Re: [PATCH] gianfar v5: implement nfc

[Joe Perches <joe@perches.com>]

On Mon, 2011-06-20 at 11:39 +0200, Sebastian Pöhn wrote:
> This patch adds all missing functionalities for nfc except GRXFH. There is so much code because hardware has not a TCAM.
> Further hardware rule space is very limited. So I had to extensively use
> optimization features. Both reasons lead to the necessity to hold all
> online flows in a linked-list.
> Signed-off-by: Sebastian Poehn <sebastian.poehn@belden.com>

Just a bit more trivia...

[]

> +/* Swaps the 0xFF80 masked bits of a1<>a2 and b1<>b2 */
> +static void gfar_swap_ff80_bits(struct gfar_filer_entry *a1,
> +		struct gfar_filer_entry *a2, struct gfar_filer_entry *b1,
> +		struct gfar_filer_entry *b2)
> +{
> +	u32 temp[4];
> +	temp[0] = a1->ctrl & 0xFF80;
> +	temp[1] = a2->ctrl & 0xFF80;
> +	temp[2] = b1->ctrl & 0xFF80;
> +	temp[3] = b2->ctrl & 0xFF80;
> +
> +	a1->ctrl &= ~0xFF80;
> +	a2->ctrl &= ~0xFF80;
> +	b1->ctrl &= ~0xFF80;
> +	b2->ctrl &= ~0xFF80;
> +
> +	a1->ctrl |= temp[1];
> +	a2->ctrl |= temp[0];
> +	b1->ctrl |= temp[3];
> +	b2->ctrl |= temp[2];
> +}

maybe add a macro similar to swap:

#define swap_bits(a, b, bits)			\
do {						\
	typeof(a) _bits = bits;			\
	typeof(a) _a_bits = (a) & _bits;	\
	typeof(a) _b_bits = (b) & _bits;	\
						\
	(a) &= ~_bits;				\
	(b) &= ~_bits;				\
						\
	(a) |= _b_bits;				\
	(b) |= _a_bits;				\
} while (0)

and use this macro directly in gfar_sort_mask_table?

	swap_bits(temp_table->fe[new_first],
		  temp_table->fe[old_first], 0xff80);
	swap_bits(temp_table->fe[new_last],
		  temp_table->fe[old_last], 0xff80);

And maybe 0xff80 should be a #define?