linux-kernel - Re: [PATCH v5 3/6] iomap: introduce io{read|write}64_{lo_hi|hi

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Date:   Sun, 30 Jul 2017 19:03:30 +0300
From:   Andy Shevchenko <andy.shevchenko@...il.com>
To:     Logan Gunthorpe <logang@...tatee.com>
Cc:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Linux-Arch <linux-arch@...r.kernel.org>,
        linux-ntb@...glegroups.com,
        linux-crypto <linux-crypto@...r.kernel.org>,
        Arnd Bergmann <arnd@...db.de>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Horia Geantă <horia.geanta@....com>,
        Stephen Bates <sbates@...thlin.com>,
        Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Paul Mackerras <paulus@...ba.org>,
        Michael Ellerman <mpe@...erman.id.au>,
        Suresh Warrier <warrier@...ux.vnet.ibm.com>,
        Nicholas Piggin <npiggin@...il.com>
Subject: Re: [PATCH v5 3/6] iomap: introduce io{read|write}64_{lo_hi|hi_lo}

On Thu, Jul 27, 2017 at 2:19 AM, Logan Gunthorpe <logang@...tatee.com> wrote:
> In order to provide non-atomic functions for io{read|write}64 that will
> use readq and writeq when appropriate. We define a number of variants
> of these functions in the generic iomap that will do non-atomic
> operations on pio but atomic operations on mmio.
>
> These functions are only defined if readq and writeq are defined. If
> they are not, then the wrappers that always use non-atomic operations
> from include/linux/io-64-nonatomic*.h will be used.

Don't you see here a slight problem?

In some cases we want to substitute atomic in favour of non-atomic
when both are defined.
So, please don't do this "smartly".

> +u64 ioread64_lo_hi(void __iomem *addr)
> +{
> +       IO_COND(addr, return pio_read64_lo_hi(port), return readq(addr));
> +       return 0xffffffffffffffffLL;
> +}

U missed u.

-- 
With Best Regards,
Andy Shevchenko