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Subject: Re: [PATCH] [RFC] arm64: export this_cpu_has_cap
To:     Arnd Bergmann <arnd@kernel.org>
Cc:     Arnd Bergmann <arnd@kernel.org>, Will Deacon <will@kernel.org>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Anshuman Khandual <anshuman.khandual@arm.com>,
        Arnd Bergmann <arnd@arndb.de>, Marc Zyngier <maz@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        David Brazdil <dbrazdil@google.com>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Catalin Marinas <catalin.marinas@arm.com>
References: <20211029113023.760421-1-arnd@kernel.org>
 <9d4e09b4-47dc-ed3c-2b6d-e0d1a081e592@arm.com> <YXw4H2BNx85KnLDh@arm.com>
From:   Suzuki K Poulose <suzuki.poulose@arm.com>
Message-ID: <e8fa9099-ec4c-d6c5-ce40-1b98ed11005c@arm.com>
Date:   Tue, 2 Nov 2021 23:16:30 +0000
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Arnd


On 29/10/2021 19:06, Catalin Marinas wrote:
> On Fri, Oct 29, 2021 at 02:31:23PM +0100, Suzuki K Poulose wrote:
>> On 29/10/2021 12:30, Arnd Bergmann wrote:
>>> From: Arnd Bergmann <arnd@arndb.de>
>>>
>>> It's now used in a coresight driver that can be a loadable module:
>>>
>>> ERROR: modpost: "this_cpu_has_cap" [drivers/hwtracing/coresight/coresight-trbe.ko] undefined!
>>>
>>> Fixes: 8a1065127d95 ("coresight: trbe: Add infrastructure for Errata handling")
>>
>> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
>> Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
>>
>> Will, Catalin, Mathieu,
>>
>> Do you have a preference on how this fix can be pulled in ? This may
>> be safe to go via coresight tree if it is not too late. Otherwise,
>> it could go via the arm64 tree.
> 
> I think Will already closed/tagged the arm64 tree for the upcoming
> merging window, though he could take it as a fix afterwards.
> 
> If it doesn't conflict with the arm64 for-next/core, it's fine by me to
> go through the coresight tree.
> 
>>> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
>>> ---
>>> Not sure if we actually want this to be exported, this is my local
>>> workaround for the randconfig build bot.
>>> ---
>>>    arch/arm64/kernel/cpufeature.c | 1 +
>>>    1 file changed, 1 insertion(+)
>>>
>>> diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
>>> index ecbdff795f5e..beccbcfa7391 100644
>>> --- a/arch/arm64/kernel/cpufeature.c
>>> +++ b/arch/arm64/kernel/cpufeature.c
>>> @@ -2864,6 +2864,7 @@ bool this_cpu_has_cap(unsigned int n)
>>>    	return false;
>>>    }
>>> +EXPORT_SYMBOL(this_cpu_has_cap);
> 
> EXPORT_SYMBOL_GPL? I think this_cpu_has_cap() is a bit more more
> specialised than cpus_have_const_cap().
> 
> With that:
> 
> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
> 

Do you plan to send an updated patch with above ?

Suzuki