1 files changed, 94 insertions, 0 deletions

diff --git a/arch/sh/mm/mmap.c b/arch/sh/mm/mmap.c
index 8837d511710a..931f4d003fa0 100644
--- a/arch/sh/mm/mmap.c
+++ b/arch/sh/mm/mmap.c
@@ -9,7 +9,101 @@
  */
 #include <linux/io.h>
 #include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/module.h>
 #include <asm/page.h>
+#include <asm/processor.h>
+
+#ifdef CONFIG_MMU
+unsigned long shm_align_mask = PAGE_SIZE - 1;   /* Sane caches */
+EXPORT_SYMBOL(shm_align_mask);
+
+/*
+ * To avoid cache aliases, we map the shared page with same color.
+ */
+#define COLOUR_ALIGN(addr, pgoff)                               \
+        ((((addr) + shm_align_mask) & ~shm_align_mask) +        \
+         (((pgoff) << PAGE_SHIFT) & shm_align_mask))
+
+unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
+        unsigned long len, unsigned long pgoff, unsigned long flags)
+{
+        struct mm_struct *mm = current->mm;
+        struct vm_area_struct *vma;
+        unsigned long start_addr;
+        int do_colour_align;
+
+        if (flags & MAP_FIXED) {
+                /* We do not accept a shared mapping if it would violate
+                 * cache aliasing constraints.
+                 */
+                if ((flags & MAP_SHARED) && (addr & shm_align_mask))
+                        return -EINVAL;
+                return addr;
+        }
+
+        if (unlikely(len > TASK_SIZE))
+                return -ENOMEM;
+
+        do_colour_align = 0;
+        if (filp || (flags & MAP_SHARED))
+                do_colour_align = 1;
+
+        if (addr) {
+                if (do_colour_align)
+                        addr = COLOUR_ALIGN(addr, pgoff);
+                else
+                        addr = PAGE_ALIGN(addr);
+
+                vma = find_vma(mm, addr);
+                if (TASK_SIZE - len >= addr &&
+                    (!vma || addr + len <= vma->vm_start))
+                        return addr;
+        }
+
+        if (len > mm->cached_hole_size) {
+                start_addr = addr = mm->free_area_cache;
+        } else {
+                mm->cached_hole_size = 0;
+                start_addr = addr = TASK_UNMAPPED_BASE;
+        }
+
+full_search:
+        if (do_colour_align)
+                addr = COLOUR_ALIGN(addr, pgoff);
+        else
+                addr = PAGE_ALIGN(mm->free_area_cache);
+
+        for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
+                /* At this point:  (!vma || addr < vma->vm_end). */
+                if (unlikely(TASK_SIZE - len < addr)) {
+                        /*
+                         * Start a new search - just in case we missed
+                         * some holes.
+                         */
+                        if (start_addr != TASK_UNMAPPED_BASE) {
+                                start_addr = addr = TASK_UNMAPPED_BASE;
+                                mm->cached_hole_size = 0;
+                                goto full_search;
+                        }
+                        return -ENOMEM;
+                }
+                if (likely(!vma || addr + len <= vma->vm_start)) {
+                        /*
+                         * Remember the place where we stopped the search:
+                         */
+                        mm->free_area_cache = addr + len;
+                        return addr;
+                }
+                if (addr + mm->cached_hole_size < vma->vm_start)
+                        mm->cached_hole_size = vma->vm_start - addr;
+
+                addr = vma->vm_end;
+                if (do_colour_align)
+                        addr = COLOUR_ALIGN(addr, pgoff);
+        }
+}
+#endif /* CONFIG_MMU */
 
 /*
  * You really shouldn't be using read() or write() on /dev/mem.  This