The prior approach using the L2 cache was flawed as it assumed L2
page entries had a 1-1 correspondence with actual pages. While the L2
cache could be extended to handle aliases with EC, this could lead to
thrashing etc. The cost of a lookup in the actual EC code bitmap is
cheap enough to perform every time considering the infrequency of calls
to ARM64EC code when compare to X86 L2 hits.
Billy Laws
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