Manish V Badarkhe 45aecff003 Implement workaround for AT speculative behaviour ... During context switching from higher EL (EL2 or higher) to lower EL can cause incorrect translation in TLB due to speculative execution of AT instruction using out-of-context translation regime. Workaround is implemented as below during EL's (EL1 or EL2) "context_restore" operation: 1. Disable page table walk using SCTLR.M and TCR.EPD0 & EPD1 bits for EL1 or EL2 (stage1 and stage2 disabled) 2. Save all system registers except TCR and SCTLR (for EL1 and EL2) 3. Do memory barrier operation (isb) to ensure all system register writes are done. 4. Restore TCR and SCTLR registers (for EL1 and EL2) Errata details are available for various CPUs as below: Cortex-A76: 1165522 Cortex-A72: 1319367 Cortex-A57: 1319537 Cortex-A55: 1530923 Cortex-A53: 1530924 More details can be found in mail-chain: https://lists.trustedfirmware.org/pipermail/tf-a/2020-April/000445.html Currently, Workaround is implemented as build option which is default disabled. Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com> Change-Id: If8545e61f782cb0c2dda7ffbaf50681c825bd2f0		2020-05-14 13:08:54 +00:00
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context.S	Implement workaround for AT speculative behaviour	2020-05-14 13:08:54 +00:00
context_mgmt.c	SPMD: Adds partially supported EL2 registers.	2020-03-03 11:38:26 +00:00
cpu_data.S	Changes necessary to support SEPARATE_NOBITS_REGION feature	2020-01-27 15:33:24 -06:00