[PATCH 0/4] microblaze: KUnit support

[PATCH 0/4] microblaze: KUnit support

[Thomas Weißschuh]

Add the necessary prerequisites and configuration to run KUnit on
microblaze.

Please note that various KUnit tests will fail with the default
configuration as the memmove() implementation from
arch/microblaze/lib/memmove.c seems to be broken.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
Thomas Weißschuh (4):
      microblaze: uaccess: Zero out destination on failed get_user()
      microblaze: reset: Call POWER_OFF handlers
      microblaze: reset: Provide a power off handler through an unaligned PC
      kunit: qemu_configs: Add microblaze configuration

 arch/microblaze/Kconfig                        |  9 +++++++++
 arch/microblaze/include/asm/uaccess.h          |  3 ++-
 arch/microblaze/kernel/reset.c                 | 22 ++++++++++++++++++++++
 tools/testing/kunit/qemu_configs/microblaze.py | 17 +++++++++++++++++
 4 files changed, 50 insertions(+), 1 deletion(-)
---
base-commit: dc59e4fea9d83f03bad6bddf3fa2e52491777482
change-id: 20260802-kunit-microblaze-7a3f6ac88b4d

Best regards,
--  
Thomas Weißschuh <linux@weissschuh.net>

[PATCH 1/4] microblaze: uaccess: Zero out destination on failed get_user()

[Thomas Weißschuh]

On failure get_user() is supposed to zero out the destination variable.
This is documented in the kdoc of the microblaze get_user()
implementation and validated in lib/tests/usercopy_kunit.c.

Currently that zeroing is missing.

Add it.

Fixes: 0d6de9532663 ("microblaze_mmu_v2: uaccess MMU update")
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 arch/microblaze/include/asm/uaccess.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/microblaze/include/asm/uaccess.h b/arch/microblaze/include/asm/uaccess.h
index afa0dd8d013f..77203af255e5 100644
--- a/arch/microblaze/include/asm/uaccess.h
+++ b/arch/microblaze/include/asm/uaccess.h
@@ -95,7 +95,8 @@ extern long __user_bad(void);
 #define get_user(x, ptr) ({				\
 	const typeof(*(ptr)) __user *__gu_ptr = (ptr);	\
 	access_ok(__gu_ptr, sizeof(*__gu_ptr)) ?	\
-		__get_user(x, __gu_ptr) : -EFAULT;	\
+		__get_user(x, __gu_ptr) :		\
+		((x) = 0, -EFAULT);			\
 })
 
 #define __get_user(x, ptr)						\

-- 
2.55.0

[PATCH 2/4] microblaze: reset: Call POWER_OFF handlers

[Thomas Weißschuh]

System power off might be implemented through sys_off handlers.

Currently these are not respected on microblaze.

On power_off call into the generic power off function which will execute
all regustered handlers.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 arch/microblaze/kernel/reset.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/microblaze/kernel/reset.c b/arch/microblaze/kernel/reset.c
index 2f66c7963084..3612a20ca16d 100644
--- a/arch/microblaze/kernel/reset.c
+++ b/arch/microblaze/kernel/reset.c
@@ -27,6 +27,7 @@ void machine_halt(void)
 
 void machine_power_off(void)
 {
+	do_kernel_power_off();
 	pr_notice("Machine power off...\n");
 	while (1)
 		;

-- 
2.55.0

[PATCH 3/4] microblaze: reset: Provide a power off handler through an unaligned PC

[Thomas Weißschuh]

microblaze is missing a generic architecture-wide power off mechanism.

To enable KUnit for microblaze it is necessary for KUnit to shut down
the machine in a way that QEMU will recognize. The machines emulated by
QEMU do not provide machine-specific power off functionality which could
be used.
However at least the petalogix-s3adsp1800 machine will abort if an
unaligned instruction is executed. An ugly message will be printed but
that is not an issue for KUnit.

Make use of this to provide a power off handler.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

---
This is quite hacky. But I didn't find a better solution.
---
 arch/microblaze/Kconfig        |  9 +++++++++
 arch/microblaze/kernel/reset.c | 21 +++++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 484ebb3baedf..0ca8999dd770 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -216,3 +216,12 @@ config MB_MANAGER
 	  Say N here unless you know what you are doing.
 
 endmenu
+
+config MB_POWER_OFF_THROUGH_UNALIGNED_PC
+	bool "Power off through unaligned PC"
+	help
+	  This options adds a power off handler which executes an unaligned PC
+	  so the machine resets in a generic way. This works for the
+	  petalogix-s3adsp1800 QEMU machine.
+
+	  Say N here unless you know what you are doing.
diff --git a/arch/microblaze/kernel/reset.c b/arch/microblaze/kernel/reset.c
index 3612a20ca16d..4af660deed3b 100644
--- a/arch/microblaze/kernel/reset.c
+++ b/arch/microblaze/kernel/reset.c
@@ -41,3 +41,24 @@ void machine_restart(char *cmd)
 	pr_emerg("Reboot failed -- System halted\n");
 	while (1);
 }
+
+#ifdef CONFIG_MB_POWER_OFF_THROUGH_UNALIGNED_PC
+static int unaligned_pc_sys_off(struct sys_off_data *data)
+{
+	__asm__(
+		"bri 1\n"
+	);
+
+	return NOTIFY_DONE;
+}
+
+static int __init register_unaligned_pc_sys_off(void)
+{
+	struct sys_off_handler *sys_off;
+
+	sys_off = register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, SYS_OFF_PRIO_LOW,
+					   unaligned_pc_sys_off, NULL);
+	return PTR_ERR_OR_ZERO(sys_off);
+}
+device_initcall(register_unaligned_pc_sys_off);
+#endif /* CONFIG_MB_POWER_OFF_THROUGH_UNALIGNED_PC */

-- 
2.55.0

[PATCH 4/4] kunit: qemu_configs: Add microblaze configuration

[Thomas Weißschuh]

Add a basic configuration to run kunit tests on microblaze.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/testing/kunit/qemu_configs/microblaze.py | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/tools/testing/kunit/qemu_configs/microblaze.py b/tools/testing/kunit/qemu_configs/microblaze.py
new file mode 100644
index 000000000000..ff012095e77d
--- /dev/null
+++ b/tools/testing/kunit/qemu_configs/microblaze.py
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0-only
+from ..qemu_config import QemuArchParams
+
+QEMU_ARCH = QemuArchParams(linux_arch='microblaze',
+						   kconfig='''
+CONFIG_CPU_BIG_ENDIAN=y
+CONFIG_SERIAL_UARTLITE=y
+CONFIG_SERIAL_UARTLITE_CONSOLE=y
+CONFIG_MB_POWER_OFF_THROUGH_UNALIGNED_PC=y
+''',
+						   qemu_arch='microblaze',
+						   kernel_path='arch/microblaze/boot/linux.bin',
+						   kernel_command_line='kunit_shutdown=poweroff',
+						   extra_qemu_params=[
+							'-M', 'petalogix-s3adsp1800',
+						   ],
+)

-- 
2.55.0

Re: [PATCH 1/4] microblaze: uaccess: Zero out destination on failed get_user()

[David Gow]

Le 04/08/2026 à 13:32, Thomas Weißschuh a écrit :
> On failure get_user() is supposed to zero out the destination variable.
> This is documented in the kdoc of the microblaze get_user()
> implementation and validated in lib/tests/usercopy_kunit.c.
> 
> Currently that zeroing is missing.
> 
> Add it.
> 
> Fixes: 0d6de9532663 ("microblaze_mmu_v2: uaccess MMU update")
> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
> ---

This test seems to be the gift which keeps on giving. Every architecture 
seems to have had a buggy get_user() at some point.

Reviewed-by: David Gow <david@davidgow.net>

Cheers,
-- David

>   arch/microblaze/include/asm/uaccess.h | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/microblaze/include/asm/uaccess.h b/arch/microblaze/include/asm/uaccess.h
> index afa0dd8d013f..77203af255e5 100644
> --- a/arch/microblaze/include/asm/uaccess.h
> +++ b/arch/microblaze/include/asm/uaccess.h
> @@ -95,7 +95,8 @@ extern long __user_bad(void);
>   #define get_user(x, ptr) ({				\
>   	const typeof(*(ptr)) __user *__gu_ptr = (ptr);	\
>   	access_ok(__gu_ptr, sizeof(*__gu_ptr)) ?	\
> -		__get_user(x, __gu_ptr) : -EFAULT;	\
> +		__get_user(x, __gu_ptr) :		\
> +		((x) = 0, -EFAULT);			\
>   })
>   
>   #define __get_user(x, ptr)						\
> 

Re: [PATCH 2/4] microblaze: reset: Call POWER_OFF handlers

[David Gow]

Le 04/08/2026 à 13:32, Thomas Weißschuh a écrit :
> System power off might be implemented through sys_off handlers.
> 
> Currently these are not respected on microblaze.
> 
> On power_off call into the generic power off function which will execute
> all regustered handlers.
> 
> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
> ---

Seems sensible enough.

Acked-by: David Gow <david@davidgow.net>

Cheers,
-- David

>   arch/microblaze/kernel/reset.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/arch/microblaze/kernel/reset.c b/arch/microblaze/kernel/reset.c
> index 2f66c7963084..3612a20ca16d 100644
> --- a/arch/microblaze/kernel/reset.c
> +++ b/arch/microblaze/kernel/reset.c
> @@ -27,6 +27,7 @@ void machine_halt(void)
>   
>   void machine_power_off(void)
>   {
> +	do_kernel_power_off();
>   	pr_notice("Machine power off...\n");
>   	while (1)
>   		;
> 

Re: [PATCH 3/4] microblaze: reset: Provide a power off handler through an unaligned PC

[David Gow]

Le 04/08/2026 à 13:32, Thomas Weißschuh a écrit :
> microblaze is missing a generic architecture-wide power off mechanism.
> 
> To enable KUnit for microblaze it is necessary for KUnit to shut down
> the machine in a way that QEMU will recognize. The machines emulated by
> QEMU do not provide machine-specific power off functionality which could
> be used.
> However at least the petalogix-s3adsp1800 machine will abort if an
> unaligned instruction is executed. An ugly message will be printed but
> that is not an issue for KUnit.
> 
> Make use of this to provide a power off handler.
> 
> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
> 
> ---
> This is quite hacky. But I didn't find a better solution.

This is hacky. It does work fine here, though, and I also don't have a 
better solution. But I'd feel better about it if a Microblaze person has 
seen it and at least not complained too loudly.

Tested-by: David Gow <david@davidgow.net>

> ---
>   arch/microblaze/Kconfig        |  9 +++++++++
>   arch/microblaze/kernel/reset.c | 21 +++++++++++++++++++++
>   2 files changed, 30 insertions(+)
> 
> diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
> index 484ebb3baedf..0ca8999dd770 100644
> --- a/arch/microblaze/Kconfig
> +++ b/arch/microblaze/Kconfig
> @@ -216,3 +216,12 @@ config MB_MANAGER
>   	  Say N here unless you know what you are doing.
>   
>   endmenu
> +
> +config MB_POWER_OFF_THROUGH_UNALIGNED_PC
> +	bool "Power off through unaligned PC"
> +	help
> +	  This options adds a power off handler which executes an unaligned PC
> +	  so the machine resets in a generic way. This works for the
> +	  petalogix-s3adsp1800 QEMU machine.
> +
> +	  Say N here unless you know what you are doing.
> diff --git a/arch/microblaze/kernel/reset.c b/arch/microblaze/kernel/reset.c
> index 3612a20ca16d..4af660deed3b 100644
> --- a/arch/microblaze/kernel/reset.c
> +++ b/arch/microblaze/kernel/reset.c
> @@ -41,3 +41,24 @@ void machine_restart(char *cmd)
>   	pr_emerg("Reboot failed -- System halted\n");
>   	while (1);
>   }
> +
> +#ifdef CONFIG_MB_POWER_OFF_THROUGH_UNALIGNED_PC
> +static int unaligned_pc_sys_off(struct sys_off_data *data)
> +{
> +	__asm__(
> +		"bri 1\n"
> +	);
> +
> +	return NOTIFY_DONE;
> +}
> +
> +static int __init register_unaligned_pc_sys_off(void)
> +{
> +	struct sys_off_handler *sys_off;
> +
> +	sys_off = register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, SYS_OFF_PRIO_LOW,
> +					   unaligned_pc_sys_off, NULL);
> +	return PTR_ERR_OR_ZERO(sys_off);
> +}
> +device_initcall(register_unaligned_pc_sys_off);
> +#endif /* CONFIG_MB_POWER_OFF_THROUGH_UNALIGNED_PC */
> 

Re: [PATCH 4/4] kunit: qemu_configs: Add microblaze configuration

[David Gow]

Le 04/08/2026 à 13:32, Thomas Weißschuh a écrit :
> Add a basic configuration to run kunit tests on microblaze.
> 
> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
> ---

Works well here, though there are still a couple of test failures (and a 
longer timeout is needed to get through them all on my machine):

 > Testing complete. Ran 965 tests: passed: 866, failed: 3, skipped: 96
 > Failures: blake2s.test_hash_alignment_consistency, 
memcpy.memmove_overlap_test, printf.dentry


I'm okay with this going in via either the microblaze or KUnit trees. 
Any preferences?

Reviewed-by: David Gow <david@davidgow.net>

Cheers,
-- David

>   tools/testing/kunit/qemu_configs/microblaze.py | 17 +++++++++++++++++
>   1 file changed, 17 insertions(+)
> 
> diff --git a/tools/testing/kunit/qemu_configs/microblaze.py b/tools/testing/kunit/qemu_configs/microblaze.py
> new file mode 100644
> index 000000000000..ff012095e77d
> --- /dev/null
> +++ b/tools/testing/kunit/qemu_configs/microblaze.py
> @@ -0,0 +1,17 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +from ..qemu_config import QemuArchParams
> +
> +QEMU_ARCH = QemuArchParams(linux_arch='microblaze',
> +						   kconfig='''
> +CONFIG_CPU_BIG_ENDIAN=y
> +CONFIG_SERIAL_UARTLITE=y
> +CONFIG_SERIAL_UARTLITE_CONSOLE=y
> +CONFIG_MB_POWER_OFF_THROUGH_UNALIGNED_PC=y
> +''',
> +						   qemu_arch='microblaze',
> +						   kernel_path='arch/microblaze/boot/linux.bin',
> +						   kernel_command_line='kunit_shutdown=poweroff',
> +						   extra_qemu_params=[
> +							'-M', 'petalogix-s3adsp1800',
> +						   ],
> +)
> 

Re: [PATCH 4/4] kunit: qemu_configs: Add microblaze configuration

[Thomas Weißschuh]

On 2026-08-05 21:59:16+0800, David Gow wrote:
> Le 04/08/2026 à 13:32, Thomas Weißschuh a écrit :
> > Add a basic configuration to run kunit tests on microblaze.
> > 
> > Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
> > ---
> 
> Works well here, though there are still a couple of test failures (and a
> longer timeout is needed to get through them all on my machine):
> 
> > Testing complete. Ran 965 tests: passed: 866, failed: 3, skipped: 96
> > Failures: blake2s.test_hash_alignment_consistency,
> memcpy.memmove_overlap_test, printf.dentry

These are all due to the broken memmove() implementation.

It should be fixed by *either*:
- Disabling CONFIG_OPT_LIB_FUNCTION
- Enabling CONFIG_OPT_LIB_ASM

> I'm okay with this going in via either the microblaze or KUnit trees. Any
> preferences?

None from me. I would have expected it to go through microblaze, though.

> Reviewed-by: David Gow <david@davidgow.net>

Thanks!

(...)