diff --git a/include/linux/cma.h b/include/linux/cma.h
new file mode 100644
index 0000000..25728a3
--- /dev/null
+++ b/include/linux/cma.h
@@ -0,0 +1,223 @@
+#ifndef __LINUX_CMA_H
+#define __LINUX_CMA_H
+
+/*
+ * Contiguous Memory Allocator
+ * Copyright (c) 2010 by Samsung Electronics.
+ * Written by Michal Nazarewicz (m.nazarewicz@samsung.com)
+ */
+
+/*
+ * Contiguous Memory Allocator
+ *
+ *   The Contiguous Memory Allocator (CMA) makes it possible for
+ *   device drivers to allocate big contiguous chunks of memory after
+ *   the system has booted.
+ *
+ *   It requires some machine- and/or platform-specific initialisation
+ *   code which prepares memory ranges to be used with CMA and later,
+ *   device drivers can allocate memory from those ranges.
+ *
+ * Why is it needed?
+ *
+ *   Various devices on embedded systems have no scatter-getter and/or
+ *   IO map support and require contiguous blocks of memory to
+ *   operate.  They include devices such as cameras, hardware video
+ *   coders, etc.
+ *
+ *   Such devices often require big memory buffers (a full HD frame
+ *   is, for instance, more then 2 mega pixels large, i.e. more than 6
+ *   MB of memory), which makes mechanisms such as kmalloc() or
+ *   alloc_page() ineffective.
+ *
+ *   At the same time, a solution where a big memory region is
+ *   reserved for a device is suboptimal since often more memory is
+ *   reserved then strictly required and, moreover, the memory is
+ *   inaccessible to page system even if device drivers don't use it.
+ *
+ *   CMA tries to solve this issue by operating on memory regions
+ *   where only movable pages can be allocated from.  This way, kernel
+ *   can use the memory for pagecache and when device driver requests
+ *   it, allocated pages can be migrated.
+ *
+ * Driver usage
+ *
+ *   For device driver to use CMA it needs to have a pointer to a CMA
+ *   context represented by a struct cma (which is an opaque data
+ *   type).
+ *
+ *   Once such pointer is obtained, device driver may allocate
+ *   contiguous memory chunk using the following function:
+ *
+ *     cm_alloc()
+ *
+ *   This function returns a pointer to struct cm (another opaque data
+ *   type) which represent a contiguous memory chunk.  This pointer
+ *   may be used with the following functions:
+ *
+ *     cm_free()    -- frees allocated contiguous memory
+ *     cm_pin()     -- pins memory
+ *     cm_unpin()   -- unpins memory
+ *     cm_vmap()    -- maps memory in kernel space
+ *     cm_vunmap()  -- unmaps memory from kernel space
+ *
+ *   See the respective functions for more information.
+ *
+ * Platform/machine integration
+ *
+ *   For device drivers to be able to use CMA platform or machine
+ *   initialisation code must create a CMA context and pass it to
+ *   device drivers.  The latter may be done by a global variable or
+ *   a platform/machine specific function.  For the former CMA
+ *   provides the following functions:
+ *
+ *     cma_init()
+ *     cma_reserve()
+ *     cma_create()
+ *
+ *   The first one initialises a portion of reserved memory so that it
+ *   can be used with CMA.  The second first tries to reserve memory
+ *   (using memblock) and then initialise it.
+ *
+ *   The cma_reserve() function must be called when memblock is still
+ *   operational and reserving memory with it is still possible.  On
+ *   ARM platform the "reserve" machine callback is a perfect place to
+ *   call it.
+ *
+ *   The last function creates a CMA context on a range of previously
+ *   initialised memory addresses.  Because it uses kmalloc() it needs
+ *   to be called after SLAB is initialised.
+ */
+
+/***************************** Kernel level API *****************************/
+
+#if defined __KERNEL__ && defined CONFIG_CMA
+
+/* CMA context */
+struct cma;
+/* Contiguous Memory chunk */
+struct cm;
+
+/**
+ * cma_init() - initialises range of physical memory to be used with CMA.
+ * @start:	start address of the memory range in bytes.
+ * @size:	size of the memory range in bytes.
+ *
+ * The range must be MAX_ORDER-1 aligned and it must have been already
+ * reserved (eg. with memblock).
+ *
+ * Returns zero on success or negative error.
+ */
+int cma_init(unsigned long start, unsigned long end);
+
+/**
+ * cma_reserve() - reserves and initialises memory to be used with CMA.
+ * @start:	start address of the memory range in bytes hint; if unsure
+ *		pass zero (will be down-aligned to MAX_ORDER-1).
+ * @size:	size of the memory to reserve in bytes (will be up-aligned
+ *		to MAX_ORDER-1).
+ * @alignment:	desired alignment in bytes (must be power of two or zero).
+ *
+ * It will use memblock to allocate memory and then initialise it for
+ * use with CMA by invoking cma_init().  It must be called early in
+ * boot process while memblock is still operational.
+ *
+ * Returns reserved's area physical address or value that yields true
+ * when checked with IS_ERR_VALUE().
+ */
+unsigned long cma_reserve(unsigned long start, unsigned long size,
+			  unsigned long alignment);
+
+/**
+ * cma_create() - creates CMA context.
+ * @start:	start address of the context in bytes.
+ * @size:	size of the context in bytes.
+ *
+ * The range must be page aligned.  The range must have been already
+ * initialised with cma_init().  Different contexts cannot overlap.
+ *
+ * Because this function uses kmalloc() it must be called after SLAB
+ * is initialised.  This in particular means that it cannot be called
+ * just after cma_reserve() since the former needs to be run way
+ * earlier.
+ *
+ * Returns pointer to CMA context or a pointer-error on error.
+ */
+struct cma *cma_create(unsigned long start, unsigned long size);
+
+/**
+ * cma_destroy() - destroys CMA context.
+ * @cma:	context to destroy.
+ */
+void cma_destroy(struct cma *cma);
+
+/**
+ * cm_alloc() - allocates contiguous memory.
+ * @cma:	CMA context to use.
+ * @size:	desired chunk size in bytes (must be non-zero).
+ * @alignent:	desired minimal alignment in bytes (must be power of two
+ *		or zero).
+ *
+ * Returns pointer to structure representing contiguous memory or
+ * a pointer-error on error.
+ */
+struct cm *cm_alloc(struct cma *cma, unsigned long size,
+		    unsigned long alignment);
+
+/**
+ * cm_free() - frees contiguous memory.
+ * @cm:	contiguous memory to free.
+ *
+ * The contiguous memory must be not be pinned (see cma_pin()) and
+ * must not be mapped to kernel space (cma_vmap()).
+ */
+void cm_free(struct cm *cm);
+
+/**
+ * cm_pin() - pins contiguous memory.
+ * @cm: contiguous memory to pin.
+ *
+ * Pinning is required to obtain contiguous memory's physical address.
+ * While memory is pinned the memory will remain valid it may change
+ * if memory is unpinned and then pinned again.  This facility is
+ * provided so that memory defragmentation can be implemented inside
+ * CMA.
+ *
+ * Each call to cm_pin() must be accompanied by call to cm_unpin() and
+ * the calls may be nested.
+ *
+ * Returns chunk's physical address or a value that yields true when
+ * tested with IS_ERR_VALUE().
+ */
+unsigned long cm_pin(struct cm *cm);
+
+/**
+ * cm_unpin() - unpins contiguous memory.
+ * @cm: contiguous memory to unpin.
+ *
+ * See cm_pin().
+ */
+void cm_unpin(struct cm *cm);
+
+/**
+ * cm_vmap() - maps memory to kernel space (or returns existing mapping).
+ * @cm: contiguous memory to map.
+ *
+ * Each call to cm_vmap() must be accompanied with call to cm_vunmap()
+ * and the calls may be nested.
+ *
+ * Returns kernel virtual address or a pointer-error.
+ */
+void *cm_vmap(struct cm *cm);
+
+/**
+ * cm_vunmap() - unmpas memory from kernel space.
+ * @cm:	contiguous memory to unmap.
+ *
+ * See cm_vmap().
+ */
+void cm_vunmap(struct cm *cm);
+
+#endif
+
+#endif
diff --git a/mm/Kconfig b/mm/Kconfig
index 7818b07..743893b 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -339,3 +339,35 @@ config CLEANCACHE
 	  in a negligible performance hit.
 
 	  If unsure, say Y to enable cleancache
+
+
+config CMA
+	bool "Contiguous Memory Allocator framework"
+	# Currently there is only one allocator so force it on
+	select MIGRATION
+	select MIGRATE_CMA
+	select GENERIC_ALLOCATOR
+	help
+	  This enables the Contiguous Memory Allocator framework which
+	  allows drivers to allocate big physically-contiguous blocks of
+	  memory for use with hardware components that do not support I/O
+	  map nor scatter-gather.
+
+	  If you select this option you will also have to select at least
+	  one allocator algorithm below.
+
+	  To make use of CMA you need to specify the regions and
+	  driver->region mapping on command line when booting the kernel.
+
+	  For more information see <include/linux/cma.h>.  If unsure, say "n".
+
+config CMA_DEBUG
+	bool "CMA debug messages (DEVELOPEMENT)"
+	depends on CMA
+	help
+	  Turns on debug messages in CMA.  This produces KERN_DEBUG
+	  messages for every CMA call as well as various messages while
+	  processing calls such as cma_alloc().  This option does not
+	  affect warning and error messages.
+
+	  This is mostly used during development.  If unsure, say "n".
diff --git a/mm/Makefile b/mm/Makefile
index 0b08d1c..c6a84f1 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -43,3 +43,4 @@ obj-$(CONFIG_HWPOISON_INJECT) += hwpoison-inject.o
 obj-$(CONFIG_DEBUG_KMEMLEAK) += kmemleak.o
 obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak-test.o
 obj-$(CONFIG_CLEANCACHE) += cleancache.o
+obj-$(CONFIG_CMA) += cma.o
diff --git a/mm/cma.c b/mm/cma.c
new file mode 100644
index 0000000..401e604
--- /dev/null
+++ b/mm/cma.c
@@ -0,0 +1,477 @@
+/*
+ * Contiguous Memory Allocator framework
+ * Copyright (c) 2010 by Samsung Electronics.
+ * Written by Michal Nazarewicz (m.nazarewicz@samsung.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License or (at your optional) any later version of the license.
+ */
+
+/*
+ * See include/linux/cma.h for details.
+ */
+
+#define pr_fmt(fmt) "cma: " fmt
+
+#ifdef CONFIG_CMA_DEBUG
+#  define DEBUG
+#endif
+
+#include <linux/cma.h>
+
+#ifndef CONFIG_NO_BOOTMEM
+#  include <linux/bootmem.h>
+#endif
+#ifdef CONFIG_HAVE_MEMBLOCK
+#  include <linux/memblock.h>
+#endif
+
+#include <linux/err.h>
+#include <linux/genalloc.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/page-isolation.h>
+#include <linux/slab.h>
+#include <linux/swap.h>
+
+#include <asm/page.h>
+
+#include "internal.h"
+
+
+/************************* Initialise CMA *************************/
+
+static struct cma_grabbed {
+	unsigned long start;
+	unsigned long size;
+} cma_grabbed[8] __initdata;
+static unsigned cma_grabbed_count __initdata;
+
+int cma_init(unsigned long start, unsigned long size)
+{
+	pr_debug("%s(%p+%p)\n", __func__, (void *)start, (void *)size);
+
+	if (!size)
+		return -EINVAL;
+	if ((start | size) & ((MAX_ORDER_NR_PAGES << PAGE_SHIFT) - 1))
+		return -EINVAL;
+	if (start + size < start)
+		return -EOVERFLOW;
+
+	if (cma_grabbed_count == ARRAY_SIZE(cma_grabbed))
+		return -ENOSPC;
+
+	cma_grabbed[cma_grabbed_count].start = start;
+	cma_grabbed[cma_grabbed_count].size  = size;
+	++cma_grabbed_count;
+	return 0;
+}
+
+unsigned long cma_reserve(unsigned long start, unsigned long size,
+			  unsigned long alignment)
+{
+	u64 addr;
+	int ret;
+
+	pr_debug("%s(%p+%p/%p)\n", __func__, (void *)start, (void *)size,
+		 (void *)alignment);
+
+	/* Sanity checks */
+	if (!size || (alignment & (alignment - 1)))
+		return (unsigned long)-EINVAL;
+
+	/* Sanitise input arguments */
+	start = ALIGN(start, MAX_ORDER_NR_PAGES << PAGE_SHIFT);
+	size &= ~((MAX_ORDER_NR_PAGES << PAGE_SHIFT) - 1);
+	if (alignment < (MAX_ORDER_NR_PAGES << PAGE_SHIFT))
+		alignment = MAX_ORDER_NR_PAGES << PAGE_SHIFT;
+
+	/* Reserve memory */
+	if (start) {
+		if (memblock_is_region_reserved(start, size) ||
+		    memblock_reserve(start, size) < 0)
+			return (unsigned long)-EBUSY;
+	} else {
+		/*
+		 * Use __memblock_alloc_base() since
+		 * memblock_alloc_base() panic()s.
+		 */
+		addr = __memblock_alloc_base(size, alignment, 0);
+		if (!addr) {
+			return (unsigned long)-ENOMEM;
+		} else if (addr + size > ~(unsigned long)0) {
+			memblock_free(addr, size);
+			return (unsigned long)-EOVERFLOW;
+		} else {
+			start = addr;
+		}
+	}
+
+	/* CMA Initialise */
+	ret = cma_init(start, size);
+	if (ret < 0) {
+		memblock_free(start, size);
+		return ret;
+	}
+	return start;
+}
+
+static int __init cma_give_back(void)
+{
+	struct cma_grabbed *r = cma_grabbed;
+	unsigned i = cma_grabbed_count;
+
+	pr_debug("%s(): will give %u range(s)\n", __func__, i);
+
+	for (; i; --i, ++r) {
+		struct page *p = phys_to_page(r->start);
+		unsigned j = r->size >> (PAGE_SHIFT + pageblock_order);
+
+		pr_debug("%s():   giving (%p+%p)\n", __func__,
+			 (void *)r->start, (void *)r->size);
+
+		do {
+			__free_pageblock_cma(p);
+			p += pageblock_nr_pages;
+		} while (--j);
+	}
+
+	return 0;
+}
+subsys_initcall(cma_give_back);
+
+
+/************************** CMA context ***************************/
+
+/* struct cma is just an alias for struct gen_alloc */
+
+struct cma *cma_create(unsigned long start, unsigned long size)
+{
+	struct gen_pool *pool;
+	int ret;
+
+	pr_debug("%s(%p+%p)\n", __func__, (void *)start, (void *)size);
+
+	if (!size)
+		return ERR_PTR(-EINVAL);
+	if ((start | size) & (PAGE_SIZE - 1))
+		return ERR_PTR(-EINVAL);
+	if (start + size < start)
+		return ERR_PTR(-EOVERFLOW);
+
+	pool = gen_pool_create(PAGE_SHIFT, -1);
+	if (unlikely(!pool))
+		return ERR_PTR(-ENOMEM);
+
+	ret = gen_pool_add(pool, start, size, -1);
+	if (unlikely(ret)) {
+		gen_pool_destroy(pool);
+		return ERR_PTR(ret);
+	}
+
+	pr_debug("%s: returning <%p>\n", __func__, (void *)pool);
+	return (void *)pool;
+}
+
+void cma_destroy(struct cma *cma)
+{
+	pr_debug("%s(<%p>)\n", __func__, (void *)cma);
+	gen_pool_destroy((void *)cma);
+}
+
+
+/************************* Allocate and free *************************/
+
+struct cm {
+	struct gen_pool *pool;
+	unsigned long phys, size;
+	atomic_t pinned, mapped;
+};
+
+/* Protects cm_alloc(), cm_free(), __cm_alloc() and __cm_free(). */
+static DEFINE_MUTEX(cma_mutex);
+
+/* Must hold cma_mutex to call these. */
+static int  __cm_alloc(unsigned long start, unsigned long size);
+static void __cm_free(unsigned long start, unsigned long size);
+
+struct cm *cm_alloc(struct cma *cma, unsigned long size,
+		    unsigned long alignment)
+{
+	unsigned long start;
+	int ret = -ENOMEM;
+	struct cm *cm;
+
+	pr_debug("%s(<%p>, %p/%p)\n", __func__, (void *)cma,
+		 (void *)size, (void *)alignment);
+
+	if (!size || (alignment & (alignment - 1)))
+		return ERR_PTR(-EINVAL);
+	size = PAGE_ALIGN(size);
+
+	cm = kmalloc(sizeof *cm, GFP_KERNEL);
+	if (!cm)
+		return ERR_PTR(-ENOMEM);
+
+	mutex_lock(&cma_mutex);
+
+	start = gen_pool_alloc_aligned((void *)cma, size,
+				       alignment ? ffs(alignment) - 1 : 0);
+	if (!start)
+		goto error1;
+
+	ret = __cm_alloc(start, size);
+	if (ret)
+		goto error2;
+
+	mutex_unlock(&cma_mutex);
+
+	cm->pool = (void *)cma;
+	cm->phys = start;
+	cm->size = size;
+	atomic_set(&cm->pinned, 0);
+	atomic_set(&cm->mapped, 0);
+
+	pr_debug("%s(): returning [%p]\n", __func__, (void *)cm);
+	return cm;
+
+error2:
+	gen_pool_free((void *)cma, start, size);
+error1:
+	mutex_unlock(&cma_mutex);
+	kfree(cm);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(cm_alloc);
+
+void cm_free(struct cm *cm)
+{
+	pr_debug("%s([%p])\n", __func__, (void *)cm);
+
+	if (WARN_ON(atomic_read(&cm->pinned) || atomic_read(&cm->mapped)))
+		return;
+
+	mutex_lock(&cma_mutex);
+
+	gen_pool_free(cm->pool, cm->phys, cm->size);
+	__cm_free(cm->phys, cm->size);
+
+	mutex_unlock(&cma_mutex);
+
+	kfree(cm);
+}
+EXPORT_SYMBOL_GPL(cm_free);
+
+
+/************************* Mapping and addresses *************************/
+
+/*
+ * Currently no-operations but keep reference counters for error
+ * checking.
+ */
+
+unsigned long cm_pin(struct cm *cm)
+{
+	pr_debug("%s([%p])\n", __func__, (void *)cm);
+	atomic_inc(&cm->pinned);
+	return cm->phys;
+}
+EXPORT_SYMBOL_GPL(cm_pin);
+
+void cm_unpin(struct cm *cm)
+{
+	pr_debug("%s([%p])\n", __func__, (void *)cm);
+	WARN_ON(!atomic_add_unless(&cm->pinned, -1, 0));
+}
+EXPORT_SYMBOL_GPL(cm_unpin);
+
+void *cm_vmap(struct cm *cm)
+{
+	pr_debug("%s([%p])\n", __func__, (void *)cm);
+	atomic_inc(&cm->mapped);
+	/*
+	 * Keep it simple...  We should do something more clever in
+	 * the future.
+	 */
+	return phys_to_virt(cm->phys);
+}
+EXPORT_SYMBOL_GPL(cm_vmap);
+
+void cm_vunmap(struct cm *cm)
+{
+	pr_debug("%s([%p])\n", __func__, (void *)cm);
+	WARN_ON(!atomic_add_unless(&cm->mapped, -1, 0));
+}
+EXPORT_SYMBOL_GPL(cm_vunmap);
+
+
+/************************* Migration stuff *************************/
+
+/* XXX Revisit */
+#ifdef phys_to_pfn
+/* nothing to do */
+#elif defined __phys_to_pfn
+#  define phys_to_pfn __phys_to_pfn
+#else
+#  warning correct phys_to_pfn implementation needed
+static unsigned long phys_to_pfn(phys_addr_t phys)
+{
+	return virt_to_pfn(phys_to_virt(phys));
+}
+#endif
+
+static unsigned long pfn_to_maxpage(unsigned long pfn)
+{
+	return pfn & ~(MAX_ORDER_NR_PAGES - 1);
+}
+
+static unsigned long pfn_to_maxpage_up(unsigned long pfn)
+{
+	return ALIGN(pfn, MAX_ORDER_NR_PAGES);
+}
+
+#define MIGRATION_RETRY	5
+static int __cm_migrate(unsigned long start, unsigned long end)
+{
+	int migration_failed = 0, ret;
+	unsigned long pfn = start;
+
+	pr_debug("%s(%p..%p)\n", __func__, (void *)start, (void *)end);
+
+	/*
+	 * Some code "borrowed" from KAMEZAWA Hiroyuki's
+	 * __alloc_contig_pages().
+	 */
+
+	for (;;) {
+		pfn = scan_lru_pages(pfn, end);
+		if (!pfn || pfn >= end)
+			break;
+
+		ret = do_migrate_range(pfn, end);
+		if (!ret) {
+			migration_failed = 0;
+		} else if (ret != -EBUSY
+			|| ++migration_failed >= MIGRATION_RETRY) {
+			return ret;
+		} else {
+			/* There are unstable pages.on pagevec. */
+			lru_add_drain_all();
+			/*
+			 * there may be pages on pcplist before
+			 * we mark the range as ISOLATED.
+			 */
+			drain_all_pages();
+		}
+		cond_resched();
+	}
+
+	if (!migration_failed) {
+		/* drop all pages in pagevec and pcp list */
+		lru_add_drain_all();
+		drain_all_pages();
+	}
+
+	/* Make sure all pages are isolated */
+	if (WARN_ON(test_pages_isolated(start, end)))
+		return -EBUSY;
+
+	return 0;
+}
+
+static int __cm_alloc(unsigned long start, unsigned long size)
+{
+	unsigned long end, _start, _end;
+	int ret;
+
+	pr_debug("%s(%p+%p)\n", __func__, (void *)start, (void *)size);
+
+	/*
+	 * What we do here is we mark all pageblocks in range as
+	 * MIGRATE_ISOLATE.  Because of the way page allocator work, we
+	 * align the range to MAX_ORDER pages so that page allocator
+	 * won't try to merge buddies from different pageblocks and
+	 * change MIGRATE_ISOLATE to some other migration type.
+	 *
+	 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
+	 * migrate the pages from an unaligned range (ie. pages that
+	 * we are interested in).  This will put all the pages in
+	 * range back to page allocator as MIGRATE_ISOLATE.
+	 *
+	 * When this is done, we take the pages in range from page
+	 * allocator removing them from the buddy system.  This way
+	 * page allocator will never consider using them.
+	 *
+	 * This lets us mark the pageblocks back as MIGRATE_CMA so
+	 * that free pages in the MAX_ORDER aligned range but not in
+	 * the unaligned, original range are put back to page
+	 * allocator so that buddy can use them.
+	 */
+
+	start = phys_to_pfn(start);
+	end   = start + (size >> PAGE_SHIFT);
+
+	pr_debug("\tisolate range(%lx, %lx)\n",
+		 pfn_to_maxpage(start), pfn_to_maxpage_up(end));
+	ret = __start_isolate_page_range(pfn_to_maxpage(start),
+					 pfn_to_maxpage_up(end), MIGRATE_CMA);
+	if (ret)
+		goto done;
+
+	pr_debug("\tmigrate range(%lx, %lx)\n", start, end);
+	ret = __cm_migrate(start, end);
+	if (ret)
+		goto done;
+
+	/*
+	 * Pages from [start, end) are within a MAX_ORDER aligned
+	 * blocks that are marked as MIGRATE_ISOLATE.  What's more,
+	 * all pages in [start, end) are free in page allocator.  What
+	 * we are going to do is to allocate all pages from [start,
+	 * end) (that is remove them from page allocater).
+	 *
+	 * The only problem is that pages at the beginning and at the
+	 * end of interesting range may be not aligned with pages that
+	 * page allocator holds, ie. they can be part of higher order
+	 * pages.  Because of this, we reserve the bigger range and
+	 * once this is done free the pages we are not interested in.
+	 */
+
+	pr_debug("\tfinding buddy\n");
+	ret = 0;
+	while (!PageBuddy(pfn_to_page(start & (~0UL << ret))))
+		if (WARN_ON(++ret >= MAX_ORDER))
+			return -EINVAL;
+
+	_start = start & (~0UL << ret);
+	pr_debug("\talloc freed(%lx, %lx)\n", _start, end);
+	_end   = alloc_contig_freed_pages(_start, end, 0);
+
+	/* Free head and tail (if any) */
+	pr_debug("\tfree contig(%lx, %lx)\n", _start, start);
+	free_contig_pages(pfn_to_page(_start), start - _start);
+	pr_debug("\tfree contig(%lx, %lx)\n", end, _end);
+	free_contig_pages(pfn_to_page(end), _end - end);
+
+	ret = 0;
+
+done:
+	pr_debug("\tundo isolate range(%lx, %lx)\n",
+		 pfn_to_maxpage(start), pfn_to_maxpage_up(end));
+	__undo_isolate_page_range(pfn_to_maxpage(start),
+				  pfn_to_maxpage_up(end), MIGRATE_CMA);
+
+	pr_debug("ret = %d\n", ret);
+	return ret;
+}
+
+static void __cm_free(unsigned long start, unsigned long size)
+{
+	pr_debug("%s(%p+%p)\n", __func__, (void *)start, (void *)size);
+
+	free_contig_pages(pfn_to_page(phys_to_pfn(start)),
+			  size >> PAGE_SHIFT);
+}
