Current implementation of Bakery Lock does tight-loop waiting upon lock
contention.
This commit reworks the implementation to use WFE instruction for
waiting, and SEV to signal lock availability. It also adds the rationale
for choosing Bakery Locks instead of exclusion primitives, and more
comments for the lock algorithm.
FixesARM-software/tf-issue#67
Change-Id: Ie351d3dbb27ec8e64dbc9507c84af07bd385a7df
Co-authored-by: Vikram Kanigiri <vikram.kanigiri@arm.com>
bakery_lock_release() expects an mpidr as the first argument however
bakery_lock_release() is calling it with the 'entry' argument it has
calculated. Rather than fixing this to pass the mpidr value it would be
much more efficient to just replace the call with
assert(bakery->owner == entry)
As this leaves no remaining users of bakery_lock_held(), we might as
well delete it.
FixesARM-software/tf-issues#27
Signed-off-by: Jon Medhurst <tixy@linaro.org>
- Add instructions for contributing to ARM Trusted Firmware.
- Update copyright text in all files to acknowledge contributors.
Change-Id: I9311aac81b00c6c167d2f8c889aea403b84450e5
Jeenu Viswambharan
Jon Medhurst
Dan Handley
Achin Gupta