refactor(cpus): undo errata mitigations
The workarounds introduced in the three patches starting at
888eafa00b99aa06b4ff688407336811a7ff439a assumed that any powerdown
request will be (forced to be) terminal. This assumption can no longer
be the case for new CPUs so there is a need to revisit these older
cores. Since we may wake up, we now need to respect the workaround's
recommendation that the workaround needs to be reverted on wakeup. So do
exactly that.
Introduce a new helper to toggle bits in assembly. This allows us to
call the workaround twice, with the first call setting the workaround
and second undoing it. This is also used for gelas' an travis' powerdown
routines. This is so the same function can be called again
Also fix the condition in the cpu helper macro as it was subtly wrong
Change-Id: Iff9e5251dc9d8670d085d88c070f78991955e7c3
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
diff --git a/lib/psci/aarch64/psci_helpers.S b/lib/psci/aarch64/psci_helpers.S
index cca08c1..088ab43 100644
--- a/lib/psci/aarch64/psci_helpers.S
+++ b/lib/psci/aarch64/psci_helpers.S
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2014-2024, Arm Limited and Contributors. All rights reserved.
+ * Copyright (c) 2014-2025, Arm Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -131,4 +131,12 @@
1:
wfi
b 1b
+
+ /*
+ * in case the WFI wasn't terminal, we have to undo errata mitigations.
+ * These will be smart enough to handle being called the same way
+ */
+ apply_erratum cortex_a710, ERRATUM(2291219), ERRATA_A710_2291219
+ apply_erratum cortex_x3, ERRATUM(2313909), ERRATA_X3_2313909, NO_GET_CPU_REV
+ apply_erratum neoverse_n2, ERRATUM(2326639), ERRATA_N2_2326639, NO_GET_CPU_REV
endfunc psci_power_down_wfi