summaryrefslogtreecommitdiff
path: root/drivers/dma-buf/heaps/cma_heap.c
blob: 28fb04eccdd0caa38093211e2de538980c1a029c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
// SPDX-License-Identifier: GPL-2.0
/*
 * DMABUF CMA heap exporter
 *
 * Copyright (C) 2012, 2019, 2020 Linaro Ltd.
 * Author: <benjamin.gaignard@linaro.org> for ST-Ericsson.
 *
 * Also utilizing parts of Andrew Davis' SRAM heap:
 * Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/
 *	Andrew F. Davis <afd@ti.com>
 */
#include <linux/cma.h>
#include <linux/dma-buf.h>
#include <linux/dma-heap.h>
#include <linux/dma-map-ops.h>
#include <linux/err.h>
#include <linux/highmem.h>
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>


struct cma_heap {
	struct dma_heap *heap;
	struct cma *cma;
};

struct cma_heap_buffer {
	struct cma_heap *heap;
	struct list_head attachments;
	struct mutex lock;
	unsigned long len;
	struct page *cma_pages;
	struct page **pages;
	pgoff_t pagecount;
	int vmap_cnt;
	void *vaddr;
};

struct dma_heap_attachment {
	struct device *dev;
	struct sg_table table;
	struct list_head list;
	bool mapped;
};

static int cma_heap_attach(struct dma_buf *dmabuf,
			   struct dma_buf_attachment *attachment)
{
	struct cma_heap_buffer *buffer = dmabuf->priv;
	struct dma_heap_attachment *a;
	int ret;

	a = kzalloc(sizeof(*a), GFP_KERNEL);
	if (!a)
		return -ENOMEM;

	ret = sg_alloc_table_from_pages(&a->table, buffer->pages,
					buffer->pagecount, 0,
					buffer->pagecount << PAGE_SHIFT,
					GFP_KERNEL);
	if (ret) {
		kfree(a);
		return ret;
	}

	a->dev = attachment->dev;
	INIT_LIST_HEAD(&a->list);
	a->mapped = false;

	attachment->priv = a;

	mutex_lock(&buffer->lock);
	list_add(&a->list, &buffer->attachments);
	mutex_unlock(&buffer->lock);

	return 0;
}

static void cma_heap_detach(struct dma_buf *dmabuf,
			    struct dma_buf_attachment *attachment)
{
	struct cma_heap_buffer *buffer = dmabuf->priv;
	struct dma_heap_attachment *a = attachment->priv;

	mutex_lock(&buffer->lock);
	list_del(&a->list);
	mutex_unlock(&buffer->lock);

	sg_free_table(&a->table);
	kfree(a);
}

static struct sg_table *cma_heap_map_dma_buf(struct dma_buf_attachment *attachment,
					     enum dma_data_direction direction)
{
	struct dma_heap_attachment *a = attachment->priv;
	struct sg_table *table = &a->table;
	int ret;

	ret = dma_map_sgtable(attachment->dev, table, direction, 0);
	if (ret)
		return ERR_PTR(-ENOMEM);
	a->mapped = true;
	return table;
}

static void cma_heap_unmap_dma_buf(struct dma_buf_attachment *attachment,
				   struct sg_table *table,
				   enum dma_data_direction direction)
{
	struct dma_heap_attachment *a = attachment->priv;

	a->mapped = false;
	dma_unmap_sgtable(attachment->dev, table, direction, 0);
}

static int cma_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
					     enum dma_data_direction direction)
{
	struct cma_heap_buffer *buffer = dmabuf->priv;
	struct dma_heap_attachment *a;

	mutex_lock(&buffer->lock);

	if (buffer->vmap_cnt)
		invalidate_kernel_vmap_range(buffer->vaddr, buffer->len);

	list_for_each_entry(a, &buffer->attachments, list) {
		if (!a->mapped)
			continue;
		dma_sync_sgtable_for_cpu(a->dev, &a->table, direction);
	}
	mutex_unlock(&buffer->lock);

	return 0;
}

static int cma_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf,
					   enum dma_data_direction direction)
{
	struct cma_heap_buffer *buffer = dmabuf->priv;
	struct dma_heap_attachment *a;

	mutex_lock(&buffer->lock);

	if (buffer->vmap_cnt)
		flush_kernel_vmap_range(buffer->vaddr, buffer->len);

	list_for_each_entry(a, &buffer->attachments, list) {
		if (!a->mapped)
			continue;
		dma_sync_sgtable_for_device(a->dev, &a->table, direction);
	}
	mutex_unlock(&buffer->lock);

	return 0;
}

static vm_fault_t cma_heap_vm_fault(struct vm_fault *vmf)
{
	struct vm_area_struct *vma = vmf->vma;
	struct cma_heap_buffer *buffer = vma->vm_private_data;

	if (vmf->pgoff > buffer->pagecount)
		return VM_FAULT_SIGBUS;

	vmf->page = buffer->pages[vmf->pgoff];
	get_page(vmf->page);

	return 0;
}

static const struct vm_operations_struct dma_heap_vm_ops = {
	.fault = cma_heap_vm_fault,
};

static int cma_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
{
	struct cma_heap_buffer *buffer = dmabuf->priv;

	if ((vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) == 0)
		return -EINVAL;

	vma->vm_ops = &dma_heap_vm_ops;
	vma->vm_private_data = buffer;

	return 0;
}

static void *cma_heap_do_vmap(struct cma_heap_buffer *buffer)
{
	void *vaddr;

	vaddr = vmap(buffer->pages, buffer->pagecount, VM_MAP, PAGE_KERNEL);
	if (!vaddr)
		return ERR_PTR(-ENOMEM);

	return vaddr;
}

static int cma_heap_vmap(struct dma_buf *dmabuf, struct iosys_map *map)
{
	struct cma_heap_buffer *buffer = dmabuf->priv;
	void *vaddr;
	int ret = 0;

	mutex_lock(&buffer->lock);
	if (buffer->vmap_cnt) {
		buffer->vmap_cnt++;
		iosys_map_set_vaddr(map, buffer->vaddr);
		goto out;
	}

	vaddr = cma_heap_do_vmap(buffer);
	if (IS_ERR(vaddr)) {
		ret = PTR_ERR(vaddr);
		goto out;
	}
	buffer->vaddr = vaddr;
	buffer->vmap_cnt++;
	iosys_map_set_vaddr(map, buffer->vaddr);
out:
	mutex_unlock(&buffer->lock);

	return ret;
}

static void cma_heap_vunmap(struct dma_buf *dmabuf, struct iosys_map *map)
{
	struct cma_heap_buffer *buffer = dmabuf->priv;

	mutex_lock(&buffer->lock);
	if (!--buffer->vmap_cnt) {
		vunmap(buffer->vaddr);
		buffer->vaddr = NULL;
	}
	mutex_unlock(&buffer->lock);
	iosys_map_clear(map);
}

static void cma_heap_dma_buf_release(struct dma_buf *dmabuf)
{
	struct cma_heap_buffer *buffer = dmabuf->priv;
	struct cma_heap *cma_heap = buffer->heap;

	if (buffer->vmap_cnt > 0) {
		WARN(1, "%s: buffer still mapped in the kernel\n", __func__);
		vunmap(buffer->vaddr);
		buffer->vaddr = NULL;
	}

	/* free page list */
	kfree(buffer->pages);
	/* release memory */
	cma_release(cma_heap->cma, buffer->cma_pages, buffer->pagecount);
	kfree(buffer);
}

static const struct dma_buf_ops cma_heap_buf_ops = {
	.attach = cma_heap_attach,
	.detach = cma_heap_detach,
	.map_dma_buf = cma_heap_map_dma_buf,
	.unmap_dma_buf = cma_heap_unmap_dma_buf,
	.begin_cpu_access = cma_heap_dma_buf_begin_cpu_access,
	.end_cpu_access = cma_heap_dma_buf_end_cpu_access,
	.mmap = cma_heap_mmap,
	.vmap = cma_heap_vmap,
	.vunmap = cma_heap_vunmap,
	.release = cma_heap_dma_buf_release,
};

static struct dma_buf *cma_heap_allocate(struct dma_heap *heap,
					 unsigned long len,
					 unsigned long fd_flags,
					 unsigned long heap_flags)
{
	struct cma_heap *cma_heap = dma_heap_get_drvdata(heap);
	struct cma_heap_buffer *buffer;
	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
	size_t size = PAGE_ALIGN(len);
	pgoff_t pagecount = size >> PAGE_SHIFT;
	unsigned long align = get_order(size);
	struct page *cma_pages;
	struct dma_buf *dmabuf;
	int ret = -ENOMEM;
	pgoff_t pg;

	buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
	if (!buffer)
		return ERR_PTR(-ENOMEM);

	INIT_LIST_HEAD(&buffer->attachments);
	mutex_init(&buffer->lock);
	buffer->len = size;

	if (align > CONFIG_CMA_ALIGNMENT)
		align = CONFIG_CMA_ALIGNMENT;

	cma_pages = cma_alloc(cma_heap->cma, pagecount, align, false);
	if (!cma_pages)
		goto free_buffer;

	/* Clear the cma pages */
	if (PageHighMem(cma_pages)) {
		unsigned long nr_clear_pages = pagecount;
		struct page *page = cma_pages;

		while (nr_clear_pages > 0) {
			void *vaddr = kmap_atomic(page);

			memset(vaddr, 0, PAGE_SIZE);
			kunmap_atomic(vaddr);
			/*
			 * Avoid wasting time zeroing memory if the process
			 * has been killed by by SIGKILL
			 */
			if (fatal_signal_pending(current))
				goto free_cma;
			page++;
			nr_clear_pages--;
		}
	} else {
		memset(page_address(cma_pages), 0, size);
	}

	buffer->pages = kmalloc_array(pagecount, sizeof(*buffer->pages), GFP_KERNEL);
	if (!buffer->pages) {
		ret = -ENOMEM;
		goto free_cma;
	}

	for (pg = 0; pg < pagecount; pg++)
		buffer->pages[pg] = &cma_pages[pg];

	buffer->cma_pages = cma_pages;
	buffer->heap = cma_heap;
	buffer->pagecount = pagecount;

	/* create the dmabuf */
	exp_info.exp_name = dma_heap_get_name(heap);
	exp_info.ops = &cma_heap_buf_ops;
	exp_info.size = buffer->len;
	exp_info.flags = fd_flags;
	exp_info.priv = buffer;
	dmabuf = dma_buf_export(&exp_info);
	if (IS_ERR(dmabuf)) {
		ret = PTR_ERR(dmabuf);
		goto free_pages;
	}
	return dmabuf;

free_pages:
	kfree(buffer->pages);
free_cma:
	cma_release(cma_heap->cma, cma_pages, pagecount);
free_buffer:
	kfree(buffer);

	return ERR_PTR(ret);
}

static const struct dma_heap_ops cma_heap_ops = {
	.allocate = cma_heap_allocate,
};

static int __add_cma_heap(struct cma *cma, void *data)
{
	struct cma_heap *cma_heap;
	struct dma_heap_export_info exp_info;

	cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL);
	if (!cma_heap)
		return -ENOMEM;
	cma_heap->cma = cma;

	exp_info.name = cma_get_name(cma);
	exp_info.ops = &cma_heap_ops;
	exp_info.priv = cma_heap;

	cma_heap->heap = dma_heap_add(&exp_info);
	if (IS_ERR(cma_heap->heap)) {
		int ret = PTR_ERR(cma_heap->heap);

		kfree(cma_heap);
		return ret;
	}

	return 0;
}

static int add_default_cma_heap(void)
{
	struct cma *default_cma = dev_get_cma_area(NULL);
	int ret = 0;

	if (default_cma)
		ret = __add_cma_heap(default_cma, NULL);

	return ret;
}
module_init(add_default_cma_heap);
MODULE_DESCRIPTION("DMA-BUF CMA Heap");
MODULE_LICENSE("GPL v2");