fix(cpus): workaround for Cortex-A710 erratum 2768515
Cortex-A710 erratum 2768515 is a Cat B erratum that applies to
all revisions <=r2p1 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/SDEN1775101/latest
Signed-off-by: Bipin Ravi <bipin.ravi@arm.com>
Change-Id: If17fe04d3fda0dba6b8aabdd837a1c53e1830ed5
diff --git a/docs/design/cpu-specific-build-macros.rst b/docs/design/cpu-specific-build-macros.rst
index d48f284..368da0a 100644
--- a/docs/design/cpu-specific-build-macros.rst
+++ b/docs/design/cpu-specific-build-macros.rst
@@ -518,6 +518,10 @@
Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0 and r2p0
of the CPU and is fixed in r2p1.
+- ``ERRATA_A710_2768515``: This applies errata 2768515 workaround to
+ Cortex-A710 CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and
+ r2p1 of the CPU and is still open.
+
For Neoverse N2, the following errata build flags are defined :
- ``ERRATA_N2_2002655``: This applies errata 2002655 workaround to Neoverse-N2
diff --git a/lib/cpus/aarch64/cortex_a710.S b/lib/cpus/aarch64/cortex_a710.S
index fed3f33..3ea55df 100644
--- a/lib/cpus/aarch64/cortex_a710.S
+++ b/lib/cpus/aarch64/cortex_a710.S
@@ -482,6 +482,30 @@
b cpu_rev_var_ls
endfunc check_errata_2371105
+/* ----------------------------------------------------
+ * Errata Workaround for Cortex-A710 Errata #2768515
+ * This applies to revisions <= r2p1 and is still open.
+ * x0: variant[4:7] and revision[0:3] of current cpu.
+ * Shall clobber: x0-x17
+ * ----------------------------------------------------
+ */
+func errata_a710_2768515_wa
+ mov x17, x30
+ bl check_errata_2768515
+ cbz x0, 1f
+
+ /* dsb before isb of power down sequence */
+ dsb sy
+1:
+ ret x17
+endfunc errata_a710_2768515_wa
+
+func check_errata_2768515
+ /* Applies to all revisions <= r2p1 */
+ mov x1, #0x21
+ b cpu_rev_var_ls
+endfunc check_errata_2768515
+
func check_errata_cve_2022_23960
#if WORKAROUND_CVE_2022_23960
mov x0, #ERRATA_APPLIES
@@ -518,6 +542,12 @@
mrs x0, CORTEX_A710_CPUPWRCTLR_EL1
orr x0, x0, #CORTEX_A710_CPUPWRCTLR_EL1_CORE_PWRDN_BIT
msr CORTEX_A710_CPUPWRCTLR_EL1, x0
+#if ERRATA_A710_2768515
+ mov x15, x30
+ bl cpu_get_rev_var
+ bl errata_a710_2768515_wa
+ mov x30, x15
+#endif /* ERRATA_A710_2768515 */
isb
ret
endfunc cortex_a710_core_pwr_dwn
@@ -550,6 +580,7 @@
report_errata ERRATA_A710_2216384, cortex_a710, 2216384
report_errata ERRATA_A710_2291219, cortex_a710, 2291219
report_errata ERRATA_A710_2371105, cortex_a710, 2371105
+ report_errata ERRATA_A710_2768515, cortex_a710, 2768515
report_errata WORKAROUND_CVE_2022_23960, cortex_a710, cve_2022_23960
report_errata ERRATA_DSU_2313941, cortex_a710, dsu_2313941
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index 8ef794b..3db86dd 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -572,6 +572,11 @@
# to revision r0p0, r1p0 and r2p0 of the Cortex-A710 cpu and is fixed in r2p1.
ERRATA_A710_2371105 ?=0
+# Flag to apply erratum 2768515 workaround during power down. This erratum
+# applies to revision r0p0, r1p0, r2p0 and r2p1 of the Cortex-A710 cpu and is
+# still open.
+ERRATA_A710_2768515 ?=0
+
# Flag to apply erratum 2067956 workaround during reset. This erratum applies
# to revision r0p0 of the Neoverse N2 cpu and is still open.
ERRATA_N2_2067956 ?=0
@@ -1208,6 +1213,10 @@
$(eval $(call assert_boolean,ERRATA_A710_2371105))
$(eval $(call add_define,ERRATA_A710_2371105))
+# Process ERRATA_A710_2768515 flag
+$(eval $(call assert_boolean,ERRATA_A710_2768515))
+$(eval $(call add_define,ERRATA_A710_2768515))
+
# Process ERRATA_N2_2067956 flag
$(eval $(call assert_boolean,ERRATA_N2_2067956))
$(eval $(call add_define,ERRATA_N2_2067956))