diff options
| author | Leon Romanovsky <leonro@nvidia.com> | 2025-09-09 16:27:41 +0300 |
|---|---|---|
| committer | Marek Szyprowski <m.szyprowski@samsung.com> | 2025-09-12 00:18:21 +0200 |
| commit | ec818caebc0809722f47004db9f74b7ab355c583 (patch) | |
| tree | 5f78426de95c8db2cf4bb99c8d916ba40a6c9a56 | |
| parent | e1d69da24fb8ee02e13dcbc281f510f01332a7f8 (diff) | |
mm/hmm: properly take MMIO path
In case peer-to-peer transaction traverses through host bridge,
the IOMMU needs to have IOMMU_MMIO flag, together with skip of
CPU sync.
The latter was handled by provided DMA_ATTR_SKIP_CPU_SYNC flag,
but IOMMU flag was missed, due to assumption that such memory
can be treated as regular one.
Reuse newly introduced DMA attribute to properly take MMIO path.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/998251caf3f9d1a3f6f8205f1f494c707fb4d8fa.1757423202.git.leonro@nvidia.com
| -rw-r--r-- | mm/hmm.c | 15 |
1 files changed, 8 insertions, 7 deletions
@@ -746,7 +746,7 @@ dma_addr_t hmm_dma_map_pfn(struct device *dev, struct hmm_dma_map *map, case PCI_P2PDMA_MAP_NONE: break; case PCI_P2PDMA_MAP_THRU_HOST_BRIDGE: - attrs |= DMA_ATTR_SKIP_CPU_SYNC; + attrs |= DMA_ATTR_MMIO; pfns[idx] |= HMM_PFN_P2PDMA; break; case PCI_P2PDMA_MAP_BUS_ADDR: @@ -776,7 +776,7 @@ dma_addr_t hmm_dma_map_pfn(struct device *dev, struct hmm_dma_map *map, goto error; dma_addr = dma_map_phys(dev, paddr, map->dma_entry_size, - DMA_BIDIRECTIONAL, 0); + DMA_BIDIRECTIONAL, attrs); if (dma_mapping_error(dev, dma_addr)) goto error; @@ -811,16 +811,17 @@ bool hmm_dma_unmap_pfn(struct device *dev, struct hmm_dma_map *map, size_t idx) if ((pfns[idx] & valid_dma) != valid_dma) return false; + if (pfns[idx] & HMM_PFN_P2PDMA) + attrs |= DMA_ATTR_MMIO; + if (pfns[idx] & HMM_PFN_P2PDMA_BUS) ; /* no need to unmap bus address P2P mappings */ - else if (dma_use_iova(state)) { - if (pfns[idx] & HMM_PFN_P2PDMA) - attrs |= DMA_ATTR_SKIP_CPU_SYNC; + else if (dma_use_iova(state)) dma_iova_unlink(dev, state, idx * map->dma_entry_size, map->dma_entry_size, DMA_BIDIRECTIONAL, attrs); - } else if (dma_need_unmap(dev)) + else if (dma_need_unmap(dev)) dma_unmap_phys(dev, dma_addrs[idx], map->dma_entry_size, - DMA_BIDIRECTIONAL, 0); + DMA_BIDIRECTIONAL, attrs); pfns[idx] &= ~(HMM_PFN_DMA_MAPPED | HMM_PFN_P2PDMA | HMM_PFN_P2PDMA_BUS); |