errata: workaround for Cortex-A710 errata 2081180

Cortex-A710 erratum 2081180 is a Cat B erratum present in r0p0, r1p0,
and r2p0 of the Cortex-A710 processor core, and it is still open.

A710 SDEN: https://developer.arm.com/documentation/SDEN1775101/1000

Signed-off-by: nayanpatel-arm <nayankumar.patel@arm.com>
Change-Id: I1e8c2bc3d8dc326947ccfd91daf9083d666b2542

docs/design/cpu-specific-build-macros.rst

@@ -365,6 +365,10 @@ For Cortex-A710, the following errata build flags are defined :
    Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
    r2p0 of the CPU. It is still open.
 
+-  ``ERRATA_A710_2081180``: This applies errata 2081180 workaround to
+   Cortex-A710 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
+   r2p0 of the CPU. It is still open.
+
 DSU Errata Workarounds
 ----------------------
 

lib/cpus/aarch64/cortex_a710.S

@@ -64,6 +64,49 @@ func check_errata_1987031
 	b	cpu_rev_var_ls
 endfunc check_errata_1987031
 
+/* --------------------------------------------------
+ * Errata Workaround for Cortex-A710 Erratum 2081180.
+ * This applies to revision r0p0, r1p0 and r2p0 of Cortex-A710.
+ * It is still open.
+ * Inputs:
+ * x0: variant[4:7] and revision[0:3] of current cpu.
+ * Shall clobber: x0-x17
+ * --------------------------------------------------
+ */
+func errata_a710_2081180_wa
+	/* Check revision. */
+	mov	x17, x30
+	bl	check_errata_2081180
+	cbz	x0, 1f
+
+	/* Apply instruction patching sequence */
+	ldr	x0,=0x3
+	msr	S3_6_c15_c8_0,x0
+	ldr	x0,=0xF3A08002
+	msr	S3_6_c15_c8_2,x0
+	ldr	x0,=0xFFF0F7FE
+	msr	S3_6_c15_c8_3,x0
+	ldr	x0,=0x10002001003FF
+	msr	S3_6_c15_c8_1,x0
+	ldr	x0,=0x4
+	msr	S3_6_c15_c8_0,x0
+	ldr	x0,=0xBF200000
+	msr	S3_6_c15_c8_2,x0
+	ldr	x0,=0xFFEF0000
+	msr	S3_6_c15_c8_3,x0
+	ldr	x0,=0x10002001003F3
+	msr	S3_6_c15_c8_1,x0
+	isb
+1:
+	ret	x17
+endfunc errata_a710_2081180_wa
+
+func check_errata_2081180
+	/* Applies to r0p0, r1p0 and r2p0 */
+	mov	x1, #0x20
+	b	cpu_rev_var_ls
+endfunc check_errata_2081180
+
 	/* ----------------------------------------------------
 	 * HW will do the cache maintenance while powering down
 	 * ----------------------------------------------------
@@ -95,6 +138,7 @@ func cortex_a710_errata_report
 	 * checking functions of each errata.
 	 */
 	report_errata ERRATA_A710_1987031, cortex_a710, 1987031
+	report_errata ERRATA_A710_2081180, cortex_a710, 2081180
 
 	ldp	x8, x30, [sp], #16
 	ret
@@ -115,6 +159,11 @@ func cortex_a710_reset_func
 	bl	errata_a710_1987031_wa
 #endif
 
+#if ERRATA_A710_2081180
+	mov	x0, x18
+	bl	errata_a710_2081180_wa
+#endif
+
 	isb
 	ret x19
 endfunc cortex_a710_reset_func

lib/cpus/cpu-ops.mk

@@ -409,6 +409,10 @@ ERRATA_V1_2139242   ?=0
 # to revisions r0p0, r1p0 and r2p0 of the Cortex-A710 cpu and is still open.
 ERRATA_A710_1987031	?=0
 
+# Flag to apply erratum 2081180 workaround during reset. This erratum applies
+# to revisions r0p0, r1p0 and r2p0 of the Cortex-A710 cpu and is still open.
+ERRATA_A710_2081180	?=0
+
 # Flag to apply DSU erratum 798953. This erratum applies to DSUs revision r0p0.
 # Applying the workaround results in higher DSU power consumption on idle.
 ERRATA_DSU_798953	?=0
@@ -750,6 +754,10 @@ $(eval $(call add_define,ERRATA_V1_2139242))
 $(eval $(call assert_boolean,ERRATA_A710_1987031))
 $(eval $(call add_define,ERRATA_A710_1987031))
 
+# Process ERRATA_A710_2081180 flag
+$(eval $(call assert_boolean,ERRATA_A710_2081180))
+$(eval $(call add_define,ERRATA_A710_2081180))
+
 # Process ERRATA_DSU_798953 flag
 $(eval $(call assert_boolean,ERRATA_DSU_798953))
 $(eval $(call add_define,ERRATA_DSU_798953))