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U2FsdGVkX18MGL1n9tNhRQB0MM97G3epmWwXpjg0EXbEvFJqTCfIEhFNEljiT4hV8gsJC0k/16B8Bv2a2nkk7EGj210o5QKoCuBhVt1KwEF0C7obtMfcd+9HyN5vHNlh+K0cCvM18RIwQWqK6Xn5mKXqT4IEAI5Oi4h+HUkKvnFi3Q+FQrhL1c0mmEs3/Zs1qtq1wYTvSOSGZgNw5oLyOudnwDQwGoxmwZQc7Nqw+1B0fBm/d7QR8XxuIxIb560cma3OYQ6JhlgO8rW28oYoQFKvf8XYpDfgcJRuzd48ILt+VCwx1mHWP/TSpMiorMIG15unnQLuC/WS0LZuHoq4cEFCCg9N8/NoTdqgZg0cJK7uFxCBA4NBMn7+6xCIB612mQbwKHUTKIj6+UxkZKRTSiJlfYmDMlMfWOrDgTlYLssnfaTTm/1s4uRbPpQmxc4hgOiw3ODM9H6incthpnPqm0eiFw7B+xG0xJPo92QGzMtXjaV6GsfqeX22wLppq3DN6e1tYB5C9+hJecwLAEAxgwwrBN0+66PjovXxEpjOCSF+WilRc+sYJ/GTn2RpNsqpq5fBJ/LfgrAFl/NiMP8d+HZPM8aQZ5oWAIkEMm+4tHU/VHzVLwyYdQUiqcreMcv7YhvS665boakdWw229OlMbDODyKOQx5ziIUd8v3fNMHZJwDX7qMIuR2Sy6Y/6pcoplG7YGEKqolQoqeA/1FSrjcYlJJlsRhojOhZKY5/NlGIBisostRk1Hs5NR+sdVrcM+2dHG5FbuH6oR7Dz6kY3VzmWRQ1jhq1/kw6UZUH32XBLuGPeQL4fcoTUikc5iE7VOvFS0b7vAnTZQrd3b8AWnrm9gc5Cxi+1clbN1O95Oh6v+F7PLNYXDQBdCCWTD7pM9+wpEAkwpd4WzhZ0hZFQc8gTMKYs0fCwRhzAwvXseupwlHK5YI0gluJm93KwEyUIimqWYDb+0/UxKBSO1xn HecY1OTQ 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, Aug 04, 2025 at 03:42:47PM +0300, Leon Romanovsky wrote: > From: Leon Romanovsky > > 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. > > Signed-off-by: Leon Romanovsky > --- > mm/hmm.c | 15 ++++++++------- > 1 file changed, 8 insertions(+), 7 deletions(-) > > diff --git a/mm/hmm.c b/mm/hmm.c > index 015ab243f0813..6556c0e074ba8 100644 > --- a/mm/hmm.c > +++ b/mm/hmm.c > @@ -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; Yeah, this is a lot cleaner Reviewed-by: Jason Gunthorpe Jason