ion_system_heap.c revision b1aced6f2dfd8c11a36643b020aa8d7040eb0557 
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 unsigned long ion_system_heap_shrink_count(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 i;
245
246	/* total number of items is whatever the page pools are holding
247	   plus whatever's in the freelist */
248	for (i = 0; i < num_orders; i++) {
249		struct ion_page_pool *pool = sys_heap->pools[i];
250		nr_total += ion_page_pool_shrink(pool, sc->gfp_mask, 0);
251	}
252	nr_total += ion_heap_freelist_size(heap) / PAGE_SIZE;
253	return nr_total;
254
255}
256
257static unsigned long ion_system_heap_shrink_scan(struct shrinker *shrinker,
258				  struct shrink_control *sc)
259{
260
261	struct ion_heap *heap = container_of(shrinker, struct ion_heap,
262					     shrinker);
263	struct ion_system_heap *sys_heap = container_of(heap,
264							struct ion_system_heap,
265							heap);
266	int nr_freed = 0;
267	int i;
268
269	if (sc->nr_to_scan == 0)
270		goto end;
271
272	/* shrink the free list first, no point in zeroing the memory if
273	   we're just going to reclaim it */
274	nr_freed += ion_heap_freelist_drain(heap, sc->nr_to_scan * PAGE_SIZE) /
275		PAGE_SIZE;
276
277	if (nr_freed >= sc->nr_to_scan)
278		goto end;
279
280	for (i = 0; i < num_orders; i++) {
281		struct ion_page_pool *pool = sys_heap->pools[i];
282
283		nr_freed += ion_page_pool_shrink(pool, sc->gfp_mask,
284						 sc->nr_to_scan);
285		if (nr_freed >= sc->nr_to_scan)
286			break;
287	}
288
289end:
290	return nr_freed;
291
292}
293
294static int ion_system_heap_debug_show(struct ion_heap *heap, struct seq_file *s,
295				      void *unused)
296{
297
298	struct ion_system_heap *sys_heap = container_of(heap,
299							struct ion_system_heap,
300							heap);
301	int i;
302	for (i = 0; i < num_orders; i++) {
303		struct ion_page_pool *pool = sys_heap->pools[i];
304		seq_printf(s, "%d order %u highmem pages in pool = %lu total\n",
305			   pool->high_count, pool->order,
306			   (1 << pool->order) * PAGE_SIZE * pool->high_count);
307		seq_printf(s, "%d order %u lowmem pages in pool = %lu total\n",
308			   pool->low_count, pool->order,
309			   (1 << pool->order) * PAGE_SIZE * pool->low_count);
310	}
311	return 0;
312}
313
314struct ion_heap *ion_system_heap_create(struct ion_platform_heap *unused)
315{
316	struct ion_system_heap *heap;
317	int i;
318
319	heap = kzalloc(sizeof(struct ion_system_heap), GFP_KERNEL);
320	if (!heap)
321		return ERR_PTR(-ENOMEM);
322	heap->heap.ops = &system_heap_ops;
323	heap->heap.type = ION_HEAP_TYPE_SYSTEM;
324	heap->heap.flags = ION_HEAP_FLAG_DEFER_FREE;
325	heap->pools = kzalloc(sizeof(struct ion_page_pool *) * num_orders,
326			      GFP_KERNEL);
327	if (!heap->pools)
328		goto err_alloc_pools;
329	for (i = 0; i < num_orders; i++) {
330		struct ion_page_pool *pool;
331		gfp_t gfp_flags = low_order_gfp_flags;
332
333		if (orders[i] > 4)
334			gfp_flags = high_order_gfp_flags;
335		pool = ion_page_pool_create(gfp_flags, orders[i]);
336		if (!pool)
337			goto err_create_pool;
338		heap->pools[i] = pool;
339	}
340
341	heap->heap.shrinker.scan_objects = ion_system_heap_shrink_scan;
342	heap->heap.shrinker.count_objects = ion_system_heap_shrink_count;
343	heap->heap.shrinker.seeks = DEFAULT_SEEKS;
344	heap->heap.shrinker.batch = 0;
345	register_shrinker(&heap->heap.shrinker);
346	heap->heap.debug_show = ion_system_heap_debug_show;
347	return &heap->heap;
348err_create_pool:
349	for (i = 0; i < num_orders; i++)
350		if (heap->pools[i])
351			ion_page_pool_destroy(heap->pools[i]);
352	kfree(heap->pools);
353err_alloc_pools:
354	kfree(heap);
355	return ERR_PTR(-ENOMEM);
356}
357
358void ion_system_heap_destroy(struct ion_heap *heap)
359{
360	struct ion_system_heap *sys_heap = container_of(heap,
361							struct ion_system_heap,
362							heap);
363	int i;
364
365	for (i = 0; i < num_orders; i++)
366		ion_page_pool_destroy(sys_heap->pools[i]);
367	kfree(sys_heap->pools);
368	kfree(sys_heap);
369}
370
371static int ion_system_contig_heap_allocate(struct ion_heap *heap,
372					   struct ion_buffer *buffer,
373					   unsigned long len,
374					   unsigned long align,
375					   unsigned long flags)
376{
377	int order = get_order(len);
378	struct page *page;
379	struct sg_table *table;
380	unsigned long i;
381	int ret;
382
383	if (align > (PAGE_SIZE << order))
384		return -EINVAL;
385
386	page = alloc_pages(low_order_gfp_flags, order);
387	if (!page)
388		return -ENOMEM;
389
390	split_page(page, order);
391
392	len = PAGE_ALIGN(len);
393	for (i = len >> PAGE_SHIFT; i < (1 << order); i++)
394		__free_page(page + i);
395
396	table = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
397	if (!table) {
398		ret = -ENOMEM;
399		goto out;
400	}
401
402	ret = sg_alloc_table(table, 1, GFP_KERNEL);
403	if (ret)
404		goto out;
405
406	sg_set_page(table->sgl, page, len, 0);
407
408	buffer->priv_virt = table;
409
410	ion_pages_sync_for_device(NULL, page, len, DMA_BIDIRECTIONAL);
411
412	return 0;
413
414out:
415	for (i = 0; i < len >> PAGE_SHIFT; i++)
416		__free_page(page + i);
417	kfree(table);
418	return ret;
419}
420
421static void ion_system_contig_heap_free(struct ion_buffer *buffer)
422{
423	struct sg_table *table = buffer->priv_virt;
424	struct page *page = sg_page(table->sgl);
425	unsigned long pages = PAGE_ALIGN(buffer->size) >> PAGE_SHIFT;
426	unsigned long i;
427
428	for (i = 0; i < pages; i++)
429		__free_page(page + i);
430	sg_free_table(table);
431	kfree(table);
432}
433
434static int ion_system_contig_heap_phys(struct ion_heap *heap,
435				       struct ion_buffer *buffer,
436				       ion_phys_addr_t *addr, size_t *len)
437{
438	struct sg_table *table = buffer->priv_virt;
439	struct page *page = sg_page(table->sgl);
440	*addr = page_to_phys(page);
441	*len = buffer->size;
442	return 0;
443}
444
445static struct sg_table *ion_system_contig_heap_map_dma(struct ion_heap *heap,
446						struct ion_buffer *buffer)
447{
448	return buffer->priv_virt;
449}
450
451static void ion_system_contig_heap_unmap_dma(struct ion_heap *heap,
452					     struct ion_buffer *buffer)
453{
454}
455
456static struct ion_heap_ops kmalloc_ops = {
457	.allocate = ion_system_contig_heap_allocate,
458	.free = ion_system_contig_heap_free,
459	.phys = ion_system_contig_heap_phys,
460	.map_dma = ion_system_contig_heap_map_dma,
461	.unmap_dma = ion_system_contig_heap_unmap_dma,
462	.map_kernel = ion_heap_map_kernel,
463	.unmap_kernel = ion_heap_unmap_kernel,
464	.map_user = ion_heap_map_user,
465};
466
467struct ion_heap *ion_system_contig_heap_create(struct ion_platform_heap *unused)
468{
469	struct ion_heap *heap;
470
471	heap = kzalloc(sizeof(struct ion_heap), GFP_KERNEL);
472	if (!heap)
473		return ERR_PTR(-ENOMEM);
474	heap->ops = &kmalloc_ops;
475	heap->type = ION_HEAP_TYPE_SYSTEM_CONTIG;
476	return heap;
477}
478
479void ion_system_contig_heap_destroy(struct ion_heap *heap)
480{
481	kfree(heap);
482}
483
484