1 /* SPDX-License-Identifier: BSD-3-Clause
2 * Copyright(c) 2010-2014 Intel Corporation
10 #include <sys/queue.h>
12 #include <rte_memory.h>
14 #include <rte_launch.h>
15 #include <rte_per_lcore.h>
16 #include <rte_lcore.h>
17 #include <rte_debug.h>
18 #include <rte_common.h>
19 #include <rte_spinlock.h>
21 #include "eal_internal_cfg.h"
22 #include "eal_memalloc.h"
23 #include "malloc_elem.h"
24 #include "malloc_heap.h"
27 malloc_elem_find_max_iova_contig(struct malloc_elem *elem, size_t align)
29 void *cur_page, *contig_seg_start, *page_end, *cur_seg_end;
30 void *data_start, *data_end;
31 rte_iova_t expected_iova;
32 struct rte_memseg *ms;
33 size_t page_sz, cur, max;
35 page_sz = (size_t)elem->msl->page_sz;
36 data_start = RTE_PTR_ADD(elem, MALLOC_ELEM_HEADER_LEN);
37 data_end = RTE_PTR_ADD(elem, elem->size - MALLOC_ELEM_TRAILER_LEN);
38 /* segment must start after header and with specified alignment */
39 contig_seg_start = RTE_PTR_ALIGN_CEIL(data_start, align);
41 /* if we're in IOVA as VA mode, or if we're in legacy mode with
42 * hugepages, all elements are IOVA-contiguous.
44 if (rte_eal_iova_mode() == RTE_IOVA_VA ||
45 (internal_config.legacy_mem && rte_eal_has_hugepages()))
46 return RTE_PTR_DIFF(data_end, contig_seg_start);
48 cur_page = RTE_PTR_ALIGN_FLOOR(contig_seg_start, page_sz);
49 ms = rte_mem_virt2memseg(cur_page, elem->msl);
51 /* do first iteration outside the loop */
52 page_end = RTE_PTR_ADD(cur_page, page_sz);
53 cur_seg_end = RTE_MIN(page_end, data_end);
54 cur = RTE_PTR_DIFF(cur_seg_end, contig_seg_start) -
55 MALLOC_ELEM_TRAILER_LEN;
57 expected_iova = ms->iova + page_sz;
58 /* memsegs are contiguous in memory */
61 cur_page = RTE_PTR_ADD(cur_page, page_sz);
63 while (cur_page < data_end) {
64 page_end = RTE_PTR_ADD(cur_page, page_sz);
65 cur_seg_end = RTE_MIN(page_end, data_end);
67 /* reset start of contiguous segment if unexpected iova */
68 if (ms->iova != expected_iova) {
69 /* next contiguous segment must start at specified
72 contig_seg_start = RTE_PTR_ALIGN(cur_page, align);
73 /* new segment start may be on a different page, so find
74 * the page and skip to next iteration to make sure
75 * we're not blowing past data end.
77 ms = rte_mem_virt2memseg(contig_seg_start, elem->msl);
79 /* don't trigger another recalculation */
80 expected_iova = ms->iova;
83 /* cur_seg_end ends on a page boundary or on data end. if we're
84 * looking at data end, then malloc trailer is already included
85 * in the calculations. if we're looking at page end, then we
86 * know there's more data past this page and thus there's space
87 * for malloc element trailer, so don't count it here.
89 cur = RTE_PTR_DIFF(cur_seg_end, contig_seg_start);
90 /* update max if cur value is bigger */
94 /* move to next page */
96 expected_iova = ms->iova + page_sz;
97 /* memsegs are contiguous in memory */
105 * Initialize a general malloc_elem header structure
108 malloc_elem_init(struct malloc_elem *elem, struct malloc_heap *heap,
109 struct rte_memseg_list *msl, size_t size)
115 memset(&elem->free_list, 0, sizeof(elem->free_list));
116 elem->state = ELEM_FREE;
124 malloc_elem_insert(struct malloc_elem *elem)
126 struct malloc_elem *prev_elem, *next_elem;
127 struct malloc_heap *heap = elem->heap;
129 /* first and last elements must be both NULL or both non-NULL */
130 if ((heap->first == NULL) != (heap->last == NULL)) {
131 RTE_LOG(ERR, EAL, "Heap is probably corrupt\n");
135 if (heap->first == NULL && heap->last == NULL) {
141 } else if (elem < heap->first) {
142 /* if lower than start */
144 next_elem = heap->first;
146 } else if (elem > heap->last) {
147 /* if higher than end */
148 prev_elem = heap->last;
152 /* the new memory is somewhere inbetween start and end */
153 uint64_t dist_from_start, dist_from_end;
155 dist_from_end = RTE_PTR_DIFF(heap->last, elem);
156 dist_from_start = RTE_PTR_DIFF(elem, heap->first);
158 /* check which is closer, and find closest list entries */
159 if (dist_from_start < dist_from_end) {
160 prev_elem = heap->first;
161 while (prev_elem->next < elem)
162 prev_elem = prev_elem->next;
163 next_elem = prev_elem->next;
165 next_elem = heap->last;
166 while (next_elem->prev > elem)
167 next_elem = next_elem->prev;
168 prev_elem = next_elem->prev;
172 /* insert new element */
173 elem->prev = prev_elem;
174 elem->next = next_elem;
176 prev_elem->next = elem;
178 next_elem->prev = elem;
182 * Attempt to find enough physically contiguous memory in this block to store
183 * our data. Assume that element has at least enough space to fit in the data,
184 * so we just check the page addresses.
187 elem_check_phys_contig(const struct rte_memseg_list *msl,
188 void *start, size_t size)
190 return eal_memalloc_is_contig(msl, start, size);
194 * calculate the starting point of where data of the requested size
195 * and alignment would fit in the current element. If the data doesn't
199 elem_start_pt(struct malloc_elem *elem, size_t size, unsigned align,
200 size_t bound, bool contig)
202 size_t elem_size = elem->size;
205 * we're allocating from the end, so adjust the size of element by
208 while (elem_size >= size) {
209 const size_t bmask = ~(bound - 1);
210 uintptr_t end_pt = (uintptr_t)elem +
211 elem_size - MALLOC_ELEM_TRAILER_LEN;
212 uintptr_t new_data_start = RTE_ALIGN_FLOOR((end_pt - size),
214 uintptr_t new_elem_start;
217 if ((new_data_start & bmask) != ((end_pt - 1) & bmask)) {
218 end_pt = RTE_ALIGN_FLOOR(end_pt, bound);
219 new_data_start = RTE_ALIGN_FLOOR((end_pt - size),
221 end_pt = new_data_start + size;
223 if (((end_pt - 1) & bmask) != (new_data_start & bmask))
227 new_elem_start = new_data_start - MALLOC_ELEM_HEADER_LEN;
229 /* if the new start point is before the exist start,
232 if (new_elem_start < (uintptr_t)elem)
236 size_t new_data_size = end_pt - new_data_start;
239 * if physical contiguousness was requested and we
240 * couldn't fit all data into one physically contiguous
241 * block, try again with lower addresses.
243 if (!elem_check_phys_contig(elem->msl,
244 (void *)new_data_start,
250 return (void *)new_elem_start;
256 * use elem_start_pt to determine if we get meet the size and
257 * alignment request from the current element
260 malloc_elem_can_hold(struct malloc_elem *elem, size_t size, unsigned align,
261 size_t bound, bool contig)
263 return elem_start_pt(elem, size, align, bound, contig) != NULL;
267 * split an existing element into two smaller elements at the given
268 * split_pt parameter.
271 split_elem(struct malloc_elem *elem, struct malloc_elem *split_pt)
273 struct malloc_elem *next_elem = elem->next;
274 const size_t old_elem_size = (uintptr_t)split_pt - (uintptr_t)elem;
275 const size_t new_elem_size = elem->size - old_elem_size;
277 malloc_elem_init(split_pt, elem->heap, elem->msl, new_elem_size);
278 split_pt->prev = elem;
279 split_pt->next = next_elem;
281 next_elem->prev = split_pt;
283 elem->heap->last = split_pt;
284 elem->next = split_pt;
285 elem->size = old_elem_size;
290 * our malloc heap is a doubly linked list, so doubly remove our element.
292 static void __rte_unused
293 remove_elem(struct malloc_elem *elem)
295 struct malloc_elem *next, *prev;
302 elem->heap->last = prev;
306 elem->heap->first = next;
313 next_elem_is_adjacent(struct malloc_elem *elem)
315 return elem->next == RTE_PTR_ADD(elem, elem->size);
319 prev_elem_is_adjacent(struct malloc_elem *elem)
321 return elem == RTE_PTR_ADD(elem->prev, elem->prev->size);
325 * Given an element size, compute its freelist index.
326 * We free an element into the freelist containing similarly-sized elements.
327 * We try to allocate elements starting with the freelist containing
328 * similarly-sized elements, and if necessary, we search freelists
329 * containing larger elements.
331 * Example element size ranges for a heap with five free lists:
332 * heap->free_head[0] - (0 , 2^8]
333 * heap->free_head[1] - (2^8 , 2^10]
334 * heap->free_head[2] - (2^10 ,2^12]
335 * heap->free_head[3] - (2^12, 2^14]
336 * heap->free_head[4] - (2^14, MAX_SIZE]
339 malloc_elem_free_list_index(size_t size)
341 #define MALLOC_MINSIZE_LOG2 8
342 #define MALLOC_LOG2_INCREMENT 2
347 if (size <= (1UL << MALLOC_MINSIZE_LOG2))
350 /* Find next power of 2 >= size. */
351 log2 = sizeof(size) * 8 - __builtin_clzl(size-1);
353 /* Compute freelist index, based on log2(size). */
354 index = (log2 - MALLOC_MINSIZE_LOG2 + MALLOC_LOG2_INCREMENT - 1) /
355 MALLOC_LOG2_INCREMENT;
357 return index <= RTE_HEAP_NUM_FREELISTS-1?
358 index: RTE_HEAP_NUM_FREELISTS-1;
362 * Add the specified element to its heap's free list.
365 malloc_elem_free_list_insert(struct malloc_elem *elem)
369 idx = malloc_elem_free_list_index(elem->size - MALLOC_ELEM_HEADER_LEN);
370 elem->state = ELEM_FREE;
371 LIST_INSERT_HEAD(&elem->heap->free_head[idx], elem, free_list);
375 * Remove the specified element from its heap's free list.
378 malloc_elem_free_list_remove(struct malloc_elem *elem)
380 LIST_REMOVE(elem, free_list);
384 * reserve a block of data in an existing malloc_elem. If the malloc_elem
385 * is much larger than the data block requested, we split the element in two.
386 * This function is only called from malloc_heap_alloc so parameter checking
387 * is not done here, as it's done there previously.
390 malloc_elem_alloc(struct malloc_elem *elem, size_t size, unsigned align,
391 size_t bound, bool contig)
393 struct malloc_elem *new_elem = elem_start_pt(elem, size, align, bound,
395 const size_t old_elem_size = (uintptr_t)new_elem - (uintptr_t)elem;
396 const size_t trailer_size = elem->size - old_elem_size - size -
397 MALLOC_ELEM_OVERHEAD;
399 malloc_elem_free_list_remove(elem);
401 if (trailer_size > MALLOC_ELEM_OVERHEAD + MIN_DATA_SIZE) {
402 /* split it, too much free space after elem */
403 struct malloc_elem *new_free_elem =
404 RTE_PTR_ADD(new_elem, size + MALLOC_ELEM_OVERHEAD);
406 split_elem(elem, new_free_elem);
407 malloc_elem_free_list_insert(new_free_elem);
409 if (elem == elem->heap->last)
410 elem->heap->last = new_free_elem;
413 if (old_elem_size < MALLOC_ELEM_OVERHEAD + MIN_DATA_SIZE) {
414 /* don't split it, pad the element instead */
415 elem->state = ELEM_BUSY;
416 elem->pad = old_elem_size;
418 /* put a dummy header in padding, to point to real element header */
419 if (elem->pad > 0) { /* pad will be at least 64-bytes, as everything
420 * is cache-line aligned */
421 new_elem->pad = elem->pad;
422 new_elem->state = ELEM_PAD;
423 new_elem->size = elem->size - elem->pad;
424 set_header(new_elem);
430 /* we are going to split the element in two. The original element
431 * remains free, and the new element is the one allocated.
432 * Re-insert original element, in case its new size makes it
433 * belong on a different list.
435 split_elem(elem, new_elem);
436 new_elem->state = ELEM_BUSY;
437 malloc_elem_free_list_insert(elem);
443 * join two struct malloc_elem together. elem1 and elem2 must
444 * be contiguous in memory.
447 join_elem(struct malloc_elem *elem1, struct malloc_elem *elem2)
449 struct malloc_elem *next = elem2->next;
450 elem1->size += elem2->size;
454 elem1->heap->last = elem1;
459 malloc_elem_join_adjacent_free(struct malloc_elem *elem)
462 * check if next element exists, is adjacent and is free, if so join
463 * with it, need to remove from free list.
465 if (elem->next != NULL && elem->next->state == ELEM_FREE &&
466 next_elem_is_adjacent(elem)) {
470 /* we will want to erase the trailer and header */
471 erase = RTE_PTR_SUB(elem->next, MALLOC_ELEM_TRAILER_LEN);
472 erase_len = MALLOC_ELEM_OVERHEAD + elem->next->pad;
474 /* remove from free list, join to this one */
475 malloc_elem_free_list_remove(elem->next);
476 join_elem(elem, elem->next);
478 /* erase header, trailer and pad */
479 memset(erase, 0, erase_len);
483 * check if prev element exists, is adjacent and is free, if so join
484 * with it, need to remove from free list.
486 if (elem->prev != NULL && elem->prev->state == ELEM_FREE &&
487 prev_elem_is_adjacent(elem)) {
488 struct malloc_elem *new_elem;
492 /* we will want to erase trailer and header */
493 erase = RTE_PTR_SUB(elem, MALLOC_ELEM_TRAILER_LEN);
494 erase_len = MALLOC_ELEM_OVERHEAD + elem->pad;
496 /* remove from free list, join to this one */
497 malloc_elem_free_list_remove(elem->prev);
499 new_elem = elem->prev;
500 join_elem(new_elem, elem);
502 /* erase header, trailer and pad */
503 memset(erase, 0, erase_len);
512 * free a malloc_elem block by adding it to the free list. If the
513 * blocks either immediately before or immediately after newly freed block
514 * are also free, the blocks are merged together.
517 malloc_elem_free(struct malloc_elem *elem)
522 ptr = RTE_PTR_ADD(elem, MALLOC_ELEM_HEADER_LEN);
523 data_len = elem->size - MALLOC_ELEM_OVERHEAD;
525 elem = malloc_elem_join_adjacent_free(elem);
527 malloc_elem_free_list_insert(elem);
531 /* decrease heap's count of allocated elements */
532 elem->heap->alloc_count--;
534 memset(ptr, 0, data_len);
539 /* assume all checks were already done */
541 malloc_elem_hide_region(struct malloc_elem *elem, void *start, size_t len)
543 struct malloc_elem *hide_start, *hide_end, *prev, *next;
544 size_t len_before, len_after;
547 hide_end = RTE_PTR_ADD(start, len);
552 /* we cannot do anything with non-adjacent elements */
553 if (next && next_elem_is_adjacent(elem)) {
554 len_after = RTE_PTR_DIFF(next, hide_end);
555 if (len_after >= MALLOC_ELEM_OVERHEAD + MIN_DATA_SIZE) {
557 split_elem(elem, hide_end);
559 malloc_elem_free_list_insert(hide_end);
560 } else if (len_after > 0) {
561 RTE_LOG(ERR, EAL, "Unaligned element, heap is probably corrupt\n");
566 /* we cannot do anything with non-adjacent elements */
567 if (prev && prev_elem_is_adjacent(elem)) {
568 len_before = RTE_PTR_DIFF(hide_start, elem);
569 if (len_before >= MALLOC_ELEM_OVERHEAD + MIN_DATA_SIZE) {
571 split_elem(elem, hide_start);
576 malloc_elem_free_list_insert(prev);
577 } else if (len_before > 0) {
578 RTE_LOG(ERR, EAL, "Unaligned element, heap is probably corrupt\n");
587 * attempt to resize a malloc_elem by expanding into any free space
588 * immediately after it in memory.
591 malloc_elem_resize(struct malloc_elem *elem, size_t size)
593 const size_t new_size = size + elem->pad + MALLOC_ELEM_OVERHEAD;
595 /* if we request a smaller size, then always return ok */
596 if (elem->size >= new_size)
599 /* check if there is a next element, it's free and adjacent */
600 if (!elem->next || elem->next->state != ELEM_FREE ||
601 !next_elem_is_adjacent(elem))
603 if (elem->size + elem->next->size < new_size)
606 /* we now know the element fits, so remove from free list,
609 malloc_elem_free_list_remove(elem->next);
610 join_elem(elem, elem->next);
612 if (elem->size - new_size >= MIN_DATA_SIZE + MALLOC_ELEM_OVERHEAD) {
613 /* now we have a big block together. Lets cut it down a bit, by splitting */
614 struct malloc_elem *split_pt = RTE_PTR_ADD(elem, new_size);
615 split_pt = RTE_PTR_ALIGN_CEIL(split_pt, RTE_CACHE_LINE_SIZE);
616 split_elem(elem, split_pt);
617 malloc_elem_free_list_insert(split_pt);
622 static inline const char *
623 elem_state_to_str(enum elem_state state)
637 malloc_elem_dump(const struct malloc_elem *elem, FILE *f)
639 fprintf(f, "Malloc element at %p (%s)\n", elem,
640 elem_state_to_str(elem->state));
641 fprintf(f, " len: 0x%zx pad: 0x%" PRIx32 "\n", elem->size, elem->pad);
642 fprintf(f, " prev: %p next: %p\n", elem->prev, elem->next);