[PATCH mm-unstable 13/17] mm: sparc64: Introduce arch_mmap_hint()

[Kalesh Singh <kaleshsingh@google.com>]

Introduce sparc64 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@google.com>
---
 arch/sparc/include/asm/pgtable_64.h |  1 +
 arch/sparc/kernel/sys_sparc_64.c    | 47 +++++++++++++++++++++--------
 2 files changed, 35 insertions(+), 13 deletions(-)

diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index 2b7f358762c1..f24a4eb2777b 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -1148,6 +1148,7 @@ static inline bool pte_access_permitted(pte_t pte, bool write)
  */
 #define HAVE_ARCH_UNMAPPED_AREA
 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
+#define HAVE_ARCH_MMAP_HINT
 
 /* We provide a special get_unmapped_area for framebuffer mmaps to try and use
  * the largest alignment possible such that larget PTEs can be used.
diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c
index c5a284df7b41..a782696e98e0 100644
--- a/arch/sparc/kernel/sys_sparc_64.c
+++ b/arch/sparc/kernel/sys_sparc_64.c
@@ -98,10 +98,39 @@ static unsigned long get_align_mask(struct file *filp, unsigned long flags)
 	return 0;
 }
 
+unsigned long arch_mmap_hint(struct file *filp, unsigned long addr,
+			     unsigned long len, unsigned long pgoff,
+			     unsigned long flags)
+{
+	unsigned long task_size = TASK_SIZE;
+	bool file_hugepage = false;
+	int do_color_align = 0;
+
+	if (!addr)
+		return 0;
+
+	if (filp && is_file_hugepages(filp))
+		file_hugepage = true;
+
+	if ((filp || (flags & MAP_SHARED)) && !file_hugepage)
+		do_color_align = 1;
+
+	if (test_thread_flag(TIF_32BIT))
+		task_size = STACK_TOP32;
+
+	if (unlikely(len > task_size || len >= VA_EXCLUDE_START))
+		return 0;
+
+	if (do_color_align)
+		addr = COLOR_ALIGN(addr, pgoff);
+	else
+		addr = PAGE_ALIGN(addr);
+
+	return generic_mmap_hint(filp, addr, len, pgoff, flags);
+}
+
 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags, vm_flags_t vm_flags)
 {
-	struct mm_struct *mm = current->mm;
-	struct vm_area_struct * vma;
 	unsigned long task_size = TASK_SIZE;
 	int do_color_align;
 	struct vm_unmapped_area_info info = {};
@@ -129,17 +158,9 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsi
 	if ((filp || (flags & MAP_SHARED)) && !file_hugepage)
 		do_color_align = 1;
 
-	if (addr) {
-		if (do_color_align)
-			addr = COLOR_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;
-	}
+	addr = arch_mmap_hint(filp, addr, len, pgoff, flags);
+	if (addr)
+		return addr;
 
 	info.length = len;
 	info.low_limit = TASK_UNMAPPED_BASE;
-- 
2.47.0.338.g60cca15819-goog