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| author | Christoph Hellwig <hch@lst.de> | 2020-03-16 20:32:15 +0100 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@mellanox.com> | 2020-03-26 14:33:38 -0300 |
| commit | 17ffdc482982af92bddb59692af1c5e1de23d184 (patch) | |
| tree | ccabdb1691c720b734896ca6eded31457b353881 /mm/hmm.c | |
| parent | 800bb1c8dc80bb4121446b56813067f3ea44edee (diff) | |
| download | linux-17ffdc482982af92bddb59692af1c5e1de23d184.tar.gz linux-17ffdc482982af92bddb59692af1c5e1de23d184.tar.bz2 linux-17ffdc482982af92bddb59692af1c5e1de23d184.zip | |
mm: simplify device private page handling in hmm_range_fault
Remove the HMM_PFN_DEVICE_PRIVATE flag, no driver has ever set this flag
on input, and the only place that uses it on output can be trivially
changed to use is_device_private_page().
This removes the ability to request that device_private pages are faulted
back into system memory.
Link: https://lore.kernel.org/r/20200316193216.920734-4-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'mm/hmm.c')
| -rw-r--r-- | mm/hmm.c | 25 |
1 files changed, 5 insertions, 20 deletions
@@ -116,15 +116,6 @@ static inline void hmm_pte_need_fault(const struct hmm_vma_walk *hmm_vma_walk, /* We aren't ask to do anything ... */ if (!(pfns & range->flags[HMM_PFN_VALID])) return; - /* If this is device memory then only fault if explicitly requested */ - if ((cpu_flags & range->flags[HMM_PFN_DEVICE_PRIVATE])) { - /* Do we fault on device memory ? */ - if (pfns & range->flags[HMM_PFN_DEVICE_PRIVATE]) { - *write_fault = pfns & range->flags[HMM_PFN_WRITE]; - *fault = true; - } - return; - } /* If CPU page table is not valid then we need to fault */ *fault = !(cpu_flags & range->flags[HMM_PFN_VALID]); @@ -262,21 +253,15 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, swp_entry_t entry = pte_to_swp_entry(pte); /* - * This is a special swap entry, ignore migration, use - * device and report anything else as error. + * Never fault in device private pages pages, but just report + * the PFN even if not present. */ if (is_device_private_entry(entry)) { - cpu_flags = range->flags[HMM_PFN_VALID] | - range->flags[HMM_PFN_DEVICE_PRIVATE]; - cpu_flags |= is_write_device_private_entry(entry) ? - range->flags[HMM_PFN_WRITE] : 0; - hmm_pte_need_fault(hmm_vma_walk, orig_pfn, cpu_flags, - &fault, &write_fault); - if (fault || write_fault) - goto fault; *pfn = hmm_device_entry_from_pfn(range, swp_offset(entry)); - *pfn |= cpu_flags; + *pfn |= range->flags[HMM_PFN_VALID]; + if (is_write_device_private_entry(entry)) + *pfn |= range->flags[HMM_PFN_WRITE]; return 0; } |