On Mon, May 10, 2021 at 11:05 PM Christoph Hellwig wrote:
>
> > +static inline bool is_dev_swiotlb_force(struct device *dev)
> > +{
> > +#ifdef CONFIG_DMA_RESTRICTED_POOL
> > + if (dev->dma_io_tlb_mem)
> > + return true;
> > +#endif /* CONFIG_DMA_RESTRICTED_POOL */
> > + return
> +static inline bool is_dev_swiotlb_force(struct device *dev)
> +{
> +#ifdef CONFIG_DMA_RESTRICTED_POOL
> + if (dev->dma_io_tlb_mem)
> + return true;
> +#endif /* CONFIG_DMA_RESTRICTED_POOL */
> + return false;
> +}
> +
> /* If SWIOTLB is active, use its maximum mapping
Regardless of swiotlb setting, the restricted DMA pool is preferred if
available.
The restricted DMA pools provide a basic level of protection against the
DMA overwriting buffer contents at unexpected times. However, to protect
against general data leakage and system memory corruption, the system
