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authorNicolas Pitre <nico@cam.org>2008-09-09 15:54:13 -0400
committerNicolas Pitre <nico@cam.org>2009-03-15 21:01:21 -0400
commit58edb515724f9e63e569536d01ac8d8f8ddb367a (patch)
tree627d3eafefd38b031e776b48d8d04d764912ec92 /arch/arm/common/dmabounce.c
parent43377453af83b8ff8c1c731da1508bd6b84ebfea (diff)
[ARM] make page_to_dma() highmem aware
If a machine class has a custom __virt_to_bus() implementation then it must provide a __arch_page_to_dma() implementation as well which is _not_ based on page_address() to support highmem. This patch fixes existing __arch_page_to_dma() and provide a default implementation otherwise. The default implementation for highmem is based on __pfn_to_bus() which is defined only when no custom __virt_to_bus() is provided by the machine class. That leaves only ebsa110 and footbridge which cannot support highmem until they provide their own __arch_page_to_dma() implementation. But highmem support on those legacy platforms with limited memory is certainly not a priority. Signed-off-by: Nicolas Pitre <nico@marvell.com>
Diffstat (limited to 'arch/arm/common/dmabounce.c')
-rw-r--r--arch/arm/common/dmabounce.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/arm/common/dmabounce.c b/arch/arm/common/dmabounce.c
index f030f0775be..734ac913599 100644
--- a/arch/arm/common/dmabounce.c
+++ b/arch/arm/common/dmabounce.c
@@ -25,6 +25,7 @@
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
+#include <linux/page-flags.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
@@ -349,6 +350,12 @@ dma_addr_t dma_map_page(struct device *dev, struct page *page,
BUG_ON(!valid_dma_direction(dir));
+ if (PageHighMem(page)) {
+ dev_err(dev, "DMA buffer bouncing of HIGHMEM pages "
+ "is not supported\n");
+ return ~0;
+ }
+
return map_single(dev, page_address(page) + offset, size, dir);
}
EXPORT_SYMBOL(dma_map_page);