Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

6 files changed, 749 insertions, 0 deletions

diff --git a/drivers/fpga/tests/.kunitconfig b/drivers/fpga/tests/.kunitconfig
new file mode 100644
index 000000000..a1c2a2974
--- /dev/null
+++ b/drivers/fpga/tests/.kunitconfig
@@ -0,0 +1,5 @@
+CONFIG_KUNIT=y
+CONFIG_FPGA=y
+CONFIG_FPGA_REGION=y
+CONFIG_FPGA_BRIDGE=y
+CONFIG_FPGA_KUNIT_TESTS=y
diff --git a/drivers/fpga/tests/Kconfig b/drivers/fpga/tests/Kconfig
new file mode 100644
index 000000000..e4a64815f
--- /dev/null
+++ b/drivers/fpga/tests/Kconfig
@@ -0,0 +1,11 @@
+config FPGA_KUNIT_TESTS
+	tristate "KUnit test for the FPGA subsystem" if !KUNIT_ALL_TESTS
+	depends on FPGA && FPGA_REGION && FPGA_BRIDGE && KUNIT=y
+	default KUNIT_ALL_TESTS
+        help
+          This builds unit tests for the FPGA subsystem
+
+          For more information on KUnit and unit tests in general,
+          please refer to the KUnit documentation in Documentation/dev-tools/kunit/.
+
+          If unsure, say N.
diff --git a/drivers/fpga/tests/Makefile b/drivers/fpga/tests/Makefile
new file mode 100644
index 000000000..bb78215c6
--- /dev/null
+++ b/drivers/fpga/tests/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for KUnit test suites for the FPGA subsystem
+#
+
+obj-$(CONFIG_FPGA_KUNIT_TESTS) += fpga-mgr-test.o fpga-bridge-test.o fpga-region-test.o
diff --git a/drivers/fpga/tests/fpga-bridge-test.c b/drivers/fpga/tests/fpga-bridge-test.c
new file mode 100644
index 000000000..124ba40e3
--- /dev/null
+++ b/drivers/fpga/tests/fpga-bridge-test.c
@@ -0,0 +1,174 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit test for the FPGA Bridge
+ *
+ * Copyright (C) 2023 Red Hat, Inc.
+ *
+ * Author: Marco Pagani <marpagan@redhat.com>
+ */
+
+#include <kunit/device.h>
+#include <kunit/test.h>
+#include <linux/fpga/fpga-bridge.h>
+#include <linux/module.h>
+#include <linux/types.h>
+
+struct bridge_stats {
+	bool enable;
+};
+
+struct bridge_ctx {
+	struct fpga_bridge *bridge;
+	struct device *dev;
+	struct bridge_stats stats;
+};
+
+/*
+ * Wrapper to avoid a cast warning when passing the action function directly
+ * to kunit_add_action().
+ */
+KUNIT_DEFINE_ACTION_WRAPPER(fpga_bridge_unregister_wrapper, fpga_bridge_unregister,
+			    struct fpga_bridge *);
+
+static int op_enable_set(struct fpga_bridge *bridge, bool enable)
+{
+	struct bridge_stats *stats = bridge->priv;
+
+	stats->enable = enable;
+
+	return 0;
+}
+
+/*
+ * Fake FPGA bridge that implements only the enable_set op to track
+ * the state.
+ */
+static const struct fpga_bridge_ops fake_bridge_ops = {
+	.enable_set = op_enable_set,
+};
+
+/**
+ * register_test_bridge() - Register a fake FPGA bridge for testing.
+ * @test: KUnit test context object.
+ * @dev_name: name of the kunit device to be registered
+ *
+ * Return: Context of the newly registered FPGA bridge.
+ */
+static struct bridge_ctx *register_test_bridge(struct kunit *test, const char *dev_name)
+{
+	struct bridge_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, dev_name);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx->dev);
+
+	ctx->bridge = fpga_bridge_register(ctx->dev, "Fake FPGA bridge", &fake_bridge_ops,
+					   &ctx->stats);
+	KUNIT_ASSERT_FALSE(test, IS_ERR_OR_NULL(ctx->bridge));
+
+	ret = kunit_add_action_or_reset(test, fpga_bridge_unregister_wrapper, ctx->bridge);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	return ctx;
+}
+
+static void fpga_bridge_test_get(struct kunit *test)
+{
+	struct bridge_ctx *ctx = test->priv;
+	struct fpga_bridge *bridge;
+
+	bridge = fpga_bridge_get(ctx->dev, NULL);
+	KUNIT_EXPECT_PTR_EQ(test, bridge, ctx->bridge);
+
+	bridge = fpga_bridge_get(ctx->dev, NULL);
+	KUNIT_EXPECT_EQ(test, PTR_ERR(bridge), -EBUSY);
+
+	fpga_bridge_put(ctx->bridge);
+}
+
+static void fpga_bridge_test_toggle(struct kunit *test)
+{
+	struct bridge_ctx *ctx = test->priv;
+	int ret;
+
+	ret = fpga_bridge_disable(ctx->bridge);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_FALSE(test, ctx->stats.enable);
+
+	ret = fpga_bridge_enable(ctx->bridge);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_TRUE(test, ctx->stats.enable);
+}
+
+/* Test the functions for getting and controlling a list of bridges */
+static void fpga_bridge_test_get_put_list(struct kunit *test)
+{
+	struct list_head bridge_list;
+	struct bridge_ctx *ctx_0, *ctx_1;
+	int ret;
+
+	ctx_0 = test->priv;
+	ctx_1 = register_test_bridge(test, "fpga-bridge-test-dev-1");
+
+	INIT_LIST_HEAD(&bridge_list);
+
+	/* Get bridge 0 and add it to the list */
+	ret = fpga_bridge_get_to_list(ctx_0->dev, NULL, &bridge_list);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	KUNIT_EXPECT_PTR_EQ(test, ctx_0->bridge,
+			    list_first_entry_or_null(&bridge_list, struct fpga_bridge, node));
+
+	/* Get bridge 1 and add it to the list */
+	ret = fpga_bridge_get_to_list(ctx_1->dev, NULL, &bridge_list);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	KUNIT_EXPECT_PTR_EQ(test, ctx_1->bridge,
+			    list_first_entry_or_null(&bridge_list, struct fpga_bridge, node));
+
+	/* Disable an then enable both bridges from the list */
+	ret = fpga_bridges_disable(&bridge_list);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	KUNIT_EXPECT_FALSE(test, ctx_0->stats.enable);
+	KUNIT_EXPECT_FALSE(test, ctx_1->stats.enable);
+
+	ret = fpga_bridges_enable(&bridge_list);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	KUNIT_EXPECT_TRUE(test, ctx_0->stats.enable);
+	KUNIT_EXPECT_TRUE(test, ctx_1->stats.enable);
+
+	/* Put and remove both bridges from the list */
+	fpga_bridges_put(&bridge_list);
+
+	KUNIT_EXPECT_TRUE(test, list_empty(&bridge_list));
+}
+
+static int fpga_bridge_test_init(struct kunit *test)
+{
+	test->priv = register_test_bridge(test, "fpga-bridge-test-dev-0");
+
+	return 0;
+}
+
+static struct kunit_case fpga_bridge_test_cases[] = {
+	KUNIT_CASE(fpga_bridge_test_get),
+	KUNIT_CASE(fpga_bridge_test_toggle),
+	KUNIT_CASE(fpga_bridge_test_get_put_list),
+	{}
+};
+
+static struct kunit_suite fpga_bridge_suite = {
+	.name = "fpga_bridge",
+	.init = fpga_bridge_test_init,
+	.test_cases = fpga_bridge_test_cases,
+};
+
+kunit_test_suite(fpga_bridge_suite);
+
+MODULE_DESCRIPTION("KUnit test for the FPGA Bridge");
+MODULE_LICENSE("GPL");
diff --git a/drivers/fpga/tests/fpga-mgr-test.c b/drivers/fpga/tests/fpga-mgr-test.c
new file mode 100644
index 000000000..62975a39e
--- /dev/null
+++ b/drivers/fpga/tests/fpga-mgr-test.c
@@ -0,0 +1,335 @@
+// 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);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, sgt);
+	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_DESCRIPTION("KUnit test for the FPGA Manager");
+MODULE_LICENSE("GPL");
diff --git a/drivers/fpga/tests/fpga-region-test.c b/drivers/fpga/tests/fpga-region-test.c
new file mode 100644
index 000000000..020ceac48
--- /dev/null
+++ b/drivers/fpga/tests/fpga-region-test.c
@@ -0,0 +1,218 @@
+// 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/device.h>
+#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/types.h>
+
+struct mgr_stats {
+	u32 write_count;
+};
+
+struct bridge_stats {
+	bool enable;
+	u32 cycles_count;
+};
+
+struct test_ctx {
+	struct fpga_manager *mgr;
+	struct device *mgr_dev;
+	struct fpga_bridge *bridge;
+	struct device *bridge_dev;
+	struct fpga_region *region;
+	struct device *region_dev;
+	struct bridge_stats bridge_stats;
+	struct mgr_stats mgr_stats;
+};
+
+/*
+ * Wrappers to avoid cast warnings when passing action functions directly
+ * to kunit_add_action().
+ */
+KUNIT_DEFINE_ACTION_WRAPPER(fpga_image_info_free_wrapper, fpga_image_info_free,
+			    struct fpga_image_info *);
+
+KUNIT_DEFINE_ACTION_WRAPPER(fpga_bridge_unregister_wrapper, fpga_bridge_unregister,
+			    struct fpga_bridge *);
+
+KUNIT_DEFINE_ACTION_WRAPPER(fpga_region_unregister_wrapper, fpga_region_unregister,
+			    struct fpga_region *);
+
+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_dev, fake_region_match);
+	KUNIT_EXPECT_PTR_EQ(test, region, ctx->region);
+
+	put_device(&region->dev);
+}
+
+/*
+ * 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_dev);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, img_info);
+
+	ret = kunit_add_action_or_reset(test, fpga_image_info_free_wrapper, img_info);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	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);
+}
+
+/*
+ * 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 };
+	int ret;
+
+	ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+	ctx->mgr_dev = kunit_device_register(test, "fpga-manager-test-dev");
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx->mgr_dev);
+
+	ctx->mgr = devm_fpga_mgr_register(ctx->mgr_dev, "Fake FPGA Manager",
+					  &fake_mgr_ops, &ctx->mgr_stats);
+	KUNIT_ASSERT_FALSE(test, IS_ERR_OR_NULL(ctx->mgr));
+
+	ctx->bridge_dev = kunit_device_register(test, "fpga-bridge-test-dev");
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx->bridge_dev);
+
+	ctx->bridge = fpga_bridge_register(ctx->bridge_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;
+
+	ret = kunit_add_action_or_reset(test, fpga_bridge_unregister_wrapper, ctx->bridge);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	ctx->region_dev = kunit_device_register(test, "fpga-region-test-dev");
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx->region_dev);
+
+	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_dev, &region_info);
+	KUNIT_ASSERT_FALSE(test, IS_ERR_OR_NULL(ctx->region));
+
+	ret = kunit_add_action_or_reset(test, fpga_region_unregister_wrapper, ctx->region);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	test->priv = ctx;
+
+	return 0;
+}
+
+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_region",
+	.init = fpga_region_test_init,
+	.test_cases = fpga_region_test_cases,
+};
+
+kunit_test_suite(fpga_region_suite);
+
+MODULE_DESCRIPTION("KUnit test for the FPGA Region");
+MODULE_LICENSE("GPL");