Fast path SMCCC_ARCH_WORKAROUND_1 calls from AArch32 #1405
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When SMCCC_ARCH_WORKAROUND_1 is invoked from a lower EL running in AArch32 state, ensure that the SMC call will take a shortcut in EL3. This minimizes the time it takes to apply the mitigation in EL3. When lower ELs run in AArch32, it is preferred that they execute the `BPIALL` instruction to invalidate the BTB. However, on some cores the `BPIALL` instruction may be a no-op and thus would benefit from making the SMCCC_ARCH_WORKAROUND_1 call go through the fast path. Change-Id: Ia38abd92efe2c4b4a8efa7b70f260e43c5bda8a5 Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>
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When SMCCC_ARCH_WORKAROUND_1 is invoked from a lower EL running in
AArch32 state, ensure that the SMC call will take a shortcut in EL3.
This minimizes the time it takes to apply the mitigation in EL3.
When lower ELs run in AArch32, it is preferred that they execute the
BPIALLinstruction to invalidate the BTB. However, on some coresthe
BPIALLinstruction may be a no-op and thus would benefit frommaking the SMCCC_ARCH_WORKAROUND_1 call go through the fast path.
Change-Id: Ia38abd92efe2c4b4a8efa7b70f260e43c5bda8a5
Signed-off-by: Dimitris Papastamos dimitris.papastamos@arm.com