diff options
Diffstat (limited to 'mm/hmm.c')
| -rw-r--r-- | mm/hmm.c | 31 |
1 files changed, 17 insertions, 14 deletions
@@ -702,23 +702,25 @@ static void hmm_pfns_special(struct hmm_range *range) } /* - * hmm_vma_get_pfns() - snapshot CPU page table for a range of virtual addresses - * @range: range being snapshotted - * Returns: -EINVAL if invalid argument, -ENOMEM out of memory, -EPERM invalid - * vma permission, 0 success + * hmm_range_snapshot() - snapshot CPU page table for a range + * @range: range + * Returns: number of valid pages in range->pfns[] (from range start + * address). This may be zero. If the return value is negative, + * then one of the following values may be returned: + * + * -EINVAL invalid arguments or mm or virtual address are in an + * invalid vma (ie either hugetlbfs or device file vma). + * -EPERM For example, asking for write, when the range is + * read-only + * -EAGAIN Caller needs to retry + * -EFAULT Either no valid vma exists for this range, or it is + * illegal to access the range * * This snapshots the CPU page table for a range of virtual addresses. Snapshot * validity is tracked by range struct. See hmm_vma_range_done() for further * information. - * - * The range struct is initialized here. It tracks the CPU page table, but only - * if the function returns success (0), in which case the caller must then call - * hmm_vma_range_done() to stop CPU page table update tracking on this range. - * - * NOT CALLING hmm_vma_range_done() IF FUNCTION RETURNS 0 WILL LEAD TO SERIOUS - * MEMORY CORRUPTION ! YOU HAVE BEEN WARNED ! */ -int hmm_vma_get_pfns(struct hmm_range *range) +long hmm_range_snapshot(struct hmm_range *range) { struct vm_area_struct *vma = range->vma; struct hmm_vma_walk hmm_vma_walk; @@ -772,6 +774,7 @@ int hmm_vma_get_pfns(struct hmm_range *range) hmm_vma_walk.fault = false; hmm_vma_walk.range = range; mm_walk.private = &hmm_vma_walk; + hmm_vma_walk.last = range->start; mm_walk.vma = vma; mm_walk.mm = vma->vm_mm; @@ -788,9 +791,9 @@ int hmm_vma_get_pfns(struct hmm_range *range) * function return 0). */ range->hmm = hmm; - return 0; + return (hmm_vma_walk.last - range->start) >> PAGE_SHIFT; } -EXPORT_SYMBOL(hmm_vma_get_pfns); +EXPORT_SYMBOL(hmm_range_snapshot); /* * hmm_vma_range_done() - stop tracking change to CPU page table over a range |