forked from Minki/linux
d88e0493a0
Replaces the shared memory pool based on two pools with a single pool. The alloc() function pointer in struct tee_shm_pool_ops gets another parameter, align. This makes it possible to make less than page aligned allocations from the optional reserved shared memory pool while still making user space allocations page aligned. With in practice unchanged behaviour using only a single pool for bookkeeping. The allocation algorithm in the static OP-TEE shared memory pool is changed from best-fit to first-fit since only the latter supports an alignment parameter. The best-fit algorithm was previously the default choice and not a conscious one. The optee and amdtee drivers are updated as needed to work with this changed pool handling. This also removes OPTEE_SHM_NUM_PRIV_PAGES which becomes obsolete with this change as the private pages can be mixed with the payload pages. The OP-TEE driver changes minimum alignment for argument struct from 8 bytes to 512 bytes. A typical OP-TEE private shm allocation is 224 bytes (argument struct with 6 parameters, needed for open session). So with an alignment of 512 well waste a bit more than 50%. Before this we had a single page reserved for this so worst case usage compared to that would be 3 pages instead of 1 page. However, this worst case only occurs if there is a high pressure from multiple threads on secure world. All in all this should scale up and down better than fixed boundaries. Reviewed-by: Sumit Garg <sumit.garg@linaro.org> Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
10 lines
251 B
Plaintext
10 lines
251 B
Plaintext
# SPDX-License-Identifier: GPL-2.0-only
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# OP-TEE Trusted Execution Environment Configuration
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config OPTEE
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tristate "OP-TEE"
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depends on HAVE_ARM_SMCCC
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depends on MMU
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help
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This implements the OP-TEE Trusted Execution Environment (TEE)
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driver.
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