fpga: add an initial KUnit suite for the FPGA Region

The suite tests the basic behaviors of the FPGA Region including
the programming and the function for finding a specific region.

Signed-off-by: Marco Pagani <marpagan@redhat.com>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/20230718130304.87048-4-marpagan@redhat.com
Signed-off-by: Xu Yilun <yilun.xu@intel.com>

drivers/fpga/tests/fpga-region-test.c

@@ -0,0 +1,211 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit test for the FPGA Region
+ *
+ * Copyright (C) 2023 Red Hat, Inc.
+ *
+ * Author: Marco Pagani <marpagan@redhat.com>
+ */
+
+#include <kunit/test.h>
+#include <linux/fpga/fpga-bridge.h>
+#include <linux/fpga/fpga-mgr.h>
+#include <linux/fpga/fpga-region.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+
+struct mgr_stats {
+	u32 write_count;
+};
+
+struct bridge_stats {
+	bool enable;
+	u32 cycles_count;
+};
+
+struct test_ctx {
+	struct fpga_manager *mgr;
+	struct platform_device *mgr_pdev;
+	struct fpga_bridge *bridge;
+	struct platform_device *bridge_pdev;
+	struct fpga_region *region;
+	struct platform_device *region_pdev;
+	struct bridge_stats bridge_stats;
+	struct mgr_stats mgr_stats;
+};
+
+static int op_write(struct fpga_manager *mgr, const char *buf, size_t count)
+{
+	struct mgr_stats *stats = mgr->priv;
+
+	stats->write_count++;
+
+	return 0;
+}
+
+/*
+ * Fake FPGA manager that implements only the write op to count the number
+ * of programming cycles. The internals of the programming sequence are
+ * tested in the Manager suite since they are outside the responsibility
+ * of the Region.
+ */
+static const struct fpga_manager_ops fake_mgr_ops = {
+	.write = op_write,
+};
+
+static int op_enable_set(struct fpga_bridge *bridge, bool enable)
+{
+	struct bridge_stats *stats = bridge->priv;
+
+	if (!stats->enable && enable)
+		stats->cycles_count++;
+
+	stats->enable = enable;
+
+	return 0;
+}
+
+/*
+ * Fake FPGA bridge that implements only enable_set op to count the number
+ * of activation cycles.
+ */
+static const struct fpga_bridge_ops fake_bridge_ops = {
+	.enable_set = op_enable_set,
+};
+
+static int fake_region_get_bridges(struct fpga_region *region)
+{
+	struct fpga_bridge *bridge = region->priv;
+
+	return fpga_bridge_get_to_list(bridge->dev.parent, region->info, &region->bridge_list);
+}
+
+static int fake_region_match(struct device *dev, const void *data)
+{
+	return dev->parent == data;
+}
+
+static void fpga_region_test_class_find(struct kunit *test)
+{
+	struct test_ctx *ctx = test->priv;
+	struct fpga_region *region;
+
+	region = fpga_region_class_find(NULL, &ctx->region_pdev->dev, fake_region_match);
+	KUNIT_EXPECT_PTR_EQ(test, region, ctx->region);
+}
+
+/*
+ * FPGA Region programming test. The Region must call get_bridges() to get
+ * and control the bridges, and then the Manager for the actual programming.
+ */
+static void fpga_region_test_program_fpga(struct kunit *test)
+{
+	struct test_ctx *ctx = test->priv;
+	struct fpga_image_info *img_info;
+	char img_buf[4];
+	int ret;
+
+	img_info = fpga_image_info_alloc(&ctx->mgr_pdev->dev);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, img_info);
+
+	img_info->buf = img_buf;
+	img_info->count = sizeof(img_buf);
+
+	ctx->region->info = img_info;
+	ret = fpga_region_program_fpga(ctx->region);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	KUNIT_EXPECT_EQ(test, 1, ctx->mgr_stats.write_count);
+	KUNIT_EXPECT_EQ(test, 1, ctx->bridge_stats.cycles_count);
+
+	fpga_bridges_put(&ctx->region->bridge_list);
+
+	ret = fpga_region_program_fpga(ctx->region);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	KUNIT_EXPECT_EQ(test, 2, ctx->mgr_stats.write_count);
+	KUNIT_EXPECT_EQ(test, 2, ctx->bridge_stats.cycles_count);
+
+	fpga_bridges_put(&ctx->region->bridge_list);
+
+	fpga_image_info_free(img_info);
+}
+
+/*
+ * The configuration used in this test suite uses a single bridge to
+ * limit the code under test to a single unit. The functions used by the
+ * Region for getting and controlling bridges are tested (with a list of
+ * multiple bridges) in the Bridge suite.
+ */
+static int fpga_region_test_init(struct kunit *test)
+{
+	struct test_ctx *ctx;
+	struct fpga_region_info region_info = { 0 };
+
+	ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+	ctx->mgr_pdev = platform_device_register_simple("mgr_pdev", PLATFORM_DEVID_AUTO, NULL, 0);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx->mgr_pdev);
+
+	ctx->mgr = devm_fpga_mgr_register(&ctx->mgr_pdev->dev, "Fake FPGA Manager", &fake_mgr_ops,
+					  &ctx->mgr_stats);
+	KUNIT_ASSERT_FALSE(test, IS_ERR_OR_NULL(ctx->mgr));
+
+	ctx->bridge_pdev = platform_device_register_simple("bridge_pdev", PLATFORM_DEVID_AUTO,
+							   NULL, 0);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx->bridge_pdev);
+
+	ctx->bridge = fpga_bridge_register(&ctx->bridge_pdev->dev, "Fake FPGA Bridge",
+					   &fake_bridge_ops, &ctx->bridge_stats);
+	KUNIT_ASSERT_FALSE(test, IS_ERR_OR_NULL(ctx->bridge));
+
+	ctx->bridge_stats.enable = true;
+
+	ctx->region_pdev = platform_device_register_simple("region_pdev", PLATFORM_DEVID_AUTO,
+							   NULL, 0);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx->region_pdev);
+
+	region_info.mgr = ctx->mgr;
+	region_info.priv = ctx->bridge;
+	region_info.get_bridges = fake_region_get_bridges;
+
+	ctx->region = fpga_region_register_full(&ctx->region_pdev->dev, &region_info);
+	KUNIT_ASSERT_FALSE(test, IS_ERR_OR_NULL(ctx->region));
+
+	test->priv = ctx;
+
+	return 0;
+}
+
+static void fpga_region_test_exit(struct kunit *test)
+{
+	struct test_ctx *ctx = test->priv;
+
+	fpga_region_unregister(ctx->region);
+	platform_device_unregister(ctx->region_pdev);
+
+	fpga_bridge_unregister(ctx->bridge);
+	platform_device_unregister(ctx->bridge_pdev);
+
+	platform_device_unregister(ctx->mgr_pdev);
+}
+
+static struct kunit_case fpga_region_test_cases[] = {
+	KUNIT_CASE(fpga_region_test_class_find),
+	KUNIT_CASE(fpga_region_test_program_fpga),
+
+	{}
+};
+
+static struct kunit_suite fpga_region_suite = {
+	.name = "fpga_mgr",
+	.init = fpga_region_test_init,
+	.exit = fpga_region_test_exit,
+	.test_cases = fpga_region_test_cases,
+};
+
+kunit_test_suite(fpga_region_suite);
+
+MODULE_LICENSE("GPL");