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| author | Leon Romanovsky <leonro@nvidia.com> | 2025-04-28 12:22:16 +0300 |
|---|---|---|
| committer | Leon Romanovsky <leon@kernel.org> | 2025-05-12 13:06:37 +0300 |
| commit | 285e871884ff3dc31c0c2c1a87f0018481bc8471 (patch) | |
| tree | 933539323da5d93a03b0ed5765494ad4955bce10 /include/linux | |
| parent | 972aa49a7c93fecdf281d2a7f4914085f3b327eb (diff) | |
| download | linux-285e871884ff3dc31c0c2c1a87f0018481bc8471.tar.xz | |
mm/hmm: let users to tag specific PFN with DMA mapped bit
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@kernel.dk>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/hmm.h | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/include/linux/hmm.h b/include/linux/hmm.h index 126a36571667..a43e56f273a1 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_DMA_MAPPED - Flag preserved on input-to-output transformation + * to mark that page is already DMA mapped * * On input: * 0 - Return the current state of the page, do not fault it. @@ -36,13 +38,19 @@ enum hmm_pfn_flags { HMM_PFN_VALID = 1UL << (BITS_PER_LONG - 1), HMM_PFN_WRITE = 1UL << (BITS_PER_LONG - 2), HMM_PFN_ERROR = 1UL << (BITS_PER_LONG - 3), - HMM_PFN_ORDER_SHIFT = (BITS_PER_LONG - 8), + /* + * Sticky flags, carried from input to output, + * don't forget to update HMM_PFN_INOUT_FLAGS + */ + HMM_PFN_DMA_MAPPED = 1UL << (BITS_PER_LONG - 4), + + HMM_PFN_ORDER_SHIFT = (BITS_PER_LONG - 9), /* Input flags */ HMM_PFN_REQ_FAULT = HMM_PFN_VALID, HMM_PFN_REQ_WRITE = HMM_PFN_WRITE, - HMM_PFN_FLAGS = 0xFFUL << HMM_PFN_ORDER_SHIFT, + HMM_PFN_FLAGS = ~((1UL << HMM_PFN_ORDER_SHIFT) - 1), }; /* @@ -58,6 +66,14 @@ static inline struct page *hmm_pfn_to_page(unsigned long hmm_pfn) } /* + * hmm_pfn_to_phys() - return physical address pointed to by a device entry + */ +static inline phys_addr_t hmm_pfn_to_phys(unsigned long hmm_pfn) +{ + return __pfn_to_phys(hmm_pfn & ~HMM_PFN_FLAGS); +} + +/* * hmm_pfn_to_map_order() - return the CPU mapping size order * * This is optionally useful to optimize processing of the pfn result |