fix(cpus): reduce generic_errata_report()'s size

For a pretty implementation and straightforward code, the CVE/erratum
dispatching of the errata status reporting was done with a macro,
closely following the old code. Unfortunately, this produces a function
that was over a kilobyte in size, which unsurprisingly doesn't fit on
some platforms.

Convert the macro to a proper C function and call it once. Also hide the
errata ordering checking behind the FEATURE_DETECTION flag to further
save space. This functionality is not necessary for most builds.
Development and platform bringup builds, which should find this
functionality useful, are expected to have FEATURE_DETECTION enabled.

This reduces the function to under 600 bytes.

Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: Ibf5376a26cbae28d9dc010128452cb3c694a3f78

docs/getting_started/build-options.rst

@@ -531,7 +531,8 @@ Common build options
    through feature specific build flags are supported by the PE or not by
    validating them either at boot phase or at runtime based on the value
    possessed by the feature flag (0 to 2) and report error messages at an early
-   stage.
+   stage. This flag will also enable errata ordering checking for ``DEBUG``
+   builds.
 
    This prevents and benefits us from EL3 runtime exceptions during context save
    and restore routines guarded by these build flags. Henceforth validating them

lib/cpus/errata_report.c

@@ -34,38 +34,51 @@
 #define CVE_FORMAT	"%s: %s: CPU workaround for CVE %u_%u was %s\n"
 #define ERRATUM_FORMAT	"%s: %s: CPU workaround for erratum %u was %s\n"
 
-#define PRINT_STATUS_DISPATCH(status, ...)					\
-	do {									\
-		assert(status <= ERRATA_MISSING);				\
-		switch (status) {						\
-		case ERRATA_NOT_APPLIES:					\
-			VERBOSE(__VA_ARGS__, "not applied");			\
-			break;							\
-		case ERRATA_APPLIES:						\
-			INFO(__VA_ARGS__, "applied");				\
-			break;							\
-		case ERRATA_MISSING:						\
-			WARN(__VA_ARGS__, "missing!");				\
-			break;							\
-		}								\
-	} while (0)
 
+static __unused void print_status(int status, char *cpu_str, uint16_t cve, uint32_t id)
+{
+	if (status == ERRATA_MISSING) {
+		if (cve) {
+			WARN(CVE_FORMAT, BL_STRING, cpu_str, cve, id, "missing!");
+		} else {
+			WARN(ERRATUM_FORMAT, BL_STRING, cpu_str, id, "missing!");
+		}
+	} else if (status == ERRATA_APPLIES) {
+		if (cve) {
+			INFO(CVE_FORMAT, BL_STRING, cpu_str, cve, id, "applied");
+		}  else {
+			INFO(ERRATUM_FORMAT, BL_STRING, cpu_str, id, "applied");
+		}
+	} else {
+		if (cve) {
+			VERBOSE(CVE_FORMAT, BL_STRING, cpu_str, cve, id, "not applied");
+		}  else {
+			VERBOSE(ERRATUM_FORMAT, BL_STRING, cpu_str, id, "not applied");
+		}
+	}
+}
 
 #if !REPORT_ERRATA
 void print_errata_status(void) {}
 #else /* !REPORT_ERRATA */
-/* New errata status message printer */
+/*
+ * New errata status message printer
+ * The order checking function is hidden behind the FEATURE_DETECTION flag to
+ * save space. This functionality is only useful on development and platform
+ * bringup builds, when FEATURE_DETECTION should be used anyway
+ */
 void __unused generic_errata_report(void)
 {
 	struct cpu_ops *cpu_ops = get_cpu_ops_ptr();
 	struct erratum_entry *entry = cpu_ops->errata_list_start;
 	struct erratum_entry *end = cpu_ops->errata_list_end;
 	long rev_var = cpu_get_rev_var();
+#if FEATURE_DETECTION
 	uint32_t last_erratum_id = 0;
 	uint16_t last_cve_yr = 0;
 	bool check_cve = false;
-	/* unused because assert goes away on release */
+	bool failed = false;
-	bool failed __unused = false;
+#endif /* FEATURE_DETECTION */
 
 	for (; entry != end; entry += 1) {
 		uint64_t status = entry->check_func(rev_var);
@@ -81,10 +94,10 @@ void __unused generic_errata_report(void)
 			status = ERRATA_MISSING;
 		}
 
-		if (entry->cve) {
+		print_status(status, cpu_ops->cpu_str, entry->cve, entry->id);
-			PRINT_STATUS_DISPATCH(status, CVE_FORMAT, BL_STRING,
-				cpu_ops->cpu_str, entry->cve, entry->id);
 
+#if FEATURE_DETECTION
+		if (entry->cve) {
 			if (last_cve_yr > entry->cve ||
 			   (last_cve_yr == entry->cve && last_erratum_id >= entry->id)) {
 				ERROR("CVE %u_%u was out of order!\n",
@@ -94,9 +107,6 @@ void __unused generic_errata_report(void)
 			check_cve = true;
 			last_cve_yr = entry->cve;
 		} else {
-			PRINT_STATUS_DISPATCH(status, ERRATUM_FORMAT, BL_STRING,
-				cpu_ops->cpu_str, entry->id);
-
 			if (last_erratum_id >= entry->id || check_cve) {
 				ERROR("Erratum %u was out of order!\n",
 				      entry->id);
@@ -104,13 +114,16 @@ void __unused generic_errata_report(void)
 			}
 		}
 		last_erratum_id = entry->id;
+#endif /* FEATURE_DETECTION */
 	}
 
+#if FEATURE_DETECTION
 	/*
 	 * enforce errata and CVEs are in ascending order and that CVEs are
 	 * after errata
 	 */
 	assert(!failed);
+#endif /* FEATURE_DETECTION */
 }
 
 /*