From mboxrd@z Thu Jan  1 00:00:00 1970
From: linux@arm.linux.org.uk (Russell King - ARM Linux)
Date: Tue, 10 Dec 2013 17:00:25 +0000
Subject: [PATCH v5 1/3] ARM: Introduce atomic MMIO modify
In-Reply-To: <20131210164907.GA11468@sirena.org.uk>
References: <1386686497-20335-1-git-send-email-ezequiel.garcia@free-electrons.com>
 <1386686497-20335-2-git-send-email-ezequiel.garcia@free-electrons.com>
 <20131210164907.GA11468@sirena.org.uk>
Message-ID: <20131210170025.GA4360@n2100.arm.linux.org.uk>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Tue, Dec 10, 2013 at 04:49:07PM +0000, Mark Brown wrote:
> On Tue, Dec 10, 2013 at 11:41:35AM -0300, Ezequiel Garcia wrote:
> 
> > +void atomic_io_modify_relaxed(void __iomem *reg, u32 mask, u32 set)
> > +{
> > +	unsigned long flags;
> > +	u32 value;
> > +
> > +	raw_spin_lock_irqsave(&__io_lock, flags);
> > +	value = readl_relaxed(reg) & ~mask;
> > +	value |= (set & mask);
> > +	writel_relaxed(value, reg);
> > +	raw_spin_unlock_irqrestore(&__io_lock, flags);
> > +}
> > +EXPORT_SYMBOL(atomic_io_modify_relaxed);
> 
> This looks quite generic - why is it in architecture specific code?

because the _relaxed IO operators don't exist on other architectures, and
there's been some discussion around whether they should with no conclusions
being reached.