drivers: dma-contiguous: add initialization from device tree

Add a function to create CMA region from previously reserved memory and
add support for handling 'shared-dma-pool' reserved-memory device tree
nodes.

Based on previous code provided by Josh Cartwright <joshc@codeaurora.org>

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Josh Cartwright <joshc@codeaurora.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/linux/cma.h b/include/linux/cma.h
index 371b93042520..0430ed05d3b9 100644
--- a/include/linux/cma.h
+++ b/include/linux/cma.h
@@ -22,6 +22,9 @@ extern int __init cma_declare_contiguous(phys_addr_t size,
                         phys_addr_t base, phys_addr_t limit,
                         phys_addr_t alignment, unsigned int order_per_bit,
                         bool fixed, struct cma **res_cma);
+extern int cma_init_reserved_mem(phys_addr_t size,
+                                        phys_addr_t base, int order_per_bit,
+                                        struct cma **res_cma);
 extern struct page *cma_alloc(struct cma *cma, int count, unsigned int align);
 extern bool cma_release(struct cma *cma, struct page *pages, int count);
 #endif