Hi Christoph,
On 2016-03-21 08:26:01 -0700, Christoph Hellwig wrote:
> On Thu, Mar 17, 2016 at 01:33:51PM +0200, Laurent Pinchart wrote:
> > The good news is that, given that no code uses this new API at the moment,
> > there isn't much to audit. The patch series implements the resource mapping
> > for arch/arm only, and makes use of it in the rcar-dmac driver only. Would you
> > like anything audited else than the arch/arm dma mapping implementation, the
> > rcar-dmac driver and the code that then deals with the dma addresses (I'm
> > thinking about the IOMMU subsystem and the ipmmu-vmsa driver in particular) ?
>
> Yes, it would be good to do an audit of all the ARM dma_ops as well
> as generic code like drivers/base/dma-*.c, lib/dma-debug.c and
> include/linux/dma-*.h
I have now done an audit to the best of my abilities, thanks to Laurent
for pointing me in the right direction. And from what I can tell we are
good.
* drivers/dma/sh/rcar-dmac.c
Once the phys_addr_t is mapped to a dma_addr_t using
dma_map_resource() it is only used to check that the transfere do not
cross 4GB boundaries and then only directly written to HW registers.
* drivers/iommu/iommu.c
- iommu_map()
Check that it's align to min page size or return -EINVAL then calls
domain->ops->map()
* drivers/iommu/ipmmu-vmsa.c
- ipmmu_map()
No logic only calls domain->ops->map()
* drivers/iommu/io-pgtable-arm.c
- arm_lpae_map()
No logic only calls __arm_lpae_map()
- __arm_lpae_map()
No logic only calls arm_lpae_init_pte()
- arm_lpae_init_pte()
Used to get a pte:
pte |= pfn_to_iopte(paddr >> data->pg_shift, data);
* drivers/iommu/io-pgtable-arm-v7s.c
- arm_v7s_map()
No logic only calls __arm_v7s_map()
- __arm_v7s_map()
No logic only calls arm_v7s_init_pte()
- arm_v7s_init_pte
Used to get a pte:
pte |= paddr & ARM_V7S_LVL_MASK(lvl);
* ARM dma-mapping
- dma_unmap_*
Only valid unmap is dma_unmap_resource() all others are an invalid
use case.
- dma_sync_single_*
Invalid use case, memmory that is mapped is device memmory
- dma_common_mmap() and dma_mmap_attrs()
Invalid use case
- dma_common_get_sgtable() and dma_get_sgtable_attrs()
Invalid use case, only for dma_alloc_* allocated memory,
- dma_mapping_error()
OK
--
Regards,
Niklas Söderlund
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