ion_system_heap.c revision bdeb9f1c4276864e97a725c8c0a8bc9a8686edfe 
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
38	for (i = 0; i < num_orders; i++)
39		if (order == orders[i])
40			return i;
41	BUG();
42	return -1;
43}
44
45static inline unsigned int order_to_size(int order)
46{
47	return PAGE_SIZE << order;
48}
49
50struct ion_system_heap {
51	struct ion_heap heap;
52	struct ion_page_pool **pools;
53};
54
55struct page_info {
56	struct page *page;
57	unsigned int order;
58	struct list_head list;
59};
60
61static struct page *alloc_buffer_page(struct ion_system_heap *heap,
62				      struct ion_buffer *buffer,
63				      unsigned long order)
64{
65	bool cached = ion_buffer_cached(buffer);
66	struct ion_page_pool *pool = heap->pools[order_to_index(order)];
67	struct page *page;
68
69	if (!cached) {
70		page = ion_page_pool_alloc(pool);
71	} else {
72		gfp_t gfp_flags = low_order_gfp_flags;
73
74		if (order > 4)
75			gfp_flags = high_order_gfp_flags;
76		page = alloc_pages(gfp_flags | __GFP_COMP, order);
77		if (!page)
78			return NULL;
79		ion_pages_sync_for_device(NULL, page, PAGE_SIZE << order,
80						DMA_BIDIRECTIONAL);
81	}
82
83	return page;
84}
85
86static void free_buffer_page(struct ion_system_heap *heap,
87			     struct ion_buffer *buffer, struct page *page,
88			     unsigned int order)
89{
90	bool cached = ion_buffer_cached(buffer);
91
92	if (!cached && !(buffer->private_flags & ION_PRIV_FLAG_SHRINKER_FREE)) {
93		struct ion_page_pool *pool = heap->pools[order_to_index(order)];
94
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	struct list_head pages;
145	struct page_info *info, *tmp_info;
146	int i = 0;
147	unsigned long size_remaining = PAGE_ALIGN(size);
148	unsigned int max_order = orders[0];
149
150	if (align > PAGE_SIZE)
151		return -EINVAL;
152
153	if (size / PAGE_SIZE > totalram_pages / 2)
154		return -ENOMEM;
155
156	INIT_LIST_HEAD(&pages);
157	while (size_remaining > 0) {
158		info = alloc_largest_available(sys_heap, buffer, size_remaining,
159						max_order);
160		if (!info)
161			goto free_pages;
162		list_add_tail(&info->list, &pages);
163		size_remaining -= PAGE_SIZE << info->order;
164		max_order = info->order;
165		i++;
166	}
167	table = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
168	if (!table)
169		goto free_pages;
170
171	if (sg_alloc_table(table, i, GFP_KERNEL))
172		goto free_table;
173
174	sg = table->sgl;
175	list_for_each_entry_safe(info, tmp_info, &pages, list) {
176		struct page *page = info->page;
177		sg_set_page(sg, page, PAGE_SIZE << info->order, 0);
178		sg = sg_next(sg);
179		list_del(&info->list);
180		kfree(info);
181	}
182
183	buffer->priv_virt = table;
184	return 0;
185
186free_table:
187	kfree(table);
188free_pages:
189	list_for_each_entry_safe(info, tmp_info, &pages, list) {
190		free_buffer_page(sys_heap, buffer, info->page, info->order);
191		kfree(info);
192	}
193	return -ENOMEM;
194}
195
196static void ion_system_heap_free(struct ion_buffer *buffer)
197{
198	struct ion_system_heap *sys_heap = container_of(buffer->heap,
199							struct ion_system_heap,
200							heap);
201	struct sg_table *table = buffer->sg_table;
202	bool cached = ion_buffer_cached(buffer);
203	struct scatterlist *sg;
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 && !(buffer->private_flags & ION_PRIV_FLAG_SHRINKER_FREE))
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 int ion_system_heap_shrink(struct ion_heap *heap, gfp_t gfp_mask,
231					int nr_to_scan)
232{
233	struct ion_system_heap *sys_heap;
234	int nr_total = 0;
235	int i;
236
237	sys_heap = container_of(heap, struct ion_system_heap, heap);
238
239	for (i = 0; i < num_orders; i++) {
240		struct ion_page_pool *pool = sys_heap->pools[i];
241
242		nr_total += ion_page_pool_shrink(pool, gfp_mask, nr_to_scan);
243	}
244
245	return nr_total;
246}
247
248static struct ion_heap_ops system_heap_ops = {
249	.allocate = ion_system_heap_allocate,
250	.free = ion_system_heap_free,
251	.map_dma = ion_system_heap_map_dma,
252	.unmap_dma = ion_system_heap_unmap_dma,
253	.map_kernel = ion_heap_map_kernel,
254	.unmap_kernel = ion_heap_unmap_kernel,
255	.map_user = ion_heap_map_user,
256	.shrink = ion_system_heap_shrink,
257};
258
259static int ion_system_heap_debug_show(struct ion_heap *heap, struct seq_file *s,
260				      void *unused)
261{
262
263	struct ion_system_heap *sys_heap = container_of(heap,
264							struct ion_system_heap,
265							heap);
266	int i;
267
268	for (i = 0; i < num_orders; i++) {
269		struct ion_page_pool *pool = sys_heap->pools[i];
270
271		seq_printf(s, "%d order %u highmem pages in pool = %lu total\n",
272			   pool->high_count, pool->order,
273			   (PAGE_SIZE << pool->order) * pool->high_count);
274		seq_printf(s, "%d order %u lowmem pages in pool = %lu total\n",
275			   pool->low_count, pool->order,
276			   (PAGE_SIZE << pool->order) * pool->low_count);
277	}
278	return 0;
279}
280
281struct ion_heap *ion_system_heap_create(struct ion_platform_heap *unused)
282{
283	struct ion_system_heap *heap;
284	int i;
285
286	heap = kzalloc(sizeof(struct ion_system_heap), GFP_KERNEL);
287	if (!heap)
288		return ERR_PTR(-ENOMEM);
289	heap->heap.ops = &system_heap_ops;
290	heap->heap.type = ION_HEAP_TYPE_SYSTEM;
291	heap->heap.flags = ION_HEAP_FLAG_DEFER_FREE;
292	heap->pools = kzalloc(sizeof(struct ion_page_pool *) * num_orders,
293			      GFP_KERNEL);
294	if (!heap->pools)
295		goto free_heap;
296	for (i = 0; i < num_orders; i++) {
297		struct ion_page_pool *pool;
298		gfp_t gfp_flags = low_order_gfp_flags;
299
300		if (orders[i] > 4)
301			gfp_flags = high_order_gfp_flags;
302		pool = ion_page_pool_create(gfp_flags, orders[i]);
303		if (!pool)
304			goto destroy_pools;
305		heap->pools[i] = pool;
306	}
307
308	heap->heap.debug_show = ion_system_heap_debug_show;
309	return &heap->heap;
310
311destroy_pools:
312	while (i--)
313		ion_page_pool_destroy(heap->pools[i]);
314	kfree(heap->pools);
315free_heap:
316	kfree(heap);
317	return ERR_PTR(-ENOMEM);
318}
319
320void ion_system_heap_destroy(struct ion_heap *heap)
321{
322	struct ion_system_heap *sys_heap = container_of(heap,
323							struct ion_system_heap,
324							heap);
325	int i;
326
327	for (i = 0; i < num_orders; i++)
328		ion_page_pool_destroy(sys_heap->pools[i]);
329	kfree(sys_heap->pools);
330	kfree(sys_heap);
331}
332
333static int ion_system_contig_heap_allocate(struct ion_heap *heap,
334					   struct ion_buffer *buffer,
335					   unsigned long len,
336					   unsigned long align,
337					   unsigned long flags)
338{
339	int order = get_order(len);
340	struct page *page;
341	struct sg_table *table;
342	unsigned long i;
343	int ret;
344
345	if (align > (PAGE_SIZE << order))
346		return -EINVAL;
347
348	page = alloc_pages(low_order_gfp_flags, order);
349	if (!page)
350		return -ENOMEM;
351
352	split_page(page, order);
353
354	len = PAGE_ALIGN(len);
355	for (i = len >> PAGE_SHIFT; i < (1 << order); i++)
356		__free_page(page + i);
357
358	table = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
359	if (!table) {
360		ret = -ENOMEM;
361		goto free_pages;
362	}
363
364	ret = sg_alloc_table(table, 1, GFP_KERNEL);
365	if (ret)
366		goto free_table;
367
368	sg_set_page(table->sgl, page, len, 0);
369
370	buffer->priv_virt = table;
371
372	ion_pages_sync_for_device(NULL, page, len, DMA_BIDIRECTIONAL);
373
374	return 0;
375
376free_table:
377	kfree(table);
378free_pages:
379	for (i = 0; i < len >> PAGE_SHIFT; i++)
380		__free_page(page + i);
381
382	return ret;
383}
384
385static void ion_system_contig_heap_free(struct ion_buffer *buffer)
386{
387	struct sg_table *table = buffer->priv_virt;
388	struct page *page = sg_page(table->sgl);
389	unsigned long pages = PAGE_ALIGN(buffer->size) >> PAGE_SHIFT;
390	unsigned long i;
391
392	for (i = 0; i < pages; i++)
393		__free_page(page + i);
394	sg_free_table(table);
395	kfree(table);
396}
397
398static int ion_system_contig_heap_phys(struct ion_heap *heap,
399				       struct ion_buffer *buffer,
400				       ion_phys_addr_t *addr, size_t *len)
401{
402	struct sg_table *table = buffer->priv_virt;
403	struct page *page = sg_page(table->sgl);
404	*addr = page_to_phys(page);
405	*len = buffer->size;
406	return 0;
407}
408
409static struct sg_table *ion_system_contig_heap_map_dma(struct ion_heap *heap,
410						struct ion_buffer *buffer)
411{
412	return buffer->priv_virt;
413}
414
415static void ion_system_contig_heap_unmap_dma(struct ion_heap *heap,
416					     struct ion_buffer *buffer)
417{
418}
419
420static struct ion_heap_ops kmalloc_ops = {
421	.allocate = ion_system_contig_heap_allocate,
422	.free = ion_system_contig_heap_free,
423	.phys = ion_system_contig_heap_phys,
424	.map_dma = ion_system_contig_heap_map_dma,
425	.unmap_dma = ion_system_contig_heap_unmap_dma,
426	.map_kernel = ion_heap_map_kernel,
427	.unmap_kernel = ion_heap_unmap_kernel,
428	.map_user = ion_heap_map_user,
429};
430
431struct ion_heap *ion_system_contig_heap_create(struct ion_platform_heap *unused)
432{
433	struct ion_heap *heap;
434
435	heap = kzalloc(sizeof(struct ion_heap), GFP_KERNEL);
436	if (!heap)
437		return ERR_PTR(-ENOMEM);
438	heap->ops = &kmalloc_ops;
439	heap->type = ION_HEAP_TYPE_SYSTEM_CONTIG;
440	return heap;
441}
442
443void ion_system_contig_heap_destroy(struct ion_heap *heap)
444{
445	kfree(heap);
446}
447