search for: hmm_pfn

hmm_range_fault() returns an array of page frame numbers and flags for how the pages are mapped in the requested process' page tables. The PFN can be used to get the struct page with hmm_pfn_to_page() and the page size order can be determined with compound_order(page) but if the page is larger than order 0 (PAGE_SIZE), there is no indication that a compound page is mapped by the CPU using a larger page size. Without this information, the caller can't safely use a large device PTE t...

...performance win of avoiding an extra scan over the pfns array doesn't seem worth the complexity. Plus pfns needs to be scanned anyhow to sort out any DEVICE_PRIVATE pages. This version replaces the uint64_t with an usigned long containing a pfn and fix flags. On input flags is filled with the HMM_PFN_REQ_* values, on successful output it is filled with HMM_PFN_* values, describing the state of the pages. amdgpu is simple to convert, it doesn't use snapshot and doesn't use per-page flags. nouveau uses only 16 hmm_pte entries at most (ie fits in a few cache lines), and it sweeps over it...

...erformance win of avoiding an extra scan over the pfns array doesn't seem worth the complexity. Plus pfns needs to be scanned anyhow to sort out any DEVICE_PRIVATE pages. This version replaces the uint64_t with an usigned long containing a pfn and fixed flags. On input flags is filled with the HMM_PFN_REQ_* values, on successful output it is filled with HMM_PFN_* values, describing the state of the pages. amdgpu is simple to convert, it doesn't use snapshot and doesn't use per-page flags. nouveau uses only 16 hmm_pte entries at most (ie fits in a few cache lines), and it sweeps over it...

...ding an extra scan over the pfns array doesn't seem worth the > complexity. Plus pfns needs to be scanned anyhow to sort out any > DEVICE_PRIVATE pages. > > This version replaces the uint64_t with an usigned long containing a pfn > and fix flags. On input flags is filled with the HMM_PFN_REQ_* values, on > successful output it is filled with HMM_PFN_* values, describing the state > of the pages. > > amdgpu is simple to convert, it doesn't use snapshot and doesn't use > per-page flags. > > nouveau uses only 16 hmm_pte entries at most (ie fits in a few ca...

...100644 --- a/lib/test_hmm.c +++ b/lib/test_hmm.c @@ -47,23 +47,8 @@ struct dmirror_bounce { unsigned long cpages; }; -#define DPT_SHIFT PAGE_SHIFT -#define DPT_VALID (1UL << 0) -#define DPT_WRITE (1UL << 1) - #define DPT_XA_TAG_WRITE 3UL -static const uint64_t dmirror_hmm_flags[HMM_PFN_FLAG_MAX] = { - [HMM_PFN_VALID] = DPT_VALID, - [HMM_PFN_WRITE] = DPT_WRITE, -}; - -static const uint64_t dmirror_hmm_values[HMM_PFN_VALUE_MAX] = { - [HMM_PFN_NONE] = 0, - [HMM_PFN_ERROR] = 0x10, - [HMM_PFN_SPECIAL] = 0x10, -}; - /* * Data structure to track address ranges and register for m...

The goal for this series is to introduce the hmm_pfn_to_map_order() function. This allows a device driver to know that a given 4K PFN is actually mapped by the CPU using a larger sized CPU page table entry and therefore the device driver can safely map system memory using larger device MMU PTEs. The series is based on 5.8.0-rc3 and is intended for Ja...

...es. This small series removes the customizable pfn format and simplifies the return code of hmm_range_fault() All the drivers are adjusted to process in the simplified format. I would appreciated tested-by's for the two drivers, thanks! v2: - Move call chain to commit message - Fix typo of HMM_PFN_REQ_FAULT - Move nouveau_hmm_convert_pfn() to nouveau_svm.c - Add acks and tested-bys v1: https://lore.kernel.org/r/0-v1-4eb72686de3c+5062-hmm_no_flags_jgg at mellanox.com Cc: Christoph Hellwig <hch at lst.de> Cc: John Hubbard <jhubbard at nvidia.com> Cc: J?r?me Glisse <jglisse at...