feat(cpus): wrappers to propagate AArch32 errata info

AArch32 is not being ported to the errata framework. However, the
runtime errata list is needed at runtime for the upcoming errata ABI.
Add wrappers to populate this information and make it accessible in the
same way as AArch64.

Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: I084720f34d6ed4e00e94b09babd3c90a5393298a

include/lib/cpus/aarch32/cpu_macros.S

 /*
- * Copyright (c) 2016-2023, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2023, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
 #ifndef CPU_MACROS_S
 #define CPU_MACROS_S
 
-#include <arch.h>
 #include <lib/cpus/cpu_ops.h>
 #include <lib/cpus/errata.h>
 
@@ -74,6 +73,29 @@
 	fill_constants CPU_MAX_PWR_DWN_OPS, \_power_down_ops
 #endif
 
+	/*
+	 * It is possible (although unlikely) that a cpu may have no errata in
+	 * code. In that case the start label will not be defined. The list is
+	 * inteded to be used in a loop, so define it as zero-length for
+	 * predictable behaviour. Since this macro is always called at the end
+	 * of the cpu file (after all errata have been parsed) we can be sure
+	 * that we are at the end of the list. Some cpus call the macro twice,
+	 * so only do this once.
+	 */
+	.pushsection .rodata.errata_entries
+	.ifndef \_name\()_errata_list_start
+		\_name\()_errata_list_start:
+	.endif
+	/* some call this multiple times, so only do this once */
+	.ifndef \_name\()_errata_list_end
+		\_name\()_errata_list_end:
+	.endif
+	.popsection
+
+	/* and now put them in cpu_ops */
+	.word \_name\()_errata_list_start
+	.word \_name\()_errata_list_end
+
 #if REPORT_ERRATA
 	.ifndef \_name\()_cpu_str
 	  /*
@@ -98,6 +120,7 @@
 	 * this class.
 	 */
 	.word \_name\()_errata_report
+	.word \_name\()_cpu_str
 
 #ifdef IMAGE_BL32
 	/* Pointers to errata lock and reported flag */
@@ -160,4 +183,77 @@
 	beq	\_label
 	.endm
 
+/*
+ * NOTE an erratum and CVE id could clash. However, both numbers are very large
+ * and the probablity is minuscule. Working around this makes code very
+ * complicated and extremely difficult to read so it is not considered. In the
+ * unlikely event that this does happen, prepending the CVE id with a 0 should
+ * resolve the conflict
+ */
+
+/*
+ * Add an entry for this erratum to the errata framework
+ *
+ * _cpu:
+ *	Name of cpu as given to declare_cpu_ops
+ *
+ * _cve:
+ *	Whether erratum is a CVE. CVE year if yes, 0 otherwise
+ *
+ * _id:
+ *	Erratum or CVE number. Please combine with the previous field with the
+ *	ERRATUM or CVE macros
+ *
+ * _chosen:
+ *	Compile time flag on whether the erratum is included
+ *
+ * _special:
+ *	The special non-standard name of an erratum
+ */
+.macro add_erratum_entry _cpu:req, _cve:req, _id:req, _chosen:req, _special
+	.pushsection .rodata.errata_entries
+		.align	2
+		.ifndef \_cpu\()_errata_list_start
+		\_cpu\()_errata_list_start:
+		.endif
+
+		/* unused on AArch32, maintain for portability */
+		.word	0
+		/* TODO(errata ABI): this prevents all checker functions from
+		 * being optimised away. Can be done away with unless the ABI
+		 * needs them */
+		.ifnb \_special
+			.word	check_errata_\_special
+		.elseif \_cve
+			.word	check_errata_cve_\_cve\()_\_id
+		.else
+			.word	check_errata_\_id
+		.endif
+		/* Will fit CVEs with up to 10 character in the ID field */
+		.word	\_id
+		.hword	\_cve
+		.byte	\_chosen
+		/* TODO(errata ABI): mitigated field for known but unmitigated
+		 * errata*/
+		.byte	0x1
+	.popsection
+.endm
+
+/*
+ * Maintain compatibility with the old scheme of "each cpu has its own reporter".
+ * TODO remove entirely once all cpus have been converted. This includes the
+ * cpu_ops entry, as print_errata_status can call this directly for all cpus
+ */
+.macro errata_report_shim _cpu:req
+	#if REPORT_ERRATA
+	func \_cpu\()_errata_report
+		push	{r12, lr}
+
+		bl generic_errata_report
+
+		pop	{r12, lr}
+		bx	lr
+	endfunc \_cpu\()_errata_report
+	#endif
+.endm
 #endif /* CPU_MACROS_S */