Merge "lib: cpu: Check SCU presence in DSU before accessing DSU registers" into integration
diff --git a/include/lib/cpus/aarch64/neoverse_n1.h b/include/lib/cpus/aarch64/neoverse_n1.h
index b50befa..9998b93 100644
--- a/include/lib/cpus/aarch64/neoverse_n1.h
+++ b/include/lib/cpus/aarch64/neoverse_n1.h
@@ -64,4 +64,12 @@
#define CPUPOR_EL3 S3_6_C15_C8_2
#define CPUPMR_EL3 S3_6_C15_C8_3
+/******************************************************************************
+ * CPU Configuration register definitions.
+ *****************************************************************************/
+#define CPUCFR_EL1 S3_0_C15_C0_0
+
+/* SCU bit of CPU Configuration Register, EL1 */
+#define SCU_SHIFT U(2)
+
#endif /* NEOVERSE_N1_H */
diff --git a/lib/cpus/aarch64/dsu_helpers.S b/lib/cpus/aarch64/dsu_helpers.S
index 100ffaa..da052d5 100644
--- a/lib/cpus/aarch64/dsu_helpers.S
+++ b/lib/cpus/aarch64/dsu_helpers.S
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2019, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2019-2020, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -72,18 +72,36 @@
* This function is called from both assembly and C environment. So it
* follows AAPCS.
*
- * Clobbers: x0-x3
+ * Clobbers: x0-x15
* -----------------------------------------------------------------------
*/
.globl check_errata_dsu_936184
.globl errata_dsu_936184_wa
+ .weak is_scu_present_in_dsu
+
+ /* --------------------------------------------------------------------
+ * Default behaviour respresents SCU is always present with DSU.
+ * CPUs can override this definition if required.
+ *
+ * Can clobber only: x0-x14
+ * --------------------------------------------------------------------
+ */
+func is_scu_present_in_dsu
+ mov x0, #1
+ ret
+endfunc is_scu_present_in_dsu
func check_errata_dsu_936184
- mov x2, #ERRATA_NOT_APPLIES
- mov x3, #ERRATA_APPLIES
+ mov x15, x30
+ bl is_scu_present_in_dsu
+ cmp x0, xzr
+ /* Default error status */
+ mov x0, #ERRATA_NOT_APPLIES
+
+ /* If SCU is not present, return without applying patch */
+ b.eq 1f
/* Erratum applies only if DSU has the ACP interface */
- mov x0, x2
mrs x1, CLUSTERCFR_EL1
ubfx x1, x1, #CLUSTERCFR_ACP_SHIFT, #1
cbz x1, 1f
@@ -92,13 +110,13 @@
mrs x1, CLUSTERIDR_EL1
/* DSU variant and revision bitfields in CLUSTERIDR are adjacent */
- ubfx x0, x1, #CLUSTERIDR_REV_SHIFT,\
+ ubfx x2, x1, #CLUSTERIDR_REV_SHIFT,\
#(CLUSTERIDR_REV_BITS + CLUSTERIDR_VAR_BITS)
- mov x1, #(0x2 << CLUSTERIDR_VAR_SHIFT)
- cmp x0, x1
- csel x0, x2, x3, hs
+ cmp x2, #(0x2 << CLUSTERIDR_VAR_SHIFT)
+ b.hs 1f
+ mov x0, #ERRATA_APPLIES
1:
- ret
+ ret x15
endfunc check_errata_dsu_936184
/* --------------------------------------------------
diff --git a/lib/cpus/aarch64/neoverse_n1.S b/lib/cpus/aarch64/neoverse_n1.S
index d537ed6..5a2b5e4 100644
--- a/lib/cpus/aarch64/neoverse_n1.S
+++ b/lib/cpus/aarch64/neoverse_n1.S
@@ -22,6 +22,19 @@
#endif
.global neoverse_n1_errata_ic_trap_handler
+ .global is_scu_present_in_dsu
+
+/*
+ * Check DSU is configured with SCU and L3 unit
+ * 1-> SCU present
+ * 0-> SCU not present
+ */
+func is_scu_present_in_dsu
+ mrs x0, CPUCFR_EL1
+ ubfx x0, x0, #SCU_SHIFT, #1
+ eor x0, x0, #1
+ ret
+endfunc is_scu_present_in_dsu
/* --------------------------------------------------
* Errata Workaround for Neoverse N1 Erratum 1043202.