littlekernel / lk

LK embedded kernel
MIT License
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[arm][gic] Ensure context switch doesn't happen from irq #276

Closed vishals4gh closed 3 years ago

vishals4gh commented 3 years ago

Context switches should not happen from within the interrupt context before interrupt is cleared by write to GIC EOIR register, without it GIC will simply keep that interrupt active even if the hardware source clears the interrupt to the gic, causing subsequent irqs from the source to not get delivered to the CPU.

This change adds an assertion that context switch doesn't happen from irq context before interrupt is EOIed. TCB field is added to convey if the current thread has interrupt context active, if so thread_resched should ideally not get called.

Signed-off-by: vannapurve vannapurve@google.com