Commit Graph

7 Commits

Author SHA1 Message Date
Suzuki K. Poulose 9cdf8ec4a8 arm64: Move cpu feature detection code
This patch moves the CPU feature detection code from
 arch/arm64/kernel/{setup.c to cpufeature.c}

The plan is to consolidate all the CPU feature handling
in cpufeature.c.

Apart from changing pr_fmt from "alternatives" to "cpu features",
there are no functional changes.

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Tested-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-21 15:33:46 +01:00
Will Deacon 2e94da1379 arm64: lse: use generic cpufeature detection for LSE atomics
Rework the cpufeature detection to support ISAR0 and use that for
detecting the presence of LSE atomics.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27 16:37:14 +01:00
James Morse 338d4f49d6 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>
2015-07-27 11:08:41 +01:00
James Morse 18ffa046c5 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>
2015-07-27 11:08:41 +01:00
James Morse 1c0763037f 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>
2015-07-27 11:08:41 +01:00
Marc Zyngier 94a9e04aa1 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 15:11:50 +01:00
Marc Zyngier 359b706473 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>
2015-03-30 11:03:43 +01:00