Paged user TAs

[jenswi-linaro]

Adds support for paged user TAs

[jenswi-linaro]

Depends on OP-TEE/optee_test#124

[d3zd3z]

There's quite a bit of code, so I wouldn't say my review has been exhaustive, but what I've seen looks good.

[jforissier]

I have tested on HiKey, this is basically OK assuming the following are addressed:

• The increase of emulated SRAM from 200 to 256 KiB is needed for HiKey, too (otherwise xtest is painfully slow). Would you like me to submit a separate PR, or do you want to add it to this series?
• xtest 1016 Storage concurency was recently modified to apply to all filesystems. It is failing with TEEC_ERROR_OUT_OF_MEMORY. Should it be disabled when TA paging is enabled? (I could not find proper memory settings to make it pass).
• Similarly, xtest 1005 Many sessions logs TEEC_ERROR_GENERIC, which I assume are out-of-memory underneath. Can be fixed with 320 KiB of SRAM.

[jenswi-linaro]

The xtest 1016 Storage concurrency is a bit tricky. When I'm testing on latest on master branch with pager enabled it sometimes fails. I'm starting to suspect that the pager itself isn't the culprit, instead it just makes it easier for race conditions to be triggered as context switch are suddenly very likely at certain addresses in the code.

[jenswi-linaro]

Rebased on master, squashed the [review] commit. Added a Hikey commit.

[jforissier]

@jenswi-linaro it looks like HiKey needs 40 KiB of HEAP_SIZE to pass xtest 6016 reliably when pager is enabled.
There's also the checkpatch error and warning to be addressed.

[jbech-linaro]

Am I'm the only one that get the feeling that we have been fiddling with increasing both stack and heap quite a few times the last year? Maybe time to do an overhaul for all devices we support and at the same time increase to something a bit bigger than we actually need? Also, it might be worth checking whether we really need all of it or if we're unnecessarily use too much of them?

[jenswi-linaro]

Rebased with the memory fiddling patches removed as it's already dealt with on master now.

[jforissier]

Working fine on HiKey.
Tested-by: Jerome Forissier <jerome.forissier@linaro.org> (HiKey)

[d3zd3z]

Acked-by: David Brown <david.brown@linaro.org>

[jenswi-linaro]

Checkpatch warnings/errors fixed, rebased and tags applied.