// 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");