fix(cpus): workaround for Cortex X3 erratum 2641945
Cortex X3 erratum 2641945 is a Cat B erratum that applies to all
revisions <= r1p0 and is fixed in r1p1.
The workaround is to disable the affected L1 data cache prefetcher
by setting CPUACTLR6_EL1[41] to 1. Doing so will incur a performance
penalty of ~1%. Contact Arm for an alternate workaround that impacts
power.
SDEN documentation:
https://developer.arm.com/documentation/2055130/latest
Change-Id: Ia6d6ac8a66936c63b8aa8d7698b937f42ba8f044
Signed-off-by: Bipin Ravi <bipin.ravi@arm.com>
diff --git a/lib/cpus/aarch64/cortex_x3.S b/lib/cpus/aarch64/cortex_x3.S
index ea89267..e5a05fc 100644
--- a/lib/cpus/aarch64/cortex_x3.S
+++ b/lib/cpus/aarch64/cortex_x3.S
@@ -61,6 +61,12 @@
check_erratum_ls cortex_x3, ERRATUM(2615812), CPU_REV(1, 1)
+workaround_runtime_start cortex_x3, ERRATUM(2641945), ERRATA_X3_2641945
+ sysreg_bit_set CORTEX_X3_CPUACTLR6_EL1, BIT(41)
+workaround_runtime_end cortex_x3, ERRATUM(2641945), NO_ISB
+
+check_erratum_ls cortex_x3, ERRATUM(2641945), CPU_REV(1, 0)
+
workaround_reset_start cortex_x3, ERRATUM(2742421), ERRATA_X3_2742421
/* Set CPUACTLR5_EL1[56:55] to 2'b01 */
sysreg_bit_set CORTEX_X3_CPUACTLR5_EL1, CORTEX_X3_CPUACTLR5_EL1_BIT_55
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index a99c082..31430ae 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -794,6 +794,10 @@
# to revisions r0p0, r1p0, r1p1 of the Cortex-X3 cpu, it is still open.
CPU_FLAG_LIST += ERRATA_X3_2615812
+# Flag to apply erratum 2641945 workaround on reset. This erratum applies
+# to revisions r0p0 and r1p0 of the Cortex-X3 cpu, it is fixed in r1p1.
+CPU_FLAG_LIST += ERRATA_X3_2641945
+
# Flag to apply erratum 2742421 workaround on reset. This erratum applies
# to revisions r0p0, r1p0 and r1p1 of the Cortex-X3 cpu, it is fixed in r1p2.
CPU_FLAG_LIST += ERRATA_X3_2742421