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Commit ee1acbfa authored by Paul Mundt's avatar Paul Mundt
Browse files

sh: Handle shm_align_mask also for HAVE_ARCH_UNMAPPED_AREA_TOPDOWN. 



Presently shm_align_mask is only looked at for the bottom up case, but we
still want this for proper colouring constraints in the topdown case.

Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent 40c8bca7

arch/sh/include/asm/cacheflush.h

+0 −2
Original line number Diff line number Diff line
@@ -75,7 +75,5 @@ extern void copy_from_user_page(struct vm_area_struct *vma, 
#define flush_cache_vmap(start, end)		flush_cache_all()

#define flush_cache_vunmap(start, end)		flush_cache_all()



#define HAVE_ARCH_UNMAPPED_AREA



#endif /* __KERNEL__ */

#endif /* __ASM_SH_CACHEFLUSH_H */

arch/sh/include/asm/pgtable.h

+4 −0
Original line number Diff line number Diff line
@@ -154,6 +154,10 @@ extern void kmap_coherent_init(void); 
#define kmap_coherent_init()	do { } while (0)

#endif



/* arch/sh/mm/mmap.c */

#define HAVE_ARCH_UNMAPPED_AREA

#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN



#include <asm-generic/pgtable.h>



#endif /* __ASM_SH_PGTABLE_H */

arch/sh/mm/mmap.c

+132 −4
Original line number Diff line number Diff line 
/*

 * arch/sh/mm/mmap.c

 *

 * Copyright (C) 2008  Paul Mundt

 * Copyright (C) 2008 - 2009  Paul Mundt

 *

 * This file is subject to the terms and conditions of the GNU General Public

 * License.  See the file "COPYING" in the main directory of this archive
@@ -21,9 +21,26 @@ 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))

static inline unsigned long COLOUR_ALIGN(unsigned long addr,

					 unsigned long pgoff)

{

	unsigned long base = (addr + shm_align_mask) & ~shm_align_mask;

	unsigned long off = (pgoff << PAGE_SHIFT) & shm_align_mask;



	return base + off;

}



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;

}



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

	unsigned long len, unsigned long pgoff, unsigned long flags)
@@ -103,6 +120,117 @@ full_search: 
			addr = COLOUR_ALIGN(addr, pgoff);

	}

}



unsigned long

arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,

			  const unsigned long len, const unsigned long pgoff,

			  const unsigned long flags)

{

	struct vm_area_struct *vma;

	struct mm_struct *mm = current->mm;

	unsigned long addr = addr0;

	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 - (pgoff << PAGE_SHIFT)) & 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;



	/* requesting a specific address */

	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;

	}



	/* 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_colour_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_colour_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_colour_align)

			addr = COLOUR_ALIGN_DOWN(addr, pgoff);

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



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;

}

#endif /* CONFIG_MMU */



/*