sh: Calculate shm alignment at runtime.

[pandora-kernel.git] / arch / sh / kernel / sys_sh.c

diff --git a/arch/sh/kernel/sys_sh.c b/arch/sh/kernel/sys_sh.c
index 0ee7bf4..b68ff70 100644 (file)
--- a/arch/sh/kernel/sys_sh.c
+++ b/arch/sh/kernel/sys_sh.c
@@ -21,6 +21,7 @@
 #include <linux/mman.h>
 #include <linux/file.h>
 #include <linux/utsname.h>
+#include <linux/module.h>
 #include <asm/cacheflush.h>
 #include <asm/uaccess.h>
 #include <asm/ipc.h>
@@ -44,11 +45,16 @@ asmlinkage int sys_pipe(unsigned long r4, unsigned long r5,
        return error;
 }
 
-#if defined(HAVE_ARCH_UNMAPPED_AREA) && defined(CONFIG_MMU)
+unsigned long shm_align_mask = PAGE_SIZE - 1;  /* Sane caches */
+
+EXPORT_SYMBOL(shm_align_mask);
+
 /*
- * To avoid cache alias, we map the shard page with same color.
+ * To avoid cache aliases, we map the shared page with same color.
  */
-#define COLOUR_ALIGN(addr)     (((addr)+SHMLBA-1)&~(SHMLBA-1))
+#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)
@@ -56,43 +62,52 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
        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 & (SHMLBA - 1)))
+               if ((flags & MAP_SHARED) && (addr & shm_align_mask))
                        return -EINVAL;
                return addr;
        }
 
-       if (len > TASK_SIZE)
+       if (unlikely(len > TASK_SIZE))
                return -ENOMEM;
 
+       do_colour_align = 0;
+       if (filp || (flags & MAP_SHARED))
+               do_colour_align = 1;
+
        if (addr) {
-               if (flags & MAP_PRIVATE)
-                       addr = PAGE_ALIGN(addr);
+               if (do_colour_align)
+                       addr = COLOUR_ALIGN(addr, pgoff);
                else
-                       addr = COLOUR_ALIGN(addr);
+                       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) {
+
+       if (len > mm->cached_hole_size) {
+               start_addr = addr = mm->free_area_cache;
+       } else {
                mm->cached_hole_size = 0;
-               mm->free_area_cache = TASK_UNMAPPED_BASE;
+               start_addr = addr = TASK_UNMAPPED_BASE;
        }
-       if (flags & MAP_PRIVATE)
-               addr = PAGE_ALIGN(mm->free_area_cache);
-       else
-               addr = COLOUR_ALIGN(mm->free_area_cache);
-       start_addr = addr;
 
 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 (TASK_SIZE - len < addr) {
+               if (unlikely(TASK_SIZE - len < addr)) {
                        /*
                         * Start a new search - just in case we missed
                         * some holes.
@@ -104,7 +119,7 @@ full_search:
                        }
                        return -ENOMEM;
                }
-               if (!vma || addr + len <= vma->vm_start) {
+               if (likely(!vma || addr + len <= vma->vm_start)) {
                        /*
                         * Remember the place where we stopped the search:
                         */
@@ -115,11 +130,10 @@ full_search:
                        mm->cached_hole_size = vma->vm_start - addr;
 
                addr = vma->vm_end;
-               if (!(flags & MAP_PRIVATE))
-                       addr = COLOUR_ALIGN(addr);
+               if (do_colour_align)
+                       addr = COLOUR_ALIGN(addr, pgoff);
        }
 }
-#endif
 
 static inline long
 do_mmap2(unsigned long addr, unsigned long len, unsigned long prot,