ion_system_heap.c revision 5c6a470557e51bb4e868c22450811726c32f5787 
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 unsigned int high_order_gfp_flags = (GFP_HIGHUSER | __GFP_ZERO |
30					    __GFP_NOWARN | __GFP_NORETRY) &
31					   ~__GFP_WAIT;
32static unsigned int low_order_gfp_flags  = (GFP_HIGHUSER | __GFP_ZERO |
33					 __GFP_NOWARN);
34static const unsigned int orders[] = {8, 4, 0};
35static const int num_orders = ARRAY_SIZE(orders);
36static int order_to_index(unsigned int order)
37{
38	int i;
39	for (i = 0; i < num_orders; i++)
40		if (order == orders[i])
41			return i;
42	BUG();
43	return -1;
44}
45
46static unsigned int order_to_size(int order)
47{
48	return PAGE_SIZE << order;
49}
50
51struct ion_system_heap {
52	struct ion_heap heap;
53	struct ion_page_pool **pools;
54};
55
56struct page_info {
57	struct page *page;
58	unsigned int order;
59	struct list_head list;
60};
61
62static struct page *alloc_buffer_page(struct ion_system_heap *heap,
63				      struct ion_buffer *buffer,
64				      unsigned long order)
65{
66	bool cached = ion_buffer_cached(buffer);
67	struct ion_page_pool *pool = heap->pools[order_to_index(order)];
68	struct page *page;
69
70	if (!cached) {
71		page = ion_page_pool_alloc(pool);
72	} else {
73		gfp_t gfp_flags = low_order_gfp_flags;
74
75		if (order > 4)
76			gfp_flags = high_order_gfp_flags;
77		page = alloc_pages(gfp_flags, order);
78		if (!page)
79			return 0;
80		ion_pages_sync_for_device(NULL, page, PAGE_SIZE << order,
81						DMA_BIDIRECTIONAL);
82	}
83	if (!page)
84		return 0;
85
86	return page;
87}
88
89static void free_buffer_page(struct ion_system_heap *heap,
90			     struct ion_buffer *buffer, struct page *page,
91			     unsigned int order)
92{
93	bool cached = ion_buffer_cached(buffer);
94
95	if (!cached) {
96		struct ion_page_pool *pool = heap->pools[order_to_index(order)];
97		ion_page_pool_free(pool, page);
98	} else {
99		__free_pages(page, order);
100	}
101}
102
103
104static struct page_info *alloc_largest_available(struct ion_system_heap *heap,
105						 struct ion_buffer *buffer,
106						 unsigned long size,
107						 unsigned int max_order)
108{
109	struct page *page;
110	struct page_info *info;
111	int i;
112
113	for (i = 0; i < num_orders; i++) {
114		if (size < order_to_size(orders[i]))
115			continue;
116		if (max_order < orders[i])
117			continue;
118
119		page = alloc_buffer_page(heap, buffer, orders[i]);
120		if (!page)
121			continue;
122
123		info = kmalloc(sizeof(struct page_info), GFP_KERNEL);
124		info->page = page;
125		info->order = orders[i];
126		return info;
127	}
128	return NULL;
129}
130
131static int ion_system_heap_allocate(struct ion_heap *heap,
132				     struct ion_buffer *buffer,
133				     unsigned long size, unsigned long align,
134				     unsigned long flags)
135{
136	struct ion_system_heap *sys_heap = container_of(heap,
137							struct ion_system_heap,
138							heap);
139	struct sg_table *table;
140	struct scatterlist *sg;
141	int ret;
142	struct list_head pages;
143	struct page_info *info, *tmp_info;
144	int i = 0;
145	long size_remaining = PAGE_ALIGN(size);
146	unsigned int max_order = orders[0];
147
148	if (align > PAGE_SIZE)
149		return -EINVAL;
150
151	INIT_LIST_HEAD(&pages);
152	while (size_remaining > 0) {
153		info = alloc_largest_available(sys_heap, buffer, size_remaining, max_order);
154		if (!info)
155			goto err;
156		list_add_tail(&info->list, &pages);
157		size_remaining -= (1 << info->order) * PAGE_SIZE;
158		max_order = info->order;
159		i++;
160	}
161	table = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
162	if (!table)
163		goto err;
164
165	ret = sg_alloc_table(table, i, GFP_KERNEL);
166	if (ret)
167		goto err1;
168
169	sg = table->sgl;
170	list_for_each_entry_safe(info, tmp_info, &pages, list) {
171		struct page *page = info->page;
172		sg_set_page(sg, page, (1 << info->order) * PAGE_SIZE, 0);
173		sg = sg_next(sg);
174		list_del(&info->list);
175		kfree(info);
176	}
177
178	buffer->priv_virt = table;
179	return 0;
180err1:
181	kfree(table);
182err:
183	list_for_each_entry_safe(info, tmp_info, &pages, list) {
184		free_buffer_page(sys_heap, buffer, info->page, info->order);
185		kfree(info);
186	}
187	return -ENOMEM;
188}
189
190void ion_system_heap_free(struct ion_buffer *buffer)
191{
192	struct ion_heap *heap = buffer->heap;
193	struct ion_system_heap *sys_heap = container_of(heap,
194							struct ion_system_heap,
195							heap);
196	struct sg_table *table = buffer->sg_table;
197	bool cached = ion_buffer_cached(buffer);
198	struct scatterlist *sg;
199	LIST_HEAD(pages);
200	int i;
201
202	/* uncached pages come from the page pools, zero them before returning
203	   for security purposes (other allocations are zerod at alloc time */
204	if (!cached)
205		ion_heap_buffer_zero(buffer);
206
207	for_each_sg(table->sgl, sg, table->nents, i)
208		free_buffer_page(sys_heap, buffer, sg_page(sg),
209				get_order(sg->length));
210	sg_free_table(table);
211	kfree(table);
212}
213
214struct sg_table *ion_system_heap_map_dma(struct ion_heap *heap,
215					 struct ion_buffer *buffer)
216{
217	return buffer->priv_virt;
218}
219
220void ion_system_heap_unmap_dma(struct ion_heap *heap,
221			       struct ion_buffer *buffer)
222{
223	return;
224}
225
226static struct ion_heap_ops system_heap_ops = {
227	.allocate = ion_system_heap_allocate,
228	.free = ion_system_heap_free,
229	.map_dma = ion_system_heap_map_dma,
230	.unmap_dma = ion_system_heap_unmap_dma,
231	.map_kernel = ion_heap_map_kernel,
232	.unmap_kernel = ion_heap_unmap_kernel,
233	.map_user = ion_heap_map_user,
234};
235
236static int ion_system_heap_shrink(struct shrinker *shrinker,
237				  struct shrink_control *sc) {
238
239	struct ion_heap *heap = container_of(shrinker, struct ion_heap,
240					     shrinker);
241	struct ion_system_heap *sys_heap = container_of(heap,
242							struct ion_system_heap,
243							heap);
244	int nr_total = 0;
245	int nr_freed = 0;
246	int i;
247
248	if (sc->nr_to_scan == 0)
249		goto end;
250
251	/* shrink the free list first, no point in zeroing the memory if
252	   we're just going to reclaim it */
253	nr_freed += ion_heap_freelist_drain(heap, sc->nr_to_scan * PAGE_SIZE) /
254		PAGE_SIZE;
255
256	if (nr_freed >= sc->nr_to_scan)
257		goto end;
258
259	for (i = 0; i < num_orders; i++) {
260		struct ion_page_pool *pool = sys_heap->pools[i];
261
262		nr_freed += ion_page_pool_shrink(pool, sc->gfp_mask,
263						 sc->nr_to_scan);
264		if (nr_freed >= sc->nr_to_scan)
265			break;
266	}
267
268end:
269	/* total number of items is whatever the page pools are holding
270	   plus whatever's in the freelist */
271	for (i = 0; i < num_orders; i++) {
272		struct ion_page_pool *pool = sys_heap->pools[i];
273		nr_total += ion_page_pool_shrink(pool, sc->gfp_mask, 0);
274	}
275	nr_total += ion_heap_freelist_size(heap) / PAGE_SIZE;
276	return nr_total;
277
278}
279
280static int ion_system_heap_debug_show(struct ion_heap *heap, struct seq_file *s,
281				      void *unused)
282{
283
284	struct ion_system_heap *sys_heap = container_of(heap,
285							struct ion_system_heap,
286							heap);
287	int i;
288	for (i = 0; i < num_orders; i++) {
289		struct ion_page_pool *pool = sys_heap->pools[i];
290		seq_printf(s, "%d order %u highmem pages in pool = %lu total\n",
291			   pool->high_count, pool->order,
292			   (1 << pool->order) * PAGE_SIZE * pool->high_count);
293		seq_printf(s, "%d order %u lowmem pages in pool = %lu total\n",
294			   pool->low_count, pool->order,
295			   (1 << pool->order) * PAGE_SIZE * pool->low_count);
296	}
297	return 0;
298}
299
300struct ion_heap *ion_system_heap_create(struct ion_platform_heap *unused)
301{
302	struct ion_system_heap *heap;
303	int i;
304
305	heap = kzalloc(sizeof(struct ion_system_heap), GFP_KERNEL);
306	if (!heap)
307		return ERR_PTR(-ENOMEM);
308	heap->heap.ops = &system_heap_ops;
309	heap->heap.type = ION_HEAP_TYPE_SYSTEM;
310	heap->heap.flags = ION_HEAP_FLAG_DEFER_FREE;
311	heap->pools = kzalloc(sizeof(struct ion_page_pool *) * num_orders,
312			      GFP_KERNEL);
313	if (!heap->pools)
314		goto err_alloc_pools;
315	for (i = 0; i < num_orders; i++) {
316		struct ion_page_pool *pool;
317		gfp_t gfp_flags = low_order_gfp_flags;
318
319		if (orders[i] > 4)
320			gfp_flags = high_order_gfp_flags;
321		pool = ion_page_pool_create(gfp_flags, orders[i]);
322		if (!pool)
323			goto err_create_pool;
324		heap->pools[i] = pool;
325	}
326
327	heap->heap.shrinker.shrink = ion_system_heap_shrink;
328	heap->heap.shrinker.seeks = DEFAULT_SEEKS;
329	heap->heap.shrinker.batch = 0;
330	register_shrinker(&heap->heap.shrinker);
331	heap->heap.debug_show = ion_system_heap_debug_show;
332	return &heap->heap;
333err_create_pool:
334	for (i = 0; i < num_orders; i++)
335		if (heap->pools[i])
336			ion_page_pool_destroy(heap->pools[i]);
337	kfree(heap->pools);
338err_alloc_pools:
339	kfree(heap);
340	return ERR_PTR(-ENOMEM);
341}
342
343void ion_system_heap_destroy(struct ion_heap *heap)
344{
345	struct ion_system_heap *sys_heap = container_of(heap,
346							struct ion_system_heap,
347							heap);
348	int i;
349
350	for (i = 0; i < num_orders; i++)
351		ion_page_pool_destroy(sys_heap->pools[i]);
352	kfree(sys_heap->pools);
353	kfree(sys_heap);
354}
355
356static int ion_system_contig_heap_allocate(struct ion_heap *heap,
357					   struct ion_buffer *buffer,
358					   unsigned long len,
359					   unsigned long align,
360					   unsigned long flags)
361{
362	int order = get_order(len);
363	struct page *page;
364	struct sg_table *table;
365	unsigned long i;
366	int ret;
367
368	if (align > (PAGE_SIZE << order))
369		return -EINVAL;
370
371	page = alloc_pages(low_order_gfp_flags, order);
372	if (!page)
373		return -ENOMEM;
374
375	split_page(page, order);
376
377	len = PAGE_ALIGN(len);
378	for (i = len >> PAGE_SHIFT; i < (1 << order); i++)
379		__free_page(page + i);
380
381	table = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
382	if (!table) {
383		ret = -ENOMEM;
384		goto out;
385	}
386
387	ret = sg_alloc_table(table, 1, GFP_KERNEL);
388	if (ret)
389		goto out;
390
391	sg_set_page(table->sgl, page, len, 0);
392
393	buffer->priv_virt = table;
394
395	ion_pages_sync_for_device(NULL, page, len, DMA_BIDIRECTIONAL);
396
397	return 0;
398
399out:
400	for (i = 0; i < len >> PAGE_SHIFT; i++)
401		__free_page(page + i);
402	kfree(table);
403	return ret;
404}
405
406void ion_system_contig_heap_free(struct ion_buffer *buffer)
407{
408	struct sg_table *table = buffer->priv_virt;
409	struct page *page = sg_page(table->sgl);
410	unsigned long pages = PAGE_ALIGN(buffer->size) >> PAGE_SHIFT;
411	unsigned long i;
412
413	for (i = 0; i < pages; i++)
414		__free_page(page + i);
415	sg_free_table(table);
416	kfree(table);
417}
418
419static int ion_system_contig_heap_phys(struct ion_heap *heap,
420				       struct ion_buffer *buffer,
421				       ion_phys_addr_t *addr, size_t *len)
422{
423	struct sg_table *table = buffer->priv_virt;
424	struct page *page = sg_page(table->sgl);
425	*addr = page_to_phys(page);
426	*len = buffer->size;
427	return 0;
428}
429
430struct sg_table *ion_system_contig_heap_map_dma(struct ion_heap *heap,
431						struct ion_buffer *buffer)
432{
433	return buffer->priv_virt;
434}
435
436void ion_system_contig_heap_unmap_dma(struct ion_heap *heap,
437				      struct ion_buffer *buffer)
438{
439}
440
441static struct ion_heap_ops kmalloc_ops = {
442	.allocate = ion_system_contig_heap_allocate,
443	.free = ion_system_contig_heap_free,
444	.phys = ion_system_contig_heap_phys,
445	.map_dma = ion_system_contig_heap_map_dma,
446	.unmap_dma = ion_system_contig_heap_unmap_dma,
447	.map_kernel = ion_heap_map_kernel,
448	.unmap_kernel = ion_heap_unmap_kernel,
449	.map_user = ion_heap_map_user,
450};
451
452struct ion_heap *ion_system_contig_heap_create(struct ion_platform_heap *unused)
453{
454	struct ion_heap *heap;
455
456	heap = kzalloc(sizeof(struct ion_heap), GFP_KERNEL);
457	if (!heap)
458		return ERR_PTR(-ENOMEM);
459	heap->ops = &kmalloc_ops;
460	heap->type = ION_HEAP_TYPE_SYSTEM_CONTIG;
461	return heap;
462}
463
464void ion_system_contig_heap_destroy(struct ion_heap *heap)
465{
466	kfree(heap);
467}
468
469