Re: [PATCH] x86/apic: Fix use of X{,2}APIC_ENABLE in asm with older binutils

From: "Russell King (Oracle)" <linux@armlinux.org.uk>
To: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: tglx@linutronix.de, James.Bottomley@hansenpartnership.com,
	arjan@linux.intel.com, arnd@arndb.de, boris.ostrovsky@oracle.com,
	brgerst@gmail.com, catalin.marinas@arm.com, deller@gmx.de,
	dwmw2@infradead.org, gpiccoli@igalia.com, guoren@kernel.org,
	jgross@suse.com, linux-arm-kernel@lists.infradead.org,
	linux-csky@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org,
	linux-riscv@lists.infradead.org, lucjan.lucjanov@gmail.com,
	mark.rutland@arm.com, mikelley@microsoft.com,
	oleksandr@natalenko.name, palmer@dabbelt.com,
	paul.walmsley@sifive.com, paulmck@kernel.org,
	pbonzini@redhat.com, pmenzel@molgen.mpg.de,
	ross.philipson@oracle.com, sabrapan@amazon.com,
	seanjc@google.com, thomas.lendacky@amd.com,
	tsbogend@alpha.franken.de, usama.arif@bytedance.com,
	will@kernel.org, x86@kernel.org, xen-devel@lists.xenproject.org,
	Jeffrey Hugo <quic_jhugo@quicinc.com>
Subject: Re: [PATCH] x86/apic: Fix use of X{,2}APIC_ENABLE in asm with older binutils
Date: Mon, 22 May 2023 12:17:04 +0100	[thread overview]
Message-ID: <ZGtPMHJM/TfklT+2@shell.armlinux.org.uk> (raw)
In-Reply-To: <20230522105738.2378364-1-andrew.cooper3@citrix.com>

Hi,

Please can you tell me what the relevance of this patch is to me, and
thus why I'm included in the Cc list? I have never touched this file,
not in its current path nor a previous path according to git.

Thanks.

On Mon, May 22, 2023 at 11:57:38AM +0100, Andrew Cooper wrote:
> "x86/smpboot: Support parallel startup of secondary CPUs" adds the first use
> of X2APIC_ENABLE in assembly, but older binutils don't tolerate the UL suffix.
> 
> Switch to using BIT() instead.
> 
> Fixes: 7e75178a0950 ("x86/smpboot: Support parallel startup of secondary CPUs")
> Reported-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
> Tested-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
> ---
>  arch/x86/include/asm/apicdef.h | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/include/asm/apicdef.h b/arch/x86/include/asm/apicdef.h
> index bf546dfb6e58..4b125e5b3187 100644
> --- a/arch/x86/include/asm/apicdef.h
> +++ b/arch/x86/include/asm/apicdef.h
> @@ -2,6 +2,8 @@
>  #ifndef _ASM_X86_APICDEF_H
>  #define _ASM_X86_APICDEF_H
>  
> +#include <linux/bits.h>
> +
>  /*
>   * Constants for various Intel APICs. (local APIC, IOAPIC, etc.)
>   *
> @@ -140,8 +142,8 @@
>  #define APIC_BASE (fix_to_virt(FIX_APIC_BASE))
>  #define APIC_BASE_MSR		0x800
>  #define APIC_X2APIC_ID_MSR	0x802
> -#define XAPIC_ENABLE	(1UL << 11)
> -#define X2APIC_ENABLE	(1UL << 10)
> +#define XAPIC_ENABLE		BIT(11)
> +#define X2APIC_ENABLE		BIT(10)
>  
>  #ifdef CONFIG_X86_32
>  # define MAX_IO_APICS 64
> 
> base-commit: 0c7ffa32dbd6b09a87fea4ad1de8b27145dfd9a6
> -- 
> 2.30.2
> 
> 

-- 
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