hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity
linux-sg2042/arch/arm64/kernel/cpufeature.c

98 lines
2.4 KiB
C
Raw Normal View History

arm64: Extract feature parsing code from cpu_errata.c As we detect more architectural features at runtime, it makes sense to reuse the existing framework whilst avoiding to call a feature an erratum... This patch extract the core capability parsing, moves it into a new file (cpufeature.c), and let the CPU errata detection code use it. Reviewed-by: Andre Przywara <andre.przywara@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-27 21:09:23 +08:00
/*
* 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) "alternatives: " fmt
#include <linux/types.h>
#include <asm/cpu.h>
#include <asm/cpufeature.h>
arm64: kernel: Add support for Privileged Access Never 'Privileged Access Never' is a new arm8.1 feature which prevents privileged code from accessing any virtual address where read or write access is also permitted at EL0. This patch enables the PAN feature on all CPUs, and modifies {get,put}_user helpers temporarily to permit access. This will catch kernel bugs where user memory is accessed directly. 'Unprivileged loads and stores' using ldtrb et al are unaffected by PAN. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: James Morse <james.morse@arm.com> [will: use ALTERNATIVE in asm and tidy up pan_enable check] Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-23 02:05:54 +08:00
#include <asm/processor.h>
arm64: Extract feature parsing code from cpu_errata.c As we detect more architectural features at runtime, it makes sense to reuse the existing framework whilst avoiding to call a feature an erratum... This patch extract the core capability parsing, moves it into a new file (cpufeature.c), and let the CPU errata detection code use it. Reviewed-by: Andre Przywara <andre.przywara@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-27 21:09:23 +08:00
arm64: kernel: Add min_field_value and use '>=' for feature detection When a new cpu feature is available, the cpu feature bits will have some initial value, which is incremented when the feature is updated. This patch changes 'register_value' to be 'min_field_value', and checks the feature bits value (interpreted as a signed int) is greater than this minimum. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-21 20:23:29 +08:00
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;
}
arm64: alternative: Introduce feature for GICv3 CPU interface Add a new item to the feature set (ARM64_HAS_SYSREG_GIC_CPUIF) to indicate that we have a system register GIC CPU interface This will help KVM switching to alternative instruction patching. Reviewed-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-06-12 19:06:36 +08:00
static bool
has_id_aa64pfr0_feature(const struct arm64_cpu_capabilities *entry)
{
u64 val;
val = read_cpuid(id_aa64pfr0_el1);
arm64: kernel: Add min_field_value and use '>=' for feature detection When a new cpu feature is available, the cpu feature bits will have some initial value, which is incremented when the feature is updated. This patch changes 'register_value' to be 'min_field_value', and checks the feature bits value (interpreted as a signed int) is greater than this minimum. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-21 20:23:29 +08:00
return feature_matches(val, entry);
arm64: alternative: Introduce feature for GICv3 CPU interface Add a new item to the feature set (ARM64_HAS_SYSREG_GIC_CPUIF) to indicate that we have a system register GIC CPU interface This will help KVM switching to alternative instruction patching. Reviewed-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-06-12 19:06:36 +08:00
}
arm64: kernel: Add support for Privileged Access Never 'Privileged Access Never' is a new arm8.1 feature which prevents privileged code from accessing any virtual address where read or write access is also permitted at EL0. This patch enables the PAN feature on all CPUs, and modifies {get,put}_user helpers temporarily to permit access. This will catch kernel bugs where user memory is accessed directly. 'Unprivileged loads and stores' using ldtrb et al are unaffected by PAN. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: James Morse <james.morse@arm.com> [will: use ALTERNATIVE in asm and tidy up pan_enable check] Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-23 02:05:54 +08:00
static bool __maybe_unused
has_id_aa64mmfr1_feature(const struct arm64_cpu_capabilities *entry)
{
u64 val;
val = read_cpuid(id_aa64mmfr1_el1);
return feature_matches(val, entry);
}
arm64: Extract feature parsing code from cpu_errata.c As we detect more architectural features at runtime, it makes sense to reuse the existing framework whilst avoiding to call a feature an erratum... This patch extract the core capability parsing, moves it into a new file (cpufeature.c), and let the CPU errata detection code use it. Reviewed-by: Andre Przywara <andre.przywara@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-27 21:09:23 +08:00
static const struct arm64_cpu_capabilities arm64_features[] = {
arm64: alternative: Introduce feature for GICv3 CPU interface Add a new item to the feature set (ARM64_HAS_SYSREG_GIC_CPUIF) to indicate that we have a system register GIC CPU interface This will help KVM switching to alternative instruction patching. Reviewed-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-06-12 19:06:36 +08:00
{
.desc = "GIC system register CPU interface",
.capability = ARM64_HAS_SYSREG_GIC_CPUIF,
.matches = has_id_aa64pfr0_feature,
arm64: kernel: Add min_field_value and use '>=' for feature detection When a new cpu feature is available, the cpu feature bits will have some initial value, which is incremented when the feature is updated. This patch changes 'register_value' to be 'min_field_value', and checks the feature bits value (interpreted as a signed int) is greater than this minimum. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-21 20:23:29 +08:00
.field_pos = 24,
.min_field_value = 1,
arm64: alternative: Introduce feature for GICv3 CPU interface Add a new item to the feature set (ARM64_HAS_SYSREG_GIC_CPUIF) to indicate that we have a system register GIC CPU interface This will help KVM switching to alternative instruction patching. Reviewed-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-06-12 19:06:36 +08:00
},
arm64: kernel: Add support for Privileged Access Never 'Privileged Access Never' is a new arm8.1 feature which prevents privileged code from accessing any virtual address where read or write access is also permitted at EL0. This patch enables the PAN feature on all CPUs, and modifies {get,put}_user helpers temporarily to permit access. This will catch kernel bugs where user memory is accessed directly. 'Unprivileged loads and stores' using ldtrb et al are unaffected by PAN. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: James Morse <james.morse@arm.com> [will: use ALTERNATIVE in asm and tidy up pan_enable check] Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-23 02:05:54 +08:00
#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 */
arm64: Extract feature parsing code from cpu_errata.c As we detect more architectural features at runtime, it makes sense to reuse the existing framework whilst avoiding to call a feature an erratum... This patch extract the core capability parsing, moves it into a new file (cpufeature.c), and let the CPU errata detection code use it. Reviewed-by: Andre Przywara <andre.przywara@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-27 21:09:23 +08:00
{},
};
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);
}
arm64: kernel: Add cpufeature 'enable' callback This patch adds an 'enable()' callback to cpu capability/feature detection, allowing features that require some setup or configuration to get this opportunity once the feature has been detected. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-21 20:23:28 +08:00
/* 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();
}
arm64: Extract feature parsing code from cpu_errata.c As we detect more architectural features at runtime, it makes sense to reuse the existing framework whilst avoiding to call a feature an erratum... This patch extract the core capability parsing, moves it into a new file (cpufeature.c), and let the CPU errata detection code use it. Reviewed-by: Andre Przywara <andre.przywara@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-27 21:09:23 +08:00
}
void check_local_cpu_features(void)
{
check_cpu_capabilities(arm64_features, "detected feature");
}