diff options
| author | Leon Romanovsky <leonro@nvidia.com> | 2025-04-28 12:22:17 +0300 |
|---|---|---|
| committer | Leon Romanovsky <leon@kernel.org> | 2025-05-12 06:06:42 -0400 |
| commit | 8cad47130566123b2c70ef2aa53be02ef1aee5e5 (patch) | |
| tree | a54ebcc3f5a574461ecf3f37d666226d990bf74b /include/linux/hmm.h | |
| parent | 285e871884ff3dc31c0c2c1a87f0018481bc8471 (diff) | |
mm/hmm: provide generic DMA managing logic
HMM callers use PFN list to populate range while calling
to hmm_range_fault(), the conversion from PFN to DMA address
is done by the callers with help of another DMA list. However,
it is wasteful on any modern platform and by doing the right
logic, that DMA list can be avoided.
Provide generic logic to manage these lists and gave an interface
to map/unmap PFNs to DMA addresses, without requiring from the callers
to be an experts in DMA core API.
Tested-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Diffstat (limited to 'include/linux/hmm.h')
| -rw-r--r-- | include/linux/hmm.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/include/linux/hmm.h b/include/linux/hmm.h index a43e56f273a1..db75ffc949a7 100644 --- a/include/linux/hmm.h +++ b/include/linux/hmm.h @@ -23,6 +23,8 @@ struct mmu_interval_notifier; * HMM_PFN_WRITE - if the page memory can be written to (requires HMM_PFN_VALID) * HMM_PFN_ERROR - accessing the pfn is impossible and the device should * fail. ie poisoned memory, special pages, no vma, etc + * HMM_PFN_P2PDMA - P2P page + * HMM_PFN_P2PDMA_BUS - Bus mapped P2P transfer * HMM_PFN_DMA_MAPPED - Flag preserved on input-to-output transformation * to mark that page is already DMA mapped * @@ -43,8 +45,10 @@ enum hmm_pfn_flags { * don't forget to update HMM_PFN_INOUT_FLAGS */ HMM_PFN_DMA_MAPPED = 1UL << (BITS_PER_LONG - 4), + HMM_PFN_P2PDMA = 1UL << (BITS_PER_LONG - 5), + HMM_PFN_P2PDMA_BUS = 1UL << (BITS_PER_LONG - 6), - HMM_PFN_ORDER_SHIFT = (BITS_PER_LONG - 9), + HMM_PFN_ORDER_SHIFT = (BITS_PER_LONG - 11), /* Input flags */ HMM_PFN_REQ_FAULT = HMM_PFN_VALID, |