Messages in this thread | | | Subject | Re: PCI DMA to small buffers on cache-incoherent arch | From | Roland Dreier <> | Date | 08 Jun 2002 17:52:49 -0700 |
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>>>>> "Anton" == Anton Blanchard <anton@samba.org> writes:
Anton> I just checked 2.5 and noticed the scsi code is _still_ Anton> DMAing to the stack! Maybe it would be worth having a debug Anton> option for x86 where it uses vmalloc for kernel stack Anton> allocation :)
Good catches, just a few comments on the patch.
Anton> Anyway attached is a patch from Todd Inglett that I updated Anton> for 2.5.
===== drivers/scsi/scsi_scan.c 1.13 vs edited ===== - /* Make sure we have something that is valid for DMA purposes */ - scsi_result = ((!shpnt->unchecked_isa_dma) - ? &scsi_result0[0] : kmalloc(512, GFP_DMA)); + scsi_result = kmalloc(512, GFP_DMA);
I don't think you should always use GFP_DMA here... probably better to do:
scsi_result = kmalloc(512, shpnt->unchecked_isa_dma ? GFP_DMA : GFP_ATOMIC);
And similarly this:
===== drivers/scsi/sr_ioctl.c 1.13 vs edited ===== + unsigned char *buffer = kmalloc(512, GFP_DMA);
should probably use GFP_KERNEL (or possibly a check of unchecked_isa_dma as above, though this doesn't seem to be needed based on the existing code).
Best, Roland - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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