Workaround for Neoverse N1 erratum 1868343
Neoverse N1 erratum 1868343 is a Cat B erratum, present in older
revisions of the Neoverse N1 processor core. The workaround is to
set a bit in the CPUACTLR_EL1 system register, which delays instruction
fetch after branch misprediction. This workaround will have a small
impact on performance.
SDEN can be found here:
https://documentation-service.arm.com/static/5f2c130260a93e65927bc92f
Signed-off-by: John Powell <john.powell@arm.com>
Change-Id: I37da2b3b2da697701b883bff9a1eff2772352844
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index 8fc3b60..7cd8ed9 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -334,6 +334,10 @@
# to revisions r3p0 - r4p0 of the Neoverse N1 cpu.
ERRATA_N1_1542419 ?=0
+# Flag to apply erratum 1868343 workaround during reset. This erratum applies
+# to revision <= r4p0 of the Neoverse N1 cpu.
+ERRATA_N1_1868343 ?=0
+
# Flag to apply DSU erratum 798953. This erratum applies to DSUs revision r0p0.
# Applying the workaround results in higher DSU power consumption on idle.
ERRATA_DSU_798953 ?=0
@@ -603,6 +607,10 @@
$(eval $(call assert_boolean,ERRATA_N1_1542419))
$(eval $(call add_define,ERRATA_N1_1542419))
+# Process ERRATA_N1_1868343 flag
+$(eval $(call assert_boolean,ERRATA_N1_1868343))
+$(eval $(call add_define,ERRATA_N1_1868343))
+
# Process ERRATA_DSU_798953 flag
$(eval $(call assert_boolean,ERRATA_DSU_798953))
$(eval $(call add_define,ERRATA_DSU_798953))