ion_system_heap.c revision ea313b5f88ed7119f79ad3f6b85e9620971b9875 
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_NO_KSWAPD) & ~__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	bool split_pages = ion_buffer_fault_user_mappings(buffer);
68	struct ion_page_pool *pool = heap->pools[order_to_index(order)];
69	struct page *page;
70
71	if (!cached) {
72		page = ion_page_pool_alloc(pool);
73	} else {
74		gfp_t gfp_flags = low_order_gfp_flags;
75
76		if (order > 4)
77			gfp_flags = high_order_gfp_flags;
78		page = alloc_pages(gfp_flags, order);
79		if (!page)
80			return 0;
81		__dma_page_cpu_to_dev(page, 0, PAGE_SIZE << order,
82				      DMA_BIDIRECTIONAL);
83	}
84	if (!page)
85		return 0;
86
87	if (split_pages)
88		split_page(page, order);
89	return page;
90}
91
92static void free_buffer_page(struct ion_system_heap *heap,
93			     struct ion_buffer *buffer, struct page *page,
94			     unsigned int order)
95{
96	bool cached = ion_buffer_cached(buffer);
97	bool split_pages = ion_buffer_fault_user_mappings(buffer);
98	int i;
99
100	if (!cached) {
101		struct ion_page_pool *pool = heap->pools[order_to_index(order)];
102		ion_page_pool_free(pool, page);
103	} else if (split_pages) {
104		for (i = 0; i < (1 << order); i++)
105			__free_page(page + i);
106	} else {
107		__free_pages(page, order);
108	}
109}
110
111
112static struct page_info *alloc_largest_available(struct ion_system_heap *heap,
113						 struct ion_buffer *buffer,
114						 unsigned long size,
115						 unsigned int max_order)
116{
117	struct page *page;
118	struct page_info *info;
119	int i;
120
121	for (i = 0; i < num_orders; i++) {
122		if (size < order_to_size(orders[i]))
123			continue;
124		if (max_order < orders[i])
125			continue;
126
127		page = alloc_buffer_page(heap, buffer, orders[i]);
128		if (!page)
129			continue;
130
131		info = kmalloc(sizeof(struct page_info), GFP_KERNEL);
132		info->page = page;
133		info->order = orders[i];
134		return info;
135	}
136	return NULL;
137}
138
139static int ion_system_heap_allocate(struct ion_heap *heap,
140				     struct ion_buffer *buffer,
141				     unsigned long size, unsigned long align,
142				     unsigned long flags)
143{
144	struct ion_system_heap *sys_heap = container_of(heap,
145							struct ion_system_heap,
146							heap);
147	struct sg_table *table;
148	struct scatterlist *sg;
149	int ret;
150	struct list_head pages;
151	struct page_info *info, *tmp_info;
152	int i = 0;
153	long size_remaining = PAGE_ALIGN(size);
154	unsigned int max_order = orders[0];
155	bool split_pages = ion_buffer_fault_user_mappings(buffer);
156
157	INIT_LIST_HEAD(&pages);
158	while (size_remaining > 0) {
159		info = alloc_largest_available(sys_heap, buffer, size_remaining, max_order);
160		if (!info)
161			goto err;
162		list_add_tail(&info->list, &pages);
163		size_remaining -= (1 << info->order) * PAGE_SIZE;
164		max_order = info->order;
165		i++;
166	}
167
168	table = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
169	if (!table)
170		goto err;
171
172	if (split_pages)
173		ret = sg_alloc_table(table, PAGE_ALIGN(size) / PAGE_SIZE,
174				     GFP_KERNEL);
175	else
176		ret = sg_alloc_table(table, i, GFP_KERNEL);
177
178	if (ret)
179		goto err1;
180
181	sg = table->sgl;
182	list_for_each_entry_safe(info, tmp_info, &pages, list) {
183		struct page *page = info->page;
184		if (split_pages) {
185			for (i = 0; i < (1 << info->order); i++) {
186				sg_set_page(sg, page + i, PAGE_SIZE, 0);
187				sg = sg_next(sg);
188			}
189		} else {
190			sg_set_page(sg, page, (1 << info->order) * PAGE_SIZE,
191				    0);
192			sg = sg_next(sg);
193		}
194		list_del(&info->list);
195		kfree(info);
196	}
197
198	buffer->priv_virt = table;
199	return 0;
200err1:
201	kfree(table);
202err:
203	list_for_each_entry(info, &pages, list) {
204		free_buffer_page(sys_heap, buffer, info->page, info->order);
205		kfree(info);
206	}
207	return -ENOMEM;
208}
209
210void ion_system_heap_free(struct ion_buffer *buffer)
211{
212	struct ion_heap *heap = buffer->heap;
213	struct ion_system_heap *sys_heap = container_of(heap,
214							struct ion_system_heap,
215							heap);
216	struct sg_table *table = buffer->sg_table;
217	bool cached = ion_buffer_cached(buffer);
218	struct scatterlist *sg;
219	LIST_HEAD(pages);
220	int i;
221
222	/* uncached pages come from the page pools, zero them before returning
223	   for security purposes (other allocations are zerod at alloc time */
224	if (!cached)
225		ion_heap_buffer_zero(buffer);
226
227	for_each_sg(table->sgl, sg, table->nents, i)
228		free_buffer_page(sys_heap, buffer, sg_page(sg),
229				get_order(sg_dma_len(sg)));
230	sg_free_table(table);
231	kfree(table);
232}
233
234struct sg_table *ion_system_heap_map_dma(struct ion_heap *heap,
235					 struct ion_buffer *buffer)
236{
237	return buffer->priv_virt;
238}
239
240void ion_system_heap_unmap_dma(struct ion_heap *heap,
241			       struct ion_buffer *buffer)
242{
243	return;
244}
245
246static struct ion_heap_ops system_heap_ops = {
247	.allocate = ion_system_heap_allocate,
248	.free = ion_system_heap_free,
249	.map_dma = ion_system_heap_map_dma,
250	.unmap_dma = ion_system_heap_unmap_dma,
251	.map_kernel = ion_heap_map_kernel,
252	.unmap_kernel = ion_heap_unmap_kernel,
253	.map_user = ion_heap_map_user,
254};
255
256static int ion_system_heap_shrink(struct shrinker *shrinker,
257				  struct shrink_control *sc) {
258
259	struct ion_heap *heap = container_of(shrinker, struct ion_heap,
260					     shrinker);
261	struct ion_system_heap *sys_heap = container_of(heap,
262							struct ion_system_heap,
263							heap);
264	int nr_total = 0;
265	int nr_freed = 0;
266	int i;
267
268	if (sc->nr_to_scan == 0)
269		goto end;
270
271	/* shrink the free list first, no point in zeroing the memory if
272	   we're just going to reclaim it */
273	nr_freed += ion_heap_freelist_drain(heap, sc->nr_to_scan * PAGE_SIZE) /
274		PAGE_SIZE;
275
276	if (nr_freed >= sc->nr_to_scan)
277		goto end;
278
279	for (i = 0; i < num_orders; i++) {
280		struct ion_page_pool *pool = sys_heap->pools[i];
281
282		nr_freed += ion_page_pool_shrink(pool, sc->gfp_mask,
283						 sc->nr_to_scan);
284		if (nr_freed >= sc->nr_to_scan)
285			break;
286	}
287
288end:
289	/* total number of items is whatever the page pools are holding
290	   plus whatever's in the freelist */
291	for (i = 0; i < num_orders; i++) {
292		struct ion_page_pool *pool = sys_heap->pools[i];
293		nr_total += ion_page_pool_shrink(pool, sc->gfp_mask, 0);
294	}
295	nr_total += ion_heap_freelist_size(heap) / PAGE_SIZE;
296	return nr_total;
297
298}
299
300static int ion_system_heap_debug_show(struct ion_heap *heap, struct seq_file *s,
301				      void *unused)
302{
303
304	struct ion_system_heap *sys_heap = container_of(heap,
305							struct ion_system_heap,
306							heap);
307	int i;
308	for (i = 0; i < num_orders; i++) {
309		struct ion_page_pool *pool = sys_heap->pools[i];
310		seq_printf(s, "%d order %u highmem pages in pool = %lu total\n",
311			   pool->high_count, pool->order,
312			   (1 << pool->order) * PAGE_SIZE * pool->high_count);
313		seq_printf(s, "%d order %u lowmem pages in pool = %lu total\n",
314			   pool->low_count, pool->order,
315			   (1 << pool->order) * PAGE_SIZE * pool->low_count);
316	}
317	return 0;
318}
319
320struct ion_heap *ion_system_heap_create(struct ion_platform_heap *unused)
321{
322	struct ion_system_heap *heap;
323	int i;
324
325	heap = kzalloc(sizeof(struct ion_system_heap), GFP_KERNEL);
326	if (!heap)
327		return ERR_PTR(-ENOMEM);
328	heap->heap.ops = &system_heap_ops;
329	heap->heap.type = ION_HEAP_TYPE_SYSTEM;
330	heap->heap.flags = ION_HEAP_FLAG_DEFER_FREE;
331	heap->pools = kzalloc(sizeof(struct ion_page_pool *) * num_orders,
332			      GFP_KERNEL);
333	if (!heap->pools)
334		goto err_alloc_pools;
335	for (i = 0; i < num_orders; i++) {
336		struct ion_page_pool *pool;
337		gfp_t gfp_flags = low_order_gfp_flags;
338
339		if (orders[i] > 4)
340			gfp_flags = high_order_gfp_flags;
341		pool = ion_page_pool_create(gfp_flags, orders[i]);
342		if (!pool)
343			goto err_create_pool;
344		heap->pools[i] = pool;
345	}
346
347	heap->heap.shrinker.shrink = ion_system_heap_shrink;
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	buffer->priv_virt = kzalloc(len, GFP_KERNEL);
383	if (!buffer->priv_virt)
384		return -ENOMEM;
385	return 0;
386}
387
388void ion_system_contig_heap_free(struct ion_buffer *buffer)
389{
390	kfree(buffer->priv_virt);
391}
392
393static int ion_system_contig_heap_phys(struct ion_heap *heap,
394				       struct ion_buffer *buffer,
395				       ion_phys_addr_t *addr, size_t *len)
396{
397	*addr = virt_to_phys(buffer->priv_virt);
398	*len = buffer->size;
399	return 0;
400}
401
402struct sg_table *ion_system_contig_heap_map_dma(struct ion_heap *heap,
403						struct ion_buffer *buffer)
404{
405	struct sg_table *table;
406	int ret;
407
408	table = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
409	if (!table)
410		return ERR_PTR(-ENOMEM);
411	ret = sg_alloc_table(table, 1, GFP_KERNEL);
412	if (ret) {
413		kfree(table);
414		return ERR_PTR(ret);
415	}
416	sg_set_page(table->sgl, virt_to_page(buffer->priv_virt), buffer->size,
417		    0);
418	return table;
419}
420
421void ion_system_contig_heap_unmap_dma(struct ion_heap *heap,
422				      struct ion_buffer *buffer)
423{
424	sg_free_table(buffer->sg_table);
425	kfree(buffer->sg_table);
426}
427
428int ion_system_contig_heap_map_user(struct ion_heap *heap,
429				    struct ion_buffer *buffer,
430				    struct vm_area_struct *vma)
431{
432	unsigned long pfn = __phys_to_pfn(virt_to_phys(buffer->priv_virt));
433	return remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
434			       vma->vm_end - vma->vm_start,
435			       vma->vm_page_prot);
436
437}
438
439static struct ion_heap_ops kmalloc_ops = {
440	.allocate = ion_system_contig_heap_allocate,
441	.free = ion_system_contig_heap_free,
442	.phys = ion_system_contig_heap_phys,
443	.map_dma = ion_system_contig_heap_map_dma,
444	.unmap_dma = ion_system_contig_heap_unmap_dma,
445	.map_kernel = ion_heap_map_kernel,
446	.unmap_kernel = ion_heap_unmap_kernel,
447	.map_user = ion_system_contig_heap_map_user,
448};
449
450struct ion_heap *ion_system_contig_heap_create(struct ion_platform_heap *unused)
451{
452	struct ion_heap *heap;
453
454	heap = kzalloc(sizeof(struct ion_heap), GFP_KERNEL);
455	if (!heap)
456		return ERR_PTR(-ENOMEM);
457	heap->ops = &kmalloc_ops;
458	heap->type = ION_HEAP_TYPE_SYSTEM_CONTIG;
459	return heap;
460}
461
462void ion_system_contig_heap_destroy(struct ion_heap *heap)
463{
464	kfree(heap);
465}
466
467