[PATCH v9 10/24] mm/hmm: let users to tag specific PFN with DMA mapped bit

[Jason Gunthorpe]

On Wed, Apr 23, 2025 at 11:13:01AM +0300, Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro at nvidia.com>
> 
> Introduce new sticky flag (HMM_PFN_DMA_MAPPED), which isn't overwritten
> by HMM range fault. Such flag allows users to tag specific PFNs with
> information if this specific PFN was already DMA mapped.
> 
> Tested-by: Jens Axboe <axboe at kernel.dk>
> Reviewed-by: Christoph Hellwig <hch at lst.de>
> Signed-off-by: Leon Romanovsky <leonro at nvidia.com>
> ---
>  include/linux/hmm.h | 17 +++++++++++++++
>  mm/hmm.c            | 51 ++++++++++++++++++++++++++++-----------------
>  2 files changed, 49 insertions(+), 19 deletions(-)

Reviewed-by: Jason Gunthorpe <jgg at nvidia.com>

This would be part of the RDMA bits

Jason