ion_system_heap.c revision f4ea823be2ca9e61522de002804c9a7a54c9be16 
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	info = kmalloc(sizeof(struct page_info), GFP_KERNEL);
112	if (!info)
113		return NULL;
114
115	for (i = 0; i < num_orders; i++) {
116		if (size < order_to_size(orders[i]))
117			continue;
118		if (max_order < orders[i])
119			continue;
120
121		page = alloc_buffer_page(heap, buffer, orders[i]);
122		if (!page)
123			continue;
124
125		info->page = page;
126		info->order = orders[i];
127		return info;
128	}
129	kfree(info);
130
131	return NULL;
132}
133
134static int ion_system_heap_allocate(struct ion_heap *heap,
135				     struct ion_buffer *buffer,
136				     unsigned long size, unsigned long align,
137				     unsigned long flags)
138{
139	struct ion_system_heap *sys_heap = container_of(heap,
140							struct ion_system_heap,
141							heap);
142	struct sg_table *table;
143	struct scatterlist *sg;
144	int ret;
145	struct list_head pages;
146	struct page_info *info, *tmp_info;
147	int i = 0;
148	long size_remaining = PAGE_ALIGN(size);
149	unsigned int max_order = orders[0];
150
151	if (align > PAGE_SIZE)
152		return -EINVAL;
153
154	INIT_LIST_HEAD(&pages);
155	while (size_remaining > 0) {
156		info = alloc_largest_available(sys_heap, buffer, size_remaining,
157						max_order);
158		if (!info)
159			goto err;
160		list_add_tail(&info->list, &pages);
161		size_remaining -= (1 << info->order) * PAGE_SIZE;
162		max_order = info->order;
163		i++;
164	}
165	table = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
166	if (!table)
167		goto err;
168
169	ret = sg_alloc_table(table, i, GFP_KERNEL);
170	if (ret)
171		goto err1;
172
173	sg = table->sgl;
174	list_for_each_entry_safe(info, tmp_info, &pages, list) {
175		struct page *page = info->page;
176		sg_set_page(sg, page, (1 << info->order) * PAGE_SIZE, 0);
177		sg = sg_next(sg);
178		list_del(&info->list);
179		kfree(info);
180	}
181
182	buffer->priv_virt = table;
183	return 0;
184err1:
185	kfree(table);
186err:
187	list_for_each_entry_safe(info, tmp_info, &pages, list) {
188		free_buffer_page(sys_heap, buffer, info->page, info->order);
189		kfree(info);
190	}
191	return -ENOMEM;
192}
193
194static void ion_system_heap_free(struct ion_buffer *buffer)
195{
196	struct ion_heap *heap = buffer->heap;
197	struct ion_system_heap *sys_heap = container_of(heap,
198							struct ion_system_heap,
199							heap);
200	struct sg_table *table = buffer->sg_table;
201	bool cached = ion_buffer_cached(buffer);
202	struct scatterlist *sg;
203	LIST_HEAD(pages);
204	int i;
205
206	/* uncached pages come from the page pools, zero them before returning
207	   for security purposes (other allocations are zerod at alloc time */
208	if (!cached)
209		ion_heap_buffer_zero(buffer);
210
211	for_each_sg(table->sgl, sg, table->nents, i)
212		free_buffer_page(sys_heap, buffer, sg_page(sg),
213				get_order(sg->length));
214	sg_free_table(table);
215	kfree(table);
216}
217
218static struct sg_table *ion_system_heap_map_dma(struct ion_heap *heap,
219						struct ion_buffer *buffer)
220{
221	return buffer->priv_virt;
222}
223
224static void ion_system_heap_unmap_dma(struct ion_heap *heap,
225				      struct ion_buffer *buffer)
226{
227	return;
228}
229
230static struct ion_heap_ops system_heap_ops = {
231	.allocate = ion_system_heap_allocate,
232	.free = ion_system_heap_free,
233	.map_dma = ion_system_heap_map_dma,
234	.unmap_dma = ion_system_heap_unmap_dma,
235	.map_kernel = ion_heap_map_kernel,
236	.unmap_kernel = ion_heap_unmap_kernel,
237	.map_user = ion_heap_map_user,
238};
239
240static unsigned long ion_system_heap_shrink_count(struct shrinker *shrinker,
241				  struct shrink_control *sc)
242{
243	struct ion_heap *heap = container_of(shrinker, struct ion_heap,
244					     shrinker);
245	struct ion_system_heap *sys_heap = container_of(heap,
246							struct ion_system_heap,
247							heap);
248	int nr_total = 0;
249	int i;
250
251	/* total number of items is whatever the page pools are holding
252	   plus whatever's in the freelist */
253	for (i = 0; i < num_orders; i++) {
254		struct ion_page_pool *pool = sys_heap->pools[i];
255		nr_total += ion_page_pool_shrink(pool, sc->gfp_mask, 0);
256	}
257	nr_total += ion_heap_freelist_size(heap) / PAGE_SIZE;
258	return nr_total;
259
260}
261
262static unsigned long ion_system_heap_shrink_scan(struct shrinker *shrinker,
263				  struct shrink_control *sc)
264{
265
266	struct ion_heap *heap = container_of(shrinker, struct ion_heap,
267					     shrinker);
268	struct ion_system_heap *sys_heap = container_of(heap,
269							struct ion_system_heap,
270							heap);
271	int nr_freed = 0;
272	int i;
273
274	if (sc->nr_to_scan == 0)
275		goto end;
276
277	/* shrink the free list first, no point in zeroing the memory if
278	   we're just going to reclaim it */
279	nr_freed += ion_heap_freelist_drain(heap, sc->nr_to_scan * PAGE_SIZE) /
280		PAGE_SIZE;
281
282	if (nr_freed >= sc->nr_to_scan)
283		goto end;
284
285	for (i = 0; i < num_orders; i++) {
286		struct ion_page_pool *pool = sys_heap->pools[i];
287
288		nr_freed += ion_page_pool_shrink(pool, sc->gfp_mask,
289						 sc->nr_to_scan);
290		if (nr_freed >= sc->nr_to_scan)
291			break;
292	}
293
294end:
295	return nr_freed;
296
297}
298
299static int ion_system_heap_debug_show(struct ion_heap *heap, struct seq_file *s,
300				      void *unused)
301{
302
303	struct ion_system_heap *sys_heap = container_of(heap,
304							struct ion_system_heap,
305							heap);
306	int i;
307	for (i = 0; i < num_orders; i++) {
308		struct ion_page_pool *pool = sys_heap->pools[i];
309		seq_printf(s, "%d order %u highmem pages in pool = %lu total\n",
310			   pool->high_count, pool->order,
311			   (1 << pool->order) * PAGE_SIZE * pool->high_count);
312		seq_printf(s, "%d order %u lowmem pages in pool = %lu total\n",
313			   pool->low_count, pool->order,
314			   (1 << pool->order) * PAGE_SIZE * pool->low_count);
315	}
316	return 0;
317}
318
319struct ion_heap *ion_system_heap_create(struct ion_platform_heap *unused)
320{
321	struct ion_system_heap *heap;
322	int i;
323
324	heap = kzalloc(sizeof(struct ion_system_heap), GFP_KERNEL);
325	if (!heap)
326		return ERR_PTR(-ENOMEM);
327	heap->heap.ops = &system_heap_ops;
328	heap->heap.type = ION_HEAP_TYPE_SYSTEM;
329	heap->heap.flags = ION_HEAP_FLAG_DEFER_FREE;
330	heap->pools = kzalloc(sizeof(struct ion_page_pool *) * num_orders,
331			      GFP_KERNEL);
332	if (!heap->pools)
333		goto err_alloc_pools;
334	for (i = 0; i < num_orders; i++) {
335		struct ion_page_pool *pool;
336		gfp_t gfp_flags = low_order_gfp_flags;
337
338		if (orders[i] > 4)
339			gfp_flags = high_order_gfp_flags;
340		pool = ion_page_pool_create(gfp_flags, orders[i]);
341		if (!pool)
342			goto err_create_pool;
343		heap->pools[i] = pool;
344	}
345
346	heap->heap.shrinker.scan_objects = ion_system_heap_shrink_scan;
347	heap->heap.shrinker.count_objects = ion_system_heap_shrink_count;
348	heap->heap.shrinker.seeks = DEFAULT_SEEKS;
349	heap->heap.shrinker.batch = 0;
350	register_shrinker(&heap->heap.shrinker);
351	heap->heap.debug_show = ion_system_heap_debug_show;
352	return &heap->heap;
353err_create_pool:
354	for (i = 0; i < num_orders; i++)
355		if (heap->pools[i])
356			ion_page_pool_destroy(heap->pools[i]);
357	kfree(heap->pools);
358err_alloc_pools:
359	kfree(heap);
360	return ERR_PTR(-ENOMEM);
361}
362
363void ion_system_heap_destroy(struct ion_heap *heap)
364{
365	struct ion_system_heap *sys_heap = container_of(heap,
366							struct ion_system_heap,
367							heap);
368	int i;
369
370	for (i = 0; i < num_orders; i++)
371		ion_page_pool_destroy(sys_heap->pools[i]);
372	kfree(sys_heap->pools);
373	kfree(sys_heap);
374}
375
376static int ion_system_contig_heap_allocate(struct ion_heap *heap,
377					   struct ion_buffer *buffer,
378					   unsigned long len,
379					   unsigned long align,
380					   unsigned long flags)
381{
382	int order = get_order(len);
383	struct page *page;
384	struct sg_table *table;
385	unsigned long i;
386	int ret;
387
388	if (align > (PAGE_SIZE << order))
389		return -EINVAL;
390
391	page = alloc_pages(low_order_gfp_flags, order);
392	if (!page)
393		return -ENOMEM;
394
395	split_page(page, order);
396
397	len = PAGE_ALIGN(len);
398	for (i = len >> PAGE_SHIFT; i < (1 << order); i++)
399		__free_page(page + i);
400
401	table = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
402	if (!table) {
403		ret = -ENOMEM;
404		goto out;
405	}
406
407	ret = sg_alloc_table(table, 1, GFP_KERNEL);
408	if (ret)
409		goto out;
410
411	sg_set_page(table->sgl, page, len, 0);
412
413	buffer->priv_virt = table;
414
415	ion_pages_sync_for_device(NULL, page, len, DMA_BIDIRECTIONAL);
416
417	return 0;
418
419out:
420	for (i = 0; i < len >> PAGE_SHIFT; i++)
421		__free_page(page + i);
422	kfree(table);
423	return ret;
424}
425
426static void ion_system_contig_heap_free(struct ion_buffer *buffer)
427{
428	struct sg_table *table = buffer->priv_virt;
429	struct page *page = sg_page(table->sgl);
430	unsigned long pages = PAGE_ALIGN(buffer->size) >> PAGE_SHIFT;
431	unsigned long i;
432
433	for (i = 0; i < pages; i++)
434		__free_page(page + i);
435	sg_free_table(table);
436	kfree(table);
437}
438
439static int ion_system_contig_heap_phys(struct ion_heap *heap,
440				       struct ion_buffer *buffer,
441				       ion_phys_addr_t *addr, size_t *len)
442{
443	struct sg_table *table = buffer->priv_virt;
444	struct page *page = sg_page(table->sgl);
445	*addr = page_to_phys(page);
446	*len = buffer->size;
447	return 0;
448}
449
450static struct sg_table *ion_system_contig_heap_map_dma(struct ion_heap *heap,
451						struct ion_buffer *buffer)
452{
453	return buffer->priv_virt;
454}
455
456static void ion_system_contig_heap_unmap_dma(struct ion_heap *heap,
457					     struct ion_buffer *buffer)
458{
459}
460
461static struct ion_heap_ops kmalloc_ops = {
462	.allocate = ion_system_contig_heap_allocate,
463	.free = ion_system_contig_heap_free,
464	.phys = ion_system_contig_heap_phys,
465	.map_dma = ion_system_contig_heap_map_dma,
466	.unmap_dma = ion_system_contig_heap_unmap_dma,
467	.map_kernel = ion_heap_map_kernel,
468	.unmap_kernel = ion_heap_unmap_kernel,
469	.map_user = ion_heap_map_user,
470};
471
472struct ion_heap *ion_system_contig_heap_create(struct ion_platform_heap *unused)
473{
474	struct ion_heap *heap;
475
476	heap = kzalloc(sizeof(struct ion_heap), GFP_KERNEL);
477	if (!heap)
478		return ERR_PTR(-ENOMEM);
479	heap->ops = &kmalloc_ops;
480	heap->type = ION_HEAP_TYPE_SYSTEM_CONTIG;
481	return heap;
482}
483
484void ion_system_contig_heap_destroy(struct ion_heap *heap)
485{
486	kfree(heap);
487}
488
489