[PATCH mm-unstable 06/17] mm: csky: Introduce arch_mmap_hint()

[Kalesh Singh]

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

Signed-off-by: Kalesh Singh <kaleshsi...@google.com>
---
 arch/csky/abiv1/inc/abi/pgtable-bits.h |  1 +
 arch/csky/abiv1/mmap.c                 | 38 ++++++++++++++++++--------
 2 files changed, 27 insertions(+), 12 deletions(-)

diff --git a/arch/csky/abiv1/inc/abi/pgtable-bits.h 
b/arch/csky/abiv1/inc/abi/pgtable-bits.h
index ae7a2f76dd42..c346a9fcb522 100644
--- a/arch/csky/abiv1/inc/abi/pgtable-bits.h
+++ b/arch/csky/abiv1/inc/abi/pgtable-bits.h
@@ -51,5 +51,6 @@
                                        ((offset) << 10)})
 
 #define HAVE_ARCH_UNMAPPED_AREA
+#define HAVE_ARCH_MMAP_HINT
 
 #endif /* __ASM_CSKY_PGTABLE_BITS_H */
diff --git a/arch/csky/abiv1/mmap.c b/arch/csky/abiv1/mmap.c
index 1047865e82a9..184921a73856 100644
--- a/arch/csky/abiv1/mmap.c
+++ b/arch/csky/abiv1/mmap.c
@@ -13,6 +13,29 @@
        ((((addr)+SHMLBA-1)&~(SHMLBA-1)) +      \
         (((pgoff)<<PAGE_SHIFT) & (SHMLBA-1)))
 
+unsigned long arch_mmap_hint(struct file *filp, unsigned long addr,
+                            unsigned long len, unsigned long pgoff,
+                            unsigned long flags)
+{
+       int do_align = 0;
+
+       if (!addr)
+               return 0;
+
+       /*
+        * We only need to do colour alignment if either the I or D
+        * caches alias.
+        */
+       do_align = filp || (flags & MAP_SHARED);
+
+       if (do_align)
+               addr = COLOUR_ALIGN(addr, pgoff);
+       else
+               addr = PAGE_ALIGN(addr);
+
+       return generic_mmap_hint(filp, addr, len, pgoff, flags);
+}
+
 /*
  * We need to ensure that shared mappings are correctly aligned to
  * avoid aliasing issues with VIPT caches.  We need to ensure that
@@ -27,7 +50,6 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
                unsigned long flags, vm_flags_t vm_flags)
 {
        struct mm_struct *mm = current->mm;
-       struct vm_area_struct *vma;
        int do_align = 0;
        struct vm_unmapped_area_info info = {
                .length = len,
@@ -55,17 +77,9 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
        if (len > TASK_SIZE)
                return -ENOMEM;
 
-       if (addr) {
-               if (do_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;
-       }
+       addr = arch_mmap_hint(filp, addr, len, pgoff, flags);
+       if (addr)
+               return addr;
 
        info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
        return vm_unmapped_area(&info);
-- 
2.47.0.338.g60cca15819-goog