[RFC,1/4] fpga: add initial KUnit test suite

  Introduce an initial KUnit suite to test the core components of the
FPGA subsystem.

The test suite consists of two test cases. The first test case checks
the programming of a static image on a fake FPGA with a single hardware
bridge. The FPGA is first programmed using a test image stored in a
buffer, and then with the same image linked to a single-entry
scatter-gather list.

The second test case models dynamic partial reconfiguration. The FPGA
is first configured with a static image that implements a
reconfigurable design containing a sub-region controlled by two soft
bridges. Then, the reconfigurable sub-region is reconfigured using
a fake partial bitstream image. After the reconfiguration, the test
checks that the soft bridges have been correctly activated.

Signed-off-by: Marco Pagani <marpagan@redhat.com>
---
 drivers/fpga/Kconfig            |   2 +
 drivers/fpga/Makefile           |   3 +
 drivers/fpga/tests/.kunitconfig |   5 +
 drivers/fpga/tests/Kconfig      |  15 ++
 drivers/fpga/tests/Makefile     |   6 +
 drivers/fpga/tests/fpga-tests.c | 264 ++++++++++++++++++++++++++++++++
 6 files changed, 295 insertions(+)
 create mode 100644 drivers/fpga/tests/.kunitconfig
 create mode 100644 drivers/fpga/tests/Kconfig
 create mode 100644 drivers/fpga/tests/Makefile
 create mode 100644 drivers/fpga/tests/fpga-tests.c
  

Hi Marco,

I've just started looking at this, but I have a couple of early comments below

On 2/3/23 09:06, Marco Pagani wrote:
> Introduce an initial KUnit suite to test the core components of the
> FPGA subsystem.
>
> The test suite consists of two test cases. The first test case checks
> the programming of a static image on a fake FPGA with a single hardware
> bridge. The FPGA is first programmed using a test image stored in a
> buffer, and then with the same image linked to a single-entry
> scatter-gather list.
>
> The second test case models dynamic partial reconfiguration. The FPGA
> is first configured with a static image that implements a
> reconfigurable design containing a sub-region controlled by two soft
> bridges. Then, the reconfigurable sub-region is reconfigured using
> a fake partial bitstream image. After the reconfiguration, the test
> checks that the soft bridges have been correctly activated.
>
> Signed-off-by: Marco Pagani <marpagan@redhat.com>
> ---
>  drivers/fpga/Kconfig            |   2 +
>  drivers/fpga/Makefile           |   3 +
>  drivers/fpga/tests/.kunitconfig |   5 +
>  drivers/fpga/tests/Kconfig      |  15 ++
>  drivers/fpga/tests/Makefile     |   6 +
>  drivers/fpga/tests/fpga-tests.c | 264 ++++++++++++++++++++++++++++++++
>  6 files changed, 295 insertions(+)
>  create mode 100644 drivers/fpga/tests/.kunitconfig
>  create mode 100644 drivers/fpga/tests/Kconfig
>  create mode 100644 drivers/fpga/tests/Makefile
>  create mode 100644 drivers/fpga/tests/fpga-tests.c
>
> diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
> index 0a00763b9f28..2f689ac4ba3a 100644
> --- a/drivers/fpga/Kconfig
> +++ b/drivers/fpga/Kconfig
> @@ -276,4 +276,6 @@ config FPGA_MGR_LATTICE_SYSCONFIG_SPI
>  	  FPGA manager driver support for Lattice FPGAs programming over slave
>  	  SPI sysCONFIG interface.
>  
> +source "drivers/fpga/tests/Kconfig"
> +
>  endif # FPGA
> diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
> index 72e554b4d2f7..352a2612623e 100644
> --- a/drivers/fpga/Makefile
> +++ b/drivers/fpga/Makefile
> @@ -55,3 +55,6 @@ obj-$(CONFIG_FPGA_DFL_NIOS_INTEL_PAC_N3000)	+= dfl-n3000-nios.o
>  
>  # Drivers for FPGAs which implement DFL
>  obj-$(CONFIG_FPGA_DFL_PCI)		+= dfl-pci.o
> +
> +# KUnit tests
> +obj-$(CONFIG_FPGA_KUNIT_TESTS)		+= tests/
> diff --git a/drivers/fpga/tests/.kunitconfig b/drivers/fpga/tests/.kunitconfig
> new file mode 100644
> index 000000000000..a1c2a2974c39
> --- /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 000000000000..5198e605b38d
> --- /dev/null
> +++ b/drivers/fpga/tests/Kconfig
> @@ -0,0 +1,15 @@
> +config FPGA_KUNIT_TESTS
> +	tristate "FPGA KUnit tests" if !KUNIT_ALL_TESTS
> +	depends on FPGA && FPGA_REGION && FPGA_BRIDGE && KUNIT
> +	default KUNIT_ALL_TESTS
> +	help
> +	  Builds unit tests for the FPGA subsystem. This option
> +	  is not useful for distributions or general kernels,
> +	  but only for kernel developers working on the FPGA
> +	  subsystem and its associated drivers.
These lines seem shorter than necessary. You can use up to 75
characters per line.

> +
> +	  For more information on KUnit and unit tests in general,
> +	  please refer to the KUnit documentation in
> +	  Documentation/dev-tools/kunit/.
> +
> +	  If in doubt, say "N".
> diff --git a/drivers/fpga/tests/Makefile b/drivers/fpga/tests/Makefile
> new file mode 100644
> index 000000000000..74346ae62457
> --- /dev/null
> +++ b/drivers/fpga/tests/Makefile
> @@ -0,0 +1,6 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fake-fpga-mgr.o
> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fake-fpga-region.o
> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fake-fpga-bridge.o
> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fpga-tests.o
> diff --git a/drivers/fpga/tests/fpga-tests.c b/drivers/fpga/tests/fpga-tests.c
> new file mode 100644
> index 000000000000..33f04079b32f
> --- /dev/null
> +++ b/drivers/fpga/tests/fpga-tests.c
> @@ -0,0 +1,264 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Test suite for the FPGA subsystem
> + *
> + * Copyright (C) 2023 Red Hat, Inc. All rights reserved.
> + *
> + * Author: Marco Pagani <marpagan@redhat.com>
> + */
> +
> +#include <kunit/test.h>
> +#include <linux/platform_device.h>
> +#include <linux/scatterlist.h>
> +
> +#include <linux/fpga/fpga-mgr.h>
> +#include <linux/fpga/fpga-region.h>
> +#include <linux/fpga/fpga-bridge.h>
> +
> +#include "fake-fpga-region.h"
> +#include "fake-fpga-bridge.h"
> +#include "fake-fpga-mgr.h"
> +
> +#define FAKE_BIT_BLOCKS		16
> +#define FAKE_BIT_SIZE		(FPGA_TEST_BIT_BLOCK * FAKE_BIT_BLOCKS)
> +
> +static u8 fake_bit[FAKE_BIT_SIZE];
> +
> +static int init_sgt_bit(struct sg_table *sgt, void *bit, size_t len)
> +{
> +	int ret;
> +
> +	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
> +	if (ret)
> +		return ret;
> +
> +	sg_init_one(sgt->sgl, bit, len);
> +
> +	return ret;
> +}
> +
> +static void free_sgt_bit(struct sg_table *sgt)
> +{
> +	if (sgt)
> +		sg_free_table(sgt);
> +}
> +
> +static void fpga_build_base_sys(struct kunit *test, struct fake_fpga_mgr *mgr_ctx,
> +				struct fake_fpga_bridge *bridge_ctx,
> +				struct fake_fpga_region *region_ctx)
> +{
> +	int ret;
> +
> +	ret = fake_fpga_mgr_register(mgr_ctx, test);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	ret = fake_fpga_bridge_register(bridge_ctx, test);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	ret = fake_fpga_region_register(region_ctx, mgr_ctx->mgr, test);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	ret = fake_fpga_region_add_bridge(region_ctx, bridge_ctx->bridge);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +}
> +
> +static void fpga_free_base_sys(struct fake_fpga_mgr *mgr_ctx,
> +			       struct fake_fpga_bridge *bridge_ctx,
> +			       struct fake_fpga_region *region_ctx)
> +{
> +	if (region_ctx)
> +		fake_fpga_region_unregister(region_ctx);
> +
> +	if (bridge_ctx)
> +		fake_fpga_bridge_unregister(bridge_ctx);
> +
> +	if (region_ctx)
> +		fake_fpga_mgr_unregister(mgr_ctx);
> +}
> +
> +static int fpga_suite_init(struct kunit_suite *suite)
> +{
> +	fake_fpga_mgr_fill_header(fake_bit);
> +
> +	return 0;
> +}
> +
> +static void fpga_base_test(struct kunit *test)
> +{
> +	int ret;
> +
> +	struct fake_fpga_mgr mgr_ctx;
> +	struct fake_fpga_bridge base_bridge_ctx;
> +	struct fake_fpga_region base_region_ctx;
> +
> +	struct fpga_image_info *test_img_info;
> +
> +	struct sg_table sgt_bit;
> +
> +	fpga_build_base_sys(test, &mgr_ctx, &base_bridge_ctx, &base_region_ctx);
> +
> +	/* Allocate a fake test image using a buffer */
> +	test_img_info = fpga_image_info_alloc(&mgr_ctx.pdev->dev);
> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_img_info);
> +
> +	test_img_info->buf = fake_bit;
> +	test_img_info->count = sizeof(fake_bit);
> +
> +	kunit_info(test, "fake bitstream size: %zu\n", test_img_info->count);
> +
> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
> +
> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_bridge_get_state(&base_bridge_ctx));
> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
> +
> +	/* Program the fake FPGA using the image buffer */
> +	base_region_ctx.region->info = test_img_info;
> +	ret = fpga_region_program_fpga(base_region_ctx.region);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	fake_fpga_mgr_check_write_buf(&mgr_ctx);
> +
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
> +
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&base_bridge_ctx));
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
> +
> +	fpga_image_info_free(test_img_info);
> +
> +	/* Allocate another fake test image using a scatter list */
> +	test_img_info = fpga_image_info_alloc(&mgr_ctx.pdev->dev);
> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_img_info);
> +
> +	ret = init_sgt_bit(&sgt_bit, fake_bit, FAKE_BIT_SIZE);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	test_img_info->sgt = &sgt_bit;
> +
> +	/* Re-program the fake FPGA using the image scatter list */
> +	base_region_ctx.region->info = test_img_info;
> +	ret = fpga_region_program_fpga(base_region_ctx.region);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	fake_fpga_mgr_check_write_sg(&mgr_ctx);
> +
> +	KUNIT_EXPECT_EQ(test, 2, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
> +
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&base_bridge_ctx));
> +	KUNIT_EXPECT_EQ(test, 2, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
> +
> +	free_sgt_bit(&sgt_bit);
> +	fpga_image_info_free(test_img_info);
> +	fpga_free_base_sys(&mgr_ctx, &base_bridge_ctx, &base_region_ctx);
> +}
> +
> +static void fpga_pr_test(struct kunit *test)
> +{
> +	int ret;
> +
> +	struct fake_fpga_mgr mgr_ctx;
> +	struct fake_fpga_bridge base_bridge_ctx;
> +	struct fake_fpga_region base_region_ctx;
> +
> +	struct fake_fpga_bridge pr_bridge_0_ctx;
> +	struct fake_fpga_bridge pr_bridge_1_ctx;
> +	struct fake_fpga_region pr_region_ctx;
> +
> +	struct fpga_image_info *test_static_img_info;
> +	struct fpga_image_info *test_pr_img_info;
> +
> +	fpga_build_base_sys(test, &mgr_ctx, &base_bridge_ctx, &base_region_ctx);
> +
> +	/* Allocate a fake test image using a buffer */
> +	test_static_img_info = fpga_image_info_alloc(&mgr_ctx.pdev->dev);
> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_static_img_info);
> +
> +	test_static_img_info->buf = fake_bit;
> +	test_static_img_info->count = sizeof(fake_bit);
> +
> +	kunit_info(test, "fake bitstream size: %zu\n", test_static_img_info->count);
> +
> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
> +
> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_bridge_get_state(&base_bridge_ctx));
> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
> +
> +	/* Program the fake FPGA using the image buffer */
> +	base_region_ctx.region->info = test_static_img_info;
> +	ret = fpga_region_program_fpga(base_region_ctx.region);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	fake_fpga_mgr_check_write_buf(&mgr_ctx);
> +
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
> +
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&base_bridge_ctx));
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
> +
> +	/* The static image contains a reconfigurable sub-region with two soft bridges */
> +	ret = fake_fpga_bridge_register(&pr_bridge_0_ctx, test);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	ret = fake_fpga_bridge_register(&pr_bridge_1_ctx, test);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	ret = fake_fpga_region_register(&pr_region_ctx, mgr_ctx.mgr, test);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	ret = fake_fpga_region_add_bridge(&pr_region_ctx, pr_bridge_0_ctx.bridge);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	ret = fake_fpga_region_add_bridge(&pr_region_ctx, pr_bridge_1_ctx.bridge);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	/* Allocate a fake partial test image using a buffer */
> +	test_pr_img_info = fpga_image_info_alloc(&mgr_ctx.pdev->dev);
> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_pr_img_info);
> +
> +	test_pr_img_info->buf = fake_bit;
> +	test_pr_img_info->count = sizeof(fake_bit) / 2;
> +	test_pr_img_info->flags = FPGA_MGR_PARTIAL_RECONFIG;
> +
> +	kunit_info(test, "fake partial bitstream size: %zu\n", test_pr_img_info->count);
> +
> +	/* Program the reconfigurable sub-region */
> +	pr_region_ctx.region->info = test_pr_img_info;
> +	ret = fpga_region_program_fpga(pr_region_ctx.region);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	fake_fpga_mgr_check_write_buf(&mgr_ctx);
> +
> +	KUNIT_EXPECT_EQ(test, 2, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
> +
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&pr_bridge_0_ctx));
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_cycles_count(&pr_bridge_0_ctx));
> +
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&pr_bridge_1_ctx));
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_cycles_count(&pr_bridge_1_ctx));
> +
> +	/* Check that the base bridge has not been disabled */
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&base_bridge_ctx));
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
> +
> +	fpga_image_info_free(test_pr_img_info);
> +	fpga_image_info_free(test_static_img_info);
> +
> +	fake_fpga_region_unregister(&pr_region_ctx);
> +	fake_fpga_bridge_unregister(&pr_bridge_0_ctx);
> +	fake_fpga_bridge_unregister(&pr_bridge_1_ctx);
> +
> +	fpga_free_base_sys(&mgr_ctx, &base_bridge_ctx, &base_region_ctx);
> +}
> +
> +static struct kunit_case fpga_test_cases[] = {
> +	KUNIT_CASE(fpga_base_test),
> +	KUNIT_CASE(fpga_pr_test),
> +	{},
> +};
> +
> +static struct kunit_suite fpga_test_suite = {
> +	.name = "fpga-tests",
> +	.suite_init = fpga_suite_init,
> +	.test_cases = fpga_test_cases,
> +};
> +
> +kunit_test_suite(fpga_test_suite);

When I try to build with these patches, I get this error:
>
> ERROR: modpost: missing MODULE_LICENSE() in drivers/fpga/tests/fpga-tests.o

I was able to fix it by adding this line at the bottom of the file:

> MODULE_LICENSE("GPL");

- Russ
  

On 2023-02-07 02:05, Russ Weight wrote:
> Hi Marco,
> 
> I've just started looking at this, but I have a couple of early comments below
>

Thanks for looking into this.

[...]
 
>> --- /dev/null
>> +++ b/drivers/fpga/tests/Kconfig
>> @@ -0,0 +1,15 @@
>> +config FPGA_KUNIT_TESTS
>> +	tristate "FPGA KUnit tests" if !KUNIT_ALL_TESTS
>> +	depends on FPGA && FPGA_REGION && FPGA_BRIDGE && KUNIT
>> +	default KUNIT_ALL_TESTS
>> +	help
>> +	  Builds unit tests for the FPGA subsystem. This option
>> +	  is not useful for distributions or general kernels,
>> +	  but only for kernel developers working on the FPGA
>> +	  subsystem and its associated drivers.
> These lines seem shorter than necessary. You can use up to 75
> characters per line.
> 

I'll reflow the text in the next revision.

[...]

>> +static struct kunit_case fpga_test_cases[] = {
>> +	KUNIT_CASE(fpga_base_test),
>> +	KUNIT_CASE(fpga_pr_test),
>> +	{},
>> +};
>> +
>> +static struct kunit_suite fpga_test_suite = {
>> +	.name = "fpga-tests",
>> +	.suite_init = fpga_suite_init,
>> +	.test_cases = fpga_test_cases,
>> +};
>> +
>> +kunit_test_suite(fpga_test_suite);
> 
> When I try to build with these patches, I get this error:
>>
>> ERROR: modpost: missing MODULE_LICENSE() in drivers/fpga/tests/fpga-tests.o
> 
> I was able to fix it by adding this line at the bottom of the file:
> 
>> MODULE_LICENSE("GPL");
> 
> - Russ
>

Right, I forgot to add module info macros to the test suite module.
I'll add MODULE_LICENSE() in the next revision.

Thanks for the feedback,
Marco
  

On 2/3/23 09:06, Marco Pagani wrote:
> Introduce an initial KUnit suite to test the core components of the
> FPGA subsystem.
>
> The test suite consists of two test cases. The first test case checks
> the programming of a static image on a fake FPGA with a single hardware
> bridge. The FPGA is first programmed using a test image stored in a
> buffer, and then with the same image linked to a single-entry
> scatter-gather list.
>
> The second test case models dynamic partial reconfiguration. The FPGA
> is first configured with a static image that implements a
> reconfigurable design containing a sub-region controlled by two soft
> bridges. Then, the reconfigurable sub-region is reconfigured using
> a fake partial bitstream image. After the reconfiguration, the test
> checks that the soft bridges have been correctly activated.
>
> Signed-off-by: Marco Pagani <marpagan@redhat.com>
> ---
>  drivers/fpga/Kconfig            |   2 +
>  drivers/fpga/Makefile           |   3 +
>  drivers/fpga/tests/.kunitconfig |   5 +
>  drivers/fpga/tests/Kconfig      |  15 ++
>  drivers/fpga/tests/Makefile     |   6 +
>  drivers/fpga/tests/fpga-tests.c | 264 ++++++++++++++++++++++++++++++++
>  6 files changed, 295 insertions(+)
>  create mode 100644 drivers/fpga/tests/.kunitconfig
>  create mode 100644 drivers/fpga/tests/Kconfig
>  create mode 100644 drivers/fpga/tests/Makefile
>  create mode 100644 drivers/fpga/tests/fpga-tests.c
>
> diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
> index 0a00763b9f28..2f689ac4ba3a 100644
> --- a/drivers/fpga/Kconfig
> +++ b/drivers/fpga/Kconfig
> @@ -276,4 +276,6 @@ config FPGA_MGR_LATTICE_SYSCONFIG_SPI
>  	  FPGA manager driver support for Lattice FPGAs programming over slave
>  	  SPI sysCONFIG interface.
>  
> +source "drivers/fpga/tests/Kconfig"
> +
>  endif # FPGA
> diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
> index 72e554b4d2f7..352a2612623e 100644
> --- a/drivers/fpga/Makefile
> +++ b/drivers/fpga/Makefile
> @@ -55,3 +55,6 @@ obj-$(CONFIG_FPGA_DFL_NIOS_INTEL_PAC_N3000)	+= dfl-n3000-nios.o
>  
>  # Drivers for FPGAs which implement DFL
>  obj-$(CONFIG_FPGA_DFL_PCI)		+= dfl-pci.o
> +
> +# KUnit tests
> +obj-$(CONFIG_FPGA_KUNIT_TESTS)		+= tests/
> diff --git a/drivers/fpga/tests/.kunitconfig b/drivers/fpga/tests/.kunitconfig
> new file mode 100644
> index 000000000000..a1c2a2974c39
> --- /dev/null
> +++ b/drivers/fpga/tests/.kunitconfig
> @@ -0,0 +1,5 @@
> +CONFIG_KUNIT=y
> +CONFIG_FPGA=y
> +CONFIG_FPGA_REGION=y
> +CONFIG_FPGA_BRIDGE=y
> +CONFIG_FPGA_KUNIT_TESTS=y
> diff --git a/drivers/fpga/tests/Kconfig b/drivers/fpga/tests/Kconfig
> new file mode 100644
> index 000000000000..5198e605b38d
> --- /dev/null
> +++ b/drivers/fpga/tests/Kconfig
> @@ -0,0 +1,15 @@
> +config FPGA_KUNIT_TESTS
> +	tristate "FPGA KUnit tests" if !KUNIT_ALL_TESTS
> +	depends on FPGA && FPGA_REGION && FPGA_BRIDGE && KUNIT
> +	default KUNIT_ALL_TESTS
> +	help
> +	  Builds unit tests for the FPGA subsystem. This option
> +	  is not useful for distributions or general kernels,
> +	  but only for kernel developers working on the FPGA
> +	  subsystem and its associated drivers.
> +
> +	  For more information on KUnit and unit tests in general,
> +	  please refer to the KUnit documentation in
> +	  Documentation/dev-tools/kunit/.
> +
> +	  If in doubt, say "N".
> diff --git a/drivers/fpga/tests/Makefile b/drivers/fpga/tests/Makefile
> new file mode 100644
> index 000000000000..74346ae62457
> --- /dev/null
> +++ b/drivers/fpga/tests/Makefile
> @@ -0,0 +1,6 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fake-fpga-mgr.o
> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fake-fpga-region.o
> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fake-fpga-bridge.o
> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fpga-tests.o
> diff --git a/drivers/fpga/tests/fpga-tests.c b/drivers/fpga/tests/fpga-tests.c
> new file mode 100644
> index 000000000000..33f04079b32f
> --- /dev/null
> +++ b/drivers/fpga/tests/fpga-tests.c
> @@ -0,0 +1,264 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Test suite for the FPGA subsystem
> + *
> + * Copyright (C) 2023 Red Hat, Inc. All rights reserved.
> + *
> + * Author: Marco Pagani <marpagan@redhat.com>
> + */
> +
> +#include <kunit/test.h>
> +#include <linux/platform_device.h>
> +#include <linux/scatterlist.h>
> +
> +#include <linux/fpga/fpga-mgr.h>
> +#include <linux/fpga/fpga-region.h>
> +#include <linux/fpga/fpga-bridge.h>
> +
> +#include "fake-fpga-region.h"
> +#include "fake-fpga-bridge.h"
> +#include "fake-fpga-mgr.h"
> +
> +#define FAKE_BIT_BLOCKS		16
> +#define FAKE_BIT_SIZE		(FPGA_TEST_BIT_BLOCK * FAKE_BIT_BLOCKS)
> +
> +static u8 fake_bit[FAKE_BIT_SIZE];

I take it "bit" in fake_bit and sgt_bit is short for "bitstream". Initially,
I found this confusing as I tend to think of a bit as a single bit. It might
be better to expand that something like "fake_bitstream" or "fake_image".

- Russ
> +
> +static int init_sgt_bit(struct sg_table *sgt, void *bit, size_t len)
> +{
> +	int ret;
> +
> +	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
> +	if (ret)
> +		return ret;
> +
> +	sg_init_one(sgt->sgl, bit, len);
> +
> +	return ret;
> +}
> +
> +static void free_sgt_bit(struct sg_table *sgt)
> +{
> +	if (sgt)
> +		sg_free_table(sgt);
> +}
> +
> +static void fpga_build_base_sys(struct kunit *test, struct fake_fpga_mgr *mgr_ctx,
> +				struct fake_fpga_bridge *bridge_ctx,
> +				struct fake_fpga_region *region_ctx)
> +{
> +	int ret;
> +
> +	ret = fake_fpga_mgr_register(mgr_ctx, test);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	ret = fake_fpga_bridge_register(bridge_ctx, test);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	ret = fake_fpga_region_register(region_ctx, mgr_ctx->mgr, test);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	ret = fake_fpga_region_add_bridge(region_ctx, bridge_ctx->bridge);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +}
> +
> +static void fpga_free_base_sys(struct fake_fpga_mgr *mgr_ctx,
> +			       struct fake_fpga_bridge *bridge_ctx,
> +			       struct fake_fpga_region *region_ctx)
> +{
> +	if (region_ctx)
> +		fake_fpga_region_unregister(region_ctx);
> +
> +	if (bridge_ctx)
> +		fake_fpga_bridge_unregister(bridge_ctx);
> +
> +	if (region_ctx)
> +		fake_fpga_mgr_unregister(mgr_ctx);
> +}
> +
> +static int fpga_suite_init(struct kunit_suite *suite)
> +{
> +	fake_fpga_mgr_fill_header(fake_bit);
> +
> +	return 0;
> +}
> +
> +static void fpga_base_test(struct kunit *test)
> +{
> +	int ret;
> +
> +	struct fake_fpga_mgr mgr_ctx;
> +	struct fake_fpga_bridge base_bridge_ctx;
> +	struct fake_fpga_region base_region_ctx;
> +
> +	struct fpga_image_info *test_img_info;
> +
> +	struct sg_table sgt_bit;
> +
> +	fpga_build_base_sys(test, &mgr_ctx, &base_bridge_ctx, &base_region_ctx);
> +
> +	/* Allocate a fake test image using a buffer */
> +	test_img_info = fpga_image_info_alloc(&mgr_ctx.pdev->dev);
> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_img_info);
> +
> +	test_img_info->buf = fake_bit;
> +	test_img_info->count = sizeof(fake_bit);
> +
> +	kunit_info(test, "fake bitstream size: %zu\n", test_img_info->count);
> +
> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
> +
> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_bridge_get_state(&base_bridge_ctx));
> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
> +
> +	/* Program the fake FPGA using the image buffer */
> +	base_region_ctx.region->info = test_img_info;
> +	ret = fpga_region_program_fpga(base_region_ctx.region);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	fake_fpga_mgr_check_write_buf(&mgr_ctx);
> +
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
> +
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&base_bridge_ctx));
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
> +
> +	fpga_image_info_free(test_img_info);
> +
> +	/* Allocate another fake test image using a scatter list */
> +	test_img_info = fpga_image_info_alloc(&mgr_ctx.pdev->dev);
> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_img_info);
> +
> +	ret = init_sgt_bit(&sgt_bit, fake_bit, FAKE_BIT_SIZE);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	test_img_info->sgt = &sgt_bit;
> +
> +	/* Re-program the fake FPGA using the image scatter list */
> +	base_region_ctx.region->info = test_img_info;
> +	ret = fpga_region_program_fpga(base_region_ctx.region);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	fake_fpga_mgr_check_write_sg(&mgr_ctx);
> +
> +	KUNIT_EXPECT_EQ(test, 2, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
> +
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&base_bridge_ctx));
> +	KUNIT_EXPECT_EQ(test, 2, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
> +
> +	free_sgt_bit(&sgt_bit);
> +	fpga_image_info_free(test_img_info);
> +	fpga_free_base_sys(&mgr_ctx, &base_bridge_ctx, &base_region_ctx);
> +}
> +
> +static void fpga_pr_test(struct kunit *test)
> +{
> +	int ret;
> +
> +	struct fake_fpga_mgr mgr_ctx;
> +	struct fake_fpga_bridge base_bridge_ctx;
> +	struct fake_fpga_region base_region_ctx;
> +
> +	struct fake_fpga_bridge pr_bridge_0_ctx;
> +	struct fake_fpga_bridge pr_bridge_1_ctx;
> +	struct fake_fpga_region pr_region_ctx;
> +
> +	struct fpga_image_info *test_static_img_info;
> +	struct fpga_image_info *test_pr_img_info;
> +
> +	fpga_build_base_sys(test, &mgr_ctx, &base_bridge_ctx, &base_region_ctx);
> +
> +	/* Allocate a fake test image using a buffer */
> +	test_static_img_info = fpga_image_info_alloc(&mgr_ctx.pdev->dev);
> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_static_img_info);
> +
> +	test_static_img_info->buf = fake_bit;
> +	test_static_img_info->count = sizeof(fake_bit);
> +
> +	kunit_info(test, "fake bitstream size: %zu\n", test_static_img_info->count);
> +
> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
> +
> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_bridge_get_state(&base_bridge_ctx));
> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
> +
> +	/* Program the fake FPGA using the image buffer */
> +	base_region_ctx.region->info = test_static_img_info;
> +	ret = fpga_region_program_fpga(base_region_ctx.region);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	fake_fpga_mgr_check_write_buf(&mgr_ctx);
> +
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
> +
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&base_bridge_ctx));
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
> +
> +	/* The static image contains a reconfigurable sub-region with two soft bridges */
> +	ret = fake_fpga_bridge_register(&pr_bridge_0_ctx, test);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	ret = fake_fpga_bridge_register(&pr_bridge_1_ctx, test);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	ret = fake_fpga_region_register(&pr_region_ctx, mgr_ctx.mgr, test);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	ret = fake_fpga_region_add_bridge(&pr_region_ctx, pr_bridge_0_ctx.bridge);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	ret = fake_fpga_region_add_bridge(&pr_region_ctx, pr_bridge_1_ctx.bridge);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	/* Allocate a fake partial test image using a buffer */
> +	test_pr_img_info = fpga_image_info_alloc(&mgr_ctx.pdev->dev);
> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_pr_img_info);
> +
> +	test_pr_img_info->buf = fake_bit;
> +	test_pr_img_info->count = sizeof(fake_bit) / 2;
> +	test_pr_img_info->flags = FPGA_MGR_PARTIAL_RECONFIG;
> +
> +	kunit_info(test, "fake partial bitstream size: %zu\n", test_pr_img_info->count);
> +
> +	/* Program the reconfigurable sub-region */
> +	pr_region_ctx.region->info = test_pr_img_info;
> +	ret = fpga_region_program_fpga(pr_region_ctx.region);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	fake_fpga_mgr_check_write_buf(&mgr_ctx);
> +
> +	KUNIT_EXPECT_EQ(test, 2, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
> +
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&pr_bridge_0_ctx));
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_cycles_count(&pr_bridge_0_ctx));
> +
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&pr_bridge_1_ctx));
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_cycles_count(&pr_bridge_1_ctx));
> +
> +	/* Check that the base bridge has not been disabled */
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&base_bridge_ctx));
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
> +
> +	fpga_image_info_free(test_pr_img_info);
> +	fpga_image_info_free(test_static_img_info);
> +
> +	fake_fpga_region_unregister(&pr_region_ctx);
> +	fake_fpga_bridge_unregister(&pr_bridge_0_ctx);
> +	fake_fpga_bridge_unregister(&pr_bridge_1_ctx);
> +
> +	fpga_free_base_sys(&mgr_ctx, &base_bridge_ctx, &base_region_ctx);
> +}
> +
> +static struct kunit_case fpga_test_cases[] = {
> +	KUNIT_CASE(fpga_base_test),
> +	KUNIT_CASE(fpga_pr_test),
> +	{},
> +};
> +
> +static struct kunit_suite fpga_test_suite = {
> +	.name = "fpga-tests",
> +	.suite_init = fpga_suite_init,
> +	.test_cases = fpga_test_cases,
> +};
> +
> +kunit_test_suite(fpga_test_suite);
  

On 2023-02-14 00:37, Russ Weight wrote:
> 
> 
> On 2/3/23 09:06, Marco Pagani wrote:
>> Introduce an initial KUnit suite to test the core components of the
>> FPGA subsystem.
>>
>> The test suite consists of two test cases. The first test case checks
>> the programming of a static image on a fake FPGA with a single hardware
>> bridge. The FPGA is first programmed using a test image stored in a
>> buffer, and then with the same image linked to a single-entry
>> scatter-gather list.
>>
>> The second test case models dynamic partial reconfiguration. The FPGA
>> is first configured with a static image that implements a
>> reconfigurable design containing a sub-region controlled by two soft
>> bridges. Then, the reconfigurable sub-region is reconfigured using
>> a fake partial bitstream image. After the reconfiguration, the test
>> checks that the soft bridges have been correctly activated.
>>
>> Signed-off-by: Marco Pagani <marpagan@redhat.com>
>> ---
>>  drivers/fpga/Kconfig            |   2 +
>>  drivers/fpga/Makefile           |   3 +
>>  drivers/fpga/tests/.kunitconfig |   5 +
>>  drivers/fpga/tests/Kconfig      |  15 ++
>>  drivers/fpga/tests/Makefile     |   6 +
>>  drivers/fpga/tests/fpga-tests.c | 264 ++++++++++++++++++++++++++++++++
>>  6 files changed, 295 insertions(+)
>>  create mode 100644 drivers/fpga/tests/.kunitconfig
>>  create mode 100644 drivers/fpga/tests/Kconfig
>>  create mode 100644 drivers/fpga/tests/Makefile
>>  create mode 100644 drivers/fpga/tests/fpga-tests.c
>>
>> diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
>> index 0a00763b9f28..2f689ac4ba3a 100644
>> --- a/drivers/fpga/Kconfig
>> +++ b/drivers/fpga/Kconfig
>> @@ -276,4 +276,6 @@ config FPGA_MGR_LATTICE_SYSCONFIG_SPI
>>  	  FPGA manager driver support for Lattice FPGAs programming over slave
>>  	  SPI sysCONFIG interface.
>>  
>> +source "drivers/fpga/tests/Kconfig"
>> +
>>  endif # FPGA
>> diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
>> index 72e554b4d2f7..352a2612623e 100644
>> --- a/drivers/fpga/Makefile
>> +++ b/drivers/fpga/Makefile
>> @@ -55,3 +55,6 @@ obj-$(CONFIG_FPGA_DFL_NIOS_INTEL_PAC_N3000)	+= dfl-n3000-nios.o
>>  
>>  # Drivers for FPGAs which implement DFL
>>  obj-$(CONFIG_FPGA_DFL_PCI)		+= dfl-pci.o
>> +
>> +# KUnit tests
>> +obj-$(CONFIG_FPGA_KUNIT_TESTS)		+= tests/
>> diff --git a/drivers/fpga/tests/.kunitconfig b/drivers/fpga/tests/.kunitconfig
>> new file mode 100644
>> index 000000000000..a1c2a2974c39
>> --- /dev/null
>> +++ b/drivers/fpga/tests/.kunitconfig
>> @@ -0,0 +1,5 @@
>> +CONFIG_KUNIT=y
>> +CONFIG_FPGA=y
>> +CONFIG_FPGA_REGION=y
>> +CONFIG_FPGA_BRIDGE=y
>> +CONFIG_FPGA_KUNIT_TESTS=y
>> diff --git a/drivers/fpga/tests/Kconfig b/drivers/fpga/tests/Kconfig
>> new file mode 100644
>> index 000000000000..5198e605b38d
>> --- /dev/null
>> +++ b/drivers/fpga/tests/Kconfig
>> @@ -0,0 +1,15 @@
>> +config FPGA_KUNIT_TESTS
>> +	tristate "FPGA KUnit tests" if !KUNIT_ALL_TESTS
>> +	depends on FPGA && FPGA_REGION && FPGA_BRIDGE && KUNIT
>> +	default KUNIT_ALL_TESTS
>> +	help
>> +	  Builds unit tests for the FPGA subsystem. This option
>> +	  is not useful for distributions or general kernels,
>> +	  but only for kernel developers working on the FPGA
>> +	  subsystem and its associated drivers.
>> +
>> +	  For more information on KUnit and unit tests in general,
>> +	  please refer to the KUnit documentation in
>> +	  Documentation/dev-tools/kunit/.
>> +
>> +	  If in doubt, say "N".
>> diff --git a/drivers/fpga/tests/Makefile b/drivers/fpga/tests/Makefile
>> new file mode 100644
>> index 000000000000..74346ae62457
>> --- /dev/null
>> +++ b/drivers/fpga/tests/Makefile
>> @@ -0,0 +1,6 @@
>> +# SPDX-License-Identifier: GPL-2.0
>> +
>> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fake-fpga-mgr.o
>> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fake-fpga-region.o
>> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fake-fpga-bridge.o
>> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fpga-tests.o
>> diff --git a/drivers/fpga/tests/fpga-tests.c b/drivers/fpga/tests/fpga-tests.c
>> new file mode 100644
>> index 000000000000..33f04079b32f
>> --- /dev/null
>> +++ b/drivers/fpga/tests/fpga-tests.c
>> @@ -0,0 +1,264 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Test suite for the FPGA subsystem
>> + *
>> + * Copyright (C) 2023 Red Hat, Inc. All rights reserved.
>> + *
>> + * Author: Marco Pagani <marpagan@redhat.com>
>> + */
>> +
>> +#include <kunit/test.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/scatterlist.h>
>> +
>> +#include <linux/fpga/fpga-mgr.h>
>> +#include <linux/fpga/fpga-region.h>
>> +#include <linux/fpga/fpga-bridge.h>
>> +
>> +#include "fake-fpga-region.h"
>> +#include "fake-fpga-bridge.h"
>> +#include "fake-fpga-mgr.h"
>> +
>> +#define FAKE_BIT_BLOCKS		16
>> +#define FAKE_BIT_SIZE		(FPGA_TEST_BIT_BLOCK * FAKE_BIT_BLOCKS)
>> +
>> +static u8 fake_bit[FAKE_BIT_SIZE];
> 
> I take it "bit" in fake_bit and sgt_bit is short for "bitstream". Initially,
> I found this confusing as I tend to think of a bit as a single bit. It might
> be better to expand that something like "fake_bitstream" or "fake_image".
> 
> - Russ


You're right. Using "bit" in the name can be confusing. I'll change it
to "fake_image" or maybe "fake_image_buf" to be consistent with the naming
convention used in the subsystem. I'll also change "test_img_info"
to "fake_img_info" to improve naming consistency.

Thanks,
Marco
  

On 2023-02-03 at 18:06:50 +0100, Marco Pagani wrote:
> Introduce an initial KUnit suite to test the core components of the
> FPGA subsystem.

I'm not familiar with kunit, and I spend some time to read the
Documentation/dev-tools/kunit/, sorry for late response.

> 
> The test suite consists of two test cases. The first test case checks
> the programming of a static image on a fake FPGA with a single hardware
> bridge. The FPGA is first programmed using a test image stored in a
> buffer, and then with the same image linked to a single-entry
> scatter-gather list.
> 
> The second test case models dynamic partial reconfiguration. The FPGA
> is first configured with a static image that implements a
> reconfigurable design containing a sub-region controlled by two soft
> bridges. Then, the reconfigurable sub-region is reconfigured using
> a fake partial bitstream image. After the reconfiguration, the test
> checks that the soft bridges have been correctly activated.
> 
> Signed-off-by: Marco Pagani <marpagan@redhat.com>
> ---
>  drivers/fpga/Kconfig            |   2 +
>  drivers/fpga/Makefile           |   3 +
>  drivers/fpga/tests/.kunitconfig |   5 +
>  drivers/fpga/tests/Kconfig      |  15 ++
>  drivers/fpga/tests/Makefile     |   6 +
>  drivers/fpga/tests/fpga-tests.c | 264 ++++++++++++++++++++++++++++++++
>  6 files changed, 295 insertions(+)
>  create mode 100644 drivers/fpga/tests/.kunitconfig
>  create mode 100644 drivers/fpga/tests/Kconfig
>  create mode 100644 drivers/fpga/tests/Makefile
>  create mode 100644 drivers/fpga/tests/fpga-tests.c
> 
> diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
> index 0a00763b9f28..2f689ac4ba3a 100644
> --- a/drivers/fpga/Kconfig
> +++ b/drivers/fpga/Kconfig
> @@ -276,4 +276,6 @@ config FPGA_MGR_LATTICE_SYSCONFIG_SPI
>  	  FPGA manager driver support for Lattice FPGAs programming over slave
>  	  SPI sysCONFIG interface.
>  
> +source "drivers/fpga/tests/Kconfig"
> +
>  endif # FPGA
> diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
> index 72e554b4d2f7..352a2612623e 100644
> --- a/drivers/fpga/Makefile
> +++ b/drivers/fpga/Makefile
> @@ -55,3 +55,6 @@ obj-$(CONFIG_FPGA_DFL_NIOS_INTEL_PAC_N3000)	+= dfl-n3000-nios.o
>  
>  # Drivers for FPGAs which implement DFL
>  obj-$(CONFIG_FPGA_DFL_PCI)		+= dfl-pci.o
> +
> +# KUnit tests
> +obj-$(CONFIG_FPGA_KUNIT_TESTS)		+= tests/
> diff --git a/drivers/fpga/tests/.kunitconfig b/drivers/fpga/tests/.kunitconfig
> new file mode 100644
> index 000000000000..a1c2a2974c39
> --- /dev/null
> +++ b/drivers/fpga/tests/.kunitconfig
> @@ -0,0 +1,5 @@
> +CONFIG_KUNIT=y
> +CONFIG_FPGA=y
> +CONFIG_FPGA_REGION=y
> +CONFIG_FPGA_BRIDGE=y
> +CONFIG_FPGA_KUNIT_TESTS=y
> diff --git a/drivers/fpga/tests/Kconfig b/drivers/fpga/tests/Kconfig
> new file mode 100644
> index 000000000000..5198e605b38d
> --- /dev/null
> +++ b/drivers/fpga/tests/Kconfig
> @@ -0,0 +1,15 @@
> +config FPGA_KUNIT_TESTS
> +	tristate "FPGA KUnit tests" if !KUNIT_ALL_TESTS
> +	depends on FPGA && FPGA_REGION && FPGA_BRIDGE && KUNIT
> +	default KUNIT_ALL_TESTS
> +	help
> +	  Builds unit tests for the FPGA subsystem. This option
> +	  is not useful for distributions or general kernels,
> +	  but only for kernel developers working on the FPGA
> +	  subsystem and its associated drivers.
> +
> +	  For more information on KUnit and unit tests in general,
> +	  please refer to the KUnit documentation in
> +	  Documentation/dev-tools/kunit/.
> +
> +	  If in doubt, say "N".
> diff --git a/drivers/fpga/tests/Makefile b/drivers/fpga/tests/Makefile
> new file mode 100644
> index 000000000000..74346ae62457
> --- /dev/null
> +++ b/drivers/fpga/tests/Makefile
> @@ -0,0 +1,6 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fake-fpga-mgr.o
> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fake-fpga-region.o
> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fake-fpga-bridge.o

It is better the patches for fake components come first, otherwise may
break the compilation. Also not friendly for review.

> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fpga-tests.o

Maybe fpga-test.o?

And could they be built in a single module? I haven't find a reason
these fake components been used alone.

> diff --git a/drivers/fpga/tests/fpga-tests.c b/drivers/fpga/tests/fpga-tests.c
> new file mode 100644
> index 000000000000..33f04079b32f
> --- /dev/null
> +++ b/drivers/fpga/tests/fpga-tests.c
> @@ -0,0 +1,264 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Test suite for the FPGA subsystem
> + *
> + * Copyright (C) 2023 Red Hat, Inc. All rights reserved.
> + *
> + * Author: Marco Pagani <marpagan@redhat.com>
> + */
> +
> +#include <kunit/test.h>
> +#include <linux/platform_device.h>
> +#include <linux/scatterlist.h>
> +
> +#include <linux/fpga/fpga-mgr.h>
> +#include <linux/fpga/fpga-region.h>
> +#include <linux/fpga/fpga-bridge.h>
> +
> +#include "fake-fpga-region.h"
> +#include "fake-fpga-bridge.h"
> +#include "fake-fpga-mgr.h"
> +
> +#define FAKE_BIT_BLOCKS		16
> +#define FAKE_BIT_SIZE		(FPGA_TEST_BIT_BLOCK * FAKE_BIT_BLOCKS)
> +
> +static u8 fake_bit[FAKE_BIT_SIZE];
> +
> +static int init_sgt_bit(struct sg_table *sgt, void *bit, size_t len)
> +{
> +	int ret;
> +
> +	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
> +	if (ret)
> +		return ret;
> +
> +	sg_init_one(sgt->sgl, bit, len);
> +
> +	return ret;
> +}
> +
> +static void free_sgt_bit(struct sg_table *sgt)
> +{
> +	if (sgt)
> +		sg_free_table(sgt);
> +}
> +
> +static void fpga_build_base_sys(struct kunit *test, struct fake_fpga_mgr *mgr_ctx,
> +				struct fake_fpga_bridge *bridge_ctx,
> +				struct fake_fpga_region *region_ctx)
> +{
> +	int ret;
> +
> +	ret = fake_fpga_mgr_register(mgr_ctx, test);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	ret = fake_fpga_bridge_register(bridge_ctx, test);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	ret = fake_fpga_region_register(region_ctx, mgr_ctx->mgr, test);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	ret = fake_fpga_region_add_bridge(region_ctx, bridge_ctx->bridge);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +}
> +
> +static void fpga_free_base_sys(struct fake_fpga_mgr *mgr_ctx,
> +			       struct fake_fpga_bridge *bridge_ctx,
> +			       struct fake_fpga_region *region_ctx)
> +{
> +	if (region_ctx)
> +		fake_fpga_region_unregister(region_ctx);
> +
> +	if (bridge_ctx)
> +		fake_fpga_bridge_unregister(bridge_ctx);
> +
> +	if (region_ctx)
> +		fake_fpga_mgr_unregister(mgr_ctx);
> +}
> +
> +static int fpga_suite_init(struct kunit_suite *suite)
> +{
> +	fake_fpga_mgr_fill_header(fake_bit);

Do we need to run it before every case? Or just run once for all cases?

> +
> +	return 0;
> +}
> +
> +static void fpga_base_test(struct kunit *test)
> +{
> +	int ret;
> +
> +	struct fake_fpga_mgr mgr_ctx;
> +	struct fake_fpga_bridge base_bridge_ctx;
> +	struct fake_fpga_region base_region_ctx;
> +
> +	struct fpga_image_info *test_img_info;
> +
> +	struct sg_table sgt_bit;
> +
> +	fpga_build_base_sys(test, &mgr_ctx, &base_bridge_ctx, &base_region_ctx);
> +
> +	/* Allocate a fake test image using a buffer */
> +	test_img_info = fpga_image_info_alloc(&mgr_ctx.pdev->dev);
> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_img_info);
> +
> +	test_img_info->buf = fake_bit;
> +	test_img_info->count = sizeof(fake_bit);
> +
> +	kunit_info(test, "fake bitstream size: %zu\n", test_img_info->count);
> +
> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
> +
> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_bridge_get_state(&base_bridge_ctx));
> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
> +
> +	/* Program the fake FPGA using the image buffer */
> +	base_region_ctx.region->info = test_img_info;
> +	ret = fpga_region_program_fpga(base_region_ctx.region);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	fake_fpga_mgr_check_write_buf(&mgr_ctx);
> +
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
> +
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&base_bridge_ctx));
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
> +
> +	fpga_image_info_free(test_img_info);
> +
> +	/* Allocate another fake test image using a scatter list */
> +	test_img_info = fpga_image_info_alloc(&mgr_ctx.pdev->dev);
> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_img_info);
> +
> +	ret = init_sgt_bit(&sgt_bit, fake_bit, FAKE_BIT_SIZE);
> +	KUNIT_ASSERT_EQ(test, ret, 0);

This is not fpga function, do we need the ASSERT?

> +
> +	test_img_info->sgt = &sgt_bit;
> +
> +	/* Re-program the fake FPGA using the image scatter list */
> +	base_region_ctx.region->info = test_img_info;
> +	ret = fpga_region_program_fpga(base_region_ctx.region);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	fake_fpga_mgr_check_write_sg(&mgr_ctx);
> +
> +	KUNIT_EXPECT_EQ(test, 2, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
> +
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&base_bridge_ctx));
> +	KUNIT_EXPECT_EQ(test, 2, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
> +
> +	free_sgt_bit(&sgt_bit);
> +	fpga_image_info_free(test_img_info);
> +	fpga_free_base_sys(&mgr_ctx, &base_bridge_ctx, &base_region_ctx);
> +}
> +
> +static void fpga_pr_test(struct kunit *test)
> +{
> +	int ret;
> +
> +	struct fake_fpga_mgr mgr_ctx;
> +	struct fake_fpga_bridge base_bridge_ctx;
> +	struct fake_fpga_region base_region_ctx;
> +
> +	struct fake_fpga_bridge pr_bridge_0_ctx;
> +	struct fake_fpga_bridge pr_bridge_1_ctx;
> +	struct fake_fpga_region pr_region_ctx;
> +
> +	struct fpga_image_info *test_static_img_info;
> +	struct fpga_image_info *test_pr_img_info;
> +
> +	fpga_build_base_sys(test, &mgr_ctx, &base_bridge_ctx, &base_region_ctx);

If we need the base region/bridge/mgr for each case, could we create
global ones in .init(), or .suite_init()?

> +
> +	/* Allocate a fake test image using a buffer */
> +	test_static_img_info = fpga_image_info_alloc(&mgr_ctx.pdev->dev);
> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_static_img_info);
> +
> +	test_static_img_info->buf = fake_bit;
> +	test_static_img_info->count = sizeof(fake_bit);

Same concern, may remove the test image info initialization from each
test case code.

> +
> +	kunit_info(test, "fake bitstream size: %zu\n", test_static_img_info->count);
> +
> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
> +
> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_bridge_get_state(&base_bridge_ctx));
> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
> +
> +	/* Program the fake FPGA using the image buffer */
> +	base_region_ctx.region->info = test_static_img_info;
> +	ret = fpga_region_program_fpga(base_region_ctx.region);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	fake_fpga_mgr_check_write_buf(&mgr_ctx);
> +
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
> +
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&base_bridge_ctx));
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
> +
> +	/* The static image contains a reconfigurable sub-region with two soft bridges */

Till now I didn't find any difference with fpga_base_test.
And I can't figure out how the "static parent region - sub pr region"
topology is created?

> +	ret = fake_fpga_bridge_register(&pr_bridge_0_ctx, test);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	ret = fake_fpga_bridge_register(&pr_bridge_1_ctx, test);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	ret = fake_fpga_region_register(&pr_region_ctx, mgr_ctx.mgr, test);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	ret = fake_fpga_region_add_bridge(&pr_region_ctx, pr_bridge_0_ctx.bridge);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	ret = fake_fpga_region_add_bridge(&pr_region_ctx, pr_bridge_1_ctx.bridge);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	/* Allocate a fake partial test image using a buffer */
> +	test_pr_img_info = fpga_image_info_alloc(&mgr_ctx.pdev->dev);
> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_pr_img_info);
> +
> +	test_pr_img_info->buf = fake_bit;
> +	test_pr_img_info->count = sizeof(fake_bit) / 2;
> +	test_pr_img_info->flags = FPGA_MGR_PARTIAL_RECONFIG;
> +
> +	kunit_info(test, "fake partial bitstream size: %zu\n", test_pr_img_info->count);
> +
> +	/* Program the reconfigurable sub-region */
> +	pr_region_ctx.region->info = test_pr_img_info;
> +	ret = fpga_region_program_fpga(pr_region_ctx.region);
> +	KUNIT_ASSERT_EQ(test, ret, 0);
> +
> +	fake_fpga_mgr_check_write_buf(&mgr_ctx);
> +
> +	KUNIT_EXPECT_EQ(test, 2, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
> +
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&pr_bridge_0_ctx));
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_cycles_count(&pr_bridge_0_ctx));
> +
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&pr_bridge_1_ctx));
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_cycles_count(&pr_bridge_1_ctx));
> +
> +	/* Check that the base bridge has not been disabled */
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&base_bridge_ctx));
> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
> +
> +	fpga_image_info_free(test_pr_img_info);
> +	fpga_image_info_free(test_static_img_info);
> +
> +	fake_fpga_region_unregister(&pr_region_ctx);
> +	fake_fpga_bridge_unregister(&pr_bridge_0_ctx);
> +	fake_fpga_bridge_unregister(&pr_bridge_1_ctx);
> +
> +	fpga_free_base_sys(&mgr_ctx, &base_bridge_ctx, &base_region_ctx);

Same concern, may put them in .exit() or suite_exit()?

> +}
> +
> +static struct kunit_case fpga_test_cases[] = {
> +	KUNIT_CASE(fpga_base_test),
> +	KUNIT_CASE(fpga_pr_test),

I feel there are too many tasks for each test case, and some duplicated
routines.

Could we have a suite for the common routine test in each case, like
region/bridge/mgr (un)register, fpga image alloc ... And another suite
which have these common routines in .init() or .suite_init().

> +	{},
> +};
> +
> +static struct kunit_suite fpga_test_suite = {
> +	.name = "fpga-tests",

I see from style.rst that:
  
  "Names should use underscores, not dashes, to separate words"

and

  "*Do not* include "test" or "kunit" directly in the subsystem name
   unless we are actually testing other tests or the kunit framework
   itself"

So IIUC I assume the name should be "fpga"?

BTW: I do see some existing test cases that are not conform to the style,
even the examples in doc itself.

Thanks,
Yilun

> +	.suite_init = fpga_suite_init,
> +	.test_cases = fpga_test_cases,
> +};
> +
> +kunit_test_suite(fpga_test_suite);
> -- 
> 2.39.1
>
  

On 2023-02-18 10:59, Xu Yilun wrote:
> On 2023-02-03 at 18:06:50 +0100, Marco Pagani wrote:
>> Introduce an initial KUnit suite to test the core components of the
>> FPGA subsystem.
> 
> I'm not familiar with kunit, and I spend some time to read the
> Documentation/dev-tools/kunit/, sorry for late response.

Thank you for reviewing.

> 
>>
>> The test suite consists of two test cases. The first test case checks
>> the programming of a static image on a fake FPGA with a single hardware
>> bridge. The FPGA is first programmed using a test image stored in a
>> buffer, and then with the same image linked to a single-entry
>> scatter-gather list.
>>
>> The second test case models dynamic partial reconfiguration. The FPGA
>> is first configured with a static image that implements a
>> reconfigurable design containing a sub-region controlled by two soft
>> bridges. Then, the reconfigurable sub-region is reconfigured using
>> a fake partial bitstream image. After the reconfiguration, the test
>> checks that the soft bridges have been correctly activated.
>>
>> Signed-off-by: Marco Pagani <marpagan@redhat.com>
>> ---
>>  drivers/fpga/Kconfig            |   2 +
>>  drivers/fpga/Makefile           |   3 +
>>  drivers/fpga/tests/.kunitconfig |   5 +
>>  drivers/fpga/tests/Kconfig      |  15 ++
>>  drivers/fpga/tests/Makefile     |   6 +
>>  drivers/fpga/tests/fpga-tests.c | 264 ++++++++++++++++++++++++++++++++
>>  6 files changed, 295 insertions(+)
>>  create mode 100644 drivers/fpga/tests/.kunitconfig
>>  create mode 100644 drivers/fpga/tests/Kconfig
>>  create mode 100644 drivers/fpga/tests/Makefile
>>  create mode 100644 drivers/fpga/tests/fpga-tests.c
>>
>> diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
>> index 0a00763b9f28..2f689ac4ba3a 100644
>> --- a/drivers/fpga/Kconfig
>> +++ b/drivers/fpga/Kconfig
>> @@ -276,4 +276,6 @@ config FPGA_MGR_LATTICE_SYSCONFIG_SPI
>>  	  FPGA manager driver support for Lattice FPGAs programming over slave
>>  	  SPI sysCONFIG interface.
>>  
>> +source "drivers/fpga/tests/Kconfig"
>> +
>>  endif # FPGA
>> diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
>> index 72e554b4d2f7..352a2612623e 100644
>> --- a/drivers/fpga/Makefile
>> +++ b/drivers/fpga/Makefile
>> @@ -55,3 +55,6 @@ obj-$(CONFIG_FPGA_DFL_NIOS_INTEL_PAC_N3000)	+= dfl-n3000-nios.o
>>  
>>  # Drivers for FPGAs which implement DFL
>>  obj-$(CONFIG_FPGA_DFL_PCI)		+= dfl-pci.o
>> +
>> +# KUnit tests
>> +obj-$(CONFIG_FPGA_KUNIT_TESTS)		+= tests/
>> diff --git a/drivers/fpga/tests/.kunitconfig b/drivers/fpga/tests/.kunitconfig
>> new file mode 100644
>> index 000000000000..a1c2a2974c39
>> --- /dev/null
>> +++ b/drivers/fpga/tests/.kunitconfig
>> @@ -0,0 +1,5 @@
>> +CONFIG_KUNIT=y
>> +CONFIG_FPGA=y
>> +CONFIG_FPGA_REGION=y
>> +CONFIG_FPGA_BRIDGE=y
>> +CONFIG_FPGA_KUNIT_TESTS=y
>> diff --git a/drivers/fpga/tests/Kconfig b/drivers/fpga/tests/Kconfig
>> new file mode 100644
>> index 000000000000..5198e605b38d
>> --- /dev/null
>> +++ b/drivers/fpga/tests/Kconfig
>> @@ -0,0 +1,15 @@
>> +config FPGA_KUNIT_TESTS
>> +	tristate "FPGA KUnit tests" if !KUNIT_ALL_TESTS
>> +	depends on FPGA && FPGA_REGION && FPGA_BRIDGE && KUNIT
>> +	default KUNIT_ALL_TESTS
>> +	help
>> +	  Builds unit tests for the FPGA subsystem. This option
>> +	  is not useful for distributions or general kernels,
>> +	  but only for kernel developers working on the FPGA
>> +	  subsystem and its associated drivers.
>> +
>> +	  For more information on KUnit and unit tests in general,
>> +	  please refer to the KUnit documentation in
>> +	  Documentation/dev-tools/kunit/.
>> +
>> +	  If in doubt, say "N".
>> diff --git a/drivers/fpga/tests/Makefile b/drivers/fpga/tests/Makefile
>> new file mode 100644
>> index 000000000000..74346ae62457
>> --- /dev/null
>> +++ b/drivers/fpga/tests/Makefile
>> @@ -0,0 +1,6 @@
>> +# SPDX-License-Identifier: GPL-2.0
>> +
>> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fake-fpga-mgr.o
>> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fake-fpga-region.o
>> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fake-fpga-bridge.o
> 
> It is better the patches for fake components come first, otherwise may
> break the compilation. Also not friendly for review.

Sorry. I'll change the order in the next version.

> 
>> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fpga-tests.o
> 
> Maybe fpga-test.o?

I'll change the name in the next version.

> 
> And could they be built in a single module? I haven't find a reason
> these fake components been used alone.
> 

My feeling is that they could also come in handy to do some general
development or testing on the subsystem. For instance, I used the fake
FPGA manager in isolation to experiment with the OF region.

Initially, the fake manager also had an of_device_id device matching
struct. However, I later removed it because it was not used for the
test setup, and I was not sure if adding an OF device matching struct
was acceptable for a test driver.

>> diff --git a/drivers/fpga/tests/fpga-tests.c b/drivers/fpga/tests/fpga-tests.c
>> new file mode 100644
>> index 000000000000..33f04079b32f
>> --- /dev/null
>> +++ b/drivers/fpga/tests/fpga-tests.c
>> @@ -0,0 +1,264 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Test suite for the FPGA subsystem
>> + *
>> + * Copyright (C) 2023 Red Hat, Inc. All rights reserved.
>> + *
>> + * Author: Marco Pagani <marpagan@redhat.com>
>> + */
>> +
>> +#include <kunit/test.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/scatterlist.h>
>> +
>> +#include <linux/fpga/fpga-mgr.h>
>> +#include <linux/fpga/fpga-region.h>
>> +#include <linux/fpga/fpga-bridge.h>
>> +
>> +#include "fake-fpga-region.h"
>> +#include "fake-fpga-bridge.h"
>> +#include "fake-fpga-mgr.h"
>> +
>> +#define FAKE_BIT_BLOCKS		16
>> +#define FAKE_BIT_SIZE		(FPGA_TEST_BIT_BLOCK * FAKE_BIT_BLOCKS)
>> +
>> +static u8 fake_bit[FAKE_BIT_SIZE];
>> +
>> +static int init_sgt_bit(struct sg_table *sgt, void *bit, size_t len)
>> +{
>> +	int ret;
>> +
>> +	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
>> +	if (ret)
>> +		return ret;
>> +
>> +	sg_init_one(sgt->sgl, bit, len);
>> +
>> +	return ret;
>> +}
>> +
>> +static void free_sgt_bit(struct sg_table *sgt)
>> +{
>> +	if (sgt)
>> +		sg_free_table(sgt);
>> +}
>> +
>> +static void fpga_build_base_sys(struct kunit *test, struct fake_fpga_mgr *mgr_ctx,
>> +				struct fake_fpga_bridge *bridge_ctx,
>> +				struct fake_fpga_region *region_ctx)
>> +{
>> +	int ret;
>> +
>> +	ret = fake_fpga_mgr_register(mgr_ctx, test);
>> +	KUNIT_ASSERT_EQ(test, ret, 0);
>> +
>> +	ret = fake_fpga_bridge_register(bridge_ctx, test);
>> +	KUNIT_ASSERT_EQ(test, ret, 0);
>> +
>> +	ret = fake_fpga_region_register(region_ctx, mgr_ctx->mgr, test);
>> +	KUNIT_ASSERT_EQ(test, ret, 0);
>> +
>> +	ret = fake_fpga_region_add_bridge(region_ctx, bridge_ctx->bridge);
>> +	KUNIT_ASSERT_EQ(test, ret, 0);
>> +}
>> +
>> +static void fpga_free_base_sys(struct fake_fpga_mgr *mgr_ctx,
>> +			       struct fake_fpga_bridge *bridge_ctx,
>> +			       struct fake_fpga_region *region_ctx)
>> +{
>> +	if (region_ctx)
>> +		fake_fpga_region_unregister(region_ctx);
>> +
>> +	if (bridge_ctx)
>> +		fake_fpga_bridge_unregister(bridge_ctx);
>> +
>> +	if (region_ctx)
>> +		fake_fpga_mgr_unregister(mgr_ctx);
>> +}
>> +
>> +static int fpga_suite_init(struct kunit_suite *suite)
>> +{
>> +	fake_fpga_mgr_fill_header(fake_bit);
> 
> Do we need to run it before every case? Or just run once for all cases?
>

Just once for all cases. So I'm calling it from the suite_init function.

For the next version, I'm thinking of allocating the image buffer using
kunit_kzalloc() instead of using a global static array.

>> +
>> +	return 0;
>> +}
>> +
>> +static void fpga_base_test(struct kunit *test)
>> +{
>> +	int ret;
>> +
>> +	struct fake_fpga_mgr mgr_ctx;
>> +	struct fake_fpga_bridge base_bridge_ctx;
>> +	struct fake_fpga_region base_region_ctx;
>> +
>> +	struct fpga_image_info *test_img_info;
>> +
>> +	struct sg_table sgt_bit;
>> +
>> +	fpga_build_base_sys(test, &mgr_ctx, &base_bridge_ctx, &base_region_ctx);
>> +
>> +	/* Allocate a fake test image using a buffer */
>> +	test_img_info = fpga_image_info_alloc(&mgr_ctx.pdev->dev);
>> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_img_info);
>> +
>> +	test_img_info->buf = fake_bit;
>> +	test_img_info->count = sizeof(fake_bit);
>> +
>> +	kunit_info(test, "fake bitstream size: %zu\n", test_img_info->count);
>> +
>> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
>> +
>> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_bridge_get_state(&base_bridge_ctx));
>> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
>> +
>> +	/* Program the fake FPGA using the image buffer */
>> +	base_region_ctx.region->info = test_img_info;
>> +	ret = fpga_region_program_fpga(base_region_ctx.region);
>> +	KUNIT_ASSERT_EQ(test, ret, 0);
>> +
>> +	fake_fpga_mgr_check_write_buf(&mgr_ctx);
>> +
>> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
>> +
>> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&base_bridge_ctx));
>> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
>> +
>> +	fpga_image_info_free(test_img_info);
>> +
>> +	/* Allocate another fake test image using a scatter list */
>> +	test_img_info = fpga_image_info_alloc(&mgr_ctx.pdev->dev);
>> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_img_info);
>> +
>> +	ret = init_sgt_bit(&sgt_bit, fake_bit, FAKE_BIT_SIZE);
>> +	KUNIT_ASSERT_EQ(test, ret, 0);
> 
> This is not fpga function, do we need the ASSERT?
>

You're right. I'll change it to EXPECT.
 
>> +
>> +	test_img_info->sgt = &sgt_bit;
>> +
>> +	/* Re-program the fake FPGA using the image scatter list */
>> +	base_region_ctx.region->info = test_img_info;
>> +	ret = fpga_region_program_fpga(base_region_ctx.region);
>> +	KUNIT_ASSERT_EQ(test, ret, 0);
>> +
>> +	fake_fpga_mgr_check_write_sg(&mgr_ctx);
>> +
>> +	KUNIT_EXPECT_EQ(test, 2, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
>> +
>> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&base_bridge_ctx));
>> +	KUNIT_EXPECT_EQ(test, 2, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
>> +
>> +	free_sgt_bit(&sgt_bit);
>> +	fpga_image_info_free(test_img_info);
>> +	fpga_free_base_sys(&mgr_ctx, &base_bridge_ctx, &base_region_ctx);
>> +}
>> +
>> +static void fpga_pr_test(struct kunit *test)
>> +{
>> +	int ret;
>> +
>> +	struct fake_fpga_mgr mgr_ctx;
>> +	struct fake_fpga_bridge base_bridge_ctx;
>> +	struct fake_fpga_region base_region_ctx;
>> +
>> +	struct fake_fpga_bridge pr_bridge_0_ctx;
>> +	struct fake_fpga_bridge pr_bridge_1_ctx;
>> +	struct fake_fpga_region pr_region_ctx;
>> +
>> +	struct fpga_image_info *test_static_img_info;
>> +	struct fpga_image_info *test_pr_img_info;
>> +
>> +	fpga_build_base_sys(test, &mgr_ctx, &base_bridge_ctx, &base_region_ctx);
> 
> If we need the base region/bridge/mgr for each case, could we create
> global ones in .init(), or .suite_init()?
>

Ok, I'll reduce code duplication in the next version. My only concern is that
I would not want to complicate the test code.

In my intentions, this is just an initial set of tests intended to lay the
foundation for other test suites. At this stage, I'm not sure if other tests
will need or use this kind of setup. So I would like to keep the test code
as simple as possible.

>> +
>> +	/* Allocate a fake test image using a buffer */
>> +	test_static_img_info = fpga_image_info_alloc(&mgr_ctx.pdev->dev);
>> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_static_img_info);
>> +
>> +	test_static_img_info->buf = fake_bit;
>> +	test_static_img_info->count = sizeof(fake_bit);
> 
> Same concern, may remove the test image info initialization from each
> test case code.
> 

Same as above, I'll reduce code duplication in the next version.

>> +
>> +	kunit_info(test, "fake bitstream size: %zu\n", test_static_img_info->count);
>> +
>> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
>> +
>> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_bridge_get_state(&base_bridge_ctx));
>> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
>> +
>> +	/* Program the fake FPGA using the image buffer */
>> +	base_region_ctx.region->info = test_static_img_info;
>> +	ret = fpga_region_program_fpga(base_region_ctx.region);
>> +	KUNIT_ASSERT_EQ(test, ret, 0);
>> +
>> +	fake_fpga_mgr_check_write_buf(&mgr_ctx);
>> +
>> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
>> +
>> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&base_bridge_ctx));
>> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
>> +
>> +	/* The static image contains a reconfigurable sub-region with two soft bridges */
> 
> Till now I didn't find any difference with fpga_base_test.
> And I can't figure out how the "static parent region - sub pr region"
> topology is created?
> 

You're right, the topology is missing. I'm preparing a new version where regions
are hierarchically organized according to the FPGA Region DT binding documentation.
I.e., the static region is the parent device of the reconfigurable region.

>> +	ret = fake_fpga_bridge_register(&pr_bridge_0_ctx, test);
>> +	KUNIT_ASSERT_EQ(test, ret, 0);
>> +
>> +	ret = fake_fpga_bridge_register(&pr_bridge_1_ctx, test);
>> +	KUNIT_ASSERT_EQ(test, ret, 0);
>> +
>> +	ret = fake_fpga_region_register(&pr_region_ctx, mgr_ctx.mgr, test);
>> +	KUNIT_ASSERT_EQ(test, ret, 0);
>> +
>> +	ret = fake_fpga_region_add_bridge(&pr_region_ctx, pr_bridge_0_ctx.bridge);
>> +	KUNIT_ASSERT_EQ(test, ret, 0);
>> +
>> +	ret = fake_fpga_region_add_bridge(&pr_region_ctx, pr_bridge_1_ctx.bridge);
>> +	KUNIT_ASSERT_EQ(test, ret, 0);
>> +
>> +	/* Allocate a fake partial test image using a buffer */
>> +	test_pr_img_info = fpga_image_info_alloc(&mgr_ctx.pdev->dev);
>> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_pr_img_info);
>> +
>> +	test_pr_img_info->buf = fake_bit;
>> +	test_pr_img_info->count = sizeof(fake_bit) / 2;
>> +	test_pr_img_info->flags = FPGA_MGR_PARTIAL_RECONFIG;
>> +
>> +	kunit_info(test, "fake partial bitstream size: %zu\n", test_pr_img_info->count);
>> +
>> +	/* Program the reconfigurable sub-region */
>> +	pr_region_ctx.region->info = test_pr_img_info;
>> +	ret = fpga_region_program_fpga(pr_region_ctx.region);
>> +	KUNIT_ASSERT_EQ(test, ret, 0);
>> +
>> +	fake_fpga_mgr_check_write_buf(&mgr_ctx);
>> +
>> +	KUNIT_EXPECT_EQ(test, 2, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
>> +
>> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&pr_bridge_0_ctx));
>> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_cycles_count(&pr_bridge_0_ctx));
>> +
>> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&pr_bridge_1_ctx));
>> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_cycles_count(&pr_bridge_1_ctx));
>> +
>> +	/* Check that the base bridge has not been disabled */
>> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&base_bridge_ctx));
>> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
>> +
>> +	fpga_image_info_free(test_pr_img_info);
>> +	fpga_image_info_free(test_static_img_info);
>> +
>> +	fake_fpga_region_unregister(&pr_region_ctx);
>> +	fake_fpga_bridge_unregister(&pr_bridge_0_ctx);
>> +	fake_fpga_bridge_unregister(&pr_bridge_1_ctx);
>> +
>> +	fpga_free_base_sys(&mgr_ctx, &base_bridge_ctx, &base_region_ctx);
> 
> Same concern, may put them in .exit() or suite_exit()?

Same as above, I'll reduce code duplication.

> 
>> +}
>> +
>> +static struct kunit_case fpga_test_cases[] = {
>> +	KUNIT_CASE(fpga_base_test),
>> +	KUNIT_CASE(fpga_pr_test),
> 
> I feel there are too many tasks for each test case, and some duplicated
> routines.
> 
> Could we have a suite for the common routine test in each case, like
> region/bridge/mgr (un)register, fpga image alloc ... And another suite
> which have these common routines in .init() or .suite_init().
>

Right, I'll reduce code duplication in the next version.

>> +	{},
>> +};
>> +
>> +static struct kunit_suite fpga_test_suite = {
>> +	.name = "fpga-tests",
> 
> I see from style.rst that:
>   
>   "Names should use underscores, not dashes, to separate words"
> 
> and
> 
>   "*Do not* include "test" or "kunit" directly in the subsystem name
>    unless we are actually testing other tests or the kunit framework
>    itself"
> 
> So IIUC I assume the name should be "fpga"?
> 
> BTW: I do see some existing test cases that are not conform to the style,
> even the examples in doc itself.

Thanks for noticing this. I'll change the name in the next version.

> 
> Thanks,
> Yilun
> 
>> +	.suite_init = fpga_suite_init,
>> +	.test_cases = fpga_test_cases,
>> +};
>> +
>> +kunit_test_suite(fpga_test_suite);
>> -- 
>> 2.39.1
>>
> 

Thanks,
Marco
  

On 2023-02-21 at 12:10:48 +0100, Marco Pagani wrote:
> 
> 
> On 2023-02-18 10:59, Xu Yilun wrote:
> > On 2023-02-03 at 18:06:50 +0100, Marco Pagani wrote:
> >> Introduce an initial KUnit suite to test the core components of the
> >> FPGA subsystem.
> > 
> > I'm not familiar with kunit, and I spend some time to read the
> > Documentation/dev-tools/kunit/, sorry for late response.
> 
> Thank you for reviewing.
> 
> > 
> >>
> >> The test suite consists of two test cases. The first test case checks
> >> the programming of a static image on a fake FPGA with a single hardware
> >> bridge. The FPGA is first programmed using a test image stored in a
> >> buffer, and then with the same image linked to a single-entry
> >> scatter-gather list.
> >>
> >> The second test case models dynamic partial reconfiguration. The FPGA
> >> is first configured with a static image that implements a
> >> reconfigurable design containing a sub-region controlled by two soft
> >> bridges. Then, the reconfigurable sub-region is reconfigured using
> >> a fake partial bitstream image. After the reconfiguration, the test
> >> checks that the soft bridges have been correctly activated.
> >>
> >> Signed-off-by: Marco Pagani <marpagan@redhat.com>
> >> ---
> >>  drivers/fpga/Kconfig            |   2 +
> >>  drivers/fpga/Makefile           |   3 +
> >>  drivers/fpga/tests/.kunitconfig |   5 +
> >>  drivers/fpga/tests/Kconfig      |  15 ++
> >>  drivers/fpga/tests/Makefile     |   6 +
> >>  drivers/fpga/tests/fpga-tests.c | 264 ++++++++++++++++++++++++++++++++
> >>  6 files changed, 295 insertions(+)
> >>  create mode 100644 drivers/fpga/tests/.kunitconfig
> >>  create mode 100644 drivers/fpga/tests/Kconfig
> >>  create mode 100644 drivers/fpga/tests/Makefile
> >>  create mode 100644 drivers/fpga/tests/fpga-tests.c
> >>
> >> diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
> >> index 0a00763b9f28..2f689ac4ba3a 100644
> >> --- a/drivers/fpga/Kconfig
> >> +++ b/drivers/fpga/Kconfig
> >> @@ -276,4 +276,6 @@ config FPGA_MGR_LATTICE_SYSCONFIG_SPI
> >>  	  FPGA manager driver support for Lattice FPGAs programming over slave
> >>  	  SPI sysCONFIG interface.
> >>  
> >> +source "drivers/fpga/tests/Kconfig"
> >> +
> >>  endif # FPGA
> >> diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
> >> index 72e554b4d2f7..352a2612623e 100644
> >> --- a/drivers/fpga/Makefile
> >> +++ b/drivers/fpga/Makefile
> >> @@ -55,3 +55,6 @@ obj-$(CONFIG_FPGA_DFL_NIOS_INTEL_PAC_N3000)	+= dfl-n3000-nios.o
> >>  
> >>  # Drivers for FPGAs which implement DFL
> >>  obj-$(CONFIG_FPGA_DFL_PCI)		+= dfl-pci.o
> >> +
> >> +# KUnit tests
> >> +obj-$(CONFIG_FPGA_KUNIT_TESTS)		+= tests/
> >> diff --git a/drivers/fpga/tests/.kunitconfig b/drivers/fpga/tests/.kunitconfig
> >> new file mode 100644
> >> index 000000000000..a1c2a2974c39
> >> --- /dev/null
> >> +++ b/drivers/fpga/tests/.kunitconfig
> >> @@ -0,0 +1,5 @@
> >> +CONFIG_KUNIT=y
> >> +CONFIG_FPGA=y
> >> +CONFIG_FPGA_REGION=y
> >> +CONFIG_FPGA_BRIDGE=y
> >> +CONFIG_FPGA_KUNIT_TESTS=y
> >> diff --git a/drivers/fpga/tests/Kconfig b/drivers/fpga/tests/Kconfig
> >> new file mode 100644
> >> index 000000000000..5198e605b38d
> >> --- /dev/null
> >> +++ b/drivers/fpga/tests/Kconfig
> >> @@ -0,0 +1,15 @@
> >> +config FPGA_KUNIT_TESTS
> >> +	tristate "FPGA KUnit tests" if !KUNIT_ALL_TESTS
> >> +	depends on FPGA && FPGA_REGION && FPGA_BRIDGE && KUNIT
> >> +	default KUNIT_ALL_TESTS
> >> +	help
> >> +	  Builds unit tests for the FPGA subsystem. This option
> >> +	  is not useful for distributions or general kernels,
> >> +	  but only for kernel developers working on the FPGA
> >> +	  subsystem and its associated drivers.
> >> +
> >> +	  For more information on KUnit and unit tests in general,
> >> +	  please refer to the KUnit documentation in
> >> +	  Documentation/dev-tools/kunit/.
> >> +
> >> +	  If in doubt, say "N".
> >> diff --git a/drivers/fpga/tests/Makefile b/drivers/fpga/tests/Makefile
> >> new file mode 100644
> >> index 000000000000..74346ae62457
> >> --- /dev/null
> >> +++ b/drivers/fpga/tests/Makefile
> >> @@ -0,0 +1,6 @@
> >> +# SPDX-License-Identifier: GPL-2.0
> >> +
> >> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fake-fpga-mgr.o
> >> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fake-fpga-region.o
> >> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fake-fpga-bridge.o
> > 
> > It is better the patches for fake components come first, otherwise may
> > break the compilation. Also not friendly for review.
> 
> Sorry. I'll change the order in the next version.
> 
> > 
> >> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fpga-tests.o
> > 
> > Maybe fpga-test.o?
> 
> I'll change the name in the next version.
> 
> > 
> > And could they be built in a single module? I haven't find a reason
> > these fake components been used alone.
> > 
> 
> My feeling is that they could also come in handy to do some general
> development or testing on the subsystem. For instance, I used the fake
> FPGA manager in isolation to experiment with the OF region.

That's fine.

> 
> Initially, the fake manager also had an of_device_id device matching
> struct. However, I later removed it because it was not used for the
> test setup, and I was not sure if adding an OF device matching struct
> was acceptable for a test driver.
> 
> >> diff --git a/drivers/fpga/tests/fpga-tests.c b/drivers/fpga/tests/fpga-tests.c
> >> new file mode 100644
> >> index 000000000000..33f04079b32f
> >> --- /dev/null
> >> +++ b/drivers/fpga/tests/fpga-tests.c
> >> @@ -0,0 +1,264 @@
> >> +// SPDX-License-Identifier: GPL-2.0
> >> +/*
> >> + * Test suite for the FPGA subsystem
> >> + *
> >> + * Copyright (C) 2023 Red Hat, Inc. All rights reserved.
> >> + *
> >> + * Author: Marco Pagani <marpagan@redhat.com>
> >> + */
> >> +
> >> +#include <kunit/test.h>
> >> +#include <linux/platform_device.h>
> >> +#include <linux/scatterlist.h>
> >> +
> >> +#include <linux/fpga/fpga-mgr.h>
> >> +#include <linux/fpga/fpga-region.h>
> >> +#include <linux/fpga/fpga-bridge.h>
> >> +
> >> +#include "fake-fpga-region.h"
> >> +#include "fake-fpga-bridge.h"
> >> +#include "fake-fpga-mgr.h"
> >> +
> >> +#define FAKE_BIT_BLOCKS		16
> >> +#define FAKE_BIT_SIZE		(FPGA_TEST_BIT_BLOCK * FAKE_BIT_BLOCKS)
> >> +
> >> +static u8 fake_bit[FAKE_BIT_SIZE];
> >> +
> >> +static int init_sgt_bit(struct sg_table *sgt, void *bit, size_t len)
> >> +{
> >> +	int ret;
> >> +
> >> +	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
> >> +	if (ret)
> >> +		return ret;
> >> +
> >> +	sg_init_one(sgt->sgl, bit, len);
> >> +
> >> +	return ret;
> >> +}
> >> +
> >> +static void free_sgt_bit(struct sg_table *sgt)
> >> +{
> >> +	if (sgt)
> >> +		sg_free_table(sgt);
> >> +}
> >> +
> >> +static void fpga_build_base_sys(struct kunit *test, struct fake_fpga_mgr *mgr_ctx,
> >> +				struct fake_fpga_bridge *bridge_ctx,
> >> +				struct fake_fpga_region *region_ctx)
> >> +{
> >> +	int ret;
> >> +
> >> +	ret = fake_fpga_mgr_register(mgr_ctx, test);
> >> +	KUNIT_ASSERT_EQ(test, ret, 0);
> >> +
> >> +	ret = fake_fpga_bridge_register(bridge_ctx, test);
> >> +	KUNIT_ASSERT_EQ(test, ret, 0);
> >> +
> >> +	ret = fake_fpga_region_register(region_ctx, mgr_ctx->mgr, test);
> >> +	KUNIT_ASSERT_EQ(test, ret, 0);
> >> +
> >> +	ret = fake_fpga_region_add_bridge(region_ctx, bridge_ctx->bridge);
> >> +	KUNIT_ASSERT_EQ(test, ret, 0);
> >> +}
> >> +
> >> +static void fpga_free_base_sys(struct fake_fpga_mgr *mgr_ctx,
> >> +			       struct fake_fpga_bridge *bridge_ctx,
> >> +			       struct fake_fpga_region *region_ctx)
> >> +{
> >> +	if (region_ctx)
> >> +		fake_fpga_region_unregister(region_ctx);
> >> +
> >> +	if (bridge_ctx)
> >> +		fake_fpga_bridge_unregister(bridge_ctx);
> >> +
> >> +	if (region_ctx)
> >> +		fake_fpga_mgr_unregister(mgr_ctx);
> >> +}
> >> +
> >> +static int fpga_suite_init(struct kunit_suite *suite)
> >> +{
> >> +	fake_fpga_mgr_fill_header(fake_bit);
> > 
> > Do we need to run it before every case? Or just run once for all cases?
> >
> 
> Just once for all cases. So I'm calling it from the suite_init function.
> 
> For the next version, I'm thinking of allocating the image buffer using
> kunit_kzalloc() instead of using a global static array.
> 
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static void fpga_base_test(struct kunit *test)
> >> +{
> >> +	int ret;
> >> +
> >> +	struct fake_fpga_mgr mgr_ctx;
> >> +	struct fake_fpga_bridge base_bridge_ctx;
> >> +	struct fake_fpga_region base_region_ctx;
> >> +
> >> +	struct fpga_image_info *test_img_info;
> >> +
> >> +	struct sg_table sgt_bit;
> >> +
> >> +	fpga_build_base_sys(test, &mgr_ctx, &base_bridge_ctx, &base_region_ctx);
> >> +
> >> +	/* Allocate a fake test image using a buffer */
> >> +	test_img_info = fpga_image_info_alloc(&mgr_ctx.pdev->dev);
> >> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_img_info);
> >> +
> >> +	test_img_info->buf = fake_bit;
> >> +	test_img_info->count = sizeof(fake_bit);
> >> +
> >> +	kunit_info(test, "fake bitstream size: %zu\n", test_img_info->count);
> >> +
> >> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
> >> +
> >> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_bridge_get_state(&base_bridge_ctx));
> >> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
> >> +
> >> +	/* Program the fake FPGA using the image buffer */
> >> +	base_region_ctx.region->info = test_img_info;
> >> +	ret = fpga_region_program_fpga(base_region_ctx.region);
> >> +	KUNIT_ASSERT_EQ(test, ret, 0);
> >> +
> >> +	fake_fpga_mgr_check_write_buf(&mgr_ctx);
> >> +
> >> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
> >> +
> >> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&base_bridge_ctx));
> >> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
> >> +
> >> +	fpga_image_info_free(test_img_info);
> >> +
> >> +	/* Allocate another fake test image using a scatter list */
> >> +	test_img_info = fpga_image_info_alloc(&mgr_ctx.pdev->dev);
> >> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_img_info);
> >> +
> >> +	ret = init_sgt_bit(&sgt_bit, fake_bit, FAKE_BIT_SIZE);
> >> +	KUNIT_ASSERT_EQ(test, ret, 0);
> > 
> > This is not fpga function, do we need the ASSERT?
> >
> 
> You're right. I'll change it to EXPECT.

Mm.. I think we may move the sgt initialization in .suite_init, and just
return ERROR for failure. Does it help to quickly find out this is an
ENV error, not a test case failure?

Thanks,
Yilun
  

On 2023-02-24 07:14, Xu Yilun wrote:
> On 2023-02-21 at 12:10:48 +0100, Marco Pagani wrote:
>>
>>
>> On 2023-02-18 10:59, Xu Yilun wrote:
>>> On 2023-02-03 at 18:06:50 +0100, Marco Pagani wrote:
>>>> Introduce an initial KUnit suite to test the core components of the
>>>> FPGA subsystem.
>>>
>>> I'm not familiar with kunit, and I spend some time to read the
>>> Documentation/dev-tools/kunit/, sorry for late response.
>>
>> Thank you for reviewing.
>>
>>>
>>>>
>>>> The test suite consists of two test cases. The first test case checks
>>>> the programming of a static image on a fake FPGA with a single hardware
>>>> bridge. The FPGA is first programmed using a test image stored in a
>>>> buffer, and then with the same image linked to a single-entry
>>>> scatter-gather list.
>>>>
>>>> The second test case models dynamic partial reconfiguration. The FPGA
>>>> is first configured with a static image that implements a
>>>> reconfigurable design containing a sub-region controlled by two soft
>>>> bridges. Then, the reconfigurable sub-region is reconfigured using
>>>> a fake partial bitstream image. After the reconfiguration, the test
>>>> checks that the soft bridges have been correctly activated.
>>>>
>>>> Signed-off-by: Marco Pagani <marpagan@redhat.com>
>>>> ---
>>>>  drivers/fpga/Kconfig            |   2 +
>>>>  drivers/fpga/Makefile           |   3 +
>>>>  drivers/fpga/tests/.kunitconfig |   5 +
>>>>  drivers/fpga/tests/Kconfig      |  15 ++
>>>>  drivers/fpga/tests/Makefile     |   6 +
>>>>  drivers/fpga/tests/fpga-tests.c | 264 ++++++++++++++++++++++++++++++++
>>>>  6 files changed, 295 insertions(+)
>>>>  create mode 100644 drivers/fpga/tests/.kunitconfig
>>>>  create mode 100644 drivers/fpga/tests/Kconfig
>>>>  create mode 100644 drivers/fpga/tests/Makefile
>>>>  create mode 100644 drivers/fpga/tests/fpga-tests.c
>>>>
>>>> diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
>>>> index 0a00763b9f28..2f689ac4ba3a 100644
>>>> --- a/drivers/fpga/Kconfig
>>>> +++ b/drivers/fpga/Kconfig
>>>> @@ -276,4 +276,6 @@ config FPGA_MGR_LATTICE_SYSCONFIG_SPI
>>>>  	  FPGA manager driver support for Lattice FPGAs programming over slave
>>>>  	  SPI sysCONFIG interface.
>>>>  
>>>> +source "drivers/fpga/tests/Kconfig"
>>>> +
>>>>  endif # FPGA
>>>> diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
>>>> index 72e554b4d2f7..352a2612623e 100644
>>>> --- a/drivers/fpga/Makefile
>>>> +++ b/drivers/fpga/Makefile
>>>> @@ -55,3 +55,6 @@ obj-$(CONFIG_FPGA_DFL_NIOS_INTEL_PAC_N3000)	+= dfl-n3000-nios.o
>>>>  
>>>>  # Drivers for FPGAs which implement DFL
>>>>  obj-$(CONFIG_FPGA_DFL_PCI)		+= dfl-pci.o
>>>> +
>>>> +# KUnit tests
>>>> +obj-$(CONFIG_FPGA_KUNIT_TESTS)		+= tests/
>>>> diff --git a/drivers/fpga/tests/.kunitconfig b/drivers/fpga/tests/.kunitconfig
>>>> new file mode 100644
>>>> index 000000000000..a1c2a2974c39
>>>> --- /dev/null
>>>> +++ b/drivers/fpga/tests/.kunitconfig
>>>> @@ -0,0 +1,5 @@
>>>> +CONFIG_KUNIT=y
>>>> +CONFIG_FPGA=y
>>>> +CONFIG_FPGA_REGION=y
>>>> +CONFIG_FPGA_BRIDGE=y
>>>> +CONFIG_FPGA_KUNIT_TESTS=y
>>>> diff --git a/drivers/fpga/tests/Kconfig b/drivers/fpga/tests/Kconfig
>>>> new file mode 100644
>>>> index 000000000000..5198e605b38d
>>>> --- /dev/null
>>>> +++ b/drivers/fpga/tests/Kconfig
>>>> @@ -0,0 +1,15 @@
>>>> +config FPGA_KUNIT_TESTS
>>>> +	tristate "FPGA KUnit tests" if !KUNIT_ALL_TESTS
>>>> +	depends on FPGA && FPGA_REGION && FPGA_BRIDGE && KUNIT
>>>> +	default KUNIT_ALL_TESTS
>>>> +	help
>>>> +	  Builds unit tests for the FPGA subsystem. This option
>>>> +	  is not useful for distributions or general kernels,
>>>> +	  but only for kernel developers working on the FPGA
>>>> +	  subsystem and its associated drivers.
>>>> +
>>>> +	  For more information on KUnit and unit tests in general,
>>>> +	  please refer to the KUnit documentation in
>>>> +	  Documentation/dev-tools/kunit/.
>>>> +
>>>> +	  If in doubt, say "N".
>>>> diff --git a/drivers/fpga/tests/Makefile b/drivers/fpga/tests/Makefile
>>>> new file mode 100644
>>>> index 000000000000..74346ae62457
>>>> --- /dev/null
>>>> +++ b/drivers/fpga/tests/Makefile
>>>> @@ -0,0 +1,6 @@
>>>> +# SPDX-License-Identifier: GPL-2.0
>>>> +
>>>> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fake-fpga-mgr.o
>>>> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fake-fpga-region.o
>>>> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fake-fpga-bridge.o
>>>
>>> It is better the patches for fake components come first, otherwise may
>>> break the compilation. Also not friendly for review.
>>
>> Sorry. I'll change the order in the next version.
>>
>>>
>>>> +obj-$(CONFIG_FPGA_KUNIT_TESTS) += fpga-tests.o
>>>
>>> Maybe fpga-test.o?
>>
>> I'll change the name in the next version.
>>
>>>
>>> And could they be built in a single module? I haven't find a reason
>>> these fake components been used alone.
>>>
>>
>> My feeling is that they could also come in handy to do some general
>> development or testing on the subsystem. For instance, I used the fake
>> FPGA manager in isolation to experiment with the OF region.
> 
> That's fine.
> 
>>
>> Initially, the fake manager also had an of_device_id device matching
>> struct. However, I later removed it because it was not used for the
>> test setup, and I was not sure if adding an OF device matching struct
>> was acceptable for a test driver.
>>
>>>> diff --git a/drivers/fpga/tests/fpga-tests.c b/drivers/fpga/tests/fpga-tests.c
>>>> new file mode 100644
>>>> index 000000000000..33f04079b32f
>>>> --- /dev/null
>>>> +++ b/drivers/fpga/tests/fpga-tests.c
>>>> @@ -0,0 +1,264 @@
>>>> +// SPDX-License-Identifier: GPL-2.0
>>>> +/*
>>>> + * Test suite for the FPGA subsystem
>>>> + *
>>>> + * Copyright (C) 2023 Red Hat, Inc. All rights reserved.
>>>> + *
>>>> + * Author: Marco Pagani <marpagan@redhat.com>
>>>> + */
>>>> +
>>>> +#include <kunit/test.h>
>>>> +#include <linux/platform_device.h>
>>>> +#include <linux/scatterlist.h>
>>>> +
>>>> +#include <linux/fpga/fpga-mgr.h>
>>>> +#include <linux/fpga/fpga-region.h>
>>>> +#include <linux/fpga/fpga-bridge.h>
>>>> +
>>>> +#include "fake-fpga-region.h"
>>>> +#include "fake-fpga-bridge.h"
>>>> +#include "fake-fpga-mgr.h"
>>>> +
>>>> +#define FAKE_BIT_BLOCKS		16
>>>> +#define FAKE_BIT_SIZE		(FPGA_TEST_BIT_BLOCK * FAKE_BIT_BLOCKS)
>>>> +
>>>> +static u8 fake_bit[FAKE_BIT_SIZE];
>>>> +
>>>> +static int init_sgt_bit(struct sg_table *sgt, void *bit, size_t len)
>>>> +{
>>>> +	int ret;
>>>> +
>>>> +	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
>>>> +	if (ret)
>>>> +		return ret;
>>>> +
>>>> +	sg_init_one(sgt->sgl, bit, len);
>>>> +
>>>> +	return ret;
>>>> +}
>>>> +
>>>> +static void free_sgt_bit(struct sg_table *sgt)
>>>> +{
>>>> +	if (sgt)
>>>> +		sg_free_table(sgt);
>>>> +}
>>>> +
>>>> +static void fpga_build_base_sys(struct kunit *test, struct fake_fpga_mgr *mgr_ctx,
>>>> +				struct fake_fpga_bridge *bridge_ctx,
>>>> +				struct fake_fpga_region *region_ctx)
>>>> +{
>>>> +	int ret;
>>>> +
>>>> +	ret = fake_fpga_mgr_register(mgr_ctx, test);
>>>> +	KUNIT_ASSERT_EQ(test, ret, 0);
>>>> +
>>>> +	ret = fake_fpga_bridge_register(bridge_ctx, test);
>>>> +	KUNIT_ASSERT_EQ(test, ret, 0);
>>>> +
>>>> +	ret = fake_fpga_region_register(region_ctx, mgr_ctx->mgr, test);
>>>> +	KUNIT_ASSERT_EQ(test, ret, 0);
>>>> +
>>>> +	ret = fake_fpga_region_add_bridge(region_ctx, bridge_ctx->bridge);
>>>> +	KUNIT_ASSERT_EQ(test, ret, 0);
>>>> +}
>>>> +
>>>> +static void fpga_free_base_sys(struct fake_fpga_mgr *mgr_ctx,
>>>> +			       struct fake_fpga_bridge *bridge_ctx,
>>>> +			       struct fake_fpga_region *region_ctx)
>>>> +{
>>>> +	if (region_ctx)
>>>> +		fake_fpga_region_unregister(region_ctx);
>>>> +
>>>> +	if (bridge_ctx)
>>>> +		fake_fpga_bridge_unregister(bridge_ctx);
>>>> +
>>>> +	if (region_ctx)
>>>> +		fake_fpga_mgr_unregister(mgr_ctx);
>>>> +}
>>>> +
>>>> +static int fpga_suite_init(struct kunit_suite *suite)
>>>> +{
>>>> +	fake_fpga_mgr_fill_header(fake_bit);
>>>
>>> Do we need to run it before every case? Or just run once for all cases?
>>>
>>
>> Just once for all cases. So I'm calling it from the suite_init function.
>>
>> For the next version, I'm thinking of allocating the image buffer using
>> kunit_kzalloc() instead of using a global static array.
>>
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>> +static void fpga_base_test(struct kunit *test)
>>>> +{
>>>> +	int ret;
>>>> +
>>>> +	struct fake_fpga_mgr mgr_ctx;
>>>> +	struct fake_fpga_bridge base_bridge_ctx;
>>>> +	struct fake_fpga_region base_region_ctx;
>>>> +
>>>> +	struct fpga_image_info *test_img_info;
>>>> +
>>>> +	struct sg_table sgt_bit;
>>>> +
>>>> +	fpga_build_base_sys(test, &mgr_ctx, &base_bridge_ctx, &base_region_ctx);
>>>> +
>>>> +	/* Allocate a fake test image using a buffer */
>>>> +	test_img_info = fpga_image_info_alloc(&mgr_ctx.pdev->dev);
>>>> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_img_info);
>>>> +
>>>> +	test_img_info->buf = fake_bit;
>>>> +	test_img_info->count = sizeof(fake_bit);
>>>> +
>>>> +	kunit_info(test, "fake bitstream size: %zu\n", test_img_info->count);
>>>> +
>>>> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
>>>> +
>>>> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_bridge_get_state(&base_bridge_ctx));
>>>> +	KUNIT_EXPECT_EQ(test, 0, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
>>>> +
>>>> +	/* Program the fake FPGA using the image buffer */
>>>> +	base_region_ctx.region->info = test_img_info;
>>>> +	ret = fpga_region_program_fpga(base_region_ctx.region);
>>>> +	KUNIT_ASSERT_EQ(test, ret, 0);
>>>> +
>>>> +	fake_fpga_mgr_check_write_buf(&mgr_ctx);
>>>> +
>>>> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_mgr_get_rcfg_count(&mgr_ctx));
>>>> +
>>>> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_state(&base_bridge_ctx));
>>>> +	KUNIT_EXPECT_EQ(test, 1, fake_fpga_bridge_get_cycles_count(&base_bridge_ctx));
>>>> +
>>>> +	fpga_image_info_free(test_img_info);
>>>> +
>>>> +	/* Allocate another fake test image using a scatter list */
>>>> +	test_img_info = fpga_image_info_alloc(&mgr_ctx.pdev->dev);
>>>> +	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_img_info);
>>>> +
>>>> +	ret = init_sgt_bit(&sgt_bit, fake_bit, FAKE_BIT_SIZE);
>>>> +	KUNIT_ASSERT_EQ(test, ret, 0);
>>>
>>> This is not fpga function, do we need the ASSERT?
>>>
>>
>> You're right. I'll change it to EXPECT.
> 
> Mm.. I think we may move the sgt initialization in .suite_init, and just
> return ERROR for failure. Does it help to quickly find out this is an
> ENV error, not a test case failure?

I looked through the documentation for guidelines on how to handle
initialization errors, but found only the eeprom example where KUNIT_ASSERT
is used to handle errors in eeprom_buffer_test_init(). Existing test suites
seem to use different approaches to handle initialization errors. Some
return an error code, while others use KUnit assertions.

I'm more inclined to follow the example in the documentation and use
KUnit assertions. Does this approach work for you?


After some thought, I'm restructuring the code to test single components
in isolation before testing them together. In this way, I think the test
suite will be more in line with the unit testing methodology.


Thanks,
Marco
  

> >>>> +	ret = init_sgt_bit(&sgt_bit, fake_bit, FAKE_BIT_SIZE);
> >>>> +	KUNIT_ASSERT_EQ(test, ret, 0);
> >>>
> >>> This is not fpga function, do we need the ASSERT?
> >>>
> >>
> >> You're right. I'll change it to EXPECT.
> > 
> > Mm.. I think we may move the sgt initialization in .suite_init, and just
> > return ERROR for failure. Does it help to quickly find out this is an
> > ENV error, not a test case failure?
> 
> I looked through the documentation for guidelines on how to handle
> initialization errors, but found only the eeprom example where KUNIT_ASSERT
> is used to handle errors in eeprom_buffer_test_init(). Existing test suites
> seem to use different approaches to handle initialization errors. Some
> return an error code, while others use KUnit assertions.
> 
> I'm more inclined to follow the example in the documentation and use
> KUnit assertions. Does this approach work for you?

It's good to me.

> 
> 
> After some thought, I'm restructuring the code to test single components
> in isolation before testing them together. In this way, I think the test
> suite will be more in line with the unit testing methodology.
> 
> 
> Thanks,
> Marco
>