem_buf_t *buf) const
00134 {
00135     return static_cast<const ns_stack_mem_t *>(buf)->len;
00136 }
00137 
00138 void NanostackMemoryManager::set_len(emac_mem_buf_t *buf, uint32_t len)
00139 {
00140     ns_stack_mem_t *mem = static_cast<ns_stack_mem_t *>(buf);
00141 
00142     mem->len = len;
00143 }