linux-kernel - Re: [PATCH v3 06/17] riscv: misaligned: use correct CONFIG_ ifdef for misaligned_access_speed

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Message-ID: <f0945e93-7ac0-4217-8095-93fff303bdf2@rivosinc.com>
Date: Fri, 14 Mar 2025 12:47:22 +0100
From: Clément Léger <cleger@...osinc.com>
To: Andrew Jones <ajones@...tanamicro.com>
Cc: Paul Walmsley <paul.walmsley@...ive.com>,
 Palmer Dabbelt <palmer@...belt.com>, Anup Patel <anup@...infault.org>,
 Atish Patra <atishp@...shpatra.org>, Shuah Khan <shuah@...nel.org>,
 Jonathan Corbet <corbet@....net>, linux-riscv@...ts.infradead.org,
 linux-kernel@...r.kernel.org, linux-doc@...r.kernel.org,
 kvm@...r.kernel.org, kvm-riscv@...ts.infradead.org,
 linux-kselftest@...r.kernel.org, Samuel Holland <samuel.holland@...ive.com>
Subject: Re: [PATCH v3 06/17] riscv: misaligned: use correct CONFIG_ ifdef for
 misaligned_access_speed

On 13/03/2025 14:06, Andrew Jones wrote:
> On Mon, Mar 10, 2025 at 04:12:13PM +0100, Clément Léger wrote:
>> misaligned_access_speed is defined under CONFIG_RISCV_SCALAR_MISALIGNED
>> but was used under CONFIG_RISCV_PROBE_UNALIGNED_ACCESS. Fix that by
>> using the correct config option.
>>
>> Signed-off-by: Clément Léger <cleger@...osinc.com>
>> ---
>>  arch/riscv/kernel/traps_misaligned.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/riscv/kernel/traps_misaligned.c b/arch/riscv/kernel/traps_misaligned.c
>> index ffac424faa88..7fe25adf2539 100644
>> --- a/arch/riscv/kernel/traps_misaligned.c
>> +++ b/arch/riscv/kernel/traps_misaligned.c
>> @@ -362,7 +362,7 @@ static int handle_scalar_misaligned_load(struct pt_regs *regs)
>>  
>>  	perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr);
>>  
>> -#ifdef CONFIG_RISCV_PROBE_UNALIGNED_ACCESS
>> +#ifdef CONFIG_RISCV_SCALAR_MISALIGNED
>>  	*this_cpu_ptr(&misaligned_access_speed) = RISCV_HWPROBE_MISALIGNED_SCALAR_EMULATED;
>>  #endif
> 
> Sure, but CONFIG_RISCV_PROBE_UNALIGNED_ACCESS selects
> CONFIG_RISCV_SCALAR_MISALIGNED, so this isn't fixing anything. 

Indeed, that is not fixing anything (hence no Fixes tag), it compiles as
a side effect of Kconfig dependencies.

> Changing it
> does make sense though since this line in handle_scalar_misaligned_load()
> "belongs" to check_unaligned_access_emulated() which is also under
> CONFIG_RISCV_SCALAR_MISALIGNED. Anyway, all this unaligned configs need a
> major cleanup.

Yes, as I said, I'd be advocating to remove all that ifdefery mess.

Thanks,

Clément

> 
> 
> Reviewed-by: Andrew Jones <ajones@...tanamicro.com>
> 
> Thanks,
> drew
> 
>>  
>> -- 
>> 2.47.2
>>
>>
>> -- 
>> kvm-riscv mailing list
>> kvm-riscv@...ts.infradead.org
>> http://lists.infradead.org/mailman/listinfo/kvm-riscv

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