1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * Test cases for bitfield helpers.
  4 */
  5
  6#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  7
  8#include <kunit/test.h>
  9#include <linux/bitfield.h>
 10
 11#define CHECK_ENC_GET_U(tp, v, field, res) do {				\
 12		{							\
 13			u##tp _res;					\
 14									\
 15			_res = u##tp##_encode_bits(v, field);		\
 16			KUNIT_ASSERT_FALSE_MSG(context, _res != res,	\
 17				       "u" #tp "_encode_bits(" #v ", " #field ") is 0x%llx != " #res "\n",	\
 18				       (u64)_res);			\
 19			KUNIT_ASSERT_FALSE(context,			\
 20				   u##tp##_get_bits(_res, field) != v);	\
 21		}							\
 22	} while (0)
 23
 24#define CHECK_ENC_GET_LE(tp, v, field, res) do {			\
 25		{							\
 26			__le##tp _res;					\
 27									\
 28			_res = le##tp##_encode_bits(v, field);		\
 29			KUNIT_ASSERT_FALSE_MSG(context,			\
 30				       _res != cpu_to_le##tp(res),	\
 31				       "le" #tp "_encode_bits(" #v ", " #field ") is 0x%llx != 0x%llx",\
 32				       (u64)le##tp##_to_cpu(_res),	\
 33				       (u64)(res));			\
 34			KUNIT_ASSERT_FALSE(context,			\
 35				   le##tp##_get_bits(_res, field) != v);\
 36		}							\
 37	} while (0)
 38
 39#define CHECK_ENC_GET_BE(tp, v, field, res) do {			\
 40		{							\
 41			__be##tp _res;					\
 42									\
 43			_res = be##tp##_encode_bits(v, field);		\
 44			KUNIT_ASSERT_FALSE_MSG(context,			\
 45				       _res != cpu_to_be##tp(res),	\
 46				       "be" #tp "_encode_bits(" #v ", " #field ") is 0x%llx != 0x%llx",	\
 47				       (u64)be##tp##_to_cpu(_res),	\
 48				       (u64)(res));			\
 49			KUNIT_ASSERT_FALSE(context,			\
 50				   be##tp##_get_bits(_res, field) != v);\
 51		}							\
 52	} while (0)
 53
 54#define CHECK_ENC_GET(tp, v, field, res) do {				\
 55		CHECK_ENC_GET_U(tp, v, field, res);			\
 56		CHECK_ENC_GET_LE(tp, v, field, res);			\
 57		CHECK_ENC_GET_BE(tp, v, field, res);			\
 58	} while (0)
 59
 60static void __init test_bitfields_constants(struct kunit *context)
 61{
 62	/*
 63	 * NOTE
 64	 * This whole function compiles (or at least should, if everything
 65	 * is going according to plan) to nothing after optimisation.
 66	 */
 67
 68	CHECK_ENC_GET(16,  1, 0x000f, 0x0001);
 69	CHECK_ENC_GET(16,  3, 0x00f0, 0x0030);
 70	CHECK_ENC_GET(16,  5, 0x0f00, 0x0500);
 71	CHECK_ENC_GET(16,  7, 0xf000, 0x7000);
 72	CHECK_ENC_GET(16, 14, 0x000f, 0x000e);
 73	CHECK_ENC_GET(16, 15, 0x00f0, 0x00f0);
 74
 75	CHECK_ENC_GET_U(8,  1, 0x0f, 0x01);
 76	CHECK_ENC_GET_U(8,  3, 0xf0, 0x30);
 77	CHECK_ENC_GET_U(8, 14, 0x0f, 0x0e);
 78	CHECK_ENC_GET_U(8, 15, 0xf0, 0xf0);
 79
 80	CHECK_ENC_GET(32,  1, 0x00000f00, 0x00000100);
 81	CHECK_ENC_GET(32,  3, 0x0000f000, 0x00003000);
 82	CHECK_ENC_GET(32,  5, 0x000f0000, 0x00050000);
 83	CHECK_ENC_GET(32,  7, 0x00f00000, 0x00700000);
 84	CHECK_ENC_GET(32, 14, 0x0f000000, 0x0e000000);
 85	CHECK_ENC_GET(32, 15, 0xf0000000, 0xf0000000);
 86
 87	CHECK_ENC_GET(64,  1, 0x00000f0000000000ull, 0x0000010000000000ull);
 88	CHECK_ENC_GET(64,  3, 0x0000f00000000000ull, 0x0000300000000000ull);
 89	CHECK_ENC_GET(64,  5, 0x000f000000000000ull, 0x0005000000000000ull);
 90	CHECK_ENC_GET(64,  7, 0x00f0000000000000ull, 0x0070000000000000ull);
 91	CHECK_ENC_GET(64, 14, 0x0f00000000000000ull, 0x0e00000000000000ull);
 92	CHECK_ENC_GET(64, 15, 0xf000000000000000ull, 0xf000000000000000ull);
 93}
 94
 95#define CHECK(tp, mask) do {						\
 96		u64 v;							\
 97									\
 98		for (v = 0; v < 1 << hweight32(mask); v++)		\
 99			KUNIT_ASSERT_FALSE(context,			\
100				tp##_encode_bits(v, mask) != v << __ffs64(mask));\
101	} while (0)
102
103static void __init test_bitfields_variables(struct kunit *context)
104{
105	CHECK(u8, 0x0f);
106	CHECK(u8, 0xf0);
107	CHECK(u8, 0x38);
108
109	CHECK(u16, 0x0038);
110	CHECK(u16, 0x0380);
111	CHECK(u16, 0x3800);
112	CHECK(u16, 0x8000);
113
114	CHECK(u32, 0x80000000);
115	CHECK(u32, 0x7f000000);
116	CHECK(u32, 0x07e00000);
117	CHECK(u32, 0x00018000);
118
119	CHECK(u64, 0x8000000000000000ull);
120	CHECK(u64, 0x7f00000000000000ull);
121	CHECK(u64, 0x0001800000000000ull);
122	CHECK(u64, 0x0000000080000000ull);
123	CHECK(u64, 0x000000007f000000ull);
124	CHECK(u64, 0x0000000018000000ull);
125	CHECK(u64, 0x0000001f8000000ull);
126}
127
128#ifdef TEST_BITFIELD_COMPILE
129static void __init test_bitfields_compile(struct kunit *context)
130{
131	/* these should fail compilation */
132	CHECK_ENC_GET(16, 16, 0x0f00, 0x1000);
133	u32_encode_bits(7, 0x06000000);
134
135	/* this should at least give a warning */
136	u16_encode_bits(0, 0x60000);
137}
138#endif
139
140static struct kunit_case __refdata bitfields_test_cases[] = {
141	KUNIT_CASE(test_bitfields_constants),
142	KUNIT_CASE(test_bitfields_variables),
143	{}
144};
145
146static struct kunit_suite bitfields_test_suite = {
147	.name = "bitfields",
148	.test_cases = bitfields_test_cases,
149};
150
151kunit_test_suites(&bitfields_test_suite);
152
153MODULE_AUTHOR("Johannes Berg <johannes@sipsolutions.net>");
154MODULE_DESCRIPTION("Test cases for bitfield helpers");
155MODULE_LICENSE("GPL");