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 <[email protected]>
---
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 <[email protected]>
---
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 */
