Hi Robin,
On 2020-04-20 22:39, Robin Murphy wrote:
On 2020-04-20 5:42 pm, Sai Prakash Ranjan wrote:
From: Sibi Sankar <sibis@xxxxxxxxxxxxxx>
Request direct mapping for modem on platforms which don't have
TrustZone
(which programs the modem SIDs) to prevent the following global faults
seen
on Cheza/Trogdor:
Not strictly true - it's patch #6/6 that prevents *those* faults (and
these days the driver should be reporting unmatched streams a little
more helpfully). This change would resolve the context faults and/or
weird memory corruption that might result from applying patch #6 alone
- this is the crazy thing where transactions sometimes go directly to
DRAM round the side of the SMMU so we can never safely remap anything,
right?
True this doesnt prevent global faults, the fault details should go to
patch6.
I'll update the commit msg something like below:
The Q6 modem sub-system has direct access to DDR through memnoc.
Also SMMU is not expected to provide access control/translation for
these SIDs
(sandboxing of the modem is achieved through XPUs engaged using SMC
calls).
Thanks,
Sai
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