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/*
* Contains CPU feature definitions
*
* Copyright (C) 2015 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/>.
*/
#define pr_fmt(fmt) "CPU features: " fmt
#include <linux/types.h>
#include <asm/cpu.h>
#include <asm/cpufeature.h>
#include <asm/processor.h>
unsigned long elf_hwcap __read_mostly;
EXPORT_SYMBOL_GPL(elf_hwcap);
#ifdef CONFIG_COMPAT
#define COMPAT_ELF_HWCAP_DEFAULT \
(COMPAT_HWCAP_HALF|COMPAT_HWCAP_THUMB|\
COMPAT_HWCAP_FAST_MULT|COMPAT_HWCAP_EDSP|\
COMPAT_HWCAP_TLS|COMPAT_HWCAP_VFP|\
COMPAT_HWCAP_VFPv3|COMPAT_HWCAP_VFPv4|\
COMPAT_HWCAP_NEON|COMPAT_HWCAP_IDIV|\
COMPAT_HWCAP_LPAE)
unsigned int compat_elf_hwcap __read_mostly = COMPAT_ELF_HWCAP_DEFAULT;
unsigned int compat_elf_hwcap2 __read_mostly;
#endif
DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS);
static bool
feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry)
{
int val = cpuid_feature_extract_field(reg, entry->field_pos);
return val >= entry->min_field_value;
}
#define __ID_FEAT_CHK(reg) \
static bool __maybe_unused \
has_##reg##_feature(const struct arm64_cpu_capabilities *entry) \
{ \
u64 val; \
\
val = read_cpuid(reg##_el1); \
return feature_matches(val, entry); \
}
__ID_FEAT_CHK(id_aa64pfr0);
__ID_FEAT_CHK(id_aa64mmfr1);
__ID_FEAT_CHK(id_aa64isar0);
static const struct arm64_cpu_capabilities arm64_features[] = {
{
.desc = "GIC system register CPU interface",
.capability = ARM64_HAS_SYSREG_GIC_CPUIF,
.matches = has_id_aa64pfr0_feature,
.field_pos = 24,
.min_field_value = 1,
},
#ifdef CONFIG_ARM64_PAN
{
.desc = "Privileged Access Never",
.capability = ARM64_HAS_PAN,
.matches = has_id_aa64mmfr1_feature,
.field_pos = 20,
.min_field_value = 1,
.enable = cpu_enable_pan,
},
#endif /* CONFIG_ARM64_PAN */
#if defined(CONFIG_AS_LSE) && defined(CONFIG_ARM64_LSE_ATOMICS)
{
.desc = "LSE atomic instructions",
.capability = ARM64_HAS_LSE_ATOMICS,
.matches = has_id_aa64isar0_feature,
.field_pos = 20,
.min_field_value = 2,
},
#endif /* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */
{},
};
void check_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
const char *info)
{
int i;
for (i = 0; caps[i].desc; i++) {
if (!caps[i].matches(&caps[i]))
continue;
if (!cpus_have_cap(caps[i].capability))
pr_info("%s %s\n", info, caps[i].desc);
cpus_set_cap(caps[i].capability);
}
/* second pass allows enable() to consider interacting capabilities */
for (i = 0; caps[i].desc; i++) {
if (cpus_have_cap(caps[i].capability) && caps[i].enable)
caps[i].enable();
}
}
void check_local_cpu_features(void)
{
check_cpu_capabilities(arm64_features, "detected feature:");
}
void __init setup_cpu_features(void)
{
u64 features;
s64 block;
u32 cwg;
int cls;
/*
* Check for sane CTR_EL0.CWG value.
*/
cwg = cache_type_cwg();
cls = cache_line_size();
if (!cwg)
pr_warn("No Cache Writeback Granule information, assuming cache line size %d\n",
cls);
if (L1_CACHE_BYTES < cls)
pr_warn("L1_CACHE_BYTES smaller than the Cache Writeback Granule (%d < %d)\n",
L1_CACHE_BYTES, cls);
/*
* ID_AA64ISAR0_EL1 contains 4-bit wide signed feature blocks.
* The blocks we test below represent incremental functionality
* for non-negative values. Negative values are reserved.
*/
features = read_cpuid(ID_AA64ISAR0_EL1);
block = cpuid_feature_extract_field(features, 4);
if (block > 0) {
switch (block) {
default:
case 2:
elf_hwcap |= HWCAP_PMULL;
case 1:
elf_hwcap |= HWCAP_AES;
case 0:
break;
}
}
if (cpuid_feature_extract_field(features, 8) > 0)
elf_hwcap |= HWCAP_SHA1;
if (cpuid_feature_extract_field(features, 12) > 0)
elf_hwcap |= HWCAP_SHA2;
if (cpuid_feature_extract_field(features, 16) > 0)
elf_hwcap |= HWCAP_CRC32;
block = cpuid_feature_extract_field(features, 20);
if (block > 0) {
switch (block) {
default:
case 2:
elf_hwcap |= HWCAP_ATOMICS;
case 1:
/* RESERVED */
case 0:
break;
}
}
#ifdef CONFIG_COMPAT
/*
* ID_ISAR5_EL1 carries similar information as above, but pertaining to
* the AArch32 32-bit execution state.
*/
features = read_cpuid(ID_ISAR5_EL1);
block = cpuid_feature_extract_field(features, 4);
if (block > 0) {
switch (block) {
default:
case 2:
compat_elf_hwcap2 |= COMPAT_HWCAP2_PMULL;
case 1:
compat_elf_hwcap2 |= COMPAT_HWCAP2_AES;
case 0:
break;
}
}
if (cpuid_feature_extract_field(features, 8) > 0)
compat_elf_hwcap2 |= COMPAT_HWCAP2_SHA1;
if (cpuid_feature_extract_field(features, 12) > 0)
compat_elf_hwcap2 |= COMPAT_HWCAP2_SHA2;
if (cpuid_feature_extract_field(features, 16) > 0)
compat_elf_hwcap2 |= COMPAT_HWCAP2_CRC32;
#endif
}
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