linux/tools/testing/scatterlist/main.c
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   1#include <stdio.h>
   2#include <assert.h>
   3
   4#include <linux/scatterlist.h>
   5
   6#define MAX_PAGES (64)
   7
   8struct test {
   9        int alloc_ret;
  10        unsigned num_pages;
  11        unsigned *pfn;
  12        unsigned *pfn_app;
  13        unsigned size;
  14        unsigned int max_seg;
  15        unsigned int expected_segments;
  16};
  17
  18static void set_pages(struct page **pages, const unsigned *array, unsigned num)
  19{
  20        unsigned int i;
  21
  22        assert(num < MAX_PAGES);
  23        for (i = 0; i < num; i++)
  24                pages[i] = (struct page *)(unsigned long)
  25                           ((1 + array[i]) * PAGE_SIZE);
  26}
  27
  28#define pfn(...) (unsigned []){ __VA_ARGS__ }
  29
  30static void fail(struct test *test, struct sg_table *st, const char *cond)
  31{
  32        unsigned int i;
  33
  34        fprintf(stderr, "Failed on '%s'!\n\n", cond);
  35
  36        printf("size = %u, max segment = %u, expected nents = %u\nst->nents = %u, st->orig_nents= %u\n",
  37               test->size, test->max_seg, test->expected_segments, st->nents,
  38               st->orig_nents);
  39
  40        printf("%u input PFNs:", test->num_pages);
  41        for (i = 0; i < test->num_pages; i++)
  42                printf(" %x", test->pfn[i]);
  43        printf("\n");
  44
  45        exit(1);
  46}
  47
  48#define VALIDATE(cond, st, test) \
  49        if (!(cond)) \
  50                fail((test), (st), #cond);
  51
  52int main(void)
  53{
  54        const unsigned int sgmax = UINT_MAX;
  55        struct test *test, tests[] = {
  56                { -EINVAL, 1, pfn(0), NULL, PAGE_SIZE, 0, 1 },
  57                { 0, 1, pfn(0), NULL, PAGE_SIZE, PAGE_SIZE + 1, 1 },
  58                { 0, 1, pfn(0), NULL, PAGE_SIZE, sgmax, 1 },
  59                { 0, 1, pfn(0), NULL, 1, sgmax, 1 },
  60                { 0, 2, pfn(0, 1), NULL, 2 * PAGE_SIZE, sgmax, 1 },
  61                { 0, 2, pfn(1, 0), NULL, 2 * PAGE_SIZE, sgmax, 2 },
  62                { 0, 3, pfn(0, 1, 2), NULL, 3 * PAGE_SIZE, sgmax, 1 },
  63                { 0, 3, pfn(0, 1, 2), NULL, 3 * PAGE_SIZE, sgmax, 1 },
  64                { 0, 3, pfn(0, 1, 2), pfn(3, 4, 5), 3 * PAGE_SIZE, sgmax, 1 },
  65                { 0, 3, pfn(0, 1, 2), pfn(4, 5, 6), 3 * PAGE_SIZE, sgmax, 2 },
  66                { 0, 3, pfn(0, 2, 1), NULL, 3 * PAGE_SIZE, sgmax, 3 },
  67                { 0, 3, pfn(0, 1, 3), NULL, 3 * PAGE_SIZE, sgmax, 2 },
  68                { 0, 3, pfn(1, 2, 4), NULL, 3 * PAGE_SIZE, sgmax, 2 },
  69                { 0, 3, pfn(1, 3, 4), NULL, 3 * PAGE_SIZE, sgmax, 2 },
  70                { 0, 4, pfn(0, 1, 3, 4), NULL, 4 * PAGE_SIZE, sgmax, 2 },
  71                { 0, 5, pfn(0, 1, 3, 4, 5), NULL, 5 * PAGE_SIZE, sgmax, 2 },
  72                { 0, 5, pfn(0, 1, 3, 4, 6), NULL, 5 * PAGE_SIZE, sgmax, 3 },
  73                { 0, 5, pfn(0, 1, 2, 3, 4), NULL, 5 * PAGE_SIZE, sgmax, 1 },
  74                { 0, 5, pfn(0, 1, 2, 3, 4), NULL, 5 * PAGE_SIZE, 2 * PAGE_SIZE,
  75                  3 },
  76                { 0, 6, pfn(0, 1, 2, 3, 4, 5), NULL, 6 * PAGE_SIZE,
  77                  2 * PAGE_SIZE, 3 },
  78                { 0, 6, pfn(0, 2, 3, 4, 5, 6), NULL, 6 * PAGE_SIZE,
  79                  2 * PAGE_SIZE, 4 },
  80                { 0, 6, pfn(0, 1, 3, 4, 5, 6), pfn(7, 8, 9, 10, 11, 12),
  81                  6 * PAGE_SIZE, 12 * PAGE_SIZE, 2 },
  82                { 0, 0, NULL, NULL, 0, 0, 0 },
  83        };
  84        unsigned int i;
  85
  86        for (i = 0, test = tests; test->expected_segments; test++, i++) {
  87                int left_pages = test->pfn_app ? test->num_pages : 0;
  88                struct sg_append_table append = {};
  89                struct page *pages[MAX_PAGES];
  90                int ret;
  91
  92                set_pages(pages, test->pfn, test->num_pages);
  93
  94                if (test->pfn_app)
  95                        ret = sg_alloc_append_table_from_pages(
  96                                &append, pages, test->num_pages, 0, test->size,
  97                                test->max_seg, left_pages, GFP_KERNEL);
  98                else
  99                        ret = sg_alloc_table_from_pages_segment(
 100                                &append.sgt, pages, test->num_pages, 0,
 101                                test->size, test->max_seg, GFP_KERNEL);
 102
 103                assert(ret == test->alloc_ret);
 104
 105                if (test->alloc_ret)
 106                        continue;
 107
 108                if (test->pfn_app) {
 109                        set_pages(pages, test->pfn_app, test->num_pages);
 110                        ret = sg_alloc_append_table_from_pages(
 111                                &append, pages, test->num_pages, 0, test->size,
 112                                test->max_seg, 0, GFP_KERNEL);
 113
 114                        assert(ret == test->alloc_ret);
 115                }
 116
 117                VALIDATE(append.sgt.nents == test->expected_segments,
 118                         &append.sgt, test);
 119                if (!test->pfn_app)
 120                        VALIDATE(append.sgt.orig_nents ==
 121                                         test->expected_segments,
 122                                 &append.sgt, test);
 123
 124                if (test->pfn_app)
 125                        sg_free_append_table(&append);
 126                else
 127                        sg_free_table(&append.sgt);
 128        }
 129
 130        assert(i == (sizeof(tests) / sizeof(tests[0])) - 1);
 131
 132        return 0;
 133}
 134