Merge commit 'v2.6.30-rc1' into core/urgent

[mv-sheeva.git] / arch / sh / mm / mmap.c

diff --git a/arch/sh/mm/mmap.c b/arch/sh/mm/mmap.c
index 8837d511710afc1bca4a6e0356d6060e2238c08a..931f4d003fa07fc66b2c4b9e14c53ac1e972c616 100644 (file)
--- 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