Re: [PATCH 2/5] drivers/net/ethernet/dec/tulip: Use standard__set_bit_le() function

From: Ben Hutchings
Date: Wed Jun 13 2012 - 11:14:22 EST


On Wed, 2012-06-13 at 23:00 +0900, Takuya Yoshikawa wrote:
> On Wed, 13 Jun 2012 22:31:13 +0900
> Akinobu Mita <akinobu.mita@xxxxxxxxx> wrote:
>
> > >> Should this hash_table be converted from u16 hash_table[32] to
> > >> DECLARE_BITMAP(hash_table, 16 * 32) to ensure that it is aligned
> > >> on long-word boundary?
> > >
> > > I think hash_table is already long-word aligned because it is placed
> > > right after a pointer.
> >
> > I recommend converting to proper bitmap. Because such an implicit
> > assumption is easily broken by someone touching this function.
>
> Do you mean something like:
> DECLARE_BITMAP(__hash_table, 16 * 32);
> u16 *hash_table = (u16 *)__hash_table;
> ?
[...]

Could this driver perhaps use:

union hash_table {
DECLARE_BITMAP(bits, 16 * 32);
__le16 words[32];
};

Ben.

--
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

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