Miscellany

static gfp_t massage_gfp_flags(const struct device *dev, gfp_t gfp)
{
        /* ignore region specifiers */
        gfp &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);

#ifdef CONFIG_ZONE_DMA
        if (dev == NULL)
                gfp |= __GFP_DMA;
        else if (dev->coherent_dma_mask < DMA_BIT_MASK(24))
                gfp |= __GFP_DMA;
        else
#endif
#ifdef CONFIG_ZONE_DMA32
             if (dev->coherent_dma_mask < DMA_BIT_MASK(32))
                gfp |= __GFP_DMA32;
        else
#endif
                ;

        /* Don't invoke OOM killer */
        gfp |= __GFP_NORETRY;

        return gfp;
}