[PATCH v4 3/6] mm/vmalloc: Extract vmap_set_ptes() to consolidate PTE mapping logic

[Wen Jiang]

Extract the common PTE mapping logic from vmap_pte_range() into a
shared helper vmap_set_ptes(). This handles both CONT_PTE and regular
PTE mappings in a single function, preparing for the next patch which
will extend vmap_pages_pte_range() to also use this helper.

The #ifdef CONFIG_HUGETLB_PAGE guard is moved inside vmap_set_ptes(),
so callers no longer need to handle the conditional compilation.

No functional change.

Signed-off-by: Wen Jiang <jiangwen6@xxxxxxxxxx>
Tested-by: Xueyuan Chen <xueyuan.chen21@xxxxxxxxx>
---
 mm/vmalloc.c | 44 +++++++++++++++++++++++++++++++-------------
 1 file changed, 31 insertions(+), 13 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 2c2f74a07f396..6660f240d27c9 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -91,6 +91,35 @@ struct vfree_deferred {
 static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred);
 
 /*** Page table manipulation functions ***/
+
+/*
+ * Set PTE mappings for the given PFN. Try CONT_PTE mappings first when
+ * supported, otherwise fall back to PAGE_SIZE mappings.
+ *
+ * Return: mapping size.
+ */
+static __always_inline unsigned long vmap_set_ptes(pte_t *pte,
+		unsigned long addr, unsigned long end, u64 pfn,
+		pgprot_t prot, unsigned int max_page_shift)
+{
+#ifdef CONFIG_HUGETLB_PAGE
+	if (max_page_shift > PAGE_SHIFT) {
+		unsigned long size;
+
+		size = arch_vmap_pte_range_map_size(addr, end, pfn, max_page_shift);
+		if (size != PAGE_SIZE) {
+			pte_t entry = pfn_pte(pfn, prot);
+
+			entry = arch_make_huge_pte(entry, ilog2(size), 0);
+			set_huge_pte_at(&init_mm, addr, pte, entry, size);
+			return size;
+		}
+	}
+#endif
+	set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
+	return PAGE_SIZE;
+}
+
 static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 			phys_addr_t phys_addr, pgprot_t prot,
 			unsigned int max_page_shift, pgtbl_mod_mask *mask)
@@ -119,19 +148,8 @@ static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 			BUG();
 		}
 
-#ifdef CONFIG_HUGETLB_PAGE
-		size = arch_vmap_pte_range_map_size(addr, end, pfn, max_page_shift);
-		if (size != PAGE_SIZE) {
-			pte_t entry = pfn_pte(pfn, prot);
-
-			entry = arch_make_huge_pte(entry, ilog2(size), 0);
-			set_huge_pte_at(&init_mm, addr, pte, entry, size);
-			pfn += PFN_DOWN(size);
-			continue;
-		}
-#endif
-		set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
-		pfn++;
+		size = vmap_set_ptes(pte, addr, end, pfn, prot, max_page_shift);
+		pfn += PFN_DOWN(size);
 	} while (pte += PFN_DOWN(size), addr += size, addr != end);
 
 	lazy_mmu_mode_disable();
-- 
2.34.1