Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Wed, 13 Feb 2019 17:52:27 +0100
From:   Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To:     Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc:     Dave Martin <Dave.Martin@arm.com>,
        Julien Grall <julien.grall@arm.com>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        linux-rt-users@vger.kernel.org,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will.deacon@arm.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH] arm64/fpsimd: Don't disable softirq when touching
 FPSIMD/SVE state
Message-ID: <20190213165227.7ekekkxazhbaqxoe@linutronix.de>
References: <20190208165513.8435-1-julien.grall@arm.com>
 <20190213143029.ad2kzg7vtuo3zpjk@linutronix.de>
 <20190213153630.GK3567@e103592.cambridge.arm.com>
 <CAKv+Gu__0uy6Y-EJGSygSYH4RqpLDWMMNFE3yauF_x7-UNcgFQ@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <CAKv+Gu__0uy6Y-EJGSygSYH4RqpLDWMMNFE3yauF_x7-UNcgFQ@mail.gmail.com>
User-Agent: NeoMutt/20180716
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 2019-02-13 16:40:00 [+0100], Ard Biesheuvel wrote:
> > > This is equal what x86 is currently doing. The naming is slightly
> > > different, there is irq_fpu_usable().
> >
> > Yes, I think it's basically the same idea.
> >
> > It's been evolving a bit on both sides, but is quite similar now.
> >
> 
> may_use_simd() only exists because we have a generic crypto SIMD
> helper, and so we needed something arch agnostic to wrap around
> irq_fpu_usable()

My question was more if this is helpful and we want to keep or if
it would be better to remove it and always disable BH as part of SIMD
operations.

Sebastian