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authorRussell King <rmk+kernel@arm.linux.org.uk>2011-07-08 21:26:59 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2011-07-12 11:08:12 +0100
commit022ae537b23cb14a391565e9ad9e9945f4b17138 (patch)
treee167c03036fcc09d7131fa364efa70c9e3d5b92a /arch/arm/mm/dma-mapping.c
parent3973c337759cd201773a0ecc7b6f39f1ea2a6287 (diff)
ARM: dma: replace ISA_DMA_THRESHOLD with a variable
ISA_DMA_THRESHOLD has been unused by non-arch code, so lets now get rid of it from ARM by replacing it with arm_dma_zone_mask. Move dma_supported() and dma_set_mask() out of line, and have dma_supported() check this new variable instead. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm/dma-mapping.c')
-rw-r--r--arch/arm/mm/dma-mapping.c35
1 files changed, 32 insertions, 3 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 82a093cee09a..0a0a1e7c20d2 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -25,9 +25,11 @@
#include <asm/tlbflush.h>
#include <asm/sizes.h>
+#include "mm.h"
+
static u64 get_coherent_dma_mask(struct device *dev)
{
- u64 mask = ISA_DMA_THRESHOLD;
+ u64 mask = (u64)arm_dma_limit;
if (dev) {
mask = dev->coherent_dma_mask;
@@ -41,10 +43,10 @@ static u64 get_coherent_dma_mask(struct device *dev)
return 0;
}
- if ((~mask) & ISA_DMA_THRESHOLD) {
+ if ((~mask) & (u64)arm_dma_limit) {
dev_warn(dev, "coherent DMA mask %#llx is smaller "
"than system GFP_DMA mask %#llx\n",
- mask, (unsigned long long)ISA_DMA_THRESHOLD);
+ mask, (u64)arm_dma_limit);
return 0;
}
}
@@ -657,6 +659,33 @@ void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
}
EXPORT_SYMBOL(dma_sync_sg_for_device);
+/*
+ * Return whether the given device DMA address mask can be supported
+ * properly. For example, if your device can only drive the low 24-bits
+ * during bus mastering, then you would pass 0x00ffffff as the mask
+ * to this function.
+ */
+int dma_supported(struct device *dev, u64 mask)
+{
+ if (mask < (u64)arm_dma_limit)
+ return 0;
+ return 1;
+}
+EXPORT_SYMBOL(dma_supported);
+
+int dma_set_mask(struct device *dev, u64 dma_mask)
+{
+ if (!dev->dma_mask || !dma_supported(dev, dma_mask))
+ return -EIO;
+
+#ifndef CONFIG_DMABOUNCE
+ *dev->dma_mask = dma_mask;
+#endif
+
+ return 0;
+}
+EXPORT_SYMBOL(dma_set_mask);
+
#define PREALLOC_DMA_DEBUG_ENTRIES 4096
static int __init dma_debug_do_init(void)