4 * Copyright(c) 2010-2012 Intel Corporation. All rights reserved.
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8 * modification, are permitted provided that the following conditions
11 * * Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * * Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
17 * * Neither the name of Intel Corporation nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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31 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 * version: DPDK.L.1.2.3-3
38 #include <sys/queue.h>
40 #include <rte_memory.h>
41 #include <rte_memzone.h>
42 #include <rte_tailq.h>
44 #include <rte_launch.h>
45 #include <rte_per_lcore.h>
46 #include <rte_lcore.h>
47 #include <rte_debug.h>
48 #include <rte_common.h>
49 #include <rte_spinlock.h>
51 #include "malloc_elem.h"
52 #include "malloc_heap.h"
54 #define MIN_DATA_SIZE (CACHE_LINE_SIZE * 2)
57 * initialise a general malloc_elem header structure
60 malloc_elem_init(struct malloc_elem *elem,
61 struct malloc_heap *heap, size_t size)
64 elem->prev = elem->next_free = NULL;
65 elem->state = ELEM_FREE;
73 * initialise a dummy malloc_elem header for the end-of-memzone marker
76 malloc_elem_mkend(struct malloc_elem *elem, struct malloc_elem *prev)
78 malloc_elem_init(elem, prev->heap, 0);
80 elem->state = ELEM_BUSY; /* mark busy so its never merged */
84 * calculate the starting point of where data of the requested size
85 * and alignment would fit in the current element. If the data doesn't
89 elem_start_pt(struct malloc_elem *elem, size_t size, unsigned align)
91 const uintptr_t end_pt = (uintptr_t)elem +
92 elem->size - MALLOC_ELEM_TRAILER_LEN;
93 const uintptr_t new_data_start = rte_align_floor_int((end_pt - size),align);
94 const uintptr_t new_elem_start = new_data_start - MALLOC_ELEM_HEADER_LEN;
96 /* if the new start point is before the exist start, it won't fit */
97 return (new_elem_start < (uintptr_t)elem) ? NULL : (void *)new_elem_start;
101 * use elem_start_pt to determine if we get meet the size and
102 * alignment request from the current element
105 malloc_elem_can_hold(struct malloc_elem *elem, size_t size, unsigned align)
107 return elem_start_pt(elem, size, align) != NULL;
111 * split an existing element into two smaller elements at the given
112 * split_pt parameter.
115 split_elem(struct malloc_elem *elem, struct malloc_elem *split_pt)
117 struct malloc_elem *next_elem = RTE_PTR_ADD(elem, elem->size);
118 const unsigned old_elem_size = (uintptr_t)split_pt - (uintptr_t)elem;
119 const unsigned new_elem_size = elem->size - old_elem_size;
121 malloc_elem_init(split_pt, elem->heap, new_elem_size);
122 split_pt->prev = elem;
123 next_elem->prev = split_pt;
124 elem->size = old_elem_size;
129 * reserve a block of data in an existing malloc_elem. If the malloc_elem
130 * is much larger than the data block requested, we split the element in two.
131 * This function is only called from malloc_heap_alloc so parameter checking
132 * is not done here, as it's done there previously.
135 malloc_elem_alloc(struct malloc_elem *elem, size_t size,
136 unsigned align, struct malloc_elem *prev_free)
138 struct malloc_elem *new_elem = elem_start_pt(elem, size, align);
139 const unsigned old_elem_size = (uintptr_t)new_elem - (uintptr_t)elem;
141 if (old_elem_size <= MALLOC_ELEM_OVERHEAD + MIN_DATA_SIZE){
142 /* don't split it, pad the element instead */
143 elem->state = ELEM_BUSY;
144 elem->pad = old_elem_size;
146 /* put a dummy header in padding, to point to real element header */
147 if (elem->pad > 0){ /* pad will be at least 64-bytes, as everything
148 * is cache-line aligned */
149 new_elem->pad = elem->pad;
150 new_elem->state = ELEM_PAD;
151 new_elem->size = elem->size - elem->pad;
152 set_header(new_elem);
154 /* remove element from free list */
155 if (prev_free == NULL)
156 elem->heap->free_head = elem->next_free;
158 prev_free->next_free = elem->next_free;
163 /* we are going to split the element in two. The original element
164 * remains free, and the new element is the one allocated, so no free list
165 * changes need to be made.
167 split_elem(elem, new_elem);
168 new_elem->state = ELEM_BUSY;
174 * joing two struct malloc_elem together. elem1 and elem2 must
175 * be contiguous in memory.
178 join_elem(struct malloc_elem *elem1, struct malloc_elem *elem2)
180 struct malloc_elem *next = RTE_PTR_ADD(elem2, elem2->size);
181 elem1->size += elem2->size;
186 * scan the free list, and remove the request element from that
187 * free list. (Free list to scan is got from heap pointer in element)
190 remove_from_free_list(struct malloc_elem *elem)
192 if (elem == elem->heap->free_head)
193 elem->heap->free_head = elem->next_free;
195 struct malloc_elem *prev_free = elem->heap->free_head;
196 while (prev_free && prev_free->next_free != elem)
197 prev_free = prev_free->next_free;
199 rte_panic("Corrupted free list\n");
200 prev_free->next_free = elem->next_free;
205 * free a malloc_elem block by adding it to the free list. If the
206 * blocks either immediately before or immediately after newly freed block
207 * are also free, the blocks are merged together.
210 malloc_elem_free(struct malloc_elem *elem)
212 if (!malloc_elem_cookies_ok(elem) || elem->state != ELEM_BUSY)
215 rte_spinlock_lock(&(elem->heap->lock));
216 struct malloc_elem *next = RTE_PTR_ADD(elem, elem->size);
217 if (next->state == ELEM_FREE){
218 /* join to this one, and remove from free list */
219 join_elem(elem, next);
220 remove_from_free_list(next);
223 /* check if previous element is free, if so join with it and return,
224 * no need to update free list, as that element is already there
226 if (elem->prev != NULL && elem->prev->state == ELEM_FREE)
227 join_elem(elem->prev, elem);
228 /* otherwise add ourselves to the free list */
230 elem->next_free = elem->heap->free_head;
231 elem->heap->free_head = elem;
232 elem->state = ELEM_FREE;
235 rte_spinlock_unlock(&(elem->heap->lock));
240 * attempt to resize a malloc_elem by expanding into any free space
241 * immediately after it in memory.
244 malloc_elem_resize(struct malloc_elem *elem, size_t size)
246 const size_t new_size = size + MALLOC_ELEM_OVERHEAD;
247 /* if we request a smaller size, then always return ok */
248 const size_t current_size = elem->size - elem->pad;
249 if (current_size >= new_size)
252 struct malloc_elem *next = RTE_PTR_ADD(elem, elem->size);
253 rte_spinlock_lock(&elem->heap->lock);
254 if (next ->state != ELEM_FREE)
256 if (current_size + next->size < new_size)
259 /* we now know the element fits, so join the two, then remove from free
262 join_elem(elem, next);
263 remove_from_free_list(next);
265 if (elem->size - new_size > MIN_DATA_SIZE + MALLOC_ELEM_OVERHEAD){
266 /* now we have a big block together. Lets cut it down a bit, by splitting */
267 struct malloc_elem *split_pt = RTE_PTR_ADD(elem, new_size);
268 split_pt = RTE_ALIGN_CEIL(split_pt, CACHE_LINE_SIZE);
269 split_elem(elem, split_pt);
270 split_pt->state = ELEM_FREE;
271 split_pt->next_free = elem->heap->free_head;
272 elem->heap->free_head = split_pt;
274 rte_spinlock_unlock(&elem->heap->lock);
278 rte_spinlock_unlock(&elem->heap->lock);