iommu/arm-smmu-v3: Fix access for STE.SHCFG
STE attributes(NSCFG, PRIVCFG, INSTCFG) use value 0 for "Use Icomming",
for some reason SHCFG doesn't follow that, and it is defined as "0b01".
Currently the driver sets SHCFG to Use Incoming for stage-2 and bypass
domains.
However according to the User Manual (ARM IHI 0070 F.b):
When SMMU_IDR1.ATTR_TYPES_OVR == 0, this field is RES0 and the
incoming Shareability attribute is used.
This patch adds a condition for writing SHCFG to Use incoming to be
compliant with the architecture, and defines ATTR_TYPE_OVR as a new
feature discovered from IDR1.
This also required to propagate the SMMU through some functions args.
There is no need to add similar condition for the newly introduced function
arm_smmu_get_ste_used() as the values of the STE are the same before and
after any transition, so this will not trigger any change. (we already
do the same for the VMID).
Although this is a misconfiguration from the driver, this has been there
for a long time, so probably no HW running Linux is affected by it.
Reported-by: Will Deacon <will@kernel.org>
Closes: https://lore.kernel.org/all/20240215134952.GA690@willie-the-truck/
Signed-off-by: Mostafa Saleh <smostafa@google.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20240323134658.464743-1-smostafa@google.com
Signed-off-by: Will Deacon <will@kernel.org>
2 files changed
