Messages in this thread | | | Date | Mon, 11 Jul 2022 11:42:43 +0100 | Subject | Re: [PATCH] swiotlb: ensure io_tlb_default_mem spinlock always initialised | From | Ben Dooks <> |
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On 11/07/2022 11:39, Christoph Hellwig wrote: > On Mon, Jul 11, 2022 at 11:24:51AM +0100, Ben Dooks wrote: >> On 11/07/2022 11:21, Christoph Hellwig wrote: >>> On Mon, Jul 11, 2022 at 11:07:17AM +0100, Robin Murphy wrote: >>>> If none of your peripherals should need SWIOTLB, then the fact that >>>> you're ending up in swiotlb_map() at all is a clear sign that >>>> something's wrong. Most likely someone's forgotten to set their DMA >>>> masks correctly. >>> >>> Yes. >> >> Possibly, we had at least one driver which attempted to set a 32 bit >> DMA mask which had to be removed as the DMA layer accepts this but >> since there is no DMA32 memory the allocator then just fails. >> >> I expect the above may need to be a separate discussion(s) of how to >> default the DMA mask and how to stop the implicit acceptance of setting >> a 32-bit DMA mask. > > No. Linux simply assumes you can do 32-bit DMA and this won't > change. So we'll need to fix your platform to support swiotlb > eventually.
Ok, is there any examples currently in the kernel that have no memory in the DMA32 zone that do use swiotlb?
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