ce51b34186
This change affects Intel CPUs only. As most platforms are doing uCode update using FIT, they aren't affected by this code either. Update microcode in MP-init using a single spinlock when running on a Hyper-Threading enabled CPU on pre FIT platforms. This will slow down the MP-init boot flow. Intel SDM and various BWGs specify to use a semaphore to update microcode on one thread per core on Hyper-Threading enabled CPUs. Due to this complex code would be necessary to determine the core #ID, initializing and picking the right semaphore out of CONFIG_MAX_CPUS / 2. Instead use the existing global spinlock already present in MPinit code. Assuming that only pre-FIT platforms with Hyper-Threading enabled and at most 8 threads will ever run into this condition, the boot delay is negligible. This change is a counterproposal to the previous published patch series being much more unsophisticated. Change-Id: I27bf5177859c12e92d6ce7a2966c965d7262b472 Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/49303 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Angel Pons <th3fanbus@gmail.com> |
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