Re: [PATCH -next] arm64: Export __cpu_logical_map

From: Catalin Marinas <catalin.marinas@arm.com>
To: Mark Rutland <mark.rutland@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>,
	Kefeng Wang <wangkefeng.wang@huawei.com>,
	Will Deacon <will@kernel.org>,
	Mikko Perttunen <mperttunen@nvidia.com>,
	Sumit Gupta <sumitg@nvidia.com>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	Hulk Robot <hulkci@huawei.com>,
	"linux-kernel@vger.kernel.org List"
	<linux-kernel@vger.kernel.org>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH -next] arm64: Export __cpu_logical_map
Date: Fri, 24 Jul 2020 10:35:28 +0100	[thread overview]
Message-ID: <20200724093528.GB23388@gaia> (raw)
In-Reply-To: <20200724091308.GA44746@C02TD0UTHF1T.local>

On Fri, Jul 24, 2020 at 10:13:52AM +0100, Mark Rutland wrote:
> On Fri, Jul 24, 2020 at 01:46:18PM +0530, Anshuman Khandual wrote:
> > On 07/24/2020 08:38 AM, Kefeng Wang wrote:
> > >> Reported-by: Hulk Robot <hulkci@huawei.com>
> > >> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> > >> ---
> > >>   arch/arm64/kernel/setup.c | 1 +
> > >>   1 file changed, 1 insertion(+)
> > >>
> > >> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
> > >> index c793276ec7ad9..3aea05fbb9998 100644
> > >> --- a/arch/arm64/kernel/setup.c
> > >> +++ b/arch/arm64/kernel/setup.c
> > >> @@ -275,6 +275,7 @@ static int __init reserve_memblock_reserved_regions(void)
> > >>   arch_initcall(reserve_memblock_reserved_regions);
> > >>     u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };
> > >> +EXPORT_SYMBOL(__cpu_logical_map);
> 
> If modules are using cpu_logical_map(), this looks sane ot me, but I
> wonder if we should instead turn cpu_logical_map() into a C wrapper in
> smp.c, or at least mark __cpu_logical_map as __ro_after_init lest
> someone have the bright idea to fiddle with it.

I'd go for a C wrapper and also change a couple of instances where we
assign a value directly to cpu_logical_map(cpu).

-- 
Catalin