1#include <stdio.h>
 2#include <assert.h>
 3
 4#include <linux/scatterlist.h>
 5
 6#define MAX_PAGES (64)
 7
 8static void set_pages(struct page **pages, const unsigned *array, unsigned num)
 9{
10	unsigned int i;
11
12	assert(num < MAX_PAGES);
13	for (i = 0; i < num; i++)
14		pages[i] = (struct page *)(unsigned long)
15			   ((1 + array[i]) * PAGE_SIZE);
16}
17
18#define pfn(...) (unsigned []){ __VA_ARGS__ }
19
20int main(void)
21{
22	const unsigned int sgmax = SCATTERLIST_MAX_SEGMENT;
23	struct test {
24		int alloc_ret;
25		unsigned num_pages;
26		unsigned *pfn;
27		unsigned size;
28		unsigned int max_seg;
29		unsigned int expected_segments;
30	} *test, tests[] = {
31		{ -EINVAL, 1, pfn(0), PAGE_SIZE, PAGE_SIZE + 1, 1 },
32		{ -EINVAL, 1, pfn(0), PAGE_SIZE, 0, 1 },
33		{ -EINVAL, 1, pfn(0), PAGE_SIZE, sgmax + 1, 1 },
34		{ 0, 1, pfn(0), PAGE_SIZE, sgmax, 1 },
35		{ 0, 1, pfn(0), 1, sgmax, 1 },
36		{ 0, 2, pfn(0, 1), 2 * PAGE_SIZE, sgmax, 1 },
37		{ 0, 2, pfn(1, 0), 2 * PAGE_SIZE, sgmax, 2 },
38		{ 0, 3, pfn(0, 1, 2), 3 * PAGE_SIZE, sgmax, 1 },
39		{ 0, 3, pfn(0, 2, 1), 3 * PAGE_SIZE, sgmax, 3 },
40		{ 0, 3, pfn(0, 1, 3), 3 * PAGE_SIZE, sgmax, 2 },
41		{ 0, 3, pfn(1, 2, 4), 3 * PAGE_SIZE, sgmax, 2 },
42		{ 0, 3, pfn(1, 3, 4), 3 * PAGE_SIZE, sgmax, 2 },
43		{ 0, 4, pfn(0, 1, 3, 4), 4 * PAGE_SIZE, sgmax, 2 },
44		{ 0, 5, pfn(0, 1, 3, 4, 5), 5 * PAGE_SIZE, sgmax, 2 },
45		{ 0, 5, pfn(0, 1, 3, 4, 6), 5 * PAGE_SIZE, sgmax, 3 },
46		{ 0, 5, pfn(0, 1, 2, 3, 4), 5 * PAGE_SIZE, sgmax, 1 },
47		{ 0, 5, pfn(0, 1, 2, 3, 4), 5 * PAGE_SIZE, 2 * PAGE_SIZE, 3 },
48		{ 0, 6, pfn(0, 1, 2, 3, 4, 5), 6 * PAGE_SIZE, 2 * PAGE_SIZE, 3 },
49		{ 0, 6, pfn(0, 2, 3, 4, 5, 6), 6 * PAGE_SIZE, 2 * PAGE_SIZE, 4 },
50		{ 0, 6, pfn(0, 1, 3, 4, 5, 6), 6 * PAGE_SIZE, 2 * PAGE_SIZE, 3 },
51		{ 0, 0, NULL, 0, 0, 0 },
52	};
53	unsigned int i;
54
55	for (i = 0, test = tests; test->expected_segments; test++, i++) {
56		struct page *pages[MAX_PAGES];
57		struct sg_table st;
58		int ret;
59
60		set_pages(pages, test->pfn, test->num_pages);
61
62		ret = __sg_alloc_table_from_pages(&st, pages, test->num_pages,
63						  0, test->size, test->max_seg,
64						  GFP_KERNEL);
65		assert(ret == test->alloc_ret);
66
67		if (test->alloc_ret)
68			continue;
69
70		assert(st.nents == test->expected_segments);
71		assert(st.orig_nents == test->expected_segments);
72
73		sg_free_table(&st);
74	}
75
76	assert(i == (sizeof(tests) / sizeof(tests[0])) - 1);
77
78	return 0;
79}