diff options
| author | Jason Gunthorpe <jgg@mellanox.com> | 2019-05-23 09:41:19 -0300 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@mellanox.com> | 2019-06-10 10:10:30 -0300 |
| commit | e36acfe6c86d13eec62321e1e86a1ce287e52e7d (patch) | |
| tree | dce3ca3311aa436c629a5443b126dd73865177df /mm/hmm.c | |
| parent | 6d7c3cde93c1d9ac0b37f78ec3f2ff052159a242 (diff) | |
| download | linux-e36acfe6c86d13eec62321e1e86a1ce287e52e7d.tar.gz | |
mm/hmm: Use hmm_mirror not mm as an argument for hmm_range_register
Ralph observes that hmm_range_register() can only be called by a driver while a mirror is registered. Make this clear in the API by passing in the mirror structure as a parameter. This also simplifies understanding the lifetime model for struct hmm, as the hmm pointer must be valid as part of a registered mirror so all we need in hmm_register_range() is a simple kref_get. Suggested-by: Ralph Campbell <rcampbell@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Philip Yang <Philip.Yang@amd.com>
Diffstat (limited to 'mm/hmm.c')
| -rw-r--r-- | mm/hmm.c | 13 |
1 files changed, 4 insertions, 9 deletions
diff --git a/mm/hmm.c b/mm/hmm.c index f6956d78e3cb..22a97ada108b 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -914,13 +914,13 @@ static void hmm_pfns_clear(struct hmm_range *range, * Track updates to the CPU page table see include/linux/hmm.h */ int hmm_range_register(struct hmm_range *range, - struct mm_struct *mm, + struct hmm_mirror *mirror, unsigned long start, unsigned long end, unsigned page_shift) { unsigned long mask = ((1UL << page_shift) - 1UL); - struct hmm *hmm; + struct hmm *hmm = mirror->hmm; range->valid = false; range->hmm = NULL; @@ -934,20 +934,15 @@ int hmm_range_register(struct hmm_range *range, range->start = start; range->end = end; - hmm = hmm_get_or_create(mm); - if (!hmm) - return -EFAULT; - /* Check if hmm_mm_destroy() was call. */ - if (hmm->mm == NULL || hmm->dead) { - hmm_put(hmm); + if (hmm->mm == NULL || hmm->dead) return -EFAULT; - } /* Initialize range to track CPU page table updates. */ mutex_lock(&hmm->lock); range->hmm = hmm; + kref_get(&hmm->kref); list_add_rcu(&range->list, &hmm->ranges); /* |