[PATCH] dma-mapping: fix sync_single_range_* DMA debugging

[Clemens Ladisch <clemens@ladisch.de>]

Commit 5fd75a7850b5 (dma-mapping: remove unnecessary sync_single_range_*
in dma_map_ops) unified not only the dma_map_ops but also the
corresponding debug_dma_sync_* calls.  This led to spurious WARN()ings
like the following because the DMA debug code was no longer able to
detect the DMA buffer base address without the separate offset parameter:

WARNING: at lib/dma-debug.c:911 check_sync+0xce/0x446()
firewire_ohci 0000:04:00.0: DMA-API: device driver tries to sync DMA memory it has not allocated [device address=0x00000000cedaa400] [size=1024 bytes]
Call Trace: ...
 [<ffffffff811326a5>] check_sync+0xce/0x446
 [<ffffffff81132ad9>] debug_dma_sync_single_for_device+0x39/0x3b
 [<ffffffffa01d6e6a>] ohci_queue_iso+0x4f3/0x77d [firewire_ohci]
 ...

To fix this, unshare the sync_single_* and sync_single_range_*
implementations so that we are able to call the correct debug_dma_sync_*
functions.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
---
 include/asm-generic/dma-mapping-common.h |   14 ++++++++++++--
 1 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/include/asm-generic/dma-mapping-common.h b/include/asm-generic/dma-mapping-common.h
index 0c80bb3..9e31514 100644
--- a/include/asm-generic/dma-mapping-common.h
+++ b/include/asm-generic/dma-mapping-common.h
@@ -123,7 +123,12 @@ static inline void dma_sync_single_range_for_cpu(struct device *dev,
 						 size_t size,
 						 enum dma_data_direction dir)
 {
-	dma_sync_single_for_cpu(dev, addr + offset, size, dir);
+	struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!valid_dma_direction(dir));
+	if (ops->sync_single_for_cpu)
+		ops->sync_single_for_cpu(dev, addr + offset, size, dir);
+	debug_dma_sync_single_range_for_cpu(dev, addr, offset, size, dir);
 }

 static inline void dma_sync_single_range_for_device(struct device *dev,
@@ -132,7 +137,12 @@ static inline void dma_sync_single_range_for_device(struct device *dev,
 						    size_t size,
 						    enum dma_data_direction dir)
 {
-	dma_sync_single_for_device(dev, addr + offset, size, dir);
+	struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!valid_dma_direction(dir));
+	if (ops->sync_single_for_device)
+		ops->sync_single_for_device(dev, addr + offset, size, dir);
+	debug_dma_sync_single_range_for_device(dev, addr, offset, size, dir);
 }

 static inline void