Messages in this thread | | | Date | Sat, 19 Jan 2019 23:57:39 +0000 | From | Will Deacon <> | Subject | Re: [PATCH v6 2/3] iommu/io-pgtable-arm-v7s: Request DMA32 memory, and improve debugging |
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On Mon, Dec 10, 2018 at 09:15:03AM +0800, Nicolas Boichat wrote: > IOMMUs using ARMv7 short-descriptor format require page tables > (level 1 and 2) to be allocated within the first 4GB of RAM, even > on 64-bit systems. > > For level 1/2 pages, ensure GFP_DMA32 is used if CONFIG_ZONE_DMA32 > is defined (e.g. on arm64 platforms). > > For level 2 pages, allocate a slab cache in SLAB_CACHE_DMA32. Note > that we do not explicitly pass GFP_DMA[32] to kmem_cache_zalloc, > as this is not strictly necessary, and would cause a warning > in mm/sl*b.c, as we did not update GFP_SLAB_BUG_MASK. > > Also, print an error when the physical address does not fit in > 32-bit, to make debugging easier in the future. > > Cc: stable@vger.kernel.org > Fixes: ad67f5a6545f ("arm64: replace ZONE_DMA with ZONE_DMA32") > Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Assuming you're routing all of this via akpm:
Acked-by: Will Deacon <will.deacon@arm.com>
Will
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