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Commit bb64f550 authored by Michel Lespinasse's avatar Michel Lespinasse Committed by Linus Torvalds
Browse files

mm: use vm_unmapped_area() on sparc64 architecture 



Update the sparc64 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 dd529596

arch/sparc/kernel/sys_sparc_64.c

+30 −114
Original line number Diff line number Diff line
@@ -84,24 +84,13 @@ static inline unsigned long COLOUR_ALIGN(unsigned long addr, 
	return base + off;

}



static inline unsigned long COLOUR_ALIGN_DOWN(unsigned long addr,

					      unsigned long pgoff)

{

	unsigned long base = addr & ~(SHMLBA-1);

	unsigned long off = (pgoff<<PAGE_SHIFT) & (SHMLBA-1);



	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)

{

	struct mm_struct *mm = current->mm;

	struct vm_area_struct * vma;

	unsigned long task_size = TASK_SIZE;

	unsigned long start_addr;

	int do_color_align;

	struct vm_unmapped_area_info info;



	if (flags & MAP_FIXED) {

		/* We do not accept a shared mapping if it would violate
@@ -134,50 +123,22 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsi 
			return addr;

	}



	if (len > mm->cached_hole_size) {

	        start_addr = addr = mm->free_area_cache;

	} else {

	        start_addr = addr = TASK_UNMAPPED_BASE;

	        mm->cached_hole_size = 0;

	}



	task_size -= len;



full_search:

	if (do_color_align)

		addr = COLOUR_ALIGN(addr, pgoff);

	else

		addr = PAGE_ALIGN(addr);

	info.flags = 0;

	info.length = len;

	info.low_limit = TASK_UNMAPPED_BASE;

	info.high_limit = min(task_size, VA_EXCLUDE_START);

	info.align_mask = do_color_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;

	info.align_offset = pgoff << PAGE_SHIFT;

	addr = vm_unmapped_area(&info);



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

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

		if (addr < VA_EXCLUDE_START &&

		    (addr + len) >= VA_EXCLUDE_START) {

			addr = VA_EXCLUDE_END;

			vma = find_vma(mm, VA_EXCLUDE_END);

		}

		if (unlikely(task_size < addr)) {

			if (start_addr != TASK_UNMAPPED_BASE) {

				start_addr = addr = TASK_UNMAPPED_BASE;

				mm->cached_hole_size = 0;

				goto full_search;

			}

			return -ENOMEM;

	if ((addr & ~PAGE_MASK) && task_size > VA_EXCLUDE_END) {

		VM_BUG_ON(addr != -ENOMEM);

		info.low_limit = VA_EXCLUDE_END;

		info.high_limit = task_size;

		addr = vm_unmapped_area(&info);

	}

		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_color_align)

			addr = COLOUR_ALIGN(addr, pgoff);

	}

	return addr;

}



unsigned long
@@ -190,6 +151,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, 
	unsigned long task_size = STACK_TOP32;

	unsigned long addr = addr0;

	int do_color_align;

	struct vm_unmapped_area_info info;



	/* This should only ever run for 32-bit processes.  */

	BUG_ON(!test_thread_flag(TIF_32BIT));
@@ -224,73 +186,27 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, 
			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_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) {

			/* 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_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)) {

			/* 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_color_align)

			addr = COLOUR_ALIGN_DOWN(addr, pgoff);

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

	info.flags = VM_UNMAPPED_AREA_TOPDOWN;

	info.length = len;

	info.low_limit = PAGE_SIZE;

	info.high_limit = mm->mmap_base;

	info.align_mask = do_color_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;

	info.align_offset = pgoff << PAGE_SHIFT;

	addr = vm_unmapped_area(&info);



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;

	if (addr & ~PAGE_MASK) {

		VM_BUG_ON(addr != -ENOMEM);

		info.flags = 0;

		info.low_limit = TASK_UNMAPPED_BASE;

		info.high_limit = STACK_TOP32;

		addr = vm_unmapped_area(&info);

	}



	return addr;

}