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>

1 files changed, 4 insertions, 1 deletions

diff --git a/mm/cma.c b/mm/cma.c
index 5aa1a6f74dec..62a5dccc3fb8 100644
--- 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;