[PATCH] irqchip: Make irqchip_init() usable on pure ACPI systems

[PATCH] irqchip: Make irqchip_init() usable on pure ACPI systems

[Huacai Chen]

Pure ACPI system (e.g., LoongArch) doesn't select OF and OF_IRQ, but it
still need irqchip_init(). So, change IRQCHIP dependency from OF_IRQ to
(OF_IRQ || ACPI_GENERIC_GSI), and guard of_irq_init() with CONFIG_OF_IRQ
in order to make irqchip_init() be usable on pure ACPI systems.

Without this patch we get such errors:

[    0.000000] NR_IRQS: 576, nr_irqs: 576, preallocated irqs: 16
[    0.000000] Kernel panic - not syncing: IPI IRQ mapping failed
[    0.000000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.0.0-rc6+ #2189
[    0.000000] Hardware name: Loongson Loongson-3A5000-7A1000-1w-CRB/Loongson-LS3A5000-7A1000-1w-CRB, BIOS vUDK2018-LoongArch-V2.0.pre-beta8 08/18/2022
[    0.000000] Stack : 0000000000000000 9000000000fa4388 900000000140c000 900000000140fb70
[    0.000000]         0000000000000000 900000000140fb70 90000000012f4aa0 900000000140fa98
[    0.000000]         900000000140fa0c 900000008140f9ff 0000000000000030 0000000000000005
[    0.000000]         900000000578f708 0000000004750000 0000000000000000 00000000ffffdfff
[    0.000000]         0000000000000000 0000000000000000 0000000000000030 000000000000002f
[    0.000000]         900000000141f000 0000000004750000 9000000001427348 00000000000000b0
[    0.000000]         90000000012f4aa0 0000000000000004 0000000000000000 9000000001020000
[    0.000000]         9000000005781b80 9000000005781ba9 0000000000000000 9000000001315e30
[    0.000000]         900000000129a3b0 9000000000222b64 0000000000000000 00000000000000b0
[    0.000000]         0000000000000004 0000000000000000 0000000000070000 0000000000000800
[    0.000000]         ...
[    0.000000] Call Trace:
[    0.000000] [<9000000000222b64>] show_stack+0x24/0x124
[    0.000000] [<9000000000fa4388>] dump_stack_lvl+0x60/0x88
[    0.000000] [<9000000000f9965c>] panic+0x130/0x2f8
[    0.000000] [<9000000000fd4324>] init_IRQ+0xa8/0x240
[    0.000000] [<9000000000fd0b38>] start_kernel+0x488/0x5f0
[    0.000000] [<9000000000fb10c4>] kernel_entry+0xc4/0xc8
[    0.000000] 
[    0.000000] ---[ end Kernel panic - not syncing: IPI IRQ mapping failed ]---

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
---
 drivers/irqchip/Kconfig   | 2 +-
 drivers/irqchip/irqchip.c | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 66b9fa408bf2..93ad04d58f17 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -3,7 +3,7 @@ menu "IRQ chip support"
 
 config IRQCHIP
 	def_bool y
-	depends on OF_IRQ
+	depends on (OF_IRQ || ACPI_GENERIC_GSI)
 
 config ARM_GIC
 	bool
diff --git a/drivers/irqchip/irqchip.c b/drivers/irqchip/irqchip.c
index 3570f0a588c4..0014b32964e0 100644
--- a/drivers/irqchip/irqchip.c
+++ b/drivers/irqchip/irqchip.c
@@ -28,7 +28,9 @@ extern struct of_device_id __irqchip_of_table[];
 
 void __init irqchip_init(void)
 {
+#ifdef CONFIG_OF_IRQ
 	of_irq_init(__irqchip_of_table);
+#endif
 	acpi_probe_device_table(irqchip);
 }
 
-- 
2.31.1

Re: [PATCH] irqchip: Make irqchip_init() usable on pure ACPI systems

[Arnd Bergmann]

On Tue, Sep 27, 2022, at 6:55 AM, Huacai Chen wrote:

> @@ -28,7 +28,9 @@ extern struct of_device_id __irqchip_of_table[];
> 
>  void __init irqchip_init(void)
>  {
> +#ifdef CONFIG_OF_IRQ
>  	of_irq_init(__irqchip_of_table);
> +#endif
>  	acpi_probe_device_table(irqchip);
>  }

I think that #ifdef should be in the include/linux/of_irq.h
header, with an empty inline function in the #else path.

   Arnd

Re: [PATCH] irqchip: Make irqchip_init() usable on pure ACPI systems

[Marc Zyngier]

On Tue, 27 Sep 2022 03:51:04 -0400,
"Arnd Bergmann" <arnd@arndb.de> wrote:
> 
> On Tue, Sep 27, 2022, at 6:55 AM, Huacai Chen wrote:
> 
> > @@ -28,7 +28,9 @@ extern struct of_device_id __irqchip_of_table[];
> > 
> >  void __init irqchip_init(void)
> >  {
> > +#ifdef CONFIG_OF_IRQ
> >  	of_irq_init(__irqchip_of_table);
> > +#endif
> >  	acpi_probe_device_table(irqchip);
> >  }
> 
> I think that #ifdef should be in the include/linux/of_irq.h
> header, with an empty inline function in the #else path.

Agreed. Please keep the C code free of #ifdefs if at all possible.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.

Re: [PATCH] irqchip: Make irqchip_init() usable on pure ACPI systems

[Huacai Chen]

On Tue, Sep 27, 2022 at 7:37 PM Marc Zyngier <maz@kernel.org> wrote:
>
> On Tue, 27 Sep 2022 03:51:04 -0400,
> "Arnd Bergmann" <arnd@arndb.de> wrote:
> >
> > On Tue, Sep 27, 2022, at 6:55 AM, Huacai Chen wrote:
> >
> > > @@ -28,7 +28,9 @@ extern struct of_device_id __irqchip_of_table[];
> > >
> > >  void __init irqchip_init(void)
> > >  {
> > > +#ifdef CONFIG_OF_IRQ
> > >     of_irq_init(__irqchip_of_table);
> > > +#endif
> > >     acpi_probe_device_table(irqchip);
> > >  }
> >
> > I think that #ifdef should be in the include/linux/of_irq.h
> > header, with an empty inline function in the #else path.
>
> Agreed. Please keep the C code free of #ifdefs if at all possible.
OK, I will send V2 for that.

Huacai
>
> Thanks,
>
>         M.
>
> --
> Without deviation from the norm, progress is not possible.
>