linux/arch/arm64/kernel/cpu_errata.c

/*
 * Contains CPU specific errata definitions
 *
 * Copyright (C) 2014 ARM Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/types.h>
#include <asm/cpu.h>
#include <asm/cputype.h>
#include <asm/cpufeature.h>

static bool __maybe_unused
is_affected_midr_range(const struct arm64_cpu_capabilities *entry, int scope)
{
	WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
	return MIDR_IS_CPU_MODEL_RANGE(read_cpuid_id(), entry->midr_model,
				       entry->midr_range_min,
				       entry->midr_range_max);
}

static bool
has_mismatched_cache_line_size(const struct arm64_cpu_capabilities *entry,
				int scope)
{
	WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
	return (read_cpuid_cachetype() & arm64_ftr_reg_ctrel0.strict_mask) !=
		(arm64_ftr_reg_ctrel0.sys_val & arm64_ftr_reg_ctrel0.strict_mask);
}

static void cpu_enable_trap_ctr_access(void *__unused)
{
	/* Clear SCTLR_EL1.UCT */
	config_sctlr_el1(SCTLR_EL1_UCT, 0);
}

#define MIDR_RANGE(model, min, max) \
	.def_scope = SCOPE_LOCAL_CPU, \
	.matches = is_affected_midr_range, \
	.midr_model = model, \
	.midr_range_min = min, \
	.midr_range_max = max

const struct arm64_cpu_capabilities arm64_errata[] = {
#if	defined(CONFIG_ARM64_ERRATUM_826319) || \
	defined(CONFIG_ARM64_ERRATUM_827319) || \
	defined(CONFIG_ARM64_ERRATUM_824069)
	{
	/* Cortex-A53 r0p[012] */
		.desc = "ARM errata 826319, 827319, 824069",
		.capability = ARM64_WORKAROUND_CLEAN_CACHE,
		MIDR_RANGE(MIDR_CORTEX_A53, 0x00, 0x02),
		.enable = cpu_enable_cache_maint_trap,
	},
#endif
#ifdef CONFIG_ARM64_ERRATUM_819472
	{
	/* Cortex-A53 r0p[01] */
		.desc = "ARM errata 819472",
		.capability = ARM64_WORKAROUND_CLEAN_CACHE,
		MIDR_RANGE(MIDR_CORTEX_A53, 0x00, 0x01),
		.enable = cpu_enable_cache_maint_trap,
	},
#endif
#ifdef CONFIG_ARM64_ERRATUM_832075
	{
	/* Cortex-A57 r0p0 - r1p2 */
		.desc = "ARM erratum 832075",
		.capability = ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE,
		MIDR_RANGE(MIDR_CORTEX_A57, 0x00,
			   (1 << MIDR_VARIANT_SHIFT) | 2),
	},
#endif
#ifdef CONFIG_ARM64_ERRATUM_834220
	{
	/* Cortex-A57 r0p0 - r1p2 */
		.desc = "ARM erratum 834220",
		.capability = ARM64_WORKAROUND_834220,
		MIDR_RANGE(MIDR_CORTEX_A57, 0x00,
			   (1 << MIDR_VARIANT_SHIFT) | 2),
	},
#endif
#ifdef CONFIG_ARM64_ERRATUM_845719
	{
	/* Cortex-A53 r0p[01234] */
		.desc = "ARM erratum 845719",
		.capability = ARM64_WORKAROUND_845719,
		MIDR_RANGE(MIDR_CORTEX_A53, 0x00, 0x04),
	},
#endif
#ifdef CONFIG_CAVIUM_ERRATUM_23154
	{
	/* Cavium ThunderX, pass 1.x */
		.desc = "Cavium erratum 23154",
		.capability = ARM64_WORKAROUND_CAVIUM_23154,
		MIDR_RANGE(MIDR_THUNDERX, 0x00, 0x01),
	},
#endif
#ifdef CONFIG_CAVIUM_ERRATUM_27456
	{
	/* Cavium ThunderX, T88 pass 1.x - 2.1 */
		.desc = "Cavium erratum 27456",
		.capability = ARM64_WORKAROUND_CAVIUM_27456,
		MIDR_RANGE(MIDR_THUNDERX, 0x00,
			   (1 << MIDR_VARIANT_SHIFT) | 1),
	},
	{
	/* Cavium ThunderX, T81 pass 1.0 */
		.desc = "Cavium erratum 27456",
		.capability = ARM64_WORKAROUND_CAVIUM_27456,
		MIDR_RANGE(MIDR_THUNDERX_81XX, 0x00, 0x00),
	},
#endif
	{
		.desc = "Mismatched cache line size",
		.capability = ARM64_MISMATCHED_CACHE_LINE_SIZE,
		.matches = has_mismatched_cache_line_size,
		.def_scope = SCOPE_LOCAL_CPU,
		.enable = cpu_enable_trap_ctr_access,
	},
	{
	}
};

/*
 * The CPU Errata work arounds are detected and applied at boot time
 * and the related information is freed soon after. If the new CPU requires
 * an errata not detected at boot, fail this CPU.
 */
void verify_local_cpu_errata_workarounds(void)
{
	const struct arm64_cpu_capabilities *caps = arm64_errata;

	for (; caps->matches; caps++)
		if (!cpus_have_cap(caps->capability) &&
			caps->matches(caps, SCOPE_LOCAL_CPU)) {
			pr_crit("CPU%d: Requires work around for %s, not detected"
					" at boot time\n",
				smp_processor_id(),
				caps->desc ? : "an erratum");
			cpu_die_early();
		}
}

void update_cpu_errata_workarounds(void)
{
	update_cpu_capabilities(arm64_errata, "enabling workaround for");
}

void __init enable_errata_workarounds(void)
{
	enable_cpu_capabilities(arm64_errata);
}