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     ns_stack_mem_t *next;
00024     void *payload;
00025     uint32_t len;
00026     uint8_t mem[];
00027 };
00028 
00029 emac_mem_buf_t *NanostackMemoryManager::alloc_heap(uint32_t size, uint32_t align)
00030 {
00031     ns_stack_mem_t *buf = static_cast<ns_stack_mem_t *>(ns_dyn_mem_temporary_alloc(sizeof(ns_stack_mem_t) + size + align));
00032     if (buf == NULL) {
00033         return NULL;
00034     }
00035 
00036     buf->next = NULL;
00037     buf->payload = buf->mem;
00038     buf->len = size;
00039 
00040     if (align) {
00041         uint32_t remainder = reinterpret_cast<uint32_t>(buf->payload) % align;
00042         if (remainder) {
00043             uint32_t offset = align - remainder;
00044             if (offset >= align) {
00045                 offset = align;
00046             }
00047 
00048             buf->payload = static_cast<char *>(buf->payload) + offset;
00049         }
00050     }
00051 
00052     return static_cast<emac_mem_buf_t *>(buf);
00053 }
00054 
00055 emac_mem_buf_t *NanostackMemoryManager::alloc_pool(uint32_t size, uint32_t align)
00056 {
00057     return alloc_heap(size, align);
00058 }
00059 
00060 uint32_t NanostackMemoryManager::get_pool_alloc_unit(uint32_t align) const
00061 {
00062     return 1536; // arbitrary nicely-aligned number big enough for Ethernet
00063 }
00064 
00065 void NanostackMemoryManager::free(emac_mem_buf_t *mem)
00066 {
00067     ns_dyn_mem_free(mem);
00068 }
00069 
00070 uint32_t NanostackMemoryManager::get_total_len(const emac_mem_buf_t *buf) const
00071 {
00072     const ns_stack_mem_t *mem = static_cast<const ns_stack_mem_t *>(buf);
00073     uint32_t total = 0;
00074 
00075     while (mem) {
00076         total += mem->len;
00077         mem = mem->next;
00078     }
00079     return total;
00080 }
00081 
00082 void NanostackMemoryManager::copy(emac_mem_buf_t *to, const emac_mem_buf_t *from)
00083 {
00084     ns_stack_mem_t *to_mem = static_cast<ns_stack_mem_t *>(to);
00085     const ns_stack_mem_t *from_mem = static_cast<const ns_stack_mem_t *>(from);
00086     MBED_ASSERT(get_total_len(to) >= get_total_len(from));
00087 
00088     uint32_t to_offset = 0;
00089     uint32_t from_offset = 0;
00090     while (from_mem) {
00091         uint32_t to_avail = to_mem->len - to_offset;
00092         uint32_t from_avail = from_mem->len - from_offset;
00093         uint32_t chunk = to_avail < from_avail ? to_avail : from_avail;
00094         uint8_t *to_ptr = static_cast<uint8_t *>(to_mem->payload) + to_offset;
00095         const uint8_t *from_ptr = static_cast<const uint8_t *>(from_mem->payload) + from_offset;
00096         memcpy(to_ptr, from_ptr, chunk);
00097         to_offset += chunk;
00098         if (to_offset == to_mem->len) {
00099             to_mem = to_mem->next;
00100             to_offset = 0;
00101         }
00102         from_offset += chunk;
00103         if (from_offset == from_mem->len) {
00104             from_mem = from_mem->next;
00105             from_offset = 0;
00106         }
00107     }
00108 }
00109 
00110 void NanostackMemoryManager::cat(emac_mem_buf_t *to_buf, emac_mem_buf_t *cat_buf)
00111 {
00112     ns_stack_mem_t *to_mem = static_cast<ns_stack_mem_t *>(to_buf);
00113     ns_stack_mem_t *cat_mem = static_cast<ns_stack_mem_t *>(cat_buf);
00114 
00115     while (to_mem->next) {
00116         to_mem = to_mem->next;
00117     }
00118 
00119     to_mem->next = cat_mem;
00120 }
00121 
00122 emac_mem_buf_t *NanostackMemoryManager::get_next(const emac_mem_buf_t *buf) const
00123 {
00124     return static_cast<const ns_stack_mem_t *>(buf)->next;
00125 }
00126 
00127 void *NanostackMemoryManager::get_ptr(const emac_mem_buf_t *buf) const
00128 {
00129     return static_cast<const ns_stack_mem_t *>(buf)->payload;
00130 }
00131 
00132 uint32_t NanostackMemoryManager::get_len(const emac_mem_buf_t *buf) const
00133 {
00134     return static_cast<const ns_stack_mem_t *>(buf)->len;
00135 }
00136 
00137 void NanostackMemoryManager::set_len(emac_mem_buf_t *buf, uint32_t len)
00138 {
00139     ns_stack_mem_t *mem = static_cast<ns_stack_mem_t *>(buf);
00140 
00141     mem->len = len;
00142 }