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Commit b6661861 authored by Michel Lespinasse's avatar Michel Lespinasse Committed by Linus Torvalds
Browse files

mm: use vm_unmapped_area() on mips architecture 



Update the mips arch_get_unmapped_area[_topdown] functions to make use of
vm_unmapped_area() instead of implementing a brute force search.

[akpm@linux-foundation.org: remove now-unused COLOUR_ALIGN_DOWN()]
Signed-off-by: default avatarMichel Lespinasse <walken@google.com>
Reviewed-by: default avatarRik 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent cdc17344

arch/mips/mm/mmap.c

+17 −94
Original line number Diff line number Diff line
@@ -45,18 +45,6 @@ static unsigned long mmap_base(unsigned long rnd) 
	return PAGE_ALIGN(TASK_SIZE - gap - rnd);

}



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;

}



#define COLOUR_ALIGN(addr, pgoff)				\

	((((addr) + shm_align_mask) & ~shm_align_mask) +	\

	 (((pgoff) << PAGE_SHIFT) & shm_align_mask))
@@ -71,6 +59,7 @@ static unsigned long arch_get_unmapped_area_common(struct file *filp, 
	struct vm_area_struct *vma;

	unsigned long addr = addr0;

	int do_color_align;

	struct vm_unmapped_area_info info;



	if (unlikely(len > TASK_SIZE))

		return -ENOMEM;
@@ -107,97 +96,31 @@ static unsigned long arch_get_unmapped_area_common(struct file *filp, 
			return addr;

	}



	if (dir == UP) {

		addr = mm->mmap_base;

		if (do_color_align)

			addr = COLOUR_ALIGN(addr, pgoff);

		else

			addr = PAGE_ALIGN(addr);



		for (vma = find_vma(current->mm, addr); ; vma = vma->vm_next) {

			/* At this point:  (!vma || addr < vma->vm_end). */

			if (TASK_SIZE - len < addr)

				return -ENOMEM;

			if (!vma || addr + len <= vma->vm_start)

				return addr;

			addr = vma->vm_end;

			if (do_color_align)

				addr = COLOUR_ALIGN(addr, pgoff);

		 }

	 } else {

		/* 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 the mapping can't fit into

		 * the requested address hole

		 */

		addr = mm->free_area_cache;

		if (do_color_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) {

				/* cache 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_color_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)) {

				/* cache the address as a hint for next time */

				return mm->free_area_cache = addr;

			}

	info.length = len;

	info.align_mask = do_color_align ? (PAGE_MASK & shm_align_mask) : 0;

	info.align_offset = pgoff << PAGE_SHIFT;



			/* 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;

	if (dir == DOWN) {

		info.flags = VM_UNMAPPED_AREA_TOPDOWN;

		info.low_limit = PAGE_SIZE;

		info.high_limit = mm->mmap_base;

		addr = vm_unmapped_area(&info);



			/* try just below the current vma->vm_start */

			addr = vma->vm_start - len;

			if (do_color_align)

				addr = COLOUR_ALIGN_DOWN(addr, pgoff);

		} while (likely(len < vma->vm_start));

		if (!(addr & ~PAGE_MASK))

			return addr;



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;

	}



	info.flags = 0;

	info.low_limit = mm->mmap_base;

	info.high_limit = TASK_SIZE;

	return vm_unmapped_area(&info);

}



unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr0,