From: Christoph Hellwig <hch@lst.de>
Date: Tue, 6 Aug 2019 19:05:49 +0300
Subject: mm/hmm: cleanup the hmm_vma_handle_pmd stub
Patch-mainline: v5.4-rc1
Git-commit: 9d3973d60f0abd3985229bd895f45e2b8974344c
References: jsc#SLE-15176, jsc#SLE-16387

Stub out the whole function when CONFIG_TRANSPARENT_HUGEPAGE is not set to
make the function easier to read.

Link: https://lore.kernel.org/r/20190806160554.14046-12-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>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 mm/hmm.c |   18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -456,13 +456,10 @@ static inline uint64_t pmd_to_hmm_pfn_fl
 				range->flags[HMM_PFN_VALID];
 }
 
-static int hmm_vma_handle_pmd(struct mm_walk *walk,
-			      unsigned long addr,
-			      unsigned long end,
-			      uint64_t *pfns,
-			      pmd_t pmd)
-{
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static int hmm_vma_handle_pmd(struct mm_walk *walk, unsigned long addr,
+		unsigned long end, uint64_t *pfns, pmd_t pmd)
+{
 	struct hmm_vma_walk *hmm_vma_walk = walk->private;
 	struct hmm_range *range = hmm_vma_walk->range;
 	unsigned long pfn, npages, i;
@@ -493,11 +490,12 @@ static int hmm_vma_handle_pmd(struct mm_
 	}
 	hmm_vma_walk->last = end;
 	return 0;
-#else
-	/* If THP is not enabled then we should never reach this code ! */
-	return -EINVAL;
-#endif
 }
+#else /* CONFIG_TRANSPARENT_HUGEPAGE */
+/* stub to allow the code below to compile */
+int hmm_vma_handle_pmd(struct mm_walk *walk, unsigned long addr,
+		unsigned long end, uint64_t *pfns, pmd_t pmd);
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
 static inline uint64_t pte_to_hmm_pfn_flags(struct hmm_range *range, pte_t pte)
 {