fix(errata): workaround for Cortex-A710 erratum 2008768
Cortex-A710 erratum 2008768 is a Cat B erratum that applies to revisions
r0p0, r1p0, and r2p0, and is fixed in r2p1. The workaround is to clear
the ED bit in each ERXCTLR_EL1 register before setting the PWRDN bit in
CPUPWRCTLR_EL1.
SDEN can be found here:
https://developer.arm.com/documentation/SDEN1775101
Signed-off-by: John Powell <john.powell@arm.com>
Change-Id: Ib2171c06da762dd4155b02c03d86766f1616381d
diff --git a/lib/cpus/aarch64/cortex_a710.S b/lib/cpus/aarch64/cortex_a710.S
index aea62ae..63d55bb 100644
--- a/lib/cpus/aarch64/cortex_a710.S
+++ b/lib/cpus/aarch64/cortex_a710.S
@@ -310,6 +310,49 @@
b cpu_rev_var_ls
endfunc check_errata_2282622
+/* ---------------------------------------------------------------
+ * Errata Workaround for Cortex-A710 Erratum 2008768.
+ * This applies to revision r0p0, r1p0 and r2p0.
+ * It is fixed in r2p1.
+ * Inputs:
+ * x0: variant[4:7] and revision[0:3] of current cpu.
+ * Shall clobber: x0, x1, x2, x17
+ * ---------------------------------------------------------------
+ */
+func errata_a710_2008768_wa
+ mov x17, x30
+ bl check_errata_2008768
+ cbz x0, 1f
+
+ /* Stash ERRSELR_EL1 in x2 */
+ mrs x2, ERRSELR_EL1
+
+ /* Select error record 0 and clear ED bit */
+ msr ERRSELR_EL1, xzr
+ mrs x1, ERXCTLR_EL1
+ bfi x1, xzr, #ERXCTLR_ED_SHIFT, #1
+ msr ERXCTLR_EL1, x1
+
+ /* Select error record 1 and clear ED bit */
+ mov x0, #1
+ msr ERRSELR_EL1, x0
+ mrs x1, ERXCTLR_EL1
+ bfi x1, xzr, #ERXCTLR_ED_SHIFT, #1
+ msr ERXCTLR_EL1, x1
+
+ /* Restore ERRSELR_EL1 from x2 */
+ msr ERRSELR_EL1, x2
+
+1:
+ ret x17
+endfunc errata_a710_2008768_wa
+
+func check_errata_2008768
+ /* Applies to r0p0, r1p0 and r2p0 */
+ mov x1, #0x20
+ b cpu_rev_var_ls
+endfunc check_errata_2008768
+
func check_errata_cve_2022_23960
#if WORKAROUND_CVE_2022_23960
mov x0, #ERRATA_APPLIES
@@ -324,6 +367,14 @@
* ----------------------------------------------------
*/
func cortex_a710_core_pwr_dwn
+
+#if ERRATA_A710_2008768
+ mov x4, x30
+ bl cpu_get_rev_var
+ bl errata_a710_2008768_wa
+ mov x30, x4
+#endif
+
/* ---------------------------------------------------
* Enable CPU power down bit in power control register
* ---------------------------------------------------
@@ -358,6 +409,7 @@
report_errata ERRATA_A710_2267065, cortex_a710, 2267065
report_errata ERRATA_A710_2136059, cortex_a710, 2136059
report_errata ERRATA_A710_2282622, cortex_a710, 2282622
+ report_errata ERRATA_A710_2008768, cortex_a710, 2008768
report_errata WORKAROUND_CVE_2022_23960, cortex_a710, cve_2022_23960
ldp x8, x30, [sp], #16
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index 462ca9d..fe98a30 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -484,6 +484,10 @@
# to revision r0p0, r1p0 and r2p0 of the Cortex-A710 cpu and is fixed in r2p1.
ERRATA_A710_2282622 ?=0
+# Flag to apply erratum 2008768 workaround during reset. This erratum applies
+# to revision r0p0, r1p0 and r2p0 of the Cortex-A710 cpu and is fixed in r2p1.
+ERRATA_A710_2008768 ?=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
@@ -990,6 +994,10 @@
$(eval $(call assert_boolean,ERRATA_A710_2282622))
$(eval $(call add_define,ERRATA_A710_2282622))
+# Process ERRATA_A710_2008768 flag
+$(eval $(call assert_boolean,ERRATA_A710_2008768))
+$(eval $(call add_define,ERRATA_A710_2008768))
+
# Process ERRATA_N2_2067956 flag
$(eval $(call assert_boolean,ERRATA_N2_2067956))
$(eval $(call add_define,ERRATA_N2_2067956))