ieee1394: sbp2: optimize DMA direction of command ORBs

Only the driver writes ORBs, the device just reads them.  Therefore
PCI_DMA_BIDIRECTIONAL can be replaced by PCI_DMA_TODEVICE which may be
cheaper on some architectures.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

diff --git a/drivers/ieee1394/sbp2.c b/drivers/ieee1394/sbp2.c
index 670a139..11595df 100644 (file)
--- a/drivers/ieee1394/sbp2.c
+++ b/drivers/ieee1394/sbp2.c
@@ -492,7 +492,7 @@ static int sbp2util_create_command_orb_pool(struct scsi_id_instance_data *scsi_i
                command->command_orb_dma =
                    pci_map_single(hi->host->pdev, &command->command_orb,
                                   sizeof(struct sbp2_command_orb),
-                                  PCI_DMA_BIDIRECTIONAL);
+                                  PCI_DMA_TODEVICE);
                SBP2_DMA_ALLOC("single command orb DMA");
                command->sge_dma =
                    pci_map_single(hi->host->pdev,
@@ -525,7 +525,7 @@ static void sbp2util_remove_command_orb_pool(struct scsi_id_instance_data *scsi_
                        /* Release our generic DMA's */
                        pci_unmap_single(host->pdev, command->command_orb_dma,
                                         sizeof(struct sbp2_command_orb),
-                                        PCI_DMA_BIDIRECTIONAL);
+                                        PCI_DMA_TODEVICE);
                        SBP2_DMA_FREE("single command orb DMA");
                        pci_unmap_single(host->pdev, command->sge_dma,
                                         sizeof(command->scatter_gather_element),
@@ -1982,7 +1982,7 @@ static void sbp2_link_orb_command(struct scsi_id_instance_data *scsi_id,
 
        pci_dma_sync_single_for_device(hi->host->pdev, command->command_orb_dma,
                                       sizeof(struct sbp2_command_orb),
-                                      PCI_DMA_BIDIRECTIONAL);
+                                      PCI_DMA_TODEVICE);
        pci_dma_sync_single_for_device(hi->host->pdev, command->sge_dma,
                                       sizeof(command->scatter_gather_element),
                                       PCI_DMA_BIDIRECTIONAL);
@@ -2012,14 +2012,14 @@ static void sbp2_link_orb_command(struct scsi_id_instance_data *scsi_id,
                 */
                pci_dma_sync_single_for_cpu(hi->host->pdev, last_orb_dma,
                                            sizeof(struct sbp2_command_orb),
-                                           PCI_DMA_BIDIRECTIONAL);
+                                           PCI_DMA_TODEVICE);
                last_orb->next_ORB_lo = cpu_to_be32(command->command_orb_dma);
                wmb();
                /* Tells hardware that this pointer is valid */
                last_orb->next_ORB_hi = 0;
                pci_dma_sync_single_for_device(hi->host->pdev, last_orb_dma,
                                               sizeof(struct sbp2_command_orb),
-                                              PCI_DMA_BIDIRECTIONAL);
+                                              PCI_DMA_TODEVICE);
                addr += SBP2_DOORBELL_OFFSET;
                data[0] = 0;
                length = 4;
@@ -2176,7 +2176,7 @@ static int sbp2_handle_status_write(struct hpsb_host *host, int nodeid, int dest
                SBP2_DEBUG("Found status for command ORB");
                pci_dma_sync_single_for_cpu(hi->host->pdev, command->command_orb_dma,
                                            sizeof(struct sbp2_command_orb),
-                                           PCI_DMA_BIDIRECTIONAL);
+                                           PCI_DMA_TODEVICE);
                pci_dma_sync_single_for_cpu(hi->host->pdev, command->sge_dma,
                                            sizeof(command->scatter_gather_element),
                                            PCI_DMA_BIDIRECTIONAL);
@@ -2365,7 +2365,7 @@ static void sbp2scsi_complete_all_commands(struct scsi_id_instance_data *scsi_id
                command = list_entry(lh, struct sbp2_command_info, list);
                pci_dma_sync_single_for_cpu(hi->host->pdev, command->command_orb_dma,
                                            sizeof(struct sbp2_command_orb),
-                                           PCI_DMA_BIDIRECTIONAL);
+                                           PCI_DMA_TODEVICE);
                pci_dma_sync_single_for_cpu(hi->host->pdev, command->sge_dma,
                                            sizeof(command->scatter_gather_element),
                                            PCI_DMA_BIDIRECTIONAL);
@@ -2548,7 +2548,7 @@ static int sbp2scsi_abort(struct scsi_cmnd *SCpnt)
                        pci_dma_sync_single_for_cpu(hi->host->pdev,
                                                    command->command_orb_dma,
                                                    sizeof(struct sbp2_command_orb),
-                                                   PCI_DMA_BIDIRECTIONAL);
+                                                   PCI_DMA_TODEVICE);
                        pci_dma_sync_single_for_cpu(hi->host->pdev,
                                                    command->sge_dma,
                                                    sizeof(command->scatter_gather_element),