ion_system_heap.c revision ea725ec8b1d2a5f6a46dd45174fcd6a5f8c9dd5b 
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 = ion_heap_alloc_pages(buffer, 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	bool split_pages = ion_buffer_fault_user_mappings(buffer);
95	int i;
96
97	if (!cached) {
98		struct ion_page_pool *pool = heap->pools[order_to_index(order)];
99		ion_page_pool_free(pool, page);
100	} else if (split_pages) {
101		for (i = 0; i < (1 << order); i++)
102			__free_page(page + i);
103	} else {
104		__free_pages(page, order);
105	}
106}
107
108
109static struct page_info *alloc_largest_available(struct ion_system_heap *heap,
110						 struct ion_buffer *buffer,
111						 unsigned long size,
112						 unsigned int max_order)
113{
114	struct page *page;
115	struct page_info *info;
116	int i;
117
118	for (i = 0; i < num_orders; i++) {
119		if (size < order_to_size(orders[i]))
120			continue;
121		if (max_order < orders[i])
122			continue;
123
124		page = alloc_buffer_page(heap, buffer, orders[i]);
125		if (!page)
126			continue;
127
128		info = kmalloc(sizeof(struct page_info), GFP_KERNEL);
129		info->page = page;
130		info->order = orders[i];
131		return info;
132	}
133	return NULL;
134}
135
136static int ion_system_heap_allocate(struct ion_heap *heap,
137				     struct ion_buffer *buffer,
138				     unsigned long size, unsigned long align,
139				     unsigned long flags)
140{
141	struct ion_system_heap *sys_heap = container_of(heap,
142							struct ion_system_heap,
143							heap);
144	struct sg_table *table;
145	struct scatterlist *sg;
146	int ret;
147	struct list_head pages;
148	struct page_info *info, *tmp_info;
149	int i = 0;
150	long size_remaining = PAGE_ALIGN(size);
151	unsigned int max_order = orders[0];
152
153	if (align > PAGE_SIZE)
154		return -EINVAL;
155
156	if (ion_buffer_fault_user_mappings(buffer))
157		return -EINVAL;
158
159	INIT_LIST_HEAD(&pages);
160	while (size_remaining > 0) {
161		info = alloc_largest_available(sys_heap, buffer, size_remaining, max_order);
162		if (!info)
163			goto err;
164		list_add_tail(&info->list, &pages);
165		size_remaining -= (1 << info->order) * PAGE_SIZE;
166		max_order = info->order;
167		i++;
168	}
169	table = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
170	if (!table)
171		goto err;
172
173	ret = sg_alloc_table(table, i, GFP_KERNEL);
174	if (ret)
175		goto err1;
176
177	sg = table->sgl;
178	list_for_each_entry_safe(info, tmp_info, &pages, list) {
179		struct page *page = info->page;
180		sg_set_page(sg, page, (1 << info->order) * PAGE_SIZE, 0);
181		sg = sg_next(sg);
182		list_del(&info->list);
183		kfree(info);
184	}
185
186	buffer->priv_virt = table;
187	return 0;
188err1:
189	kfree(table);
190err:
191	list_for_each_entry_safe(info, tmp_info, &pages, list) {
192		free_buffer_page(sys_heap, buffer, info->page, info->order);
193		kfree(info);
194	}
195	return -ENOMEM;
196}
197
198void ion_system_heap_free(struct ion_buffer *buffer)
199{
200	struct ion_heap *heap = buffer->heap;
201	struct ion_system_heap *sys_heap = container_of(heap,
202							struct ion_system_heap,
203							heap);
204	struct sg_table *table = buffer->sg_table;
205	bool cached = ion_buffer_cached(buffer);
206	struct scatterlist *sg;
207	LIST_HEAD(pages);
208	int i;
209
210	/* uncached pages come from the page pools, zero them before returning
211	   for security purposes (other allocations are zerod at alloc time */
212	if (!cached)
213		ion_heap_buffer_zero(buffer);
214
215	for_each_sg(table->sgl, sg, table->nents, i)
216		free_buffer_page(sys_heap, buffer, sg_page(sg),
217				get_order(sg->length));
218	sg_free_table(table);
219	kfree(table);
220}
221
222struct sg_table *ion_system_heap_map_dma(struct ion_heap *heap,
223					 struct ion_buffer *buffer)
224{
225	return buffer->priv_virt;
226}
227
228void ion_system_heap_unmap_dma(struct ion_heap *heap,
229			       struct ion_buffer *buffer)
230{
231	return;
232}
233
234static struct ion_heap_ops system_heap_ops = {
235	.allocate = ion_system_heap_allocate,
236	.free = ion_system_heap_free,
237	.map_dma = ion_system_heap_map_dma,
238	.unmap_dma = ion_system_heap_unmap_dma,
239	.map_kernel = ion_heap_map_kernel,
240	.unmap_kernel = ion_heap_unmap_kernel,
241	.map_user = ion_heap_map_user,
242};
243
244static int ion_system_heap_shrink(struct shrinker *shrinker,
245				  struct shrink_control *sc) {
246
247	struct ion_heap *heap = container_of(shrinker, struct ion_heap,
248					     shrinker);
249	struct ion_system_heap *sys_heap = container_of(heap,
250							struct ion_system_heap,
251							heap);
252	int nr_total = 0;
253	int nr_freed = 0;
254	int i;
255
256	if (sc->nr_to_scan == 0)
257		goto end;
258
259	/* shrink the free list first, no point in zeroing the memory if
260	   we're just going to reclaim it */
261	nr_freed += ion_heap_freelist_drain(heap, sc->nr_to_scan * PAGE_SIZE) /
262		PAGE_SIZE;
263
264	if (nr_freed >= sc->nr_to_scan)
265		goto end;
266
267	for (i = 0; i < num_orders; i++) {
268		struct ion_page_pool *pool = sys_heap->pools[i];
269
270		nr_freed += ion_page_pool_shrink(pool, sc->gfp_mask,
271						 sc->nr_to_scan);
272		if (nr_freed >= sc->nr_to_scan)
273			break;
274	}
275
276end:
277	/* total number of items is whatever the page pools are holding
278	   plus whatever's in the freelist */
279	for (i = 0; i < num_orders; i++) {
280		struct ion_page_pool *pool = sys_heap->pools[i];
281		nr_total += ion_page_pool_shrink(pool, sc->gfp_mask, 0);
282	}
283	nr_total += ion_heap_freelist_size(heap) / PAGE_SIZE;
284	return nr_total;
285
286}
287
288static int ion_system_heap_debug_show(struct ion_heap *heap, struct seq_file *s,
289				      void *unused)
290{
291
292	struct ion_system_heap *sys_heap = container_of(heap,
293							struct ion_system_heap,
294							heap);
295	int i;
296	for (i = 0; i < num_orders; i++) {
297		struct ion_page_pool *pool = sys_heap->pools[i];
298		seq_printf(s, "%d order %u highmem pages in pool = %lu total\n",
299			   pool->high_count, pool->order,
300			   (1 << pool->order) * PAGE_SIZE * pool->high_count);
301		seq_printf(s, "%d order %u lowmem pages in pool = %lu total\n",
302			   pool->low_count, pool->order,
303			   (1 << pool->order) * PAGE_SIZE * pool->low_count);
304	}
305	return 0;
306}
307
308struct ion_heap *ion_system_heap_create(struct ion_platform_heap *unused)
309{
310	struct ion_system_heap *heap;
311	int i;
312
313	heap = kzalloc(sizeof(struct ion_system_heap), GFP_KERNEL);
314	if (!heap)
315		return ERR_PTR(-ENOMEM);
316	heap->heap.ops = &system_heap_ops;
317	heap->heap.type = ION_HEAP_TYPE_SYSTEM;
318	heap->heap.flags = ION_HEAP_FLAG_DEFER_FREE;
319	heap->pools = kzalloc(sizeof(struct ion_page_pool *) * num_orders,
320			      GFP_KERNEL);
321	if (!heap->pools)
322		goto err_alloc_pools;
323	for (i = 0; i < num_orders; i++) {
324		struct ion_page_pool *pool;
325		gfp_t gfp_flags = low_order_gfp_flags;
326
327		if (orders[i] > 4)
328			gfp_flags = high_order_gfp_flags;
329		pool = ion_page_pool_create(gfp_flags, orders[i]);
330		if (!pool)
331			goto err_create_pool;
332		heap->pools[i] = pool;
333	}
334
335	heap->heap.shrinker.shrink = ion_system_heap_shrink;
336	heap->heap.shrinker.seeks = DEFAULT_SEEKS;
337	heap->heap.shrinker.batch = 0;
338	register_shrinker(&heap->heap.shrinker);
339	heap->heap.debug_show = ion_system_heap_debug_show;
340	return &heap->heap;
341err_create_pool:
342	for (i = 0; i < num_orders; i++)
343		if (heap->pools[i])
344			ion_page_pool_destroy(heap->pools[i]);
345	kfree(heap->pools);
346err_alloc_pools:
347	kfree(heap);
348	return ERR_PTR(-ENOMEM);
349}
350
351void ion_system_heap_destroy(struct ion_heap *heap)
352{
353	struct ion_system_heap *sys_heap = container_of(heap,
354							struct ion_system_heap,
355							heap);
356	int i;
357
358	for (i = 0; i < num_orders; i++)
359		ion_page_pool_destroy(sys_heap->pools[i]);
360	kfree(sys_heap->pools);
361	kfree(sys_heap);
362}
363
364static int ion_system_contig_heap_allocate(struct ion_heap *heap,
365					   struct ion_buffer *buffer,
366					   unsigned long len,
367					   unsigned long align,
368					   unsigned long flags)
369{
370	int order = get_order(len);
371
372	if (align > (PAGE_SIZE << order))
373		return -EINVAL;
374
375	if (ion_buffer_fault_user_mappings(buffer))
376		return -EINVAL;
377
378	buffer->priv_virt = kzalloc(len, GFP_KERNEL);
379	if (!buffer->priv_virt)
380		return -ENOMEM;
381	return 0;
382}
383
384void ion_system_contig_heap_free(struct ion_buffer *buffer)
385{
386	kfree(buffer->priv_virt);
387}
388
389static int ion_system_contig_heap_phys(struct ion_heap *heap,
390				       struct ion_buffer *buffer,
391				       ion_phys_addr_t *addr, size_t *len)
392{
393	*addr = virt_to_phys(buffer->priv_virt);
394	*len = buffer->size;
395	return 0;
396}
397
398struct sg_table *ion_system_contig_heap_map_dma(struct ion_heap *heap,
399						struct ion_buffer *buffer)
400{
401	struct sg_table *table;
402	int ret;
403
404	table = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
405	if (!table)
406		return ERR_PTR(-ENOMEM);
407	ret = sg_alloc_table(table, 1, GFP_KERNEL);
408	if (ret) {
409		kfree(table);
410		return ERR_PTR(ret);
411	}
412	sg_set_page(table->sgl, virt_to_page(buffer->priv_virt), buffer->size,
413		    0);
414	return table;
415}
416
417void ion_system_contig_heap_unmap_dma(struct ion_heap *heap,
418				      struct ion_buffer *buffer)
419{
420	sg_free_table(buffer->sg_table);
421	kfree(buffer->sg_table);
422}
423
424static struct ion_heap_ops kmalloc_ops = {
425	.allocate = ion_system_contig_heap_allocate,
426	.free = ion_system_contig_heap_free,
427	.phys = ion_system_contig_heap_phys,
428	.map_dma = ion_system_contig_heap_map_dma,
429	.unmap_dma = ion_system_contig_heap_unmap_dma,
430	.map_kernel = ion_heap_map_kernel,
431	.unmap_kernel = ion_heap_unmap_kernel,
432	.map_user = ion_heap_map_user,
433};
434
435struct ion_heap *ion_system_contig_heap_create(struct ion_platform_heap *unused)
436{
437	struct ion_heap *heap;
438
439	heap = kzalloc(sizeof(struct ion_heap), GFP_KERNEL);
440	if (!heap)
441		return ERR_PTR(-ENOMEM);
442	heap->ops = &kmalloc_ops;
443	heap->type = ION_HEAP_TYPE_SYSTEM_CONTIG;
444	return heap;
445}
446
447void ion_system_contig_heap_destroy(struct ion_heap *heap)
448{
449	kfree(heap);
450}
451
452