diff options
| author | Robin Murphy <robin.murphy@arm.com> | 2020-01-10 18:21:51 +0300 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2020-01-10 18:52:24 +0300 |
| commit | 7618e479098226799207e021e8b0c2c28a23c96b (patch) | |
| tree | 88d16130a3dcd4a363164def8493788fc7e28604 /drivers/iommu/io-pgtable-arm-v7s.c | |
| parent | 30d2acb67348537dbf3180057c11f092f4603090 (diff) | |
| download | linux-7618e479098226799207e021e8b0c2c28a23c96b.tar.xz | |
iommu/io-pgtable-arm: Improve attribute handling
By VMSA rules, using Normal Non-Cacheable type with a shareability
attribute of anything other than Outer Shareable is liable to lead into
unpredictable territory:
| Overlaying the shareability attribute (B3-1377, ARM DDI 0406C.c)
|
| A memory region with a resultant memory type attribute of Normal, and
| a resultant cacheability attribute of Inner Non-cacheable, Outer
| Non-cacheable, must have a resultant shareability attribute of Outer
| Shareable, otherwise shareability is UNPREDICTABLE
Although the SMMU architectures seem to give some slightly stronger
guarantees of Non-Cacheable output types becoming implicitly Outer
Shareable in most cases, we may as well be explicit and not take any
chances. It's also weird that LPAE attribute handling is currently split
between prot_to_pte() and init_pte() given that it can all be statically
determined up-front. Thus, collect *all* the LPAE attributes into
prot_to_pte() in order to logically pick the shareability based on the
incoming IOMMU API prot value, and tweak the short-descriptor code to
stop setting TTBR0.NOS for Non-Cacheable walks.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'drivers/iommu/io-pgtable-arm-v7s.c')
| -rw-r--r-- | drivers/iommu/io-pgtable-arm-v7s.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c index eac886f7619d..697ffffe34df 100644 --- a/drivers/iommu/io-pgtable-arm-v7s.c +++ b/drivers/iommu/io-pgtable-arm-v7s.c @@ -823,10 +823,9 @@ static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg, wmb(); /* TTBR */ - cfg->arm_v7s_cfg.ttbr = virt_to_phys(data->pgd) | - ARM_V7S_TTBR_S | ARM_V7S_TTBR_NOS | - (cfg->coherent_walk ? - (ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_WBWA) | + cfg->arm_v7s_cfg.ttbr = virt_to_phys(data->pgd) | ARM_V7S_TTBR_S | + (cfg->coherent_walk ? (ARM_V7S_TTBR_NOS | + ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_WBWA) | ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_WBWA)) : (ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_NC) | ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_NC))); |