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From:   John Garry <john.garry@huawei.com>
Subject: Question on FIELD_PREP() for static array
To:     Andrew Morton <akpm@linux-foundation.org>,
        Andy Shevchenko <andy.shevchenko@gmail.com>,
        Kalle Valo <kvalo@codeaurora.org>, <johannes@sipsolutions.net>,
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        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
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(to: get_maintainers -f include/linux/bitfield.h)

Hi,

I would like to use FIELD_PREP() macro for assigning a static array, 
like this:
function()
{
	static u32 val[2] = {FIELD_PREP(GENMASK_ULL(10, 0), 5), 0};

}

However the compiler complains of non-const expression:
./include/linux/bitfield.h:88:2: error: initializer element is not constant
    ({        \

Specifically it doesn't like the __BF_FIELD_CHECK() in FIELD_PREP().

Any ideas on compiler trickery we could do with the FIELD_PREP() 
definition to avoid this issue (i.e. enforce the check but only use the 
constant value)?

Thanks in advance,
John