[PATCH v7 1/7] arm64/hugetlb: Extend batching of multiple CONT_PTE in a single PTE setup

[Wen Jiang]

From: "Barry Song (Xiaomi)" <baohua at kernel.org>

For sizes aligned to CONT_PTE_SIZE and smaller than PMD_SIZE,
we can handle CONT_PTE_SIZE groups together.

These additional sizes are mapping spans used by non-hugetlbfs(vmalloc)
mm code, not new HugeTLB hstate sizes.

Signed-off-by: Barry Song (Xiaomi) <baohua at kernel.org>
Signed-off-by: Wen Jiang <jiangwen6 at xiaomi.com>
Tested-by: Xueyuan Chen <xueyuan.chen21 at gmail.com>
Tested-by: Leo Yan <leo.yan at arm.com>
Reviewed-by: Dev Jain <dev.jain at arm.com>
---
 arch/arm64/mm/hugetlbpage.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index a42c05cf56408..7ce159483a354 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -94,6 +94,11 @@ static int find_num_contig(struct mm_struct *mm, unsigned long addr,
 	return CONT_PTES;
 }

+/*
+ * num_contig_ptes(), set_huge_pte_at() and arch_make_huge_pte() can be
+ * used by non-hugetlbfs(vmalloc) mm code to set multiple huge mappings
+ * at the PTE level.
+ */
 static inline int num_contig_ptes(unsigned long size, size_t *pgsize)
 {
 	int contig_ptes = 1;
@@ -110,6 +115,12 @@ static inline int num_contig_ptes(unsigned long size, size_t *pgsize)
 		contig_ptes = CONT_PTES;
 		break;
 	default:
+		if (size > 0 && size < PMD_SIZE &&
+				IS_ALIGNED(size, CONT_PTE_SIZE)) {
+			*pgsize = PAGE_SIZE;
+			contig_ptes = size >> PAGE_SHIFT;
+			break;
+		}
 		WARN_ON(!__hugetlb_valid_size(size));
 	}

@@ -359,6 +370,10 @@ pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags)
 	case CONT_PTE_SIZE:
 		return pte_mkcont(entry);
 	default:
+		if (pagesize > 0 && pagesize < PMD_SIZE &&
+				IS_ALIGNED(pagesize, CONT_PTE_SIZE))
+			return pte_mkcont(entry);
+
 		break;
 	}
 	pr_warn("%s: unrecognized huge page size 0x%lx\n",
--
2.34.1