fix(errata): workaround for DSU-110 erratum 2313941
DSU-110 erratum 2313941 is a Cat B erratum and applies to revisions
r0p0, r1p0, r2p0, r2p1, r3p0, r3p1 and is still open.
The workaround sets IMP_CLUSTERACTLR_EL1[16:15] bits to 0b11 to disable
clock gating of the SCLK domain. This will increase the idle power
consumption.
This patch applies the fix for Cortex-X2/A510/A710 and Neoverse N2.
SDEN can be found here:
https://developer.arm.com/documentation/SDEN1781796/latest
Signed-off-by: Bipin Ravi <bipin.ravi@arm.com>
Change-Id: I54d948b23e8e01aaf1898ed9fe4e2255dd209318
Signed-off-by: Bipin Ravi <bipin.ravi@arm.com>
diff --git a/lib/cpus/aarch64/cortex_a510.S b/lib/cpus/aarch64/cortex_a510.S
index 34e1082..f444077 100644
--- a/lib/cpus/aarch64/cortex_a510.S
+++ b/lib/cpus/aarch64/cortex_a510.S
@@ -301,6 +301,7 @@
report_errata ERRATA_A510_2250311, cortex_a510, 2250311
report_errata ERRATA_A510_2218950, cortex_a510, 2218950
report_errata ERRATA_A510_2172148, cortex_a510, 2172148
+ report_errata ERRATA_DSU_2313941, cortex_a510, dsu_2313941
ldp x8, x30, [sp], #16
ret
@@ -312,12 +313,15 @@
/* Disable speculative loads */
msr SSBS, xzr
- isb
/* Get the CPU revision and stash it in x18. */
bl cpu_get_rev_var
mov x18, x0
+#if ERRATA_DSU_2313941
+ bl errata_dsu_2313941_wa
+#endif
+
#if ERRATA_A510_1922240
mov x0, x18
bl errata_cortex_a510_1922240_wa
@@ -353,6 +357,7 @@
bl errata_cortex_a510_2172148_wa
#endif
+ isb
ret x19
endfunc cortex_a510_reset_func
diff --git a/lib/cpus/aarch64/cortex_a710.S b/lib/cpus/aarch64/cortex_a710.S
index 63d55bb..5d8e9a6 100644
--- a/lib/cpus/aarch64/cortex_a710.S
+++ b/lib/cpus/aarch64/cortex_a710.S
@@ -411,6 +411,7 @@
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
+ report_errata ERRATA_DSU_2313941, cortex_a710, dsu_2313941
ldp x8, x30, [sp], #16
ret
@@ -426,6 +427,10 @@
bl cpu_get_rev_var
mov x18, x0
+#if ERRATA_DSU_2313941
+ bl errata_dsu_2313941_wa
+#endif
+
#if ERRATA_A710_1987031
mov x0, x18
bl errata_a710_1987031_wa
diff --git a/lib/cpus/aarch64/cortex_x2.S b/lib/cpus/aarch64/cortex_x2.S
index 90a906b..3e0810b 100644
--- a/lib/cpus/aarch64/cortex_x2.S
+++ b/lib/cpus/aarch64/cortex_x2.S
@@ -305,6 +305,7 @@
report_errata ERRATA_X2_2147715, cortex_x2, 2147715
report_errata ERRATA_X2_2216384, cortex_x2, 2216384
report_errata WORKAROUND_CVE_2022_23960, cortex_x2, cve_2022_23960
+ report_errata ERRATA_DSU_2313941, cortex_x2, dsu_2313941
ldp x8, x30, [sp], #16
ret
@@ -316,12 +317,15 @@
/* Disable speculative loads */
msr SSBS, xzr
- isb
/* Get the CPU revision and stash it in x18. */
bl cpu_get_rev_var
mov x18, x0
+#if ERRATA_DSU_2313941
+ bl errata_dsu_2313941_wa
+#endif
+
#if ERRATA_X2_2002765
mov x0, x18
bl errata_cortex_x2_2002765_wa
@@ -367,7 +371,7 @@
#endif /* IMAGE_BL31 && WORKAROUND_CVE_2022_23960 */
isb
- ret x19
+ ret x19
endfunc cortex_x2_reset_func
/* ---------------------------------------------
diff --git a/lib/cpus/aarch64/dsu_helpers.S b/lib/cpus/aarch64/dsu_helpers.S
index da052d5..419b6ea 100644
--- a/lib/cpus/aarch64/dsu_helpers.S
+++ b/lib/cpus/aarch64/dsu_helpers.S
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2019-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2019-2022, Arm Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -139,3 +139,57 @@
1:
ret x17
endfunc errata_dsu_936184_wa
+
+ /* -----------------------------------------------------------------------
+ * DSU erratum 2313941 check function
+ * Checks the DSU variant, revision and configuration to determine if
+ * the erratum applies. Erratum applies on all configurations of the
+ * DSU and if revision-variant is r0p0, r1p0, r2p0, r2p1, r3p0, r3p1.
+ *
+ * The erratum is still open.
+ *
+ * This function is called from both assembly and C environment. So it
+ * follows AAPCS.
+ *
+ * Clobbers: x0-x3
+ * -----------------------------------------------------------------------
+ */
+ .globl check_errata_dsu_2313941
+ .globl errata_dsu_2313941_wa
+
+func check_errata_dsu_2313941
+ mov x2, #ERRATA_APPLIES
+ mov x3, #ERRATA_NOT_APPLIES
+
+ /* Check if DSU version is less than or equal to r3p1 */
+ mrs x1, CLUSTERIDR_EL1
+
+ /* DSU variant and revision bitfields in CLUSTERIDR are adjacent */
+ ubfx x0, x1, #CLUSTERIDR_REV_SHIFT,\
+ #(CLUSTERIDR_REV_BITS + CLUSTERIDR_VAR_BITS)
+ mov x1, #(0x31 << CLUSTERIDR_REV_SHIFT)
+ cmp x0, x1
+ csel x0, x2, x3, LS
+ ret
+endfunc check_errata_dsu_2313941
+
+ /* --------------------------------------------------
+ * Errata Workaround for DSU erratum #2313941.
+ *
+ * Can clobber only: x0-x17
+ * --------------------------------------------------
+ */
+func errata_dsu_2313941_wa
+ mov x17, x30
+ bl check_errata_dsu_2313941
+ cbz x0, 1f
+
+ /* If erratum applies, disable high-level clock gating */
+ mrs x0, CLUSTERACTLR_EL1
+ orr x0, x0, #CLUSTERACTLR_EL1_DISABLE_SCLK_GATING
+ msr CLUSTERACTLR_EL1, x0
+ isb
+1:
+ ret x17
+endfunc errata_dsu_2313941_wa
+
diff --git a/lib/cpus/aarch64/neoverse_n2.S b/lib/cpus/aarch64/neoverse_n2.S
index b93f2a6..5b796dc 100644
--- a/lib/cpus/aarch64/neoverse_n2.S
+++ b/lib/cpus/aarch64/neoverse_n2.S
@@ -367,6 +367,10 @@
orr x0, x0, #NEOVERSE_N2_CPUACTLR2_EL1_BIT_2
msr NEOVERSE_N2_CPUACTLR2_EL1, x0
+#if ERRATA_DSU_2313941
+ bl errata_dsu_2313941_wa
+#endif
+
#if ERRATA_N2_2067956
mov x0, x18
bl errata_n2_2067956_wa
@@ -493,6 +497,7 @@
report_errata ERRATA_N2_2242400, neoverse_n2, 2242400
report_errata ERRATA_N2_2280757, neoverse_n2, 2280757
report_errata WORKAROUND_CVE_2022_23960, neoverse_n2, cve_2022_23960
+ report_errata ERRATA_DSU_2313941, neoverse_n2, dsu_2313941
ldp x8, x30, [sp], #16
ret
diff --git a/lib/cpus/cpu-ops.mk b/lib/cpus/cpu-ops.mk
index eb17dfd..e14bb24 100644
--- a/lib/cpus/cpu-ops.mk
+++ b/lib/cpus/cpu-ops.mk
@@ -1,5 +1,5 @@
#
-# Copyright (c) 2014-2022, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2014-2022, Arm Limited and Contributors. All rights reserved.
# Copyright (c) 2020-2022, NVIDIA Corporation. All rights reserved.
#
# SPDX-License-Identifier: BSD-3-Clause
@@ -614,6 +614,11 @@
# higher DSU power consumption on idle.
ERRATA_DSU_936184 ?=0
+# Flag to apply DSU erratum 2313941. This erratum applies to DSUs revisions
+# r0p0, r1p0, r2p0, r2p1, r3p0, r3p1 and is still open. Applying the workaround
+# results in higher DSU power consumption on idle.
+ERRATA_DSU_2313941 ?=0
+
# Process ERRATA_A9_794073 flag
$(eval $(call assert_boolean,ERRATA_A9_794073))
$(eval $(call add_define,ERRATA_A9_794073))
@@ -1138,6 +1143,10 @@
$(eval $(call assert_boolean,ERRATA_DSU_936184))
$(eval $(call add_define,ERRATA_DSU_936184))
+# Process ERRATA_DSU_2313941 flag
+$(eval $(call assert_boolean,ERRATA_DSU_2313941))
+$(eval $(call add_define,ERRATA_DSU_2313941))
+
# Errata build flags
ifneq (${ERRATA_A53_843419},0)
TF_LDFLAGS_aarch64 += --fix-cortex-a53-843419