sh: Handle shm_align_mask also for HAVE_ARCH_UNMAPPED_AREA_TOPDOWN.

Presently shm_align_mask is only looked at for the bottom up case, but we
still want this for proper colouring constraints in the topdown case.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

diff --git a/arch/sh/include/asm/cacheflush.h b/arch/sh/include/asm/cacheflush.h
index 09acbc3..4c5462d 100644 (file)
--- a/arch/sh/include/asm/cacheflush.h
+++ b/arch/sh/include/asm/cacheflush.h
@@ -75,7 +75,5 @@ extern void copy_from_user_page(struct vm_area_struct *vma,
 #define flush_cache_vmap(start, end)           flush_cache_all()
 #define flush_cache_vunmap(start, end)         flush_cache_all()
 
-#define HAVE_ARCH_UNMAPPED_AREA
-
 #endif /* __KERNEL__ */
 #endif /* __ASM_SH_CACHEFLUSH_H */

diff --git a/arch/sh/include/asm/pgtable.h b/arch/sh/include/asm/pgtable.h
index b517ae0..2a011b1 100644 (file)
--- a/arch/sh/include/asm/pgtable.h
+++ b/arch/sh/include/asm/pgtable.h
@@ -154,6 +154,10 @@ extern void kmap_coherent_init(void);
 #define kmap_coherent_init()   do { } while (0)
 #endif
 
+/* arch/sh/mm/mmap.c */
+#define HAVE_ARCH_UNMAPPED_AREA
+#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
+
 #include <asm-generic/pgtable.h>
 
 #endif /* __ASM_SH_PGTABLE_H */

diff --git a/arch/sh/mm/mmap.c b/arch/sh/mm/mmap.c
index 931f4d0..1b5fdfb 100644 (file)
--- a/arch/sh/mm/mmap.c
+++ b/arch/sh/mm/mmap.c
@@ -1,7 +1,7 @@
 /*
  * arch/sh/mm/mmap.c
  *
- * Copyright (C) 2008  Paul Mundt
+ * Copyright (C) 2008 - 2009  Paul Mundt
  *
  * This file is subject to the terms and conditions of the GNU General Public
  * License.  See the file "COPYING" in the main directory of this archive
@@ -21,9 +21,26 @@ 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))
+static inline unsigned long COLOUR_ALIGN(unsigned long addr,
+                                        unsigned long pgoff)
+{
+       unsigned long base = (addr + shm_align_mask) & ~shm_align_mask;
+       unsigned long off = (pgoff << PAGE_SHIFT) & shm_align_mask;
+
+       return base + off;
+}
+
+static inline unsigned long COLOUR_ALIGN_DOWN(unsigned long addr,
+                                             unsigned long pgoff)
+{
+       unsigned long base = addr & ~shm_align_mask;
+       unsigned long off = (pgoff << PAGE_SHIFT) & shm_align_mask;
+
+       if (base + off <= addr)
+               return base + off;
+
+       return base - off;
+}
 
 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
        unsigned long len, unsigned long pgoff, unsigned long flags)
@@ -103,6 +120,117 @@ full_search:
                        addr = COLOUR_ALIGN(addr, pgoff);
        }
 }
+
+unsigned long
+arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
+                         const unsigned long len, const unsigned long pgoff,
+                         const unsigned long flags)
+{
+       struct vm_area_struct *vma;
+       struct mm_struct *mm = current->mm;
+       unsigned long addr = addr0;
+       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 - (pgoff << PAGE_SHIFT)) & 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;
+
+       /* requesting a specific address */
+       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;
+       }
+
+       /* check if free_area_cache is useful for us */
+       if (len <= mm->cached_hole_size) {
+               mm->cached_hole_size = 0;
+               mm->free_area_cache = mm->mmap_base;
+       }
+
+       /* either no address requested or can't fit in requested address hole */
+       addr = mm->free_area_cache;
+       if (do_colour_align) {
+               unsigned long base = COLOUR_ALIGN_DOWN(addr-len, pgoff);
+
+               addr = base + len;
+       }
+
+       /* make sure it can fit in the remaining address space */
+       if (likely(addr > len)) {
+               vma = find_vma(mm, addr-len);
+               if (!vma || addr <= vma->vm_start) {
+                       /* remember the address as a hint for next time */
+                       return (mm->free_area_cache = addr-len);
+               }
+       }
+
+       if (unlikely(mm->mmap_base < len))
+               goto bottomup;
+
+       addr = mm->mmap_base-len;
+       if (do_colour_align)
+               addr = COLOUR_ALIGN_DOWN(addr, pgoff);
+
+       do {
+               /*
+                * Lookup failure means no vma is above this address,
+                * else if new region fits below vma->vm_start,
+                * return with success:
+                */
+               vma = find_vma(mm, addr);
+               if (likely(!vma || addr+len <= vma->vm_start)) {
+                       /* remember the address as a hint for next time */
+                       return (mm->free_area_cache = addr);
+               }
+
+               /* remember the largest hole we saw so far */
+               if (addr + mm->cached_hole_size < vma->vm_start)
+                       mm->cached_hole_size = vma->vm_start - addr;
+
+               /* try just below the current vma->vm_start */
+               addr = vma->vm_start-len;
+               if (do_colour_align)
+                       addr = COLOUR_ALIGN_DOWN(addr, pgoff);
+       } while (likely(len < vma->vm_start));
+
+bottomup:
+       /*
+        * A failed mmap() very likely causes application failure,
+        * so fall back to the bottom-up function here. This scenario
+        * can happen with large stack limits and large mmap()
+        * allocations.
+        */
+       mm->cached_hole_size = ~0UL;
+       mm->free_area_cache = TASK_UNMAPPED_BASE;
+       addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
+       /*
+        * Restore the topdown base:
+        */
+       mm->free_area_cache = mm->mmap_base;
+       mm->cached_hole_size = ~0UL;
+
+       return addr;
+}
 #endif /* CONFIG_MMU */
 
 /*