From: Liam R. Howlett <Liam.Howlett@Oracle.com>
Date: Wed, 2 Dec 2020 18:15:58 +0000 (-0500)
Subject: mm/gup: Add mm_populate_vma() for use when the vma is known
X-Git-Tag: howlett/maple_spf/20210128~57
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=49a624b21b427e4fb4a9e54c8fe6533f2b8272c9;p=users%2Fjedix%2Flinux-maple.git

mm/gup: Add mm_populate_vma() for use when the vma is known

When a vma is known, avoid calling mm_populate to search for the vma to
populate.

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---

diff --git a/include/linux/mm.h b/include/linux/mm.h
index ad82ab61beba..2e3151fdb8cc 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2588,8 +2588,12 @@ static inline void mm_populate(unsigned long addr, unsigned long len)
 	/* Ignore errors */
 	(void) __mm_populate(addr, len, 1);
 }
+extern void mm_populate_vma(struct vm_area_struct *vma, unsigned long start,
+			    unsigned long end);
 #else
 static inline void mm_populate(unsigned long addr, unsigned long len) {}
+void mm_populate_vma(struct vm_area_struct *vma, unsigned long start,
+		     unsigned long end) {}
 #endif
 
 /* These take the mm semaphore themselves */
diff --git a/mm/gup.c b/mm/gup.c
index 3e086b073624..55686fc8128e 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1411,6 +1411,26 @@ long populate_vma_page_range(struct vm_area_struct *vma,
 				NULL, NULL, locked);
 }
 
+/*
+ * mm_populate_vma() - Populate a single range in a single vma.
+ * @vma: The vma to populate.
+ * @start: The start address to populate
+ * @end: The end address to stop populating
+ *
+ * Note: Ignores errors.
+ */
+void mm_populate_vma(struct vm_area_struct *vma, unsigned long start,
+		unsigned long end)
+{
+	struct mm_struct *mm = current->mm;
+	int locked = 1;
+
+	mmap_read_lock(mm);
+	populate_vma_page_range(vma, start, end, &locked);
+	if (locked)
+		mmap_read_unlock(mm);
+}
+
 /*
  * __mm_populate - populate and/or mlock pages within a range of address space.
  *