tools/testing/scatterlist/main.c

   1 #include <stdio.h>
   2 #include <assert.h>
   3
   4 #include <linux/scatterlist.h>
   5
   6 #define MAX_PAGES (64)
   7
   8 static 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
  20 int 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 }