Re: [PATCH 2/7] DAC960: don't use block layer bounce buffers

[Johannes Thumshirn]

Looks good,
Reviewed-by: Johannes Thumshirn 
-- 
Johannes Thumshirn  Storage
jthumsh...@suse.de+49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)
Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850

[PATCH 2/7] DAC960: don't use block layer bounce buffers

[Christoph Hellwig]

DAC960 just sets the block bounce limit to the dma mask, which means
that the iommu or swiotlb already take care of the bounce buffering,
and the block bouncing can be removed.

Signed-off-by: Christoph Hellwig 
---
 drivers/block/DAC960.c | 9 ++---
 drivers/block/DAC960.h | 1 -
 2 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/drivers/block/DAC960.c b/drivers/block/DAC960.c
index f781eff7d23e..c9ba48519d0f 100644
--- a/drivers/block/DAC960.c
+++ b/drivers/block/DAC960.c
@@ -1179,7 +1179,6 @@ static bool 
DAC960_V1_EnableMemoryMailboxInterface(DAC960_Controller_T
 
   if (pci_set_dma_mask(Controller->PCIDevice, DMA_BIT_MASK(32)))
return DAC960_Failure(Controller, "DMA mask out of range");
-  Controller->BounceBufferLimit = DMA_BIT_MASK(32);
 
   if ((hw_type == DAC960_PD_Controller) || (hw_type == DAC960_P_Controller)) {
 CommandMailboxesSize =  0;
@@ -1380,11 +1379,8 @@ static bool 
DAC960_V2_EnableMemoryMailboxInterface(DAC960_Controller_T
   dma_addr_t   CommandMailboxDMA;
   DAC960_V2_CommandStatus_T CommandStatus;
 
-   if (!pci_set_dma_mask(Controller->PCIDevice, DMA_BIT_MASK(64)))
-   Controller->BounceBufferLimit = DMA_BIT_MASK(64);
-   else if (!pci_set_dma_mask(Controller->PCIDevice, DMA_BIT_MASK(32)))
-   Controller->BounceBufferLimit = DMA_BIT_MASK(32);
-   else
+   if (pci_set_dma_mask(Controller->PCIDevice, DMA_BIT_MASK(64)) &&
+   pci_set_dma_mask(Controller->PCIDevice, DMA_BIT_MASK(32)))
return DAC960_Failure(Controller, "DMA mask out of range");
 
   /* This is a temporary dma mapping, used only in the scope of this function 
*/
@@ -2540,7 +2536,6 @@ static bool 
DAC960_RegisterBlockDevice(DAC960_Controller_T *Controller)
continue;
}
Controller->RequestQueue[n] = RequestQueue;
-   blk_queue_bounce_limit(RequestQueue, Controller->BounceBufferLimit);
RequestQueue->queuedata = Controller;
blk_queue_max_segments(RequestQueue, 
Controller->DriverScatterGatherLimit);
blk_queue_max_hw_sectors(RequestQueue, Controller->MaxBlocksPerCommand);
diff --git a/drivers/block/DAC960.h b/drivers/block/DAC960.h
index 21aff470d268..1439e651928b 100644
--- a/drivers/block/DAC960.h
+++ b/drivers/block/DAC960.h
@@ -2295,7 +2295,6 @@ typedef struct DAC960_Controller
   unsigned short MaxBlocksPerCommand;
   unsigned short ControllerScatterGatherLimit;
   unsigned short DriverScatterGatherLimit;
-  u64  BounceBufferLimit;
   unsigned int CombinedStatusBufferLength;
   unsigned int InitialStatusLength;
   unsigned int CurrentStatusLength;
-- 
2.17.0