mm: use vm_unmapped_area() in hugetlbfs on tile architecture

Update the tile hugetlb_get_unmapped_area function to make use of
vm_unmapped_area() instead of implementing a brute force search.

[akpm@linux-foundation.org: fix build]
Signed-off-by: Michel Lespinasse <walken@google.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 25 insertions, 114 deletions

diff --git a/arch/tile/mm/hugetlbpage.c b/arch/tile/mm/hugetlbpage.c
index 812e2d037972..650ccff8378c 100644
--- a/arch/tile/mm/hugetlbpage.c
+++ b/arch/tile/mm/hugetlbpage.c
@@ -231,42 +231,15 @@ static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
                 unsigned long pgoff, unsigned long flags)
 {
         struct hstate *h = hstate_file(file);
-        struct mm_struct *mm = current->mm;
-        struct vm_area_struct *vma;
-        unsigned long start_addr;
-
-        if (len > mm->cached_hole_size) {
-                start_addr = mm->free_area_cache;
-        } else {
-                start_addr = TASK_UNMAPPED_BASE;
-                mm->cached_hole_size = 0;
-        }
-
-full_search:
-        addr = ALIGN(start_addr, huge_page_size(h));
-
-        for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
-                /* At this point:  (!vma || addr < vma->vm_end). */
-                if (TASK_SIZE - len < addr) {
-                        /*
-                         * Start a new search - just in case we missed
-                         * some holes.
-                         */
-                        if (start_addr != TASK_UNMAPPED_BASE) {
-                                start_addr = TASK_UNMAPPED_BASE;
-                                mm->cached_hole_size = 0;
-                                goto full_search;
-                        }
-                        return -ENOMEM;
-                }
-                if (!vma || addr + len <= vma->vm_start) {
-                        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 = ALIGN(vma->vm_end, huge_page_size(h));
-        }
+        struct vm_unmapped_area_info info;
+
+        info.flags = 0;
+        info.length = len;
+        info.low_limit = TASK_UNMAPPED_BASE;
+        info.high_limit = TASK_SIZE;
+        info.align_mask = PAGE_MASK & ~huge_page_mask(h);
+        info.align_offset = 0;
+        return vm_unmapped_area(&info);
 }
 
 static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
@@ -274,92 +247,30 @@ static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
                 unsigned long pgoff, unsigned long flags)
 {
         struct hstate *h = hstate_file(file);
-        struct mm_struct *mm = current->mm;
-        struct vm_area_struct *vma, *prev_vma;
-        unsigned long base = mm->mmap_base, addr = addr0;
-        unsigned long largest_hole = mm->cached_hole_size;
-        int first_time = 1;
-
-        /* don't allow allocations above current base */
-        if (mm->free_area_cache > base)
-                mm->free_area_cache = base;
-
-        if (len <= largest_hole) {
-                largest_hole = 0;
-                mm->free_area_cache  = base;
-        }
-try_again:
-        /* make sure it can fit in the remaining address space */
-        if (mm->free_area_cache < len)
-                goto fail;
-
-        /* either no address requested or can't fit in requested address hole */
-        addr = (mm->free_area_cache - len) & huge_page_mask(h);
-        do {
-                /*
-                 * Lookup failure means no vma is above this address,
-                 * i.e. return with success:
-                 */
-                vma = find_vma_prev(mm, addr, &prev_vma);
-                if (!vma) {
-                        return addr;
-                        break;
-                }
-
-                /*
-                 * new region fits between prev_vma->vm_end and
-                 * vma->vm_start, use it:
-                 */
-                if (addr + len <= vma->vm_start &&
-                            (!prev_vma || (addr >= prev_vma->vm_end))) {
-                        /* remember the address as a hint for next time */
-                        mm->cached_hole_size = largest_hole;
-                        mm->free_area_cache = addr;
-                        return addr;
-                } else {
-                        /* pull free_area_cache down to the first hole */
-                        if (mm->free_area_cache == vma->vm_end) {
-                                mm->free_area_cache = vma->vm_start;
-                                mm->cached_hole_size = largest_hole;
-                        }
-                }
+        struct vm_unmapped_area_info info;
+        unsigned long addr;
 
-                /* remember the largest hole we saw so far */
-                if (addr + largest_hole < vma->vm_start)
-                        largest_hole = vma->vm_start - addr;
+        info.flags = VM_UNMAPPED_AREA_TOPDOWN;
+        info.length = len;
+        info.low_limit = PAGE_SIZE;
+        info.high_limit = current->mm->mmap_base;
+        info.align_mask = PAGE_MASK & ~huge_page_mask(h);
+        info.align_offset = 0;
+        addr = vm_unmapped_area(&info);
 
-                /* try just below the current vma->vm_start */
-                addr = (vma->vm_start - len) & huge_page_mask(h);
-
-        } while (len <= vma->vm_start);
-
-fail:
-        /*
-         * if hint left us with no space for the requested
-         * mapping then try again:
-         */
-        if (first_time) {
-                mm->free_area_cache = base;
-                largest_hole = 0;
-                first_time = 0;
-                goto try_again;
-        }
         /*
          * 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->free_area_cache = TASK_UNMAPPED_BASE;
-        mm->cached_hole_size = ~0UL;
-        addr = hugetlb_get_unmapped_area_bottomup(file, addr0,
-                        len, pgoff, flags);
-
-        /*
-         * Restore the topdown base:
-         */
-        mm->free_area_cache = base;
-        mm->cached_hole_size = ~0UL;
+        if (addr & ~PAGE_MASK) {
+                VM_BUG_ON(addr != -ENOMEM);
+                info.flags = 0;
+                info.low_limit = TASK_UNMAPPED_BASE;
+                info.high_limit = TASK_SIZE;
+                addr = vm_unmapped_area(&info);
+        }
 
         return addr;
 }