Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [PATCH v5 05/22] powerpc/irq: Add helper to set regs->softe
To:     Nicholas Piggin <npiggin@gmail.com>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Michael Ellerman <mpe@ellerman.id.au>, msuchanek@suse.de,
        Paul Mackerras <paulus@samba.org>
Cc:     linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
References: <cover.1612796617.git.christophe.leroy@csgroup.eu>
 <5f37d1177a751fdbca79df461d283850ca3a34a2.1612796617.git.christophe.leroy@csgroup.eu>
 <1612832745.vhjk6358hf.astroid@bobo.none>
From:   Christophe Leroy <christophe.leroy@csgroup.eu>
Message-ID: <258ac0c6-ef40-86d4-2ce4-772cfc4a95e5@csgroup.eu>
Date:   Tue, 9 Feb 2021 06:57:47 +0100
User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:78.0) Gecko/20100101
 Thunderbird/78.7.0
MIME-Version: 1.0
In-Reply-To: <1612832745.vhjk6358hf.astroid@bobo.none>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: fr
Content-Transfer-Encoding: 8bit
Precedence: bulk


Le 09/02/2021 à 02:11, Nicholas Piggin a écrit :
> Excerpts from Christophe Leroy's message of February 9, 2021 1:10 am:
>> regs->softe doesn't exist on PPC32.
>>
>> Add irq_soft_mask_regs_set_state() helper to set regs->softe.
>> This helper will void on PPC32.
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>>   arch/powerpc/include/asm/hw_irq.h | 11 +++++++++--
>>   1 file changed, 9 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
>> index 614957f74cee..ed0c3b049dfd 100644
>> --- a/arch/powerpc/include/asm/hw_irq.h
>> +++ b/arch/powerpc/include/asm/hw_irq.h
>> @@ -38,6 +38,8 @@
>>   #define PACA_IRQ_MUST_HARD_MASK	(PACA_IRQ_EE)
>>   #endif
>>   
>> +#endif /* CONFIG_PPC64 */
>> +
>>   /*
>>    * flags for paca->irq_soft_mask
>>    */
>> @@ -46,8 +48,6 @@
>>   #define IRQS_PMI_DISABLED	2
>>   #define IRQS_ALL_DISABLED	(IRQS_DISABLED | IRQS_PMI_DISABLED)
>>   
>> -#endif /* CONFIG_PPC64 */
>> -
>>   #ifndef __ASSEMBLY__
>>   
>>   #ifdef CONFIG_PPC64
>> @@ -287,6 +287,10 @@ extern void irq_set_pending_from_srr1(unsigned long srr1);
>>   
>>   extern void force_external_irq_replay(void);
>>   
>> +static inline void irq_soft_mask_regs_set_state(struct pt_regs *regs, unsigned long val)
>> +{
>> +	regs->softe = val;
>> +}
>>   #else /* CONFIG_PPC64 */
>>   
>>   static inline unsigned long arch_local_save_flags(void)
>> @@ -355,6 +359,9 @@ static inline bool arch_irq_disabled_regs(struct pt_regs *regs)
>>   
>>   static inline void may_hard_irq_enable(void) { }
>>   
>> +static inline void irq_soft_mask_regs_set_state(struct pt_regs *regs, unsigned long val)
>> +{
>> +}
>>   #endif /* CONFIG_PPC64 */
>>   
>>   #define ARCH_IRQ_INIT_FLAGS	IRQ_NOREQUEST
> 
> What I don't like about this where you use it is it kind of pollutes
> the ppc32 path with this function which is not valid to use.
> 
> I would prefer if you had this purely so it could compile with:
> 
>    if (IS_ENABLED(CONFIG_PPC64)))
>        irq_soft_mask_regs_set_state(regs, blah);
> 
> And then you could make the ppc32 cause a link error if it did not
> get eliminated at compile time (e.g., call an undefined function).
> 
> You could do the same with the kuap_ functions to change some ifdefs
> to IS_ENABLED.
> 
> That's just my preference but if you prefer this way I guess that's
> okay.

I see you didn't change your mind since last April :)

I'll see what I can do.

Christophe