SOP_DISTANCE
void __iomem *dest = pbuf->start + SOP_DISTANCE;
dest -= SOP_DISTANCE;
dend -= SOP_DISTANCE;
void __iomem *dest = pbuf->start + SOP_DISTANCE;
dest += SOP_DISTANCE;
xend += SOP_DISTANCE;
dest -= SOP_DISTANCE;
dest += SOP_DISTANCE;
dest += SOP_DISTANCE;
xend += SOP_DISTANCE;
dest -= SOP_DISTANCE;
dest += SOP_DISTANCE;
dest += SOP_DISTANCE;
dest -= SOP_DISTANCE;
dend -= SOP_DISTANCE;