On Wed, Jul 01, 2026 at 11:19:20AM +0530, Aneesh Kumar K.V (Arm) wrote:
> @@ -88,37 +88,40 @@ static inline dma_addr_t dma_direct_map_phys(struct
> device *dev,
> {
> dma_addr_t dma_addr;
>
> + /*
> + * For a device requiring unencrypted DMA, MMIO memory is treated
> + * as shared by default.
> + */
> + if (force_dma_unencrypted(dev) && (attrs & DMA_ATTR_MMIO))
> + attrs |= DMA_ATTR_CC_SHARED;
> +
> if (is_swiotlb_force_bounce(dev)) {
> - if (!(attrs & DMA_ATTR_CC_SHARED)) {
> - if (attrs & (DMA_ATTR_MMIO | DMA_ATTR_REQUIRE_COHERENT))
> - return DMA_MAPPING_ERROR;
> + if (attrs & (DMA_ATTR_MMIO | DMA_ATTR_REQUIRE_COHERENT))
> + return DMA_MAPPING_ERROR;
>
> - return swiotlb_map(dev, phys, size, dir, attrs);
> - }
> - } else if (attrs & DMA_ATTR_CC_SHARED) {
> - return DMA_MAPPING_ERROR;
> + return swiotlb_map(dev, phys, size, dir, attrs);
> }
>
> - if (attrs & DMA_ATTR_MMIO) {
> - dma_addr = phys;
> - if (unlikely(!dma_capable(dev, dma_addr, size, false, attrs)))
> - goto err_overflow;
> - } else if (attrs & DMA_ATTR_CC_SHARED) {
> + if (attrs & DMA_ATTR_CC_SHARED)
> dma_addr = phys_to_dma_unencrypted(dev, phys);
> + else
> + dma_addr = phys_to_dma_encrypted(dev, phys);
Maybe things should be adjusted so this can be
phys_to_dma_direct(dev, phys, (attrs & DMA_ATTR_CC_SHARED)
?
It would also be nice if swiotlb.c could do the same
Stated another way, maybe we should get rid of
phys_to_dma_unencrypted/encrypted() entirely and just have the bool
variation since that seems to be what everyone wants.
Jason
