lib/cpus/errata_report.c

/*
 * Copyright (c) 2017-2021, ARM Limited and Contributors. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

/* Runtime firmware routines to report errata status for the current CPU. */

#include <assert.h>
#include <stdbool.h>

#include <arch_helpers.h>
#include <common/debug.h>
#include <lib/cpus/cpu_ops.h>
#include <lib/cpus/errata.h>
#include <lib/el3_runtime/cpu_data.h>
#include <lib/spinlock.h>

#ifdef IMAGE_BL1
# define BL_STRING	"BL1"
#elif defined(__aarch64__) && defined(IMAGE_BL31)
# define BL_STRING	"BL31"
#elif !defined(__aarch64__) && defined(IMAGE_BL32)
# define BL_STRING	"BL32"
#elif defined(IMAGE_BL2) && BL2_AT_EL3
# define BL_STRING "BL2"
#else
# error This image should not be printing errata status
#endif

/* Errata format: BL stage, CPU, errata ID, message */
#define ERRATA_FORMAT	"%s: %s: CPU workaround for %s was %s\n"

#if !REPORT_ERRATA
void print_errata_status(void) {}
#else /* !REPORT_ERRATA */
/*
 * Returns whether errata needs to be reported. Passed arguments are private to
 * a CPU type.
 */
static __unused int errata_needs_reporting(spinlock_t *lock, uint32_t *reported)
{
	bool report_now;

	/* If already reported, return false. */
	if (*reported != 0U)
		return 0;

	/*
	 * Acquire lock. Determine whether status needs reporting, and then mark
	 * report status to true.
	 */
	spin_lock(lock);
	report_now = (*reported == 0U);
	if (report_now)
		*reported = 1;
	spin_unlock(lock);

	return report_now;
}

/*
 * Function to print errata status for the calling CPU (and others of the same
 * type). Must be called only:
 *   - when MMU and data caches are enabled;
 *   - after cpu_ops have been initialized in per-CPU data.
 */
void print_errata_status(void)
{
	struct cpu_ops *cpu_ops;
#ifdef IMAGE_BL1
	/*
	 * BL1 doesn't have per-CPU data. So retrieve the CPU operations
	 * directly.
	 */
	cpu_ops = get_cpu_ops_ptr();

	if (cpu_ops->errata_func != NULL) {
		cpu_ops->errata_func();
	}
#else /* IMAGE_BL1 */
	cpu_ops = (void *) get_cpu_data(cpu_ops_ptr);

	assert(cpu_ops != NULL);

	if (cpu_ops->errata_func == NULL) {
		return;
	}

	if (errata_needs_reporting(cpu_ops->errata_lock, cpu_ops->errata_reported)) {
		cpu_ops->errata_func();
	}
#endif /* IMAGE_BL1 */
}

/*
 * Print errata status message.
 *
 * Unknown: WARN
 * Missing: WARN
 * Applied: INFO
 * Not applied: VERBOSE
 */
void errata_print_msg(unsigned int status, const char *cpu, const char *id)
{
	/* Errata status strings */
	static const char *const errata_status_str[] = {
		[ERRATA_NOT_APPLIES] = "not applied",
		[ERRATA_APPLIES] = "applied",
		[ERRATA_MISSING] = "missing!"
	};
	static const char *const __unused bl_str = BL_STRING;
	const char *msg __unused;


	assert(status < ARRAY_SIZE(errata_status_str));
	assert(cpu != NULL);
	assert(id != NULL);

	msg = errata_status_str[status];

	switch (status) {
	case ERRATA_NOT_APPLIES:
		VERBOSE(ERRATA_FORMAT, bl_str, cpu, id, msg);
		break;

	case ERRATA_APPLIES:
		INFO(ERRATA_FORMAT, bl_str, cpu, id, msg);
		break;

	case ERRATA_MISSING:
		WARN(ERRATA_FORMAT, bl_str, cpu, id, msg);
		break;

	default:
		WARN(ERRATA_FORMAT, bl_str, cpu, id, "unknown");
		break;
	}
}
#endif /* !REPORT_ERRATA */