memremap: remove to_vmem_altmap

	unsigned long alloc;

};

#ifdef CONFIG_ZONE_DEVICE

struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start);

#else

static inline struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start)

{

	return NULL;

}

#endif

/*

 * Specialize ZONE_DEVICE memory into multiple types each having differents

 * usage.

	altmap->alloc -= nr_pfns;

}

struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start)

{

	/*

	 * 'memmap_start' is the virtual address for the first "struct

	 * page" in this range of the vmemmap array.  In the case of

	 * CONFIG_SPARSEMEM_VMEMMAP a page_to_pfn conversion is simple

	 * pointer arithmetic, so we can perform this to_vmem_altmap()

	 * conversion without concern for the initialization state of

	 * the struct page fields.

	 */

	struct page *page = (struct page *) memmap_start;

	struct dev_pagemap *pgmap;

	/*

	 * Unconditionally retrieve a dev_pagemap associated with the

	 * given physical address, this is only for use in the

	 * arch_{add|remove}_memory() for setting up and tearing down

	 * the memmap.

	 */

	rcu_read_lock();

	pgmap = find_dev_pagemap(__pfn_to_phys(page_to_pfn(page)));

	rcu_read_unlock();

	return pgmap ? pgmap->altmap : NULL;

}

/**

 * get_dev_pagemap() - take a new live reference on the dev_pagemap for @pfn

 * @pfn: page frame number to lookup page_map