Re: [PATCH update] ieee1394: sbp2: enforce s/g segment size limit

From: Stefan Richter
Date: Thu Aug 14 2008 - 03:12:45 EST


On 14 Aug, FUJITA Tomonori wrote:
> On Wed, 13 Aug 2008 12:19:59 +0200 (CEST)
> Stefan Richter <stefanr@xxxxxxxxxxxxxxxxx> wrote:
>> I keep the original scsi_sg_count to call dma_unmap_sg with it
>> later.
>
> You need to keep it? You can access to it via scsi_sg_count when
> calling dma_unmap_sg? Seems that firewire code does.

Yes, I can easily do it this way; fixed below.

[...nents in dma_unmap_sg...]
> This is from Documentation/DMA-mapping.txt

Right. How did I forget about that?



From: Stefan Richter <stefanr@xxxxxxxxxxxxxxxxx>
Subject: ieee1394: sbp2: remove redundant struct members

Signed-off-by: Stefan Richter <stefanr@xxxxxxxxxxxxxxxxx>
---
drivers/ieee1394/sbp2.c | 14 +++++---------
drivers/ieee1394/sbp2.h | 4 ----
2 files changed, 5 insertions(+), 13 deletions(-)

Index: linux/drivers/ieee1394/sbp2.c
===================================================================
--- linux.orig/drivers/ieee1394/sbp2.c
+++ linux/drivers/ieee1394/sbp2.c
@@ -656,11 +656,11 @@ static struct sbp2_command_info *sbp2uti
static void sbp2util_mark_command_completed(struct sbp2_lu *lu,
struct sbp2_command_info *cmd)
{
- if (cmd->sg_buffer) {
- dma_unmap_sg(lu->ud->ne->host->device.parent, cmd->sg_buffer,
- cmd->sg_count, cmd->sg_dir);
- cmd->sg_buffer = NULL;
- }
+ if (scsi_sg_count(cmd->Current_SCpnt) > 0)
+ dma_unmap_sg(lu->ud->ne->host->device.parent,
+ scsi_sglist(cmd->Current_SCpnt),
+ scsi_sg_count(cmd->Current_SCpnt),
+ cmd->Current_SCpnt->sc_data_direction);
list_move_tail(&cmd->list, &lu->cmd_orb_completed);
}

@@ -1505,10 +1505,6 @@ static int sbp2_prep_command_orb_sg(stru
if (n == 0)
return -ENOMEM;

- cmd->sg_buffer = sg;
- cmd->sg_count = sg_count;
- cmd->sg_dir = dma_dir;
-
orb->data_descriptor_hi = ORB_SET_NODE_ID(hi->host->node_id);
orb->misc |= ORB_SET_DIRECTION(orb_direction);

Index: linux/drivers/ieee1394/sbp2.h
===================================================================
--- linux.orig/drivers/ieee1394/sbp2.h
+++ linux/drivers/ieee1394/sbp2.h
@@ -252,10 +252,6 @@ struct sbp2_command_info {
struct sbp2_unrestricted_page_table
scatter_gather_element[SG_ALL] __attribute__((aligned(8)));
dma_addr_t sge_dma;
-
- struct scatterlist *sg_buffer;
- int sg_count;
- enum dma_data_direction sg_dir;
};

/* Per FireWire host */


--
Stefan Richter
-=====-==--- =--- -===-
http://arcgraph.de/sr/

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