ion_system_heap.c revision c13bd1c4eb714c08214e897fcbe51b13e0e0f279 
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		arm_dma_ops.sync_single_for_device(NULL,
81			pfn_to_dma(NULL, page_to_pfn(page)),
82			PAGE_SIZE << order, DMA_BIDIRECTIONAL);
83	}
84	if (!page)
85		return 0;
86
87	return page;
88}
89
90static void free_buffer_page(struct ion_system_heap *heap,
91			     struct ion_buffer *buffer, struct page *page,
92			     unsigned int order)
93{
94	bool cached = ion_buffer_cached(buffer);
95	bool split_pages = ion_buffer_fault_user_mappings(buffer);
96	int i;
97
98	if (!cached) {
99		struct ion_page_pool *pool = heap->pools[order_to_index(order)];
100		ion_page_pool_free(pool, page);
101	} else if (split_pages) {
102		for (i = 0; i < (1 << order); i++)
103			__free_page(page + i);
104	} else {
105		__free_pages(page, order);
106	}
107}
108
109
110static struct page_info *alloc_largest_available(struct ion_system_heap *heap,
111						 struct ion_buffer *buffer,
112						 unsigned long size,
113						 unsigned int max_order)
114{
115	struct page *page;
116	struct page_info *info;
117	int i;
118
119	for (i = 0; i < num_orders; i++) {
120		if (size < order_to_size(orders[i]))
121			continue;
122		if (max_order < orders[i])
123			continue;
124
125		page = alloc_buffer_page(heap, buffer, orders[i]);
126		if (!page)
127			continue;
128
129		info = kmalloc(sizeof(struct page_info), GFP_KERNEL);
130		info->page = page;
131		info->order = orders[i];
132		return info;
133	}
134	return NULL;
135}
136
137static int ion_system_heap_allocate(struct ion_heap *heap,
138				     struct ion_buffer *buffer,
139				     unsigned long size, unsigned long align,
140				     unsigned long flags)
141{
142	struct ion_system_heap *sys_heap = container_of(heap,
143							struct ion_system_heap,
144							heap);
145	struct sg_table *table;
146	struct scatterlist *sg;
147	int ret;
148	struct list_head pages;
149	struct page_info *info, *tmp_info;
150	int i = 0;
151	long size_remaining = PAGE_ALIGN(size);
152	unsigned int max_order = orders[0];
153
154	INIT_LIST_HEAD(&pages);
155	while (size_remaining > 0) {
156		info = alloc_largest_available(sys_heap, buffer, size_remaining, max_order);
157		if (!info)
158			goto err;
159		list_add_tail(&info->list, &pages);
160		size_remaining -= (1 << info->order) * PAGE_SIZE;
161		max_order = info->order;
162		i++;
163	}
164
165	table = kmalloc(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(info, &pages, list) {
188		free_buffer_page(sys_heap, buffer, info->page, info->order);
189		kfree(info);
190	}
191	return -ENOMEM;
192}
193
194void 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_dma_len(sg)));
214	sg_free_table(table);
215	kfree(table);
216}
217
218struct sg_table *ion_system_heap_map_dma(struct ion_heap *heap,
219					 struct ion_buffer *buffer)
220{
221	return buffer->priv_virt;
222}
223
224void 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 int ion_system_heap_shrink(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 nr_freed = 0;
250	int i;
251
252	if (sc->nr_to_scan == 0)
253		goto end;
254
255	/* shrink the free list first, no point in zeroing the memory if
256	   we're just going to reclaim it */
257	nr_freed += ion_heap_freelist_drain(heap, sc->nr_to_scan * PAGE_SIZE) /
258		PAGE_SIZE;
259
260	if (nr_freed >= sc->nr_to_scan)
261		goto end;
262
263	for (i = 0; i < num_orders; i++) {
264		struct ion_page_pool *pool = sys_heap->pools[i];
265
266		nr_freed += ion_page_pool_shrink(pool, sc->gfp_mask,
267						 sc->nr_to_scan);
268		if (nr_freed >= sc->nr_to_scan)
269			break;
270	}
271
272end:
273	/* total number of items is whatever the page pools are holding
274	   plus whatever's in the freelist */
275	for (i = 0; i < num_orders; i++) {
276		struct ion_page_pool *pool = sys_heap->pools[i];
277		nr_total += ion_page_pool_shrink(pool, sc->gfp_mask, 0);
278	}
279	nr_total += ion_heap_freelist_size(heap) / PAGE_SIZE;
280	return nr_total;
281
282}
283
284static int ion_system_heap_debug_show(struct ion_heap *heap, struct seq_file *s,
285				      void *unused)
286{
287
288	struct ion_system_heap *sys_heap = container_of(heap,
289							struct ion_system_heap,
290							heap);
291	int i;
292	for (i = 0; i < num_orders; i++) {
293		struct ion_page_pool *pool = sys_heap->pools[i];
294		seq_printf(s, "%d order %u highmem pages in pool = %lu total\n",
295			   pool->high_count, pool->order,
296			   (1 << pool->order) * PAGE_SIZE * pool->high_count);
297		seq_printf(s, "%d order %u lowmem pages in pool = %lu total\n",
298			   pool->low_count, pool->order,
299			   (1 << pool->order) * PAGE_SIZE * pool->low_count);
300	}
301	return 0;
302}
303
304struct ion_heap *ion_system_heap_create(struct ion_platform_heap *unused)
305{
306	struct ion_system_heap *heap;
307	int i;
308
309	heap = kzalloc(sizeof(struct ion_system_heap), GFP_KERNEL);
310	if (!heap)
311		return ERR_PTR(-ENOMEM);
312	heap->heap.ops = &system_heap_ops;
313	heap->heap.type = ION_HEAP_TYPE_SYSTEM;
314	heap->heap.flags = ION_HEAP_FLAG_DEFER_FREE;
315	heap->pools = kzalloc(sizeof(struct ion_page_pool *) * num_orders,
316			      GFP_KERNEL);
317	if (!heap->pools)
318		goto err_alloc_pools;
319	for (i = 0; i < num_orders; i++) {
320		struct ion_page_pool *pool;
321		gfp_t gfp_flags = low_order_gfp_flags;
322
323		if (orders[i] > 4)
324			gfp_flags = high_order_gfp_flags;
325		pool = ion_page_pool_create(gfp_flags, orders[i]);
326		if (!pool)
327			goto err_create_pool;
328		heap->pools[i] = pool;
329	}
330
331	heap->heap.shrinker.shrink = ion_system_heap_shrink;
332	heap->heap.shrinker.seeks = DEFAULT_SEEKS;
333	heap->heap.shrinker.batch = 0;
334	register_shrinker(&heap->heap.shrinker);
335	heap->heap.debug_show = ion_system_heap_debug_show;
336	return &heap->heap;
337err_create_pool:
338	for (i = 0; i < num_orders; i++)
339		if (heap->pools[i])
340			ion_page_pool_destroy(heap->pools[i]);
341	kfree(heap->pools);
342err_alloc_pools:
343	kfree(heap);
344	return ERR_PTR(-ENOMEM);
345}
346
347void ion_system_heap_destroy(struct ion_heap *heap)
348{
349	struct ion_system_heap *sys_heap = container_of(heap,
350							struct ion_system_heap,
351							heap);
352	int i;
353
354	for (i = 0; i < num_orders; i++)
355		ion_page_pool_destroy(sys_heap->pools[i]);
356	kfree(sys_heap->pools);
357	kfree(sys_heap);
358}
359
360static int ion_system_contig_heap_allocate(struct ion_heap *heap,
361					   struct ion_buffer *buffer,
362					   unsigned long len,
363					   unsigned long align,
364					   unsigned long flags)
365{
366	buffer->priv_virt = kzalloc(len, GFP_KERNEL);
367	if (!buffer->priv_virt)
368		return -ENOMEM;
369	return 0;
370}
371
372void ion_system_contig_heap_free(struct ion_buffer *buffer)
373{
374	kfree(buffer->priv_virt);
375}
376
377static int ion_system_contig_heap_phys(struct ion_heap *heap,
378				       struct ion_buffer *buffer,
379				       ion_phys_addr_t *addr, size_t *len)
380{
381	*addr = virt_to_phys(buffer->priv_virt);
382	*len = buffer->size;
383	return 0;
384}
385
386struct sg_table *ion_system_contig_heap_map_dma(struct ion_heap *heap,
387						struct ion_buffer *buffer)
388{
389	struct sg_table *table;
390	int ret;
391
392	table = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
393	if (!table)
394		return ERR_PTR(-ENOMEM);
395	ret = sg_alloc_table(table, 1, GFP_KERNEL);
396	if (ret) {
397		kfree(table);
398		return ERR_PTR(ret);
399	}
400	sg_set_page(table->sgl, virt_to_page(buffer->priv_virt), buffer->size,
401		    0);
402	return table;
403}
404
405void ion_system_contig_heap_unmap_dma(struct ion_heap *heap,
406				      struct ion_buffer *buffer)
407{
408	sg_free_table(buffer->sg_table);
409	kfree(buffer->sg_table);
410}
411
412int ion_system_contig_heap_map_user(struct ion_heap *heap,
413				    struct ion_buffer *buffer,
414				    struct vm_area_struct *vma)
415{
416	unsigned long pfn = __phys_to_pfn(virt_to_phys(buffer->priv_virt));
417	return remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
418			       vma->vm_end - vma->vm_start,
419			       vma->vm_page_prot);
420
421}
422
423static struct ion_heap_ops kmalloc_ops = {
424	.allocate = ion_system_contig_heap_allocate,
425	.free = ion_system_contig_heap_free,
426	.phys = ion_system_contig_heap_phys,
427	.map_dma = ion_system_contig_heap_map_dma,
428	.unmap_dma = ion_system_contig_heap_unmap_dma,
429	.map_kernel = ion_heap_map_kernel,
430	.unmap_kernel = ion_heap_unmap_kernel,
431	.map_user = ion_system_contig_heap_map_user,
432};
433
434struct ion_heap *ion_system_contig_heap_create(struct ion_platform_heap *unused)
435{
436	struct ion_heap *heap;
437
438	heap = kzalloc(sizeof(struct ion_heap), GFP_KERNEL);
439	if (!heap)
440		return ERR_PTR(-ENOMEM);
441	heap->ops = &kmalloc_ops;
442	heap->type = ION_HEAP_TYPE_SYSTEM_CONTIG;
443	return heap;
444}
445
446void ion_system_contig_heap_destroy(struct ion_heap *heap)
447{
448	kfree(heap);
449}
450
451