[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <Y34j0BgRTVS6KG4i@smile.fi.intel.com>
Date: Wed, 23 Nov 2022 15:44:48 +0200
From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To: Rahul Tanwar <rtanwar@...linear.com>
Cc: linux-kernel@...r.kernel.org, devicetree@...r.kernel.org,
Thomas Gleixner <tglx@...utronix.de>,
Marc Zyngier <maz@...nel.org>,
Rob Herring <robh+dt@...nel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
"H. Peter Anvin" <hpa@...or.com>, linux-lgm-soc@...linear.com
Subject: Re: [PATCH v4 4/4] x86/of: Add support for boot time interrupt
delivery mode configuration
On Wed, Nov 23, 2022 at 06:08:50PM +0800, Rahul Tanwar wrote:
> Presently, init/boot time interrupt delivery mode is enumerated
> only for ACPI enabled systems by parsing MADT table or for older
> systems by parsing MP table. But for OF based x86 systems, it is
> assumed & hardcoded to legacy PIC mode. This causes boot time crash
> for platforms which do not use 8259 compliant legacy PIC.
>
> Add support for configuration of init time interrupt delivery mode
> for x86 OF based systems by introducing a new optional boolean
> property 'intel,virtual-wire-mode' for interrupt-controller node
> of local APIC. This property emulates IMCRP Bit 7 of MP feature
> info byte 2 of MP floating pointer structure.
>
> Defaults to legacy PIC mode if absent. Configures it to virtual
> wire compatibility mode if present.
>From code perspective looks good to me, but you need to have a blessing by DT
people for first two patches.
With whatever property name agreed on,
Reviewed-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
> Signed-off-by: Rahul Tanwar <rtanwar@...linear.com>
> ---
> arch/x86/kernel/devicetree.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
> index fcc6f1b7818f..458e43490414 100644
> --- a/arch/x86/kernel/devicetree.c
> +++ b/arch/x86/kernel/devicetree.c
> @@ -167,7 +167,14 @@ static void __init dtb_lapic_setup(void)
> return;
> }
> smp_found_config = 1;
> - pic_mode = 1;
> + if (of_property_read_bool(dn, "intel,virtual-wire-mode")) {
> + pr_info("Virtual Wire compatibility mode.\n");
> + pic_mode = 0;
> + } else {
> + pr_info("IMCR and PIC compatibility mode.\n");
> + pic_mode = 1;
> + }
> +
> register_lapic_address(lapic_addr);
> }
>
> --
> 2.17.1
>
--
With Best Regards,
Andy Shevchenko
Powered by blists - more mailing lists