ion_system_heap.c revision def5c4926b3f691dfbcef39a94f206c0f0f3a92f 
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		arm_dma_ops.sync_single_for_device(NULL,
82			pfn_to_dma(NULL, page_to_pfn(page)),
83			PAGE_SIZE << order, DMA_BIDIRECTIONAL);
84	}
85	if (!page)
86		return 0;
87
88	if (split_pages)
89		split_page(page, order);
90	return page;
91}
92
93static void free_buffer_page(struct ion_system_heap *heap,
94			     struct ion_buffer *buffer, struct page *page,
95			     unsigned int order)
96{
97	bool cached = ion_buffer_cached(buffer);
98	bool split_pages = ion_buffer_fault_user_mappings(buffer);
99	int i;
100
101	if (!cached) {
102		struct ion_page_pool *pool = heap->pools[order_to_index(order)];
103		ion_page_pool_free(pool, page);
104	} else if (split_pages) {
105		for (i = 0; i < (1 << order); i++)
106			__free_page(page + i);
107	} else {
108		__free_pages(page, order);
109	}
110}
111
112
113static struct page_info *alloc_largest_available(struct ion_system_heap *heap,
114						 struct ion_buffer *buffer,
115						 unsigned long size,
116						 unsigned int max_order)
117{
118	struct page *page;
119	struct page_info *info;
120	int i;
121
122	for (i = 0; i < num_orders; i++) {
123		if (size < order_to_size(orders[i]))
124			continue;
125		if (max_order < orders[i])
126			continue;
127
128		page = alloc_buffer_page(heap, buffer, orders[i]);
129		if (!page)
130			continue;
131
132		info = kmalloc(sizeof(struct page_info), GFP_KERNEL);
133		info->page = page;
134		info->order = orders[i];
135		return info;
136	}
137	return NULL;
138}
139
140static int ion_system_heap_allocate(struct ion_heap *heap,
141				     struct ion_buffer *buffer,
142				     unsigned long size, unsigned long align,
143				     unsigned long flags)
144{
145	struct ion_system_heap *sys_heap = container_of(heap,
146							struct ion_system_heap,
147							heap);
148	struct sg_table *table;
149	struct scatterlist *sg;
150	int ret;
151	struct list_head pages;
152	struct page_info *info, *tmp_info;
153	int i = 0;
154	long size_remaining = PAGE_ALIGN(size);
155	unsigned int max_order = orders[0];
156	bool split_pages = ion_buffer_fault_user_mappings(buffer);
157
158	INIT_LIST_HEAD(&pages);
159	while (size_remaining > 0) {
160		info = alloc_largest_available(sys_heap, buffer, size_remaining, max_order);
161		if (!info)
162			goto err;
163		list_add_tail(&info->list, &pages);
164		size_remaining -= (1 << info->order) * PAGE_SIZE;
165		max_order = info->order;
166		i++;
167	}
168
169	table = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
170	if (!table)
171		goto err;
172
173	if (split_pages)
174		ret = sg_alloc_table(table, PAGE_ALIGN(size) / PAGE_SIZE,
175				     GFP_KERNEL);
176	else
177		ret = sg_alloc_table(table, i, GFP_KERNEL);
178
179	if (ret)
180		goto err1;
181
182	sg = table->sgl;
183	list_for_each_entry_safe(info, tmp_info, &pages, list) {
184		struct page *page = info->page;
185		if (split_pages) {
186			for (i = 0; i < (1 << info->order); i++) {
187				sg_set_page(sg, page + i, PAGE_SIZE, 0);
188				sg = sg_next(sg);
189			}
190		} else {
191			sg_set_page(sg, page, (1 << info->order) * PAGE_SIZE,
192				    0);
193			sg = sg_next(sg);
194		}
195		list_del(&info->list);
196		kfree(info);
197	}
198
199	buffer->priv_virt = table;
200	return 0;
201err1:
202	kfree(table);
203err:
204	list_for_each_entry(info, &pages, list) {
205		free_buffer_page(sys_heap, buffer, info->page, info->order);
206		kfree(info);
207	}
208	return -ENOMEM;
209}
210
211void ion_system_heap_free(struct ion_buffer *buffer)
212{
213	struct ion_heap *heap = buffer->heap;
214	struct ion_system_heap *sys_heap = container_of(heap,
215							struct ion_system_heap,
216							heap);
217	struct sg_table *table = buffer->sg_table;
218	bool cached = ion_buffer_cached(buffer);
219	struct scatterlist *sg;
220	LIST_HEAD(pages);
221	int i;
222
223	/* uncached pages come from the page pools, zero them before returning
224	   for security purposes (other allocations are zerod at alloc time */
225	if (!cached)
226		ion_heap_buffer_zero(buffer);
227
228	for_each_sg(table->sgl, sg, table->nents, i)
229		free_buffer_page(sys_heap, buffer, sg_page(sg),
230				get_order(sg_dma_len(sg)));
231	sg_free_table(table);
232	kfree(table);
233}
234
235struct sg_table *ion_system_heap_map_dma(struct ion_heap *heap,
236					 struct ion_buffer *buffer)
237{
238	return buffer->priv_virt;
239}
240
241void ion_system_heap_unmap_dma(struct ion_heap *heap,
242			       struct ion_buffer *buffer)
243{
244	return;
245}
246
247static struct ion_heap_ops system_heap_ops = {
248	.allocate = ion_system_heap_allocate,
249	.free = ion_system_heap_free,
250	.map_dma = ion_system_heap_map_dma,
251	.unmap_dma = ion_system_heap_unmap_dma,
252	.map_kernel = ion_heap_map_kernel,
253	.unmap_kernel = ion_heap_unmap_kernel,
254	.map_user = ion_heap_map_user,
255};
256
257static int ion_system_heap_shrink(struct shrinker *shrinker,
258				  struct shrink_control *sc) {
259
260	struct ion_heap *heap = container_of(shrinker, struct ion_heap,
261					     shrinker);
262	struct ion_system_heap *sys_heap = container_of(heap,
263							struct ion_system_heap,
264							heap);
265	int nr_total = 0;
266	int nr_freed = 0;
267	int i;
268
269	if (sc->nr_to_scan == 0)
270		goto end;
271
272	/* shrink the free list first, no point in zeroing the memory if
273	   we're just going to reclaim it */
274	nr_freed += ion_heap_freelist_drain(heap, sc->nr_to_scan * PAGE_SIZE) /
275		PAGE_SIZE;
276
277	if (nr_freed >= sc->nr_to_scan)
278		goto end;
279
280	for (i = 0; i < num_orders; i++) {
281		struct ion_page_pool *pool = sys_heap->pools[i];
282
283		nr_freed += ion_page_pool_shrink(pool, sc->gfp_mask,
284						 sc->nr_to_scan);
285		if (nr_freed >= sc->nr_to_scan)
286			break;
287	}
288
289end:
290	/* total number of items is whatever the page pools are holding
291	   plus whatever's in the freelist */
292	for (i = 0; i < num_orders; i++) {
293		struct ion_page_pool *pool = sys_heap->pools[i];
294		nr_total += ion_page_pool_shrink(pool, sc->gfp_mask, 0);
295	}
296	nr_total += ion_heap_freelist_size(heap) / PAGE_SIZE;
297	return nr_total;
298
299}
300
301static int ion_system_heap_debug_show(struct ion_heap *heap, struct seq_file *s,
302				      void *unused)
303{
304
305	struct ion_system_heap *sys_heap = container_of(heap,
306							struct ion_system_heap,
307							heap);
308	int i;
309	for (i = 0; i < num_orders; i++) {
310		struct ion_page_pool *pool = sys_heap->pools[i];
311		seq_printf(s, "%d order %u highmem pages in pool = %lu total\n",
312			   pool->high_count, pool->order,
313			   (1 << pool->order) * PAGE_SIZE * pool->high_count);
314		seq_printf(s, "%d order %u lowmem pages in pool = %lu total\n",
315			   pool->low_count, pool->order,
316			   (1 << pool->order) * PAGE_SIZE * pool->low_count);
317	}
318	return 0;
319}
320
321struct ion_heap *ion_system_heap_create(struct ion_platform_heap *unused)
322{
323	struct ion_system_heap *heap;
324	int i;
325
326	heap = kzalloc(sizeof(struct ion_system_heap), GFP_KERNEL);
327	if (!heap)
328		return ERR_PTR(-ENOMEM);
329	heap->heap.ops = &system_heap_ops;
330	heap->heap.type = ION_HEAP_TYPE_SYSTEM;
331	heap->heap.flags = ION_HEAP_FLAG_DEFER_FREE;
332	heap->pools = kzalloc(sizeof(struct ion_page_pool *) * num_orders,
333			      GFP_KERNEL);
334	if (!heap->pools)
335		goto err_alloc_pools;
336	for (i = 0; i < num_orders; i++) {
337		struct ion_page_pool *pool;
338		gfp_t gfp_flags = low_order_gfp_flags;
339
340		if (orders[i] > 4)
341			gfp_flags = high_order_gfp_flags;
342		pool = ion_page_pool_create(gfp_flags, orders[i]);
343		if (!pool)
344			goto err_create_pool;
345		heap->pools[i] = pool;
346	}
347
348	heap->heap.shrinker.shrink = ion_system_heap_shrink;
349	heap->heap.shrinker.seeks = DEFAULT_SEEKS;
350	heap->heap.shrinker.batch = 0;
351	register_shrinker(&heap->heap.shrinker);
352	heap->heap.debug_show = ion_system_heap_debug_show;
353	return &heap->heap;
354err_create_pool:
355	for (i = 0; i < num_orders; i++)
356		if (heap->pools[i])
357			ion_page_pool_destroy(heap->pools[i]);
358	kfree(heap->pools);
359err_alloc_pools:
360	kfree(heap);
361	return ERR_PTR(-ENOMEM);
362}
363
364void ion_system_heap_destroy(struct ion_heap *heap)
365{
366	struct ion_system_heap *sys_heap = container_of(heap,
367							struct ion_system_heap,
368							heap);
369	int i;
370
371	for (i = 0; i < num_orders; i++)
372		ion_page_pool_destroy(sys_heap->pools[i]);
373	kfree(sys_heap->pools);
374	kfree(sys_heap);
375}
376
377static int ion_system_contig_heap_allocate(struct ion_heap *heap,
378					   struct ion_buffer *buffer,
379					   unsigned long len,
380					   unsigned long align,
381					   unsigned long flags)
382{
383	buffer->priv_virt = kzalloc(len, GFP_KERNEL);
384	if (!buffer->priv_virt)
385		return -ENOMEM;
386	return 0;
387}
388
389void ion_system_contig_heap_free(struct ion_buffer *buffer)
390{
391	kfree(buffer->priv_virt);
392}
393
394static int ion_system_contig_heap_phys(struct ion_heap *heap,
395				       struct ion_buffer *buffer,
396				       ion_phys_addr_t *addr, size_t *len)
397{
398	*addr = virt_to_phys(buffer->priv_virt);
399	*len = buffer->size;
400	return 0;
401}
402
403struct sg_table *ion_system_contig_heap_map_dma(struct ion_heap *heap,
404						struct ion_buffer *buffer)
405{
406	struct sg_table *table;
407	int ret;
408
409	table = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
410	if (!table)
411		return ERR_PTR(-ENOMEM);
412	ret = sg_alloc_table(table, 1, GFP_KERNEL);
413	if (ret) {
414		kfree(table);
415		return ERR_PTR(ret);
416	}
417	sg_set_page(table->sgl, virt_to_page(buffer->priv_virt), buffer->size,
418		    0);
419	return table;
420}
421
422void ion_system_contig_heap_unmap_dma(struct ion_heap *heap,
423				      struct ion_buffer *buffer)
424{
425	sg_free_table(buffer->sg_table);
426	kfree(buffer->sg_table);
427}
428
429int ion_system_contig_heap_map_user(struct ion_heap *heap,
430				    struct ion_buffer *buffer,
431				    struct vm_area_struct *vma)
432{
433	unsigned long pfn = __phys_to_pfn(virt_to_phys(buffer->priv_virt));
434	return remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
435			       vma->vm_end - vma->vm_start,
436			       vma->vm_page_prot);
437
438}
439
440static struct ion_heap_ops kmalloc_ops = {
441	.allocate = ion_system_contig_heap_allocate,
442	.free = ion_system_contig_heap_free,
443	.phys = ion_system_contig_heap_phys,
444	.map_dma = ion_system_contig_heap_map_dma,
445	.unmap_dma = ion_system_contig_heap_unmap_dma,
446	.map_kernel = ion_heap_map_kernel,
447	.unmap_kernel = ion_heap_unmap_kernel,
448	.map_user = ion_system_contig_heap_map_user,
449};
450
451struct ion_heap *ion_system_contig_heap_create(struct ion_platform_heap *unused)
452{
453	struct ion_heap *heap;
454
455	heap = kzalloc(sizeof(struct ion_heap), GFP_KERNEL);
456	if (!heap)
457		return ERR_PTR(-ENOMEM);
458	heap->ops = &kmalloc_ops;
459	heap->type = ION_HEAP_TYPE_SYSTEM_CONTIG;
460	return heap;
461}
462
463void ion_system_contig_heap_destroy(struct ion_heap *heap)
464{
465	kfree(heap);
466}
467
468