[PATCH mm-unstable 07/17] mm: loongarch: Introduce arch_mmap_hint()

[Kalesh Singh]

Introduce loongarch arch_mmap_hint() and define HAVE_ARCH_MMAP_HINT.
This is a preparatory patch, no functional change is introduced.

Signed-off-by: Kalesh Singh <kaleshsingh at google.com>
---
 arch/loongarch/include/asm/pgtable.h |  1 +
 arch/loongarch/mm/mmap.c             | 40 ++++++++++++++++++----------
 2 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h
index da346733a1da..326a6c4b7488 100644
--- a/arch/loongarch/include/asm/pgtable.h
+++ b/arch/loongarch/include/asm/pgtable.h
@@ -624,6 +624,7 @@ static inline long pmd_protnone(pmd_t pmd)
  */
 #define HAVE_ARCH_UNMAPPED_AREA
 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
+#define HAVE_ARCH_MMAP_HINT
 
 #endif /* !__ASSEMBLY__ */
 
diff --git a/arch/loongarch/mm/mmap.c b/arch/loongarch/mm/mmap.c
index 914e82ff3f65..b7db43fabca1 100644
--- a/arch/loongarch/mm/mmap.c
+++ b/arch/loongarch/mm/mmap.c
@@ -17,12 +17,32 @@
 
 enum mmap_allocation_direction {UP, DOWN};
 
+unsigned long arch_mmap_hint(struct file *filp, unsigned long addr,
+			     unsigned long len, unsigned long pgoff,
+			     unsigned long flags)
+{
+	int do_color_align = 0;
+
+	if (!addr)
+		return 0;
+
+	if (filp || (flags & MAP_SHARED))
+		do_color_align = 1;
+
+	if (do_color_align)
+		addr = COLOUR_ALIGN(addr, pgoff);
+	else
+		addr = PAGE_ALIGN(addr);
+
+	return generic_mmap_hint(filp, addr, len, pgoff, flags);
+}
+
+
 static unsigned long arch_get_unmapped_area_common(struct file *filp,
 	unsigned long addr0, unsigned long len, unsigned long pgoff,
 	unsigned long flags, enum mmap_allocation_direction dir)
 {
 	struct mm_struct *mm = current->mm;
-	struct vm_area_struct *vma;
 	unsigned long addr = addr0;
 	int do_color_align;
 	struct vm_unmapped_area_info info = {};
@@ -45,23 +65,15 @@ static unsigned long arch_get_unmapped_area_common(struct file *filp,
 		return addr;
 	}
 
+	/* requesting a specific address */
+	addr = arch_mmap_hint(filp, addr, len, pgoff, flags);
+	if (addr)
+		return addr;
+
 	do_color_align = 0;
 	if (filp || (flags & MAP_SHARED))
 		do_color_align = 1;
 
-	/* requesting a specific address */
-	if (addr) {
-		if (do_color_align)
-			addr = COLOUR_ALIGN(addr, pgoff);
-		else
-			addr = PAGE_ALIGN(addr);
-
-		vma = find_vma(mm, addr);
-		if (TASK_SIZE - len >= addr &&
-		    (!vma || addr + len <= vm_start_gap(vma)))
-			return addr;
-	}
-
 	info.length = len;
 	info.align_mask = do_color_align ? (PAGE_MASK & SHM_ALIGN_MASK) : 0;
 	info.align_offset = pgoff << PAGE_SHIFT;
-- 
2.47.0.338.g60cca15819-goog