ARM: change ARM_DMA_ZONE_SIZE into a variable
Having this value defined at compile time prevents multiple machines with
conflicting definitions to coexist. Move it to a variable in preparation
for having a per machine value selected at run time. This is relevant
only when CONFIG_ZONE_DMA is selected.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
diff --git a/arch/arm/include/asm/dma.h b/arch/arm/include/asm/dma.h
index 4200554..fcf15de 100644
--- a/arch/arm/include/asm/dma.h
+++ b/arch/arm/include/asm/dma.h
@@ -6,10 +6,13 @@
/*
* This is the maximum virtual address which can be DMA'd from.
*/
-#ifndef ARM_DMA_ZONE_SIZE
-#define MAX_DMA_ADDRESS 0xffffffff
+#ifndef CONFIG_ZONE_DMA
+#define MAX_DMA_ADDRESS 0xffffffffUL
#else
-#define MAX_DMA_ADDRESS (PAGE_OFFSET + ARM_DMA_ZONE_SIZE)
+#define MAX_DMA_ADDRESS ({ \
+ extern unsigned long arm_dma_zone_size; \
+ arm_dma_zone_size ? \
+ (PAGE_OFFSET + arm_dma_zone_size) : 0xffffffffUL; })
#endif
#ifdef CONFIG_ISA_DMA_API
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 17d6cd0c..4a8a01e 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -28,6 +28,7 @@
#include <asm/sizes.h>
#include <asm/tlb.h>
#include <asm/fixmap.h>
+#include <asm/memory.h>
#include <asm/mach/arch.h>
#include <asm/mach/map.h>
@@ -212,6 +213,14 @@
}
#ifdef CONFIG_ZONE_DMA
+
+#ifdef ARM_DMA_ZONE_SIZE
+unsigned long arm_dma_zone_size = ARM_DMA_ZONE_SIZE;
+#else
+unsigned long arm_dma_zone_size __read_mostly;
+#endif
+EXPORT_SYMBOL(arm_dma_zone_size);
+
/*
* The DMA mask corresponding to the maximum bus address allocatable
* using GFP_DMA. The default here places no restriction on DMA
@@ -275,19 +284,17 @@
#endif
}
-#ifdef ARM_DMA_ZONE_SIZE
-#ifndef CONFIG_ZONE_DMA
-#error ARM_DMA_ZONE_SIZE set but no DMA zone to limit allocations
-#endif
-
+#ifdef CONFIG_ZONE_DMA
/*
* Adjust the sizes according to any special requirements for
* this machine type.
*/
- arm_adjust_dma_zone(zone_size, zhole_size,
- ARM_DMA_ZONE_SIZE >> PAGE_SHIFT);
-
- arm_dma_limit = PHYS_OFFSET + ARM_DMA_ZONE_SIZE - 1;
+ 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);