Re: [v3 PATCH 2/8] RISC-V: Move cpuid to hartid mapping to SMP.

From: Atish Patra <atish.patra@wdc.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: "linux-riscv@lists.infradead.org"
	<linux-riscv@lists.infradead.org>,
	"Patrick Stählin" <me@packi.ch>,
	"Albert Ou" <aou@eecs.berkeley.edu>,
	"Damien Le Moal" <Damien.LeMoal@wdc.com>,
	"Jason Cooper" <jason@lakedaemon.net>,
	"Alan Kao" <alankao@andestech.com>,
	"Dmitriy Cherkasov" <dmitriy@oss-tech.org>,
	"Anup Patel" <anup@brainfault.org>,
	"Daniel Lezcano" <daniel.lezcano@linaro.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"Zong Li" <zongbox@gmail.com>,
	"Palmer Dabbelt" <palmer@sifive.com>,
	"Paul Walmsley" <paul.walmsley@sifive.com>,
	"Andreas Schwab" <schwab@suse.de>,
	"Marc Zyngier" <marc.zyngier@arm.com>,
	"Thomas Gleixner" <tglx@linutronix.de>
Subject: Re: [v3 PATCH 2/8] RISC-V: Move cpuid to hartid mapping to SMP.
Date: Fri, 8 Feb 2019 14:56:57 -0800	[thread overview]
Message-ID: <1090db6a-f4c1-a522-7c2d-d7367846df35@wdc.com> (raw)
In-Reply-To: <20190208090316.GB16932@infradead.org>

On 2/8/19 1:03 AM, Christoph Hellwig wrote:
> On Thu, Feb 07, 2019 at 05:51:15PM -0800, Atish Patra wrote:
>> Currently, logical CPU id to physical hartid mapping is
>> defined for both smp and non-smp configurations. This
>> is not required as we need this only for smp configuration.
>> The mapping function can define directly boot_cpu_hartid
>> for non-smp use case.
> 
> Please use up your available 72 chars for the changelog.  (probably also
> in other patches).
> 

Sorry. I will fix all patches to use 72 chars.

>>
>> The reverse mapping function i.e. hartid to cpuid can be called
>> for any valid but not booted harts. So it should return default
>> cpu 0 only if it is a boot hartid.
>>
>> Signed-off-by: Atish Patra <atish.patra@wdc.com>
>> Reviewed-by: Anup Patel <anup@brainfault.org>
>> ---
>>   arch/riscv/include/asm/smp.h | 14 +++++++++++---
>>   arch/riscv/kernel/setup.c    |  9 ---------
>>   arch/riscv/kernel/smp.c      |  9 +++++++++
>>   3 files changed, 20 insertions(+), 12 deletions(-)
>>
>> diff --git a/arch/riscv/include/asm/smp.h b/arch/riscv/include/asm/smp.h
>> index 41aa73b4..21fd2d75 100644
>> --- a/arch/riscv/include/asm/smp.h
>> +++ b/arch/riscv/include/asm/smp.h
>> @@ -22,12 +22,13 @@
>>   /*
>>    * Mapping between linux logical cpu index and hartid.
>>    */
>> -extern unsigned long __cpuid_to_hartid_map[NR_CPUS];
>> -#define cpuid_to_hartid_map(cpu)    __cpuid_to_hartid_map[cpu]
>>   
>> +extern unsigned long boot_cpu_hartid;
>>   struct seq_file;
> 
> We usually try to keep forward declatations at the top of the file.
> 
> Can you add the new external declaration below the forward one?
> 
Sure.

Regards,
Atish
> Otherwise looks good:
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> 