Re: [PATCH v4 14/18] ARM64 / ACPI: Add GICv2 specific ACPI boot support

Catalin Marinas
2014-09-15T16:43:12Z

On Mon, Sep 15, 2014 at 05:16:21PM +0100, Jon Masters wrote:
> On 09/15/2014 11:01 AM, Catalin Marinas wrote:
> > On Fri, Sep 12, 2014 at 03:00:12PM +0100, Hanjun Guo wrote:
> >> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
> >> index 5b3546b..9869377 100644
> >> --- a/arch/arm64/kernel/acpi.c
> >> +++ b/arch/arm64/kernel/acpi.c
> >> @@ -23,6 +23,7 @@
> >> #include <linux/irqdomain.h>
> >> #include <linux/bootmem.h>
> >> #include <linux/smp.h>
> >> +#include <linux/irqchip/arm-gic-acpi.h>
> >>
> >> #include <asm/cputype.h>
> >> #include <asm/cpu_ops.h>
> >> @@ -312,6 +313,28 @@ void __init acpi_boot_table_init(void)
> >> pr_err("Can't find FADT or error happened during parsing FADT\n");
> >> }
> >>
> >> +void __init acpi_gic_init(void)
> >> +{
> >> + struct acpi_table_header *table;
> >> + acpi_status status;
> >> + acpi_size tbl_size;
> >> + int err;
> >> +
> >> + status = acpi_get_table_with_size(ACPI_SIG_MADT, 0, &table, &tbl_size);
> >> + if (ACPI_FAILURE(status)) {
> >> + const char *msg = acpi_format_exception(status);
> >> +
> >> + pr_err("Failed to get MADT table, %s\n", msg);
> >> + return;
> >> + }
> >> +
> >> + err = gic_v2_acpi_init(table);
> >> + if (err)
> >> + pr_err("Failed to initialize GIC IRQ controller");
> >> +
> >> + early_acpi_os_unmap_memory((char *)table, tbl_size);
> >> +}
> >
> > Maybe this was discussed already but why does this function need to live
> > under arch/arm64? Isn't the driver code more appropriate?
>
> Well there's two halves to this, right? There's the MADT parsing/setup,
> which is architecture specific, and then there's the GIC irqchip
> initialization which lives under drivers.

I think it gets worse, this function is called from irqchip_init(). I
would have been slightly happier if it was called from the arm64
init_IRQ(). But putting an ARM specific GIC initialisation call in a
generic irqchip_init() just looks weird. Can we do anything better here?

>
> Jon.
>
>

--
Catalin