// SPDX-License-Identifier: GPL-2.0
/*
 * KUnit test for the FPGA Manager
 *
 * Copyright (C) 2023 Red Hat, Inc.
 *
 * Author: Marco Pagani <marpagan@redhat.com>
 */

#include <kunit/device.h>
#include <kunit/test.h>
#include <linux/fpga/fpga-mgr.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/types.h>

#define HEADER_FILL		'H'
#define IMAGE_FILL		'P'
#define IMAGE_BLOCK		1024

#define HEADER_SIZE		IMAGE_BLOCK
#define IMAGE_SIZE		(IMAGE_BLOCK * 4)

struct mgr_stats {
	bool header_match;
	bool image_match;
	u32 seq_num;
	u32 op_parse_header_seq;
	u32 op_write_init_seq;
	u32 op_write_seq;
	u32 op_write_sg_seq;
	u32 op_write_complete_seq;
	enum fpga_mgr_states op_parse_header_state;
	enum fpga_mgr_states op_write_init_state;
	enum fpga_mgr_states op_write_state;
	enum fpga_mgr_states op_write_sg_state;
	enum fpga_mgr_states op_write_complete_state;
};

struct mgr_ctx {
	struct fpga_image_info *img_info;
	struct fpga_manager *mgr;
	struct device *dev;
	struct mgr_stats stats;
};

/*
 * Wrappers to avoid cast warnings when passing action functions directly
 * to kunit_add_action().
 */
KUNIT_DEFINE_ACTION_WRAPPER(sg_free_table_wrapper, sg_free_table,
			    struct sg_table *);

KUNIT_DEFINE_ACTION_WRAPPER(fpga_image_info_free_wrapper, fpga_image_info_free,
			    struct fpga_image_info *);

/**
 * init_test_buffer() - Allocate and initialize a test image in a buffer.
 * @test: KUnit test context object.
 * @count: image size in bytes.
 *
 * Return: pointer to the newly allocated image.
 */
static char *init_test_buffer(struct kunit *test, size_t count)
{
	char *buf;

	KUNIT_ASSERT_GE(test, count, HEADER_SIZE);

	buf = kunit_kzalloc(test, count, GFP_KERNEL);
	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buf);

	memset(buf, HEADER_FILL, HEADER_SIZE);
	memset(buf + HEADER_SIZE, IMAGE_FILL, count - HEADER_SIZE);

	return buf;
}

/*
 * Check the image header. Do not return an error code if the image check fails
 * since, in this case, it is a failure of the FPGA manager itself, not this
 * op that tests it.
 */
static int op_parse_header(struct fpga_manager *mgr, struct fpga_image_info *info,
			   const char *buf, size_t count)
{
	struct mgr_stats *stats = mgr->priv;
	size_t i;

	stats->op_parse_header_state = mgr->state;
	stats->op_parse_header_seq = stats->seq_num++;

	/* Set header_size and data_size for later */
	info->header_size = HEADER_SIZE;
	info->data_size = info->count - HEADER_SIZE;

	stats->header_match = true;
	for (i = 0; i < info->header_size; i++) {
		if (buf[i] != HEADER_FILL) {
			stats->header_match = false;
			break;
		}
	}

	return 0;
}

static int op_write_init(struct fpga_manager *mgr, struct fpga_image_info *info,
			 const char *buf, size_t count)
{
	struct mgr_stats *stats = mgr->priv;

	stats->op_write_init_state = mgr->state;
	stats->op_write_init_seq = stats->seq_num++;

	return 0;
}

/*
 * Check the image data. As with op_parse_header, do not return an error code
 * if the image check fails.
 */
static int op_write(struct fpga_manager *mgr, const char *buf, size_t count)
{
	struct mgr_stats *stats = mgr->priv;
	size_t i;

	stats->op_write_state = mgr->state;
	stats->op_write_seq = stats->seq_num++;

	stats->image_match = true;
	for (i = 0; i < count; i++) {
		if (buf[i] != IMAGE_FILL) {
			stats->image_match = false;
			break;
		}
	}

	return 0;
}

/*
 * Check the image data, but first skip the header since write_sg will get
 * the whole image in sg_table. As with op_parse_header, do not return an
 * error code if the image check fails.
 */
static int op_write_sg(struct fpga_manager *mgr, struct sg_table *sgt)
{
	struct mgr_stats *stats = mgr->priv;
	struct sg_mapping_iter miter;
	char *img;
	size_t i;

	stats->op_write_sg_state = mgr->state;
	stats->op_write_sg_seq = stats->seq_num++;

	stats->image_match = true;
	sg_miter_start(&miter, sgt->sgl, sgt->nents, SG_MITER_FROM_SG);

	if (!sg_miter_skip(&miter, HEADER_SIZE)) {
		stats->image_match = false;
		goto out;
	}

	while (sg_miter_next(&miter)) {
		img = miter.addr;
		for (i = 0; i < miter.length; i++) {
			if (img[i] != IMAGE_FILL) {
				stats->image_match = false;
				goto out;
			}
		}
	}
out:
	sg_miter_stop(&miter);
	return 0;
}

static int op_write_complete(struct fpga_manager *mgr, struct fpga_image_info *info)
{
	struct mgr_stats *stats = mgr->priv;

	stats->op_write_complete_state = mgr->state;
	stats->op_write_complete_seq = stats->seq_num++;

	return 0;
}

/*
 * Fake FPGA manager that implements all ops required to check the programming
 * sequence using a single contiguous buffer and a scatter gather table.
 */
static const struct fpga_manager_ops fake_mgr_ops = {
	.skip_header = true,
	.parse_header = op_parse_header,
	.write_init = op_write_init,
	.write = op_write,
	.write_sg = op_write_sg,
	.write_complete = op_write_complete,
};

static void fpga_mgr_test_get(struct kunit *test)
{
	struct mgr_ctx *ctx = test->priv;
	struct fpga_manager *mgr;

	mgr = fpga_mgr_get(ctx->dev);
	KUNIT_EXPECT_PTR_EQ(test, mgr, ctx->mgr);

	fpga_mgr_put(ctx->mgr);
}

static void fpga_mgr_test_lock(struct kunit *test)
{
	struct mgr_ctx *ctx = test->priv;
	int ret;

	ret = fpga_mgr_lock(ctx->mgr);
	KUNIT_EXPECT_EQ(test, ret, 0);

	ret = fpga_mgr_lock(ctx->mgr);
	KUNIT_EXPECT_EQ(test, ret, -EBUSY);

	fpga_mgr_unlock(ctx->mgr);
}

/* Check the programming sequence using an image in a buffer */
static void fpga_mgr_test_img_load_buf(struct kunit *test)
{
	struct mgr_ctx *ctx = test->priv;
	char *img_buf;
	int ret;

	img_buf = init_test_buffer(test, IMAGE_SIZE);

	ctx->img_info->count = IMAGE_SIZE;
	ctx->img_info->buf = img_buf;

	ret = fpga_mgr_load(ctx->mgr, ctx->img_info);
	KUNIT_EXPECT_EQ(test, ret, 0);

	KUNIT_EXPECT_TRUE(test, ctx->stats.header_match);
	KUNIT_EXPECT_TRUE(test, ctx->stats.image_match);

	KUNIT_EXPECT_EQ(test, ctx->stats.op_parse_header_state, FPGA_MGR_STATE_PARSE_HEADER);
	KUNIT_EXPECT_EQ(test, ctx->stats.op_write_init_state, FPGA_MGR_STATE_WRITE_INIT);
	KUNIT_EXPECT_EQ(test, ctx->stats.op_write_state, FPGA_MGR_STATE_WRITE);
	KUNIT_EXPECT_EQ(test, ctx->stats.op_write_complete_state, FPGA_MGR_STATE_WRITE_COMPLETE);

	KUNIT_EXPECT_EQ(test, ctx->stats.op_write_init_seq, ctx->stats.op_parse_header_seq + 1);
	KUNIT_EXPECT_EQ(test, ctx->stats.op_write_seq, ctx->stats.op_parse_header_seq + 2);
	KUNIT_EXPECT_EQ(test, ctx->stats.op_write_complete_seq, ctx->stats.op_parse_header_seq + 3);
}

/* Check the programming sequence using an image in a scatter gather table */
static void fpga_mgr_test_img_load_sgt(struct kunit *test)
{
	struct mgr_ctx *ctx = test->priv;
	struct sg_table *sgt;
	char *img_buf;
	int ret;

	img_buf = init_test_buffer(test, IMAGE_SIZE);

	sgt = kunit_kzalloc(test, sizeof(*sgt), GFP_KERNEL);
	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
	KUNIT_ASSERT_EQ(test, ret, 0);
	sg_init_one(sgt->sgl, img_buf, IMAGE_SIZE);

	ret = kunit_add_action_or_reset(test, sg_free_table_wrapper, sgt);
	KUNIT_ASSERT_EQ(test, ret, 0);

	ctx->img_info->sgt = sgt;

	ret = fpga_mgr_load(ctx->mgr, ctx->img_info);
	KUNIT_EXPECT_EQ(test, ret, 0);

	KUNIT_EXPECT_TRUE(test, ctx->stats.header_match);
	KUNIT_EXPECT_TRUE(test, ctx->stats.image_match);

	KUNIT_EXPECT_EQ(test, ctx->stats.op_parse_header_state, FPGA_MGR_STATE_PARSE_HEADER);
	KUNIT_EXPECT_EQ(test, ctx->stats.op_write_init_state, FPGA_MGR_STATE_WRITE_INIT);
	KUNIT_EXPECT_EQ(test, ctx->stats.op_write_sg_state, FPGA_MGR_STATE_WRITE);
	KUNIT_EXPECT_EQ(test, ctx->stats.op_write_complete_state, FPGA_MGR_STATE_WRITE_COMPLETE);

	KUNIT_EXPECT_EQ(test, ctx->stats.op_write_init_seq, ctx->stats.op_parse_header_seq + 1);
	KUNIT_EXPECT_EQ(test, ctx->stats.op_write_sg_seq, ctx->stats.op_parse_header_seq + 2);
	KUNIT_EXPECT_EQ(test, ctx->stats.op_write_complete_seq, ctx->stats.op_parse_header_seq + 3);
}

static int fpga_mgr_test_init(struct kunit *test)
{
	struct mgr_ctx *ctx;
	int ret;

	ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);

	ctx->dev = kunit_device_register(test, "fpga-manager-test-dev");
	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx->dev);

	ctx->mgr = devm_fpga_mgr_register(ctx->dev, "Fake FPGA Manager", &fake_mgr_ops,
					  &ctx->stats);
	KUNIT_ASSERT_FALSE(test, IS_ERR_OR_NULL(ctx->mgr));

	ctx->img_info = fpga_image_info_alloc(ctx->dev);
	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx->img_info);

	ret = kunit_add_action_or_reset(test, fpga_image_info_free_wrapper, ctx->img_info);
	KUNIT_ASSERT_EQ(test, ret, 0);

	test->priv = ctx;

	return 0;
}

static struct kunit_case fpga_mgr_test_cases[] = {
	KUNIT_CASE(fpga_mgr_test_get),
	KUNIT_CASE(fpga_mgr_test_lock),
	KUNIT_CASE(fpga_mgr_test_img_load_buf),
	KUNIT_CASE(fpga_mgr_test_img_load_sgt),
	{}
};

static struct kunit_suite fpga_mgr_suite = {
	.name = "fpga_mgr",
	.init = fpga_mgr_test_init,
	.test_cases = fpga_mgr_test_cases,
};

kunit_test_suite(fpga_mgr_suite);

MODULE_LICENSE("GPL");