Jason Gunthorpe <[email protected]> writes:
>> > static inline dma_addr_t dma_direct_map_phys(struct device *dev,
>> > phys_addr_t phys, size_t size, enum dma_data_direction dir,
>> > unsigned long attrs, bool flush)
>> > {
>> > dma_addr_t dma_addr;
>> >
>> > if (is_swiotlb_force_bounce(dev)) {
>> > if (attrs & (DMA_ATTR_MMIO | DMA_ATTR_REQUIRE_COHERENT))
>> > 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;
>> > goto dma_mapped;
>>
>> I suspect P2P is probably broken on CC because this doesn't make
>> sense..
>
> Actually, I suppose it is fully broken because it will jump to swiotlb
> and then should fail.
>
>> This should flow into the
>> phys_to_dma_unencrypted/phys_to_dma_encrypted block as well AFAICT, it
>> shouldn't just assign phys. Assigning phys to dma on a CC system is
>> always wrong, right?
>>
>> It is is more like
>>
>> /* To be updated, callers should specify MMIO | CC_SHARED instead of
>> * implying it. */
>> if (attrs & DMA_ATTR_MMIO)
>> attrs |= DMA_ATTR_CC_SHARED;
>
> So no need for this if, we can go directly to marking the MMIO callers
> with DMA_ATTR_CC_SHARED once this is fixed for mmio:
>
>> if (attrs & DMA_ATTR_CC_SHARED) {
>> dma_addr = phys_to_dma_unencrypted(dev, phys);
>> } else {
>> dma_addr = phys_to_dma_encrypted(dev, phys);
>> }
>
> Jasn
I am wondering whether this is better
static inline dma_addr_t dma_direct_map_phys(struct device *dev,
phys_addr_t phys, size_t size, enum dma_data_direction dir,
unsigned long attrs, bool flush)
{
dma_addr_t dma_addr;
/*
* For a device requiring unencrypted DMA, MMIO memory is treated
* as shared.
*/
if (force_dma_unencrypted(dev) && (attrs & DMA_ATTR_MMIO))
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);
if (attrs & DMA_ATTR_MMIO) {
if (unlikely(!dma_capable(dev, dma_addr, size, false, attrs)))
goto err_overflow;
goto dma_mapped;
}
....
-aneesh
