Perfect! ACK!
Thanks for the suggestion.
Sincerely -- Mark Salyzyn
On May 3, 2008, at 6:51 AM, Matthew Wilcox wrote:
. . .
Thanks for the explanation of the quirks and options. I don't want to
drop support for any cards, I just want to make aacraid not rely on
the meaning of num_physpages.
The question aacraid wants to ask is "Does this device have to
do DAC to access memory?" The answer can be affected by an IOMMU or
by memory layout. It's far from clear what question num_physpages is
intended to answer; there are different bits of the kernel using it in
interesting ways. But we do have a function designed to answer the
question you want to ask: dma_get_required_mask(). This may be an
expensive question to ask, so in the below patch I cache the answer in
the aac_dev.
Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
diff --git a/drivers/scsi/aacraid/aachba.c b/drivers/scsi/aacraid/
aachba.c
index 460d402..cd0865d 100644
--- a/drivers/scsi/aacraid/aachba.c
+++ b/drivers/scsi/aacraid/aachba.c
@@ -1201,9 +1201,8 @@ static int aac_scsi_32(struct fib * fib,
struct scsi_cmnd * cmd)
static int aac_scsi_32_64(struct fib * fib, struct scsi_cmnd * cmd)
{
- if ((sizeof(dma_addr_t) > 4) &&
- (num_physpages > (0xFFFFFFFFULL >> PAGE_SHIFT)) &&
- (fib->dev->adapter_info.options & AAC_OPT_SGMAP_HOST64))
+ if ((sizeof(dma_addr_t) > 4) && fib->dev->needs_dac &&
+ (fib->dev->adapter_info.options & AAC_OPT_SGMAP_HOST64))
return FAILED;
return aac_scsi_32(fib, cmd);
}
@@ -1394,6 +1393,9 @@ int aac_get_adapter_info(struct aac_dev* dev)
rcode = -ENOMEM;
}
}
+ if (dma_get_required_mask(&dev->pdev->dev) > DMA_32BIT_MASK)
+ dev->needs_dac = 1;
+
/*
* Deal with configuring for the individualized limits of each packet
* interface.
diff --git a/drivers/scsi/aacraid/aacraid.h b/drivers/scsi/aacraid/
aacraid.h
index 113ca9c..a06c817 100644
--- a/drivers/scsi/aacraid/aacraid.h
+++ b/drivers/scsi/aacraid/aacraid.h
@@ -1016,6 +1016,7 @@ struct aac_dev
u8 jbod;
u8 cache_protected;
u8 dac_support;
+ u8 needs_dac;
u8 raid_scsi_mode;
u8 comm_interface;
# define AAC_COMM_PRODUCER 0
--
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