ion_system_heap.c revision c13d1df947f1c312143eda77a754149d0043e4d3 
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
170	table = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
171	if (!table)
172		goto err;
173
174	ret = sg_alloc_table(table, i, GFP_KERNEL);
175	if (ret)
176		goto err1;
177
178	sg = table->sgl;
179	list_for_each_entry_safe(info, tmp_info, &pages, list) {
180		struct page *page = info->page;
181		sg_set_page(sg, page, (1 << info->order) * PAGE_SIZE, 0);
182		sg = sg_next(sg);
183		list_del(&info->list);
184		kfree(info);
185	}
186
187	buffer->priv_virt = table;
188	return 0;
189err1:
190	kfree(table);
191err:
192	list_for_each_entry(info, &pages, list) {
193		free_buffer_page(sys_heap, buffer, info->page, info->order);
194		kfree(info);
195	}
196	return -ENOMEM;
197}
198
199void ion_system_heap_free(struct ion_buffer *buffer)
200{
201	struct ion_heap *heap = buffer->heap;
202	struct ion_system_heap *sys_heap = container_of(heap,
203							struct ion_system_heap,
204							heap);
205	struct sg_table *table = buffer->sg_table;
206	bool cached = ion_buffer_cached(buffer);
207	struct scatterlist *sg;
208	LIST_HEAD(pages);
209	int i;
210
211	/* uncached pages come from the page pools, zero them before returning
212	   for security purposes (other allocations are zerod at alloc time */
213	if (!cached)
214		ion_heap_buffer_zero(buffer);
215
216	for_each_sg(table->sgl, sg, table->nents, i)
217		free_buffer_page(sys_heap, buffer, sg_page(sg),
218				get_order(sg->length));
219	sg_free_table(table);
220	kfree(table);
221}
222
223struct sg_table *ion_system_heap_map_dma(struct ion_heap *heap,
224					 struct ion_buffer *buffer)
225{
226	return buffer->priv_virt;
227}
228
229void ion_system_heap_unmap_dma(struct ion_heap *heap,
230			       struct ion_buffer *buffer)
231{
232	return;
233}
234
235static struct ion_heap_ops system_heap_ops = {
236	.allocate = ion_system_heap_allocate,
237	.free = ion_system_heap_free,
238	.map_dma = ion_system_heap_map_dma,
239	.unmap_dma = ion_system_heap_unmap_dma,
240	.map_kernel = ion_heap_map_kernel,
241	.unmap_kernel = ion_heap_unmap_kernel,
242	.map_user = ion_heap_map_user,
243};
244
245static int ion_system_heap_shrink(struct shrinker *shrinker,
246				  struct shrink_control *sc) {
247
248	struct ion_heap *heap = container_of(shrinker, struct ion_heap,
249					     shrinker);
250	struct ion_system_heap *sys_heap = container_of(heap,
251							struct ion_system_heap,
252							heap);
253	int nr_total = 0;
254	int nr_freed = 0;
255	int i;
256
257	if (sc->nr_to_scan == 0)
258		goto end;
259
260	/* shrink the free list first, no point in zeroing the memory if
261	   we're just going to reclaim it */
262	nr_freed += ion_heap_freelist_drain(heap, sc->nr_to_scan * PAGE_SIZE) /
263		PAGE_SIZE;
264
265	if (nr_freed >= sc->nr_to_scan)
266		goto end;
267
268	for (i = 0; i < num_orders; i++) {
269		struct ion_page_pool *pool = sys_heap->pools[i];
270
271		nr_freed += ion_page_pool_shrink(pool, sc->gfp_mask,
272						 sc->nr_to_scan);
273		if (nr_freed >= sc->nr_to_scan)
274			break;
275	}
276
277end:
278	/* total number of items is whatever the page pools are holding
279	   plus whatever's in the freelist */
280	for (i = 0; i < num_orders; i++) {
281		struct ion_page_pool *pool = sys_heap->pools[i];
282		nr_total += ion_page_pool_shrink(pool, sc->gfp_mask, 0);
283	}
284	nr_total += ion_heap_freelist_size(heap) / PAGE_SIZE;
285	return nr_total;
286
287}
288
289static int ion_system_heap_debug_show(struct ion_heap *heap, struct seq_file *s,
290				      void *unused)
291{
292
293	struct ion_system_heap *sys_heap = container_of(heap,
294							struct ion_system_heap,
295							heap);
296	int i;
297	for (i = 0; i < num_orders; i++) {
298		struct ion_page_pool *pool = sys_heap->pools[i];
299		seq_printf(s, "%d order %u highmem pages in pool = %lu total\n",
300			   pool->high_count, pool->order,
301			   (1 << pool->order) * PAGE_SIZE * pool->high_count);
302		seq_printf(s, "%d order %u lowmem pages in pool = %lu total\n",
303			   pool->low_count, pool->order,
304			   (1 << pool->order) * PAGE_SIZE * pool->low_count);
305	}
306	return 0;
307}
308
309struct ion_heap *ion_system_heap_create(struct ion_platform_heap *unused)
310{
311	struct ion_system_heap *heap;
312	int i;
313
314	heap = kzalloc(sizeof(struct ion_system_heap), GFP_KERNEL);
315	if (!heap)
316		return ERR_PTR(-ENOMEM);
317	heap->heap.ops = &system_heap_ops;
318	heap->heap.type = ION_HEAP_TYPE_SYSTEM;
319	heap->heap.flags = ION_HEAP_FLAG_DEFER_FREE;
320	heap->pools = kzalloc(sizeof(struct ion_page_pool *) * num_orders,
321			      GFP_KERNEL);
322	if (!heap->pools)
323		goto err_alloc_pools;
324	for (i = 0; i < num_orders; i++) {
325		struct ion_page_pool *pool;
326		gfp_t gfp_flags = low_order_gfp_flags;
327
328		if (orders[i] > 4)
329			gfp_flags = high_order_gfp_flags;
330		pool = ion_page_pool_create(gfp_flags, orders[i]);
331		if (!pool)
332			goto err_create_pool;
333		heap->pools[i] = pool;
334	}
335
336	heap->heap.shrinker.shrink = ion_system_heap_shrink;
337	heap->heap.shrinker.seeks = DEFAULT_SEEKS;
338	heap->heap.shrinker.batch = 0;
339	register_shrinker(&heap->heap.shrinker);
340	heap->heap.debug_show = ion_system_heap_debug_show;
341	return &heap->heap;
342err_create_pool:
343	for (i = 0; i < num_orders; i++)
344		if (heap->pools[i])
345			ion_page_pool_destroy(heap->pools[i]);
346	kfree(heap->pools);
347err_alloc_pools:
348	kfree(heap);
349	return ERR_PTR(-ENOMEM);
350}
351
352void ion_system_heap_destroy(struct ion_heap *heap)
353{
354	struct ion_system_heap *sys_heap = container_of(heap,
355							struct ion_system_heap,
356							heap);
357	int i;
358
359	for (i = 0; i < num_orders; i++)
360		ion_page_pool_destroy(sys_heap->pools[i]);
361	kfree(sys_heap->pools);
362	kfree(sys_heap);
363}
364
365static int ion_system_contig_heap_allocate(struct ion_heap *heap,
366					   struct ion_buffer *buffer,
367					   unsigned long len,
368					   unsigned long align,
369					   unsigned long flags)
370{
371	int order = get_order(len);
372
373	if (align > (PAGE_SIZE << order))
374		return -EINVAL;
375
376	if (ion_buffer_fault_user_mappings(buffer))
377		return -EINVAL;
378
379	buffer->priv_virt = kzalloc(len, GFP_KERNEL);
380	if (!buffer->priv_virt)
381		return -ENOMEM;
382	return 0;
383}
384
385void ion_system_contig_heap_free(struct ion_buffer *buffer)
386{
387	kfree(buffer->priv_virt);
388}
389
390static int ion_system_contig_heap_phys(struct ion_heap *heap,
391				       struct ion_buffer *buffer,
392				       ion_phys_addr_t *addr, size_t *len)
393{
394	*addr = virt_to_phys(buffer->priv_virt);
395	*len = buffer->size;
396	return 0;
397}
398
399struct sg_table *ion_system_contig_heap_map_dma(struct ion_heap *heap,
400						struct ion_buffer *buffer)
401{
402	struct sg_table *table;
403	int ret;
404
405	table = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
406	if (!table)
407		return ERR_PTR(-ENOMEM);
408	ret = sg_alloc_table(table, 1, GFP_KERNEL);
409	if (ret) {
410		kfree(table);
411		return ERR_PTR(ret);
412	}
413	sg_set_page(table->sgl, virt_to_page(buffer->priv_virt), buffer->size,
414		    0);
415	return table;
416}
417
418void ion_system_contig_heap_unmap_dma(struct ion_heap *heap,
419				      struct ion_buffer *buffer)
420{
421	sg_free_table(buffer->sg_table);
422	kfree(buffer->sg_table);
423}
424
425int ion_system_contig_heap_map_user(struct ion_heap *heap,
426				    struct ion_buffer *buffer,
427				    struct vm_area_struct *vma)
428{
429	unsigned long pfn = __phys_to_pfn(virt_to_phys(buffer->priv_virt));
430	return remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
431			       vma->vm_end - vma->vm_start,
432			       vma->vm_page_prot);
433
434}
435
436static struct ion_heap_ops kmalloc_ops = {
437	.allocate = ion_system_contig_heap_allocate,
438	.free = ion_system_contig_heap_free,
439	.phys = ion_system_contig_heap_phys,
440	.map_dma = ion_system_contig_heap_map_dma,
441	.unmap_dma = ion_system_contig_heap_unmap_dma,
442	.map_kernel = ion_heap_map_kernel,
443	.unmap_kernel = ion_heap_unmap_kernel,
444	.map_user = ion_system_contig_heap_map_user,
445};
446
447struct ion_heap *ion_system_contig_heap_create(struct ion_platform_heap *unused)
448{
449	struct ion_heap *heap;
450
451	heap = kzalloc(sizeof(struct ion_heap), GFP_KERNEL);
452	if (!heap)
453		return ERR_PTR(-ENOMEM);
454	heap->ops = &kmalloc_ops;
455	heap->type = ION_HEAP_TYPE_SYSTEM_CONTIG;
456	return heap;
457}
458
459void ion_system_contig_heap_destroy(struct ion_heap *heap)
460{
461	kfree(heap);
462}
463
464