1#include <linux/device.h>
2#include <linux/dma-map-ops.h>
3#include <linux/dma-mapping.h>
4#include <linux/dmapool.h>
5#include <linux/kernel.h>
6#include <linux/ktime.h>
7#include <linux/module.h>
8
9#define NR_TESTS (100)
10
11struct dma_pool_pair {
12	dma_addr_t dma;
13	void *v;
14};
15
16struct dmapool_parms {
17	size_t size;
18	size_t align;
19	size_t boundary;
20};
21
22static const struct dmapool_parms pool_parms[] = {
23	{ .size = 16, .align = 16, .boundary = 0 },
24	{ .size = 64, .align = 64, .boundary = 0 },
25	{ .size = 256, .align = 256, .boundary = 0 },
26	{ .size = 1024, .align = 1024, .boundary = 0 },
27	{ .size = 4096, .align = 4096, .boundary = 0 },
28	{ .size = 68, .align = 32, .boundary = 4096 },
29};
30
31static struct dma_pool *pool;
32static struct device test_dev;
33static u64 dma_mask;
34
35static inline int nr_blocks(int size)
36{
37	return clamp_t(int, (PAGE_SIZE / size) * 512, 1024, 8192);
38}
39
40static int dmapool_test_alloc(struct dma_pool_pair *p, int blocks)
41{
42	int i;
43
44	for (i = 0; i < blocks; i++) {
45		p[i].v = dma_pool_alloc(pool, GFP_KERNEL,
46					&p[i].dma);
47		if (!p[i].v)
48			goto pool_fail;
49	}
50
51	for (i = 0; i < blocks; i++)
52		dma_pool_free(pool, p[i].v, p[i].dma);
53
54	return 0;
55
56pool_fail:
57	for (--i; i >= 0; i--)
58		dma_pool_free(pool, p[i].v, p[i].dma);
59	return -ENOMEM;
60}
61
62static int dmapool_test_block(const struct dmapool_parms *parms)
63{
64	int blocks = nr_blocks(parms->size);
65	ktime_t start_time, end_time;
66	struct dma_pool_pair *p;
67	int i, ret;
68
69	p = kcalloc(blocks, sizeof(*p), GFP_KERNEL);
70	if (!p)
71		return -ENOMEM;
72
73	pool = dma_pool_create("test pool", &test_dev, parms->size,
74			       parms->align, parms->boundary);
75	if (!pool) {
76		ret = -ENOMEM;
77		goto free_pairs;
78	}
79
80	start_time = ktime_get();
81	for (i = 0; i < NR_TESTS; i++) {
82		ret = dmapool_test_alloc(p, blocks);
83		if (ret)
84			goto free_pool;
85		if (need_resched())
86			cond_resched();
87	}
88	end_time = ktime_get();
89
90	printk("dmapool test: size:%-4zu align:%-4zu blocks:%-4d time:%llu\n",
91		parms->size, parms->align, blocks,
92		ktime_us_delta(end_time, start_time));
93
94free_pool:
95	dma_pool_destroy(pool);
96free_pairs:
97	kfree(p);
98	return ret;
99}
100
101static void dmapool_test_release(struct device *dev)
102{
103}
104
105static int dmapool_checks(void)
106{
107	int i, ret;
108
109	ret = dev_set_name(&test_dev, "dmapool-test");
110	if (ret)
111		return ret;
112
113	ret = device_register(&test_dev);
114	if (ret) {
115		printk("%s: register failed:%d\n", __func__, ret);
116		goto put_device;
117	}
118
119	test_dev.release = dmapool_test_release;
120	set_dma_ops(&test_dev, NULL);
121	test_dev.dma_mask = &dma_mask;
122	ret = dma_set_mask_and_coherent(&test_dev, DMA_BIT_MASK(64));
123	if (ret) {
124		printk("%s: mask failed:%d\n", __func__, ret);
125		goto del_device;
126	}
127
128	for (i = 0; i < ARRAY_SIZE(pool_parms); i++) {
129		ret = dmapool_test_block(&pool_parms[i]);
130		if (ret)
131			break;
132	}
133
134del_device:
135	device_del(&test_dev);
136put_device:
137	put_device(&test_dev);
138	return ret;
139}
140
141static void dmapool_exit(void)
142{
143}
144
145module_init(dmapool_checks);
146module_exit(dmapool_exit);
147MODULE_LICENSE("GPL");
148