[PATCH 2/2] lib: Add test for bitmap_cut()

From: Stefano Brivio
Date: Mon Jun 08 2020 - 05:13:51 EST


Based on an original patch by Yury Norov: introduce a test for
bitmap_cut() that also makes sure functionality is as described for
partially overlapping src and dst.

Co-authored-by: Yury Norov <yury.norov@xxxxxxxxx>
Signed-off-by: Stefano Brivio <sbrivio@xxxxxxxxxx>
---
lib/test_bitmap.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 60 insertions(+)

diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c
index 6b13150667f5..2c16adec5922 100644
--- a/lib/test_bitmap.c
+++ b/lib/test_bitmap.c
@@ -610,6 +610,65 @@ static void __init test_for_each_set_clump8(void)
expect_eq_clump8(start, CLUMP_EXP_NUMBITS, clump_exp, &clump);
}

+struct test_bitmap_cut {
+ unsigned int first;
+ unsigned int cut;
+ unsigned int nbits;
+ unsigned long in[4];
+ unsigned long expected[4];
+};
+
+static struct test_bitmap_cut test_cut[] = {
+ { 0, 0, 8, { 0x0000000aUL, }, { 0x0000000aUL, }, },
+ { 0, 0, 32, { 0xdadadeadUL, }, { 0xdadadeadUL, }, },
+ { 0, 3, 8, { 0x000000aaUL, }, { 0x00000015UL, }, },
+ { 3, 3, 8, { 0x000000aaUL, }, { 0x00000012UL, }, },
+ { 0, 1, 32, { 0xa5a5a5a5UL, }, { 0x52d2d2d2UL, }, },
+ { 0, 8, 32, { 0xdeadc0deUL, }, { 0x00deadc0UL, }, },
+ { 1, 1, 32, { 0x5a5a5a5aUL, }, { 0x2d2d2d2cUL, }, },
+ { 0, 15, 32, { 0xa5a5a5a5UL, }, { 0x00014b4bUL, }, },
+ { 0, 16, 32, { 0xa5a5a5a5UL, }, { 0x0000a5a5UL, }, },
+ { 15, 15, 32, { 0xa5a5a5a5UL, }, { 0x000125a5UL, }, },
+ { 15, 16, 32, { 0xa5a5a5a5UL, }, { 0x0000a5a5UL, }, },
+ { 16, 15, 32, { 0xa5a5a5a5UL, }, { 0x0001a5a5UL, }, },
+
+ { BITS_PER_LONG, BITS_PER_LONG, BITS_PER_LONG,
+ { 0xa5a5a5a5UL, 0xa5a5a5a5UL, },
+ { 0xa5a5a5a5UL, 0xa5a5a5a5UL, },
+ },
+ { 1, BITS_PER_LONG - 1, BITS_PER_LONG,
+ { 0xa5a5a5a5UL, 0xa5a5a5a5UL, },
+ { 0x00000001UL, 0x00000001UL, },
+ },
+
+ { 0, BITS_PER_LONG * 2, BITS_PER_LONG * 2 + 1,
+ { 0xa5a5a5a5UL, 0x00000001UL, 0x00000001UL, 0x00000001UL },
+ { 0x00000001UL, },
+ },
+ { 16, BITS_PER_LONG * 2 + 1, BITS_PER_LONG * 2 + 1 + 16,
+ { 0x0000ffffUL, 0x5a5a5a5aUL, 0x5a5a5a5aUL, 0x5a5a5a5aUL },
+ { 0x2d2dffffUL, },
+ },
+};
+
+static void __init test_bitmap_cut(void)
+{
+ unsigned long b[4], *in = &b[1], *out = &b[0]; /* Partial overlap */
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(test_cut); i++) {
+ struct test_bitmap_cut *t = &test_cut[i];
+
+ memcpy(in, t->in, sizeof(t->in));
+
+ bitmap_cut(out, in, t->first, t->cut, t->nbits);
+ if (!bitmap_equal(out, t->expected, t->nbits)) {
+ pr_err("bitmap_cut failed: expected %*pb, got %*pb\n",
+ t->nbits, t->expected, t->nbits, out);
+ }
+ }
+}
+
static void __init selftest(void)
{
test_zero_clear();
@@ -623,6 +682,7 @@ static void __init selftest(void)
test_bitmap_parselist_user();
test_mem_optimisations();
test_for_each_set_clump8();
+ test_bitmap_cut();
}

KSTM_MODULE_LOADERS(test_bitmap);
--
2.26.2