ion_system_heap.c revision e1d855b02f5ac4c3a6cbeaa253958b2708826b9f 
1/*
2 * drivers/staging/android/ion/ion_system_heap.c
3 *
4 * Copyright (C) 2011 Google, Inc.
5 *
6 * This software is licensed under the terms of the GNU General Public
7 * License version 2, as published by the Free Software Foundation, and
8 * may be copied, distributed, and modified under those terms.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 * GNU General Public License for more details.
14 *
15 */
16
17#include <asm/page.h>
18#include <linux/dma-mapping.h>
19#include <linux/err.h>
20#include <linux/highmem.h>
21#include <linux/mm.h>
22#include <linux/scatterlist.h>
23#include <linux/seq_file.h>
24#include <linux/slab.h>
25#include <linux/vmalloc.h>
26#include "ion.h"
27#include "ion_priv.h"
28
29static gfp_t high_order_gfp_flags = (GFP_HIGHUSER | __GFP_ZERO | __GFP_NOWARN |
30				     __GFP_NORETRY) & ~__GFP_WAIT;
31static gfp_t low_order_gfp_flags  = (GFP_HIGHUSER | __GFP_ZERO | __GFP_NOWARN);
32static const unsigned int orders[] = {8, 4, 0};
33static const int num_orders = ARRAY_SIZE(orders);
34static int order_to_index(unsigned int order)
35{
36	int i;
37	for (i = 0; i < num_orders; i++)
38		if (order == orders[i])
39			return i;
40	BUG();
41	return -1;
42}
43
44static unsigned int order_to_size(int order)
45{
46	return PAGE_SIZE << order;
47}
48
49struct ion_system_heap {
50	struct ion_heap heap;
51	struct ion_page_pool **pools;
52};
53
54struct page_info {
55	struct page *page;
56	unsigned int order;
57	struct list_head list;
58};
59
60static struct page *alloc_buffer_page(struct ion_system_heap *heap,
61				      struct ion_buffer *buffer,
62				      unsigned long order)
63{
64	bool cached = ion_buffer_cached(buffer);
65	struct ion_page_pool *pool = heap->pools[order_to_index(order)];
66	struct page *page;
67
68	if (!cached) {
69		page = ion_page_pool_alloc(pool);
70	} else {
71		gfp_t gfp_flags = low_order_gfp_flags;
72
73		if (order > 4)
74			gfp_flags = high_order_gfp_flags;
75		page = alloc_pages(gfp_flags, order);
76		if (!page)
77			return NULL;
78		ion_pages_sync_for_device(NULL, page, PAGE_SIZE << order,
79						DMA_BIDIRECTIONAL);
80	}
81	if (!page)
82		return NULL;
83
84	return page;
85}
86
87static void free_buffer_page(struct ion_system_heap *heap,
88			     struct ion_buffer *buffer, struct page *page,
89			     unsigned int order)
90{
91	bool cached = ion_buffer_cached(buffer);
92
93	if (!cached) {
94		struct ion_page_pool *pool = heap->pools[order_to_index(order)];
95		ion_page_pool_free(pool, page);
96	} else {
97		__free_pages(page, order);
98	}
99}
100
101
102static struct page_info *alloc_largest_available(struct ion_system_heap *heap,
103						 struct ion_buffer *buffer,
104						 unsigned long size,
105						 unsigned int max_order)
106{
107	struct page *page;
108	struct page_info *info;
109	int i;
110
111	for (i = 0; i < num_orders; i++) {
112		if (size < order_to_size(orders[i]))
113			continue;
114		if (max_order < orders[i])
115			continue;
116
117		page = alloc_buffer_page(heap, buffer, orders[i]);
118		if (!page)
119			continue;
120
121		info = kmalloc(sizeof(struct page_info), GFP_KERNEL);
122		info->page = page;
123		info->order = orders[i];
124		return info;
125	}
126	return NULL;
127}
128
129static int ion_system_heap_allocate(struct ion_heap *heap,
130				     struct ion_buffer *buffer,
131				     unsigned long size, unsigned long align,
132				     unsigned long flags)
133{
134	struct ion_system_heap *sys_heap = container_of(heap,
135							struct ion_system_heap,
136							heap);
137	struct sg_table *table;
138	struct scatterlist *sg;
139	int ret;
140	struct list_head pages;
141	struct page_info *info, *tmp_info;
142	int i = 0;
143	long size_remaining = PAGE_ALIGN(size);
144	unsigned int max_order = orders[0];
145
146	if (align > PAGE_SIZE)
147		return -EINVAL;
148
149	INIT_LIST_HEAD(&pages);
150	while (size_remaining > 0) {
151		info = alloc_largest_available(sys_heap, buffer, size_remaining,
152						max_order);
153		if (!info)
154			goto err;
155		list_add_tail(&info->list, &pages);
156		size_remaining -= (1 << info->order) * PAGE_SIZE;
157		max_order = info->order;
158		i++;
159	}
160	table = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
161	if (!table)
162		goto err;
163
164	ret = sg_alloc_table(table, i, GFP_KERNEL);
165	if (ret)
166		goto err1;
167
168	sg = table->sgl;
169	list_for_each_entry_safe(info, tmp_info, &pages, list) {
170		struct page *page = info->page;
171		sg_set_page(sg, page, (1 << info->order) * PAGE_SIZE, 0);
172		sg = sg_next(sg);
173		list_del(&info->list);
174		kfree(info);
175	}
176
177	buffer->priv_virt = table;
178	return 0;
179err1:
180	kfree(table);
181err:
182	list_for_each_entry_safe(info, tmp_info, &pages, list) {
183		free_buffer_page(sys_heap, buffer, info->page, info->order);
184		kfree(info);
185	}
186	return -ENOMEM;
187}
188
189static void ion_system_heap_free(struct ion_buffer *buffer)
190{
191	struct ion_heap *heap = buffer->heap;
192	struct ion_system_heap *sys_heap = container_of(heap,
193							struct ion_system_heap,
194							heap);
195	struct sg_table *table = buffer->sg_table;
196	bool cached = ion_buffer_cached(buffer);
197	struct scatterlist *sg;
198	LIST_HEAD(pages);
199	int i;
200
201	/* uncached pages come from the page pools, zero them before returning
202	   for security purposes (other allocations are zerod at alloc time */
203	if (!cached)
204		ion_heap_buffer_zero(buffer);
205
206	for_each_sg(table->sgl, sg, table->nents, i)
207		free_buffer_page(sys_heap, buffer, sg_page(sg),
208				get_order(sg->length));
209	sg_free_table(table);
210	kfree(table);
211}
212
213static struct sg_table *ion_system_heap_map_dma(struct ion_heap *heap,
214						struct ion_buffer *buffer)
215{
216	return buffer->priv_virt;
217}
218
219static void ion_system_heap_unmap_dma(struct ion_heap *heap,
220				      struct ion_buffer *buffer)
221{
222	return;
223}
224
225static struct ion_heap_ops system_heap_ops = {
226	.allocate = ion_system_heap_allocate,
227	.free = ion_system_heap_free,
228	.map_dma = ion_system_heap_map_dma,
229	.unmap_dma = ion_system_heap_unmap_dma,
230	.map_kernel = ion_heap_map_kernel,
231	.unmap_kernel = ion_heap_unmap_kernel,
232	.map_user = ion_heap_map_user,
233};
234
235static int ion_system_heap_shrink(struct shrinker *shrinker,
236				  struct shrink_control *sc) {
237
238	struct ion_heap *heap = container_of(shrinker, struct ion_heap,
239					     shrinker);
240	struct ion_system_heap *sys_heap = container_of(heap,
241							struct ion_system_heap,
242							heap);
243	int nr_total = 0;
244	int nr_freed = 0;
245	int i;
246
247	if (sc->nr_to_scan == 0)
248		goto end;
249
250	/* shrink the free list first, no point in zeroing the memory if
251	   we're just going to reclaim it */
252	nr_freed += ion_heap_freelist_drain(heap, sc->nr_to_scan * PAGE_SIZE) /
253		PAGE_SIZE;
254
255	if (nr_freed >= sc->nr_to_scan)
256		goto end;
257
258	for (i = 0; i < num_orders; i++) {
259		struct ion_page_pool *pool = sys_heap->pools[i];
260
261		nr_freed += ion_page_pool_shrink(pool, sc->gfp_mask,
262						 sc->nr_to_scan);
263		if (nr_freed >= sc->nr_to_scan)
264			break;
265	}
266
267end:
268	/* total number of items is whatever the page pools are holding
269	   plus whatever's in the freelist */
270	for (i = 0; i < num_orders; i++) {
271		struct ion_page_pool *pool = sys_heap->pools[i];
272		nr_total += ion_page_pool_shrink(pool, sc->gfp_mask, 0);
273	}
274	nr_total += ion_heap_freelist_size(heap) / PAGE_SIZE;
275	return nr_total;
276
277}
278
279static int ion_system_heap_debug_show(struct ion_heap *heap, struct seq_file *s,
280				      void *unused)
281{
282
283	struct ion_system_heap *sys_heap = container_of(heap,
284							struct ion_system_heap,
285							heap);
286	int i;
287	for (i = 0; i < num_orders; i++) {
288		struct ion_page_pool *pool = sys_heap->pools[i];
289		seq_printf(s, "%d order %u highmem pages in pool = %lu total\n",
290			   pool->high_count, pool->order,
291			   (1 << pool->order) * PAGE_SIZE * pool->high_count);
292		seq_printf(s, "%d order %u lowmem pages in pool = %lu total\n",
293			   pool->low_count, pool->order,
294			   (1 << pool->order) * PAGE_SIZE * pool->low_count);
295	}
296	return 0;
297}
298
299struct ion_heap *ion_system_heap_create(struct ion_platform_heap *unused)
300{
301	struct ion_system_heap *heap;
302	int i;
303
304	heap = kzalloc(sizeof(struct ion_system_heap), GFP_KERNEL);
305	if (!heap)
306		return ERR_PTR(-ENOMEM);
307	heap->heap.ops = &system_heap_ops;
308	heap->heap.type = ION_HEAP_TYPE_SYSTEM;
309	heap->heap.flags = ION_HEAP_FLAG_DEFER_FREE;
310	heap->pools = kzalloc(sizeof(struct ion_page_pool *) * num_orders,
311			      GFP_KERNEL);
312	if (!heap->pools)
313		goto err_alloc_pools;
314	for (i = 0; i < num_orders; i++) {
315		struct ion_page_pool *pool;
316		gfp_t gfp_flags = low_order_gfp_flags;
317
318		if (orders[i] > 4)
319			gfp_flags = high_order_gfp_flags;
320		pool = ion_page_pool_create(gfp_flags, orders[i]);
321		if (!pool)
322			goto err_create_pool;
323		heap->pools[i] = pool;
324	}
325
326	heap->heap.shrinker.shrink = ion_system_heap_shrink;
327	heap->heap.shrinker.seeks = DEFAULT_SEEKS;
328	heap->heap.shrinker.batch = 0;
329	register_shrinker(&heap->heap.shrinker);
330	heap->heap.debug_show = ion_system_heap_debug_show;
331	return &heap->heap;
332err_create_pool:
333	for (i = 0; i < num_orders; i++)
334		if (heap->pools[i])
335			ion_page_pool_destroy(heap->pools[i]);
336	kfree(heap->pools);
337err_alloc_pools:
338	kfree(heap);
339	return ERR_PTR(-ENOMEM);
340}
341
342void ion_system_heap_destroy(struct ion_heap *heap)
343{
344	struct ion_system_heap *sys_heap = container_of(heap,
345							struct ion_system_heap,
346							heap);
347	int i;
348
349	for (i = 0; i < num_orders; i++)
350		ion_page_pool_destroy(sys_heap->pools[i]);
351	kfree(sys_heap->pools);
352	kfree(sys_heap);
353}
354
355static int ion_system_contig_heap_allocate(struct ion_heap *heap,
356					   struct ion_buffer *buffer,
357					   unsigned long len,
358					   unsigned long align,
359					   unsigned long flags)
360{
361	int order = get_order(len);
362	struct page *page;
363	struct sg_table *table;
364	unsigned long i;
365	int ret;
366
367	if (align > (PAGE_SIZE << order))
368		return -EINVAL;
369
370	page = alloc_pages(low_order_gfp_flags, order);
371	if (!page)
372		return -ENOMEM;
373
374	split_page(page, order);
375
376	len = PAGE_ALIGN(len);
377	for (i = len >> PAGE_SHIFT; i < (1 << order); i++)
378		__free_page(page + i);
379
380	table = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
381	if (!table) {
382		ret = -ENOMEM;
383		goto out;
384	}
385
386	ret = sg_alloc_table(table, 1, GFP_KERNEL);
387	if (ret)
388		goto out;
389
390	sg_set_page(table->sgl, page, len, 0);
391
392	buffer->priv_virt = table;
393
394	ion_pages_sync_for_device(NULL, page, len, DMA_BIDIRECTIONAL);
395
396	return 0;
397
398out:
399	for (i = 0; i < len >> PAGE_SHIFT; i++)
400		__free_page(page + i);
401	kfree(table);
402	return ret;
403}
404
405static void ion_system_contig_heap_free(struct ion_buffer *buffer)
406{
407	struct sg_table *table = buffer->priv_virt;
408	struct page *page = sg_page(table->sgl);
409	unsigned long pages = PAGE_ALIGN(buffer->size) >> PAGE_SHIFT;
410	unsigned long i;
411
412	for (i = 0; i < pages; i++)
413		__free_page(page + i);
414	sg_free_table(table);
415	kfree(table);
416}
417
418static int ion_system_contig_heap_phys(struct ion_heap *heap,
419				       struct ion_buffer *buffer,
420				       ion_phys_addr_t *addr, size_t *len)
421{
422	struct sg_table *table = buffer->priv_virt;
423	struct page *page = sg_page(table->sgl);
424	*addr = page_to_phys(page);
425	*len = buffer->size;
426	return 0;
427}
428
429static struct sg_table *ion_system_contig_heap_map_dma(struct ion_heap *heap,
430						struct ion_buffer *buffer)
431{
432	return buffer->priv_virt;
433}
434
435static void ion_system_contig_heap_unmap_dma(struct ion_heap *heap,
436					     struct ion_buffer *buffer)
437{
438}
439
440static struct ion_heap_ops kmalloc_ops = {
441	.allocate = ion_system_contig_heap_allocate,
442	.free = ion_system_contig_heap_free,
443	.phys = ion_system_contig_heap_phys,
444	.map_dma = ion_system_contig_heap_map_dma,
445	.unmap_dma = ion_system_contig_heap_unmap_dma,
446	.map_kernel = ion_heap_map_kernel,
447	.unmap_kernel = ion_heap_unmap_kernel,
448	.map_user = ion_heap_map_user,
449};
450
451struct ion_heap *ion_system_contig_heap_create(struct ion_platform_heap *unused)
452{
453	struct ion_heap *heap;
454
455	heap = kzalloc(sizeof(struct ion_heap), GFP_KERNEL);
456	if (!heap)
457		return ERR_PTR(-ENOMEM);
458	heap->ops = &kmalloc_ops;
459	heap->type = ION_HEAP_TYPE_SYSTEM_CONTIG;
460	return heap;
461}
462
463void ion_system_contig_heap_destroy(struct ion_heap *heap)
464{
465	kfree(heap);
466}
467
468