fix(cpus): workaround for Neoverse N1 erratum 2743102
Neoverse N1 erratum 2743102 is a Cat B erratum that applies to
all revisions <=r4p1 and is still open. The workaround is to
insert a dsb before the isb in the power down sequence.
SDEN documentation:
https://developer.arm.com/documentation/SDEN885747/latest
Signed-off-by: Bipin Ravi <bipin.ravi@arm.com>
Change-Id: I81a8793c1a118764df3ac97b67f5e088f56f6a20
diff --git a/lib/cpus/aarch64/neoverse_n1.S b/lib/cpus/aarch64/neoverse_n1.S
index b75b0c1..ec62519 100644
--- a/lib/cpus/aarch64/neoverse_n1.S
+++ b/lib/cpus/aarch64/neoverse_n1.S
@@ -468,6 +468,30 @@
b cpu_rev_var_range
endfunc check_errata_1946160
+ /* ----------------------------------------------------
+ * Errata Workaround for Neoverse N1 Errata #2743102
+ * This applies to revisions <= r4p1 and is still open.
+ * x0: variant[4:7] and revision[0:3] of current cpu.
+ * Shall clobber: x0-x17
+ * ----------------------------------------------------
+ */
+func errata_n1_2743102_wa
+ mov x17, x30
+ bl check_errata_2743102
+ cbz x0, 1f
+
+ /* dsb before isb of power down sequence */
+ dsb sy
+1:
+ ret x17
+endfunc errata_n1_2743102_wa
+
+func check_errata_2743102
+ /* Applies to all revisions <= r4p1 */
+ mov x1, #0x41
+ b cpu_rev_var_ls
+endfunc check_errata_2743102
+
func check_errata_cve_2022_23960
#if WORKAROUND_CVE_2022_23960
mov x0, #ERRATA_APPLIES
@@ -613,6 +637,12 @@
mrs x0, NEOVERSE_N1_CPUPWRCTLR_EL1
orr x0, x0, #NEOVERSE_N1_CORE_PWRDN_EN_MASK
msr NEOVERSE_N1_CPUPWRCTLR_EL1, x0
+#if ERRATA_N1_2743102
+ mov x15, x30
+ bl cpu_get_rev_var
+ bl errata_n1_2743102_wa
+ mov x30, x15
+#endif /* ERRATA_N1_2743102 */
isb
ret
endfunc neoverse_n1_core_pwr_dwn
@@ -645,6 +675,7 @@
report_errata ERRATA_N1_1542419, neoverse_n1, 1542419
report_errata ERRATA_N1_1868343, neoverse_n1, 1868343
report_errata ERRATA_N1_1946160, neoverse_n1, 1946160
+ report_errata ERRATA_N1_2743102, neoverse_n1, 2743102
report_errata ERRATA_DSU_936184, neoverse_n1, dsu_936184
report_errata WORKAROUND_CVE_2022_23960, neoverse_n1, cve_2022_23960
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index b4421dd..f53bad1 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -450,6 +450,10 @@
# exists in revisions r0p0, r1p0, and r2p0 as well but there is no workaround.
ERRATA_N1_1946160 ?=0
+# Flag to apply erratum 2743102 workaround during powerdown. This erratum
+# applies to all revisions <= r4p1 of the Neoverse N1 cpu and is still open.
+ERRATA_N1_2743102 ?=0
+
# Flag to apply erratum 2002655 workaround during reset. This erratum applies
# to revisions r0p0 of the Neoverse-N2 cpu, it is still open.
ERRATA_N2_2002655 ?=0
@@ -1072,6 +1076,10 @@
$(eval $(call assert_boolean,ERRATA_N1_1946160))
$(eval $(call add_define,ERRATA_N1_1946160))
+# Process ERRATA_N1_2743102 flag
+$(eval $(call assert_boolean,ERRATA_N1_2743102))
+$(eval $(call add_define,ERRATA_N1_2743102))
+#
# Process ERRATA_N2_2002655 flag
$(eval $(call assert_boolean,ERRATA_N2_2002655))
$(eval $(call add_define,ERRATA_N2_2002655))