[RFC 02/10] mm/hmm: Remove dead check for HugeTLB and FS DAX

[Alistair Popple]

pud_huge() returns true only for a HugeTLB page. pud_devmap() is only
used by FS DAX pages. These two things are mutually exclusive so this
code is dead code and can be removed.

Signed-off-by: Alistair Popple <apop...@nvidia.com>
---
 mm/hmm.c | 33 ---------------------------------
 1 file changed, 33 deletions(-)

diff --git a/mm/hmm.c b/mm/hmm.c
index 277ddca..5bbfb0e 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -411,9 +411,6 @@ static inline unsigned long pud_to_hmm_pfn_flags(struct 
hmm_range *range,
 static int hmm_vma_walk_pud(pud_t *pudp, unsigned long start, unsigned long 
end,
                struct mm_walk *walk)
 {
-       struct hmm_vma_walk *hmm_vma_walk = walk->private;
-       struct hmm_range *range = hmm_vma_walk->range;
-       unsigned long addr = start;
        pud_t pud;
        spinlock_t *ptl = pud_trans_huge_lock(pudp, walk->vma);
 
@@ -429,39 +426,9 @@ static int hmm_vma_walk_pud(pud_t *pudp, unsigned long 
start, unsigned long end,
                return hmm_vma_walk_hole(start, end, -1, walk);
        }
 
-       if (pud_huge(pud) && pud_devmap(pud)) {
-               unsigned long i, npages, pfn;
-               unsigned int required_fault;
-               unsigned long *hmm_pfns;
-               unsigned long cpu_flags;
-
-               if (!pud_present(pud)) {
-                       spin_unlock(ptl);
-                       return hmm_vma_walk_hole(start, end, -1, walk);
-               }
-
-               i = (addr - range->start) >> PAGE_SHIFT;
-               npages = (end - addr) >> PAGE_SHIFT;
-               hmm_pfns = &range->hmm_pfns[i];
-
-               cpu_flags = pud_to_hmm_pfn_flags(range, pud);
-               required_fault = hmm_range_need_fault(hmm_vma_walk, hmm_pfns,
-                                                     npages, cpu_flags);
-               if (required_fault) {
-                       spin_unlock(ptl);
-                       return hmm_vma_fault(addr, end, required_fault, walk);
-               }
-
-               pfn = pud_pfn(pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
-               for (i = 0; i < npages; ++i, ++pfn)
-                       hmm_pfns[i] = pfn | cpu_flags;
-               goto out_unlock;
-       }
-
        /* Ask for the PUD to be split */
        walk->action = ACTION_SUBTREE;
 
-out_unlock:
        spin_unlock(ptl);
        return 0;
 }
-- 
git-series 0.9.1