https://github.com/torvalds/linux
Tip revision: 2ef96a5bb12be62ef75b5828c0aab838ebb29cb8 authored by Linus Torvalds on 10 May 2020, 22:16:58 UTC
Linux 5.7-rc5
Linux 5.7-rc5
Tip revision: 2ef96a5
main.c
#include <stdio.h>
#include <assert.h>
#include <linux/scatterlist.h>
#define MAX_PAGES (64)
static void set_pages(struct page **pages, const unsigned *array, unsigned num)
{
unsigned int i;
assert(num < MAX_PAGES);
for (i = 0; i < num; i++)
pages[i] = (struct page *)(unsigned long)
((1 + array[i]) * PAGE_SIZE);
}
#define pfn(...) (unsigned []){ __VA_ARGS__ }
int main(void)
{
const unsigned int sgmax = SCATTERLIST_MAX_SEGMENT;
struct test {
int alloc_ret;
unsigned num_pages;
unsigned *pfn;
unsigned size;
unsigned int max_seg;
unsigned int expected_segments;
} *test, tests[] = {
{ -EINVAL, 1, pfn(0), PAGE_SIZE, PAGE_SIZE + 1, 1 },
{ -EINVAL, 1, pfn(0), PAGE_SIZE, 0, 1 },
{ -EINVAL, 1, pfn(0), PAGE_SIZE, sgmax + 1, 1 },
{ 0, 1, pfn(0), PAGE_SIZE, sgmax, 1 },
{ 0, 1, pfn(0), 1, sgmax, 1 },
{ 0, 2, pfn(0, 1), 2 * PAGE_SIZE, sgmax, 1 },
{ 0, 2, pfn(1, 0), 2 * PAGE_SIZE, sgmax, 2 },
{ 0, 3, pfn(0, 1, 2), 3 * PAGE_SIZE, sgmax, 1 },
{ 0, 3, pfn(0, 2, 1), 3 * PAGE_SIZE, sgmax, 3 },
{ 0, 3, pfn(0, 1, 3), 3 * PAGE_SIZE, sgmax, 2 },
{ 0, 3, pfn(1, 2, 4), 3 * PAGE_SIZE, sgmax, 2 },
{ 0, 3, pfn(1, 3, 4), 3 * PAGE_SIZE, sgmax, 2 },
{ 0, 4, pfn(0, 1, 3, 4), 4 * PAGE_SIZE, sgmax, 2 },
{ 0, 5, pfn(0, 1, 3, 4, 5), 5 * PAGE_SIZE, sgmax, 2 },
{ 0, 5, pfn(0, 1, 3, 4, 6), 5 * PAGE_SIZE, sgmax, 3 },
{ 0, 5, pfn(0, 1, 2, 3, 4), 5 * PAGE_SIZE, sgmax, 1 },
{ 0, 5, pfn(0, 1, 2, 3, 4), 5 * PAGE_SIZE, 2 * PAGE_SIZE, 3 },
{ 0, 6, pfn(0, 1, 2, 3, 4, 5), 6 * PAGE_SIZE, 2 * PAGE_SIZE, 3 },
{ 0, 6, pfn(0, 2, 3, 4, 5, 6), 6 * PAGE_SIZE, 2 * PAGE_SIZE, 4 },
{ 0, 6, pfn(0, 1, 3, 4, 5, 6), 6 * PAGE_SIZE, 2 * PAGE_SIZE, 3 },
{ 0, 0, NULL, 0, 0, 0 },
};
unsigned int i;
for (i = 0, test = tests; test->expected_segments; test++, i++) {
struct page *pages[MAX_PAGES];
struct sg_table st;
int ret;
set_pages(pages, test->pfn, test->num_pages);
ret = __sg_alloc_table_from_pages(&st, pages, test->num_pages,
0, test->size, test->max_seg,
GFP_KERNEL);
assert(ret == test->alloc_ret);
if (test->alloc_ret)
continue;
assert(st.nents == test->expected_segments);
assert(st.orig_nents == test->expected_segments);
sg_free_table(&st);
}
assert(i == (sizeof(tests) / sizeof(tests[0])) - 1);
return 0;
}