ARM: integrate CMA with DMA-mapping subsystem
This patch adds support for CMA to dma-mapping subsystem for ARM
architecture. By default a global CMA area is used, but specific devices
are allowed to have their private memory areas if required (they can be
created with dma_declare_contiguous() function during board
initialisation).
Contiguous memory areas reserved for DMA are remapped with 2-level page
tables on boot. Once a buffer is requested, a low memory kernel mapping
is updated to to match requested memory access type.
GFP_ATOMIC allocations are performed from special pool which is created
early during boot. This way remapping page attributes is not needed on
allocation time.
CMA has been enabled unconditionally for ARMv6+ systems.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
CC: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Rob Clark <rob.clark@linaro.org>
Tested-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Tested-by: Robert Nelson <robertcnelson@gmail.com>
Tested-by: Barry Song <Baohua.Song@csr.com>
Conflicts:
arch/arm/include/asm/mach/map.h
arch/arm/mm/init.c
arch/arm/mm/mm.h
arch/arm/mm/mmu.c
Change-Id: I85e3b43a9fa1e3c4d33cbc85fff6dee1b815041d
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 59e252b..32f61f5 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -22,6 +22,7 @@
#include <linux/gfp.h>
#include <linux/memblock.h>
#include <linux/sort.h>
+#include <linux/dma-contiguous.h>
#include <asm/mach-types.h>
#include <asm/memblock.h>
@@ -235,6 +236,17 @@
}
#endif
+void __init setup_dma_zone(struct machine_desc *mdesc)
+{
+#ifdef CONFIG_ZONE_DMA
+ if (mdesc->dma_zone_size) {
+ arm_dma_zone_size = mdesc->dma_zone_size;
+ arm_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1;
+ } else
+ arm_dma_limit = 0xffffffff;
+#endif
+}
+
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
static void __init arm_bootmem_free_apnm(unsigned long max_low,
unsigned long max_high)
@@ -305,12 +317,9 @@
* Adjust the sizes according to any special requirements for
* this machine type.
*/
- if (arm_dma_zone_size) {
+ if (arm_dma_zone_size)
arm_adjust_dma_zone(zone_size, zhole_size,
arm_dma_zone_size >> PAGE_SHIFT);
- arm_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1;
- } else
- arm_dma_limit = 0xffffffff;
#endif
free_area_init_node(0, zone_size, min, zhole_size);
@@ -425,6 +434,12 @@
if (mdesc->reserve)
mdesc->reserve();
+ /*
+ * reserve memory for DMA contigouos allocations,
+ * must come from DMA area inside low memory
+ */
+ dma_contiguous_reserve(min(arm_dma_limit, arm_lowmem_limit));
+
arm_memblock_steal_permitted = false;
memblock_allow_resize();
memblock_dump_all();