ARM: dma-mapping: don't allow DMA mappings to be marked executable

DMA mapping permissions were being derived from pgprot_kernel directly
without using PAGE_KERNEL.  This causes them to be marked with executable
permission, which is not what we want.  Fix this.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
static int __free_from_pool(void *start, size_t size)
{
	struct dma_pool *pool = &atomic_pool;
	unsigned long pageno, count;
	unsigned long flags;

	if (!__in_atomic_pool(start, size))
		return 0;

	pageno = (start - pool->vaddr) >> PAGE_SHIFT;
	count = size >> PAGE_SHIFT;

	spin_lock_irqsave(&pool->lock, flags);
	bitmap_clear(pool->bitmap, pageno, count);
	spin_unlock_irqrestore(&pool->lock, flags);

	return 1;
}

static int __free_from_pool(void *start, size_t size)
{
	struct dma_pool *pool = &atomic_pool;
	unsigned long pageno, count;
	unsigned long flags;

	if (!__in_atomic_pool(start, size))
		return 0;

	pageno = (start - pool->vaddr) >> PAGE_SHIFT;
	count = size >> PAGE_SHIFT;

	spin_lock_irqsave(&pool->lock, flags);
	bitmap_clear(pool->bitmap, pageno, count);
	spin_unlock_irqrestore(&pool->lock, flags);

	return 1;
}
