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ieee1394: sbp2: optimize DMA direction of s/g tables 

Unlike the name suggests, "cmd->scatter_gather_element" holds only the
s/g table, not the actual s/g elements.  Since the table is only read
but never written by the device, DMA_BIDIRECTIONAL can be replaced by
DMA_TO_DEVICE which may be cheaper on some architectures.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This commit is contained in:
Stefan Richter 2007-02-04 20:54:57 +01:00
parent 0555659d63
commit 2446a79f4f
1 changed files with 6 additions and 6 deletions
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12
drivers/ieee1394/sbp2.c
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@ -489,7 +489,7 @@ static int sbp2util_create_command_orb_pool(struct sbp2_lu *lu)
cmd->sge_dma = dma_map_single(hi->host->device.parent,
&cmd->scatter_gather_element,
sizeof(cmd->scatter_gather_element),
DMA_BIDIRECTIONAL);
DMA_TO_DEVICE);
INIT_LIST_HEAD(&cmd->list);
list_add_tail(&cmd->list, &lu->cmd_orb_completed);
}
@ -514,7 +514,7 @@ static void sbp2util_remove_command_orb_pool(struct sbp2_lu *lu)
DMA_TO_DEVICE);
dma_unmap_single(host->device.parent, cmd->sge_dma,
sizeof(cmd->scatter_gather_element),
DMA_BIDIRECTIONAL);
DMA_TO_DEVICE);
kfree(cmd);
}
spin_unlock_irqrestore(&lu->cmd_orb_lock, flags);
@ -1633,7 +1633,7 @@ static void sbp2_link_orb_command(struct sbp2_lu *lu,
DMA_TO_DEVICE);
dma_sync_single_for_device(hi->host->device.parent, cmd->sge_dma,
sizeof(cmd->scatter_gather_element),
DMA_BIDIRECTIONAL);
DMA_TO_DEVICE);
/* check to see if there are any previous orbs to use */
spin_lock_irqsave(&lu->cmd_orb_lock, flags);
@ -1799,7 +1799,7 @@ static int sbp2_handle_status_write(struct hpsb_host *host, int nodeid,
DMA_TO_DEVICE);
dma_sync_single_for_cpu(hi->host->device.parent, cmd->sge_dma,
sizeof(cmd->scatter_gather_element),
DMA_BIDIRECTIONAL);
DMA_TO_DEVICE);
/* Grab SCSI command pointers and check status. */
/*
* FIXME: If the src field in the status is 1, the ORB DMA must
@ -1931,7 +1931,7 @@ static void sbp2scsi_complete_all_commands(struct sbp2_lu *lu, u32 status)
DMA_TO_DEVICE);
dma_sync_single_for_cpu(hi->host->device.parent, cmd->sge_dma,
sizeof(cmd->scatter_gather_element),
DMA_BIDIRECTIONAL);
DMA_TO_DEVICE);
sbp2util_mark_command_completed(lu, cmd);
if (cmd->Current_SCpnt) {
cmd->Current_SCpnt->result = status << 16;
@ -2062,7 +2062,7 @@ static int sbp2scsi_abort(struct scsi_cmnd *SCpnt)
dma_sync_single_for_cpu(hi->host->device.parent,
cmd->sge_dma,
sizeof(cmd->scatter_gather_element),
DMA_BIDIRECTIONAL);
DMA_TO_DEVICE);
sbp2util_mark_command_completed(lu, cmd);
if (cmd->Current_SCpnt) {
cmd->Current_SCpnt->result = DID_ABORT << 16;