sched_ext: Maintain an online cid mask in the scheduler arenagrafted

Schedulers on the default cid mapping treat [0, nr_online_cids) as the
online set and restart on hotplug. Schedulers that install their own mapping
with scx_bpf_cid_override() have no way to learn which cids are online: the
count no longer identifies members and the CPU-form cpumask is unusable from
cid programs. This is an obvious hole in the cid API.

Add scx_bpf_online_cmask(), a kernel-maintained cmask in the scheduler's
arena, allocated alongside the per-CPU scratch masks and populated after the
cid mapping is finalized and before ops.init(), for child schedulers too.
The pointer stays valid through ops.exit() with no reference to take. It is
the arena offset as a void pointer, the same form struct_ops arena arguments
arrive in. The verifier types the void return as a scalar for the program's
arena cast.

The mask follows the SCX hotplug notifications: seeded from cpu_active_mask
and updated before ops.cid_online/offline() runs, so it lags cpu_online_mask
only inside a hotplug transition. Updates walk the scheduler list under the
lock that also serializes unlinking. Reads are live, not atomic snapshots.
Root initialization excludes hotplug.

v2: Reworded the getter kerneldoc (Andrea Righi).

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>

1 files changed, 474 insertions, 0 deletions

diff --git a/lib/packing_test.c b/lib/packing_test.c
new file mode 100644
index 000000000..ce3b83d33
--- /dev/null
+++ b/lib/packing_test.c
@@ -0,0 +1,474 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2024, Vladimir Oltean <olteanv@gmail.com>
+ * Copyright (c) 2024, Intel Corporation.
+ */
+#include <kunit/test.h>
+#include <linux/packing.h>
+
+struct packing_test_case {
+	const char *desc;
+	const u8 *pbuf;
+	size_t pbuf_size;
+	u64 uval;
+	size_t start_bit;
+	size_t end_bit;
+	u8 quirks;
+};
+
+#define NO_QUIRKS	0
+
+/**
+ * PBUF - Initialize .pbuf and .pbuf_size
+ * @array: elements of constant physical buffer
+ *
+ * Initializes the .pbuf and .pbuf_size fields of a struct packing_test_case
+ * with a constant array of the specified elements.
+ */
+#define PBUF(array...)					\
+	.pbuf = (const u8[]){ array },			\
+	.pbuf_size = sizeof((const u8 []){ array })
+
+static const struct packing_test_case cases[] = {
+	/* These tests pack and unpack a magic 64-bit value
+	 * (0xcafedeadbeefcafe) at a fixed logical offset (32) within an
+	 * otherwise zero array of 128 bits (16 bytes). They test all possible
+	 * bit layouts of the 128 bit buffer.
+	 */
+	{
+		.desc = "no quirks, 16 bytes",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0xca, 0xfe, 0xde, 0xad,
+		     0xbe, 0xef, 0xca, 0xfe, 0x00, 0x00, 0x00, 0x00),
+		.uval = 0xcafedeadbeefcafe,
+		.start_bit = 95,
+		.end_bit = 32,
+		.quirks = NO_QUIRKS,
+	},
+	{
+		.desc = "lsw32 first, 16 bytes",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0xbe, 0xef, 0xca, 0xfe,
+		     0xca, 0xfe, 0xde, 0xad, 0x00, 0x00, 0x00, 0x00),
+		.uval = 0xcafedeadbeefcafe,
+		.start_bit = 95,
+		.end_bit = 32,
+		.quirks = QUIRK_LSW32_IS_FIRST,
+	},
+	{
+		.desc = "little endian words, 16 bytes",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0xad, 0xde, 0xfe, 0xca,
+		     0xfe, 0xca, 0xef, 0xbe, 0x00, 0x00, 0x00, 0x00),
+		.uval = 0xcafedeadbeefcafe,
+		.start_bit = 95,
+		.end_bit = 32,
+		.quirks = QUIRK_LITTLE_ENDIAN,
+	},
+	{
+		.desc = "lsw32 first + little endian words, 16 bytes",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0xfe, 0xca, 0xef, 0xbe,
+		     0xad, 0xde, 0xfe, 0xca, 0x00, 0x00, 0x00, 0x00),
+		.uval = 0xcafedeadbeefcafe,
+		.start_bit = 95,
+		.end_bit = 32,
+		.quirks = QUIRK_LSW32_IS_FIRST | QUIRK_LITTLE_ENDIAN,
+	},
+	{
+		.desc = "msb right, 16 bytes",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0x53, 0x7f, 0x7b, 0xb5,
+		     0x7d, 0xf7, 0x53, 0x7f, 0x00, 0x00, 0x00, 0x00),
+		.uval = 0xcafedeadbeefcafe,
+		.start_bit = 95,
+		.end_bit = 32,
+		.quirks = QUIRK_MSB_ON_THE_RIGHT,
+	},
+	{
+		.desc = "msb right + lsw32 first, 16 bytes",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0x7d, 0xf7, 0x53, 0x7f,
+		     0x53, 0x7f, 0x7b, 0xb5, 0x00, 0x00, 0x00, 0x00),
+		.uval = 0xcafedeadbeefcafe,
+		.start_bit = 95,
+		.end_bit = 32,
+		.quirks = QUIRK_MSB_ON_THE_RIGHT | QUIRK_LSW32_IS_FIRST,
+	},
+	{
+		.desc = "msb right + little endian words, 16 bytes",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0xb5, 0x7b, 0x7f, 0x53,
+		     0x7f, 0x53, 0xf7, 0x7d, 0x00, 0x00, 0x00, 0x00),
+		.uval = 0xcafedeadbeefcafe,
+		.start_bit = 95,
+		.end_bit = 32,
+		.quirks = QUIRK_MSB_ON_THE_RIGHT | QUIRK_LITTLE_ENDIAN,
+	},
+	{
+		.desc = "msb right + lsw32 first + little endian words, 16 bytes",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0x7f, 0x53, 0xf7, 0x7d,
+		     0xb5, 0x7b, 0x7f, 0x53, 0x00, 0x00, 0x00, 0x00),
+		.uval = 0xcafedeadbeefcafe,
+		.start_bit = 95,
+		.end_bit = 32,
+		.quirks = QUIRK_MSB_ON_THE_RIGHT | QUIRK_LSW32_IS_FIRST | QUIRK_LITTLE_ENDIAN,
+	},
+	/* These tests pack and unpack a magic 64-bit value
+	 * (0xcafedeadbeefcafe) at a fixed logical offset (32) within an
+	 * otherwise zero array of varying size from 18 bytes to 24 bytes.
+	 */
+	{
+		.desc = "no quirks, 18 bytes",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xca, 0xfe,
+		     0xde, 0xad, 0xbe, 0xef, 0xca, 0xfe, 0x00, 0x00,
+		     0x00, 0x00),
+		.uval = 0xcafedeadbeefcafe,
+		.start_bit = 95,
+		.end_bit = 32,
+		.quirks = NO_QUIRKS,
+	},
+	{
+		.desc = "no quirks, 19 bytes",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xca,
+		     0xfe, 0xde, 0xad, 0xbe, 0xef, 0xca, 0xfe, 0x00,
+		     0x00, 0x00, 0x00),
+		.uval = 0xcafedeadbeefcafe,
+		.start_bit = 95,
+		.end_bit = 32,
+		.quirks = NO_QUIRKS,
+	},
+	{
+		.desc = "no quirks, 20 bytes",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		     0xca, 0xfe, 0xde, 0xad, 0xbe, 0xef, 0xca, 0xfe,
+		     0x00, 0x00, 0x00, 0x00),
+		.uval = 0xcafedeadbeefcafe,
+		.start_bit = 95,
+		.end_bit = 32,
+		.quirks = NO_QUIRKS,
+	},
+	{
+		.desc = "no quirks, 22 bytes",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		     0x00, 0x00, 0xca, 0xfe, 0xde, 0xad, 0xbe, 0xef,
+		     0xca, 0xfe, 0x00, 0x00, 0x00, 0x00),
+		.uval = 0xcafedeadbeefcafe,
+		.start_bit = 95,
+		.end_bit = 32,
+		.quirks = NO_QUIRKS,
+	},
+	{
+		.desc = "no quirks, 24 bytes",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		     0x00, 0x00, 0x00, 0x00, 0xca, 0xfe, 0xde, 0xad,
+		     0xbe, 0xef, 0xca, 0xfe, 0x00, 0x00, 0x00, 0x00),
+		.uval = 0xcafedeadbeefcafe,
+		.start_bit = 95,
+		.end_bit = 32,
+		.quirks = NO_QUIRKS,
+	},
+	{
+		.desc = "lsw32 first + little endian words, 18 bytes",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0xfe, 0xca, 0xef, 0xbe,
+		     0xad, 0xde, 0xfe, 0xca, 0x00, 0x00, 0x00, 0x00,
+		     0x00, 0x00),
+		.uval = 0xcafedeadbeefcafe,
+		.start_bit = 95,
+		.end_bit = 32,
+		.quirks = QUIRK_LSW32_IS_FIRST | QUIRK_LITTLE_ENDIAN,
+	},
+	{
+		.desc = "lsw32 first + little endian words, 19 bytes",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0xfe, 0xca, 0xef, 0xbe,
+		     0xad, 0xde, 0xfe, 0xca, 0x00, 0x00, 0x00, 0x00,
+		     0x00, 0x00, 0x00),
+		.uval = 0xcafedeadbeefcafe,
+		.start_bit = 95,
+		.end_bit = 32,
+		.quirks = QUIRK_LSW32_IS_FIRST | QUIRK_LITTLE_ENDIAN,
+	},
+	{
+		.desc = "lsw32 first + little endian words, 20 bytes",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0xfe, 0xca, 0xef, 0xbe,
+		     0xad, 0xde, 0xfe, 0xca, 0x00, 0x00, 0x00, 0x00,
+		     0x00, 0x00, 0x00, 0x00),
+		.uval = 0xcafedeadbeefcafe,
+		.start_bit = 95,
+		.end_bit = 32,
+		.quirks = QUIRK_LSW32_IS_FIRST | QUIRK_LITTLE_ENDIAN,
+	},
+	{
+		.desc = "lsw32 first + little endian words, 22 bytes",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0xfe, 0xca, 0xef, 0xbe,
+		     0xad, 0xde, 0xfe, 0xca, 0x00, 0x00, 0x00, 0x00,
+		     0x00, 0x00, 0x00, 0x00, 0x00, 0x00),
+		.uval = 0xcafedeadbeefcafe,
+		.start_bit = 95,
+		.end_bit = 32,
+		.quirks = QUIRK_LSW32_IS_FIRST | QUIRK_LITTLE_ENDIAN,
+	},
+	{
+		.desc = "lsw32 first + little endian words, 24 bytes",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0xfe, 0xca, 0xef, 0xbe,
+		     0xad, 0xde, 0xfe, 0xca, 0x00, 0x00, 0x00, 0x00,
+		     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00),
+		.uval = 0xcafedeadbeefcafe,
+		.start_bit = 95,
+		.end_bit = 32,
+		.quirks = QUIRK_LSW32_IS_FIRST | QUIRK_LITTLE_ENDIAN,
+	},
+	/* These tests pack and unpack a magic 64-bit value
+	 * (0x1122334455667788) at an odd starting bit (43) within an
+	 * otherwise zero array of 128 bits (16 bytes). They test all possible
+	 * bit layouts of the 128 bit buffer.
+	 */
+	{
+		.desc = "no quirks, 16 bytes, non-aligned",
+		PBUF(0x00, 0x00, 0x00, 0x89, 0x11, 0x9a, 0x22, 0xab,
+		     0x33, 0xbc, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00),
+		.uval = 0x1122334455667788,
+		.start_bit = 106,
+		.end_bit = 43,
+		.quirks = NO_QUIRKS,
+	},
+	{
+		.desc = "lsw32 first, 16 bytes, non-aligned",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0x33, 0xbc, 0x40, 0x00,
+		     0x11, 0x9a, 0x22, 0xab, 0x00, 0x00, 0x00, 0x89),
+		.uval = 0x1122334455667788,
+		.start_bit = 106,
+		.end_bit = 43,
+		.quirks = QUIRK_LSW32_IS_FIRST,
+	},
+	{
+		.desc = "little endian words, 16 bytes, non-aligned",
+		PBUF(0x89, 0x00, 0x00, 0x00, 0xab, 0x22, 0x9a, 0x11,
+		     0x00, 0x40, 0xbc, 0x33, 0x00, 0x00, 0x00, 0x00),
+		.uval = 0x1122334455667788,
+		.start_bit = 106,
+		.end_bit = 43,
+		.quirks = QUIRK_LITTLE_ENDIAN,
+	},
+	{
+		.desc = "lsw32 first + little endian words, 16 bytes, non-aligned",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0x00, 0x40, 0xbc, 0x33,
+		     0xab, 0x22, 0x9a, 0x11, 0x89, 0x00, 0x00, 0x00),
+		.uval = 0x1122334455667788,
+		.start_bit = 106,
+		.end_bit = 43,
+		.quirks = QUIRK_LSW32_IS_FIRST | QUIRK_LITTLE_ENDIAN,
+	},
+	{
+		.desc = "msb right, 16 bytes, non-aligned",
+		PBUF(0x00, 0x00, 0x00, 0x91, 0x88, 0x59, 0x44, 0xd5,
+		     0xcc, 0x3d, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00),
+		.uval = 0x1122334455667788,
+		.start_bit = 106,
+		.end_bit = 43,
+		.quirks = QUIRK_MSB_ON_THE_RIGHT,
+	},
+	{
+		.desc = "msb right + lsw32 first, 16 bytes, non-aligned",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0xcc, 0x3d, 0x02, 0x00,
+		     0x88, 0x59, 0x44, 0xd5, 0x00, 0x00, 0x00, 0x91),
+		.uval = 0x1122334455667788,
+		.start_bit = 106,
+		.end_bit = 43,
+		.quirks = QUIRK_MSB_ON_THE_RIGHT | QUIRK_LSW32_IS_FIRST,
+	},
+	{
+		.desc = "msb right + little endian words, 16 bytes, non-aligned",
+		PBUF(0x91, 0x00, 0x00, 0x00, 0xd5, 0x44, 0x59, 0x88,
+		     0x00, 0x02, 0x3d, 0xcc, 0x00, 0x00, 0x00, 0x00),
+		.uval = 0x1122334455667788,
+		.start_bit = 106,
+		.end_bit = 43,
+		.quirks = QUIRK_MSB_ON_THE_RIGHT | QUIRK_LITTLE_ENDIAN,
+	},
+	{
+		.desc = "msb right + lsw32 first + little endian words, 16 bytes, non-aligned",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x3d, 0xcc,
+		     0xd5, 0x44, 0x59, 0x88, 0x91, 0x00, 0x00, 0x00),
+		.uval = 0x1122334455667788,
+		.start_bit = 106,
+		.end_bit = 43,
+		.quirks = QUIRK_MSB_ON_THE_RIGHT | QUIRK_LSW32_IS_FIRST | QUIRK_LITTLE_ENDIAN,
+	},
+	/* These tests pack and unpack a u64 with all bits set
+	 * (0xffffffffffffffff) at an odd starting bit (43) within an
+	 * otherwise zero array of 128 bits (16 bytes). They test all possible
+	 * bit layouts of the 128 bit buffer.
+	 */
+	{
+		.desc = "no quirks, 16 bytes, non-aligned, 0xff",
+		PBUF(0x00, 0x00, 0x07, 0xff, 0xff, 0xff, 0xff, 0xff,
+		     0xff, 0xff, 0xf8, 0x00, 0x00, 0x00, 0x00, 0x00),
+		.uval = 0xffffffffffffffff,
+		.start_bit = 106,
+		.end_bit = 43,
+		.quirks = NO_QUIRKS,
+	},
+	{
+		.desc = "lsw32 first, 16 bytes, non-aligned, 0xff",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xf8, 0x00,
+		     0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x07, 0xff),
+		.uval = 0xffffffffffffffff,
+		.start_bit = 106,
+		.end_bit = 43,
+		.quirks = QUIRK_LSW32_IS_FIRST,
+	},
+	{
+		.desc = "little endian words, 16 bytes, non-aligned, 0xff",
+		PBUF(0xff, 0x07, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff,
+		     0x00, 0xf8, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00),
+		.uval = 0xffffffffffffffff,
+		.start_bit = 106,
+		.end_bit = 43,
+		.quirks = QUIRK_LITTLE_ENDIAN,
+	},
+	{
+		.desc = "lsw32 first + little endian words, 16 bytes, non-aligned, 0xff",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0x00, 0xf8, 0xff, 0xff,
+		     0xff, 0xff, 0xff, 0xff, 0xff, 0x07, 0x00, 0x00),
+		.uval = 0xffffffffffffffff,
+		.start_bit = 106,
+		.end_bit = 43,
+		.quirks = QUIRK_LSW32_IS_FIRST | QUIRK_LITTLE_ENDIAN,
+	},
+	{
+		.desc = "msb right, 16 bytes, non-aligned, 0xff",
+		PBUF(0x00, 0x00, 0xe0, 0xff, 0xff, 0xff, 0xff, 0xff,
+		     0xff, 0xff, 0x1f, 0x00, 0x00, 0x00, 0x00, 0x00),
+		.uval = 0xffffffffffffffff,
+		.start_bit = 106,
+		.end_bit = 43,
+		.quirks = QUIRK_MSB_ON_THE_RIGHT,
+	},
+	{
+		.desc = "msb right + lsw32 first, 16 bytes, non-aligned, 0xff",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0x1f, 0x00,
+		     0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0xe0, 0xff),
+		.uval = 0xffffffffffffffff,
+		.start_bit = 106,
+		.end_bit = 43,
+		.quirks = QUIRK_MSB_ON_THE_RIGHT | QUIRK_LSW32_IS_FIRST,
+	},
+	{
+		.desc = "msb right + little endian words, 16 bytes, non-aligned, 0xff",
+		PBUF(0xff, 0xe0, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff,
+		     0x00, 0x1f, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00),
+		.uval = 0xffffffffffffffff,
+		.start_bit = 106,
+		.end_bit = 43,
+		.quirks = QUIRK_MSB_ON_THE_RIGHT | QUIRK_LITTLE_ENDIAN,
+	},
+	{
+		.desc = "msb right + lsw32 first + little endian words, 16 bytes, non-aligned, 0xff",
+		PBUF(0x00, 0x00, 0x00, 0x00, 0x00, 0x1f, 0xff, 0xff,
+		     0xff, 0xff, 0xff, 0xff, 0xff, 0xe0, 0x00, 0x00),
+		.uval = 0xffffffffffffffff,
+		.start_bit = 106,
+		.end_bit = 43,
+		.quirks = QUIRK_MSB_ON_THE_RIGHT | QUIRK_LSW32_IS_FIRST | QUIRK_LITTLE_ENDIAN,
+	},
+};
+
+KUNIT_ARRAY_PARAM_DESC(packing, cases, desc);
+
+static void packing_test_pack(struct kunit *test)
+{
+	const struct packing_test_case *params = test->param_value;
+	u8 *pbuf;
+	int err;
+
+	pbuf = kunit_kzalloc(test, params->pbuf_size, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, pbuf);
+
+	err = pack(pbuf, params->uval, params->start_bit, params->end_bit,
+		   params->pbuf_size, params->quirks);
+
+	KUNIT_EXPECT_EQ_MSG(test, err, 0, "pack() returned %pe\n", ERR_PTR(err));
+	KUNIT_EXPECT_MEMEQ(test, pbuf, params->pbuf, params->pbuf_size);
+}
+
+static void packing_test_unpack(struct kunit *test)
+{
+	const struct packing_test_case *params = test->param_value;
+	u64 uval;
+	int err;
+
+	err = unpack(params->pbuf, &uval, params->start_bit, params->end_bit,
+		     params->pbuf_size, params->quirks);
+	KUNIT_EXPECT_EQ_MSG(test, err, 0, "unpack() returned %pe\n", ERR_PTR(err));
+	KUNIT_EXPECT_EQ(test, uval, params->uval);
+}
+
+#define PACKED_BUF_SIZE 8
+
+typedef struct __packed { u8 buf[PACKED_BUF_SIZE]; } packed_buf_t;
+
+struct test_data {
+	u32 field3;
+	u16 field2;
+	u16 field4;
+	u16 field6;
+	u8 field1;
+	u8 field5;
+};
+
+static const struct packed_field_u8 test_fields[] = {
+	PACKED_FIELD(63, 61, struct test_data, field1),
+	PACKED_FIELD(60, 52, struct test_data, field2),
+	PACKED_FIELD(51, 28, struct test_data, field3),
+	PACKED_FIELD(27, 14, struct test_data, field4),
+	PACKED_FIELD(13, 9, struct test_data, field5),
+	PACKED_FIELD(8, 0, struct test_data, field6),
+};
+
+static void packing_test_pack_fields(struct kunit *test)
+{
+	const struct test_data data = {
+		.field1 = 0x2,
+		.field2 = 0x100,
+		.field3 = 0xF00050,
+		.field4 = 0x7D3,
+		.field5 = 0x9,
+		.field6 = 0x10B,
+	};
+	packed_buf_t expect = {
+		.buf = { 0x50, 0x0F, 0x00, 0x05, 0x01, 0xF4, 0xD3, 0x0B },
+	};
+	packed_buf_t buf = {};
+
+	pack_fields(&buf, sizeof(buf), &data, test_fields, 0);
+
+	KUNIT_EXPECT_MEMEQ(test, &expect, &buf, sizeof(buf));
+}
+
+static void packing_test_unpack_fields(struct kunit *test)
+{
+	const packed_buf_t buf = {
+		.buf = { 0x17, 0x28, 0x10, 0x19, 0x3D, 0xA9, 0x07, 0x9C },
+	};
+	struct test_data data = {};
+
+	unpack_fields(&buf, sizeof(buf), &data, test_fields, 0);
+
+	KUNIT_EXPECT_EQ(test, 0, data.field1);
+	KUNIT_EXPECT_EQ(test, 0x172, data.field2);
+	KUNIT_EXPECT_EQ(test, 0x810193, data.field3);
+	KUNIT_EXPECT_EQ(test, 0x36A4, data.field4);
+	KUNIT_EXPECT_EQ(test, 0x3, data.field5);
+	KUNIT_EXPECT_EQ(test, 0x19C, data.field6);
+}
+
+static struct kunit_case packing_test_cases[] = {
+	KUNIT_CASE_PARAM(packing_test_pack, packing_gen_params),
+	KUNIT_CASE_PARAM(packing_test_unpack, packing_gen_params),
+	KUNIT_CASE(packing_test_pack_fields),
+	KUNIT_CASE(packing_test_unpack_fields),
+	{},
+};
+
+static struct kunit_suite packing_test_suite = {
+	.name = "packing",
+	.test_cases = packing_test_cases,
+};
+
+kunit_test_suite(packing_test_suite);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("KUnit tests for packing library");