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-rw-r--r--arch/sh/mm/mmap.c94
1 files changed, 94 insertions, 0 deletions
diff --git a/arch/sh/mm/mmap.c b/arch/sh/mm/mmap.c
index 8837d51..931f4d0 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
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