mm: cma: Always consider a 0 base address reservation as dynamic

The fixed parameter to cma_declare_contiguous() tells the function
whether the given base address must be honoured or should be considered
as a hint only. The API considers a zero base address as meaning any
base address, which must never be considered as a fixed value.

Part of the implementation correctly checks both fixed and base != 0,
but two locations check the fixed value only. Set fixed to false when
base is 0 to fix that and simplify the code.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

diff --git a/mm/cma.c b/mm/cma.c
index 5aa1a6f..62a5dcc 100644 (file)
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -245,6 +245,9 @@ int __init cma_declare_contiguous(phys_addr_t base,
        size = ALIGN(size, alignment);
        limit &= ~(alignment - 1);
 
+       if (!base)
+               fixed = false;
+
        /* size should be aligned with order_per_bit */
        if (!IS_ALIGNED(size >> PAGE_SHIFT, 1 << order_per_bit))
                return -EINVAL;
@@ -268,7 +271,7 @@ int __init cma_declare_contiguous(phys_addr_t base,
        }
 
        /* Reserve memory */
-       if (base && fixed) {
+       if (fixed) {
                if (memblock_is_region_reserved(base, size) ||
                    memblock_reserve(base, size) < 0) {
                        ret = -EBUSY;