fix(cpus): workaround for Neoverse-N2 erratum 2326639
Neoverse-N2 erratum 2326639 is a Cat B erratum that applies to revision
r0p0 and is fixed in r0p1. The workaround is to set CPUACTLR2_EL1[36] to
1 before the power down sequence that sets CORE_PWRDN_EN. This allows
the cpu to retry the power down and prevents the deadlock. TF-A never
clears this bit even if it wakes up from the wfi in the sequence since
it is not expected to do anything but retry to power down after and the
bit is cleared on reset.
SDEN can be found here:
https://developer.arm.com/documentation/SDEN1982442/latest/
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: I9a325c5b9b498798e5efd5c79a4a6d5bed97c619
diff --git a/include/lib/cpus/aarch64/neoverse_n2.h b/include/lib/cpus/aarch64/neoverse_n2.h
index 3ff817c..cb1be5b 100644
--- a/include/lib/cpus/aarch64/neoverse_n2.h
+++ b/include/lib/cpus/aarch64/neoverse_n2.h
@@ -39,6 +39,7 @@
#define NEOVERSE_N2_CPUACTLR2_EL1 S3_0_C15_C1_1
#define NEOVERSE_N2_CPUACTLR2_EL1_BIT_0 (ULL(1) << 0)
#define NEOVERSE_N2_CPUACTLR2_EL1_BIT_2 (ULL(1) << 2)
+#define NEOVERSE_N2_CPUACTLR2_EL1_BIT_36 (ULL(1) << 36)
#define NEOVERSE_N2_CPUACTLR2_EL1_BIT_40 (ULL(1) << 40)
/*******************************************************************************