b51c6ac220
We finalize the system wide capabilities after the SMP CPUs are booted by the kernel. This is used as a marker for deciding various checks in the kernel. e.g, sanity check the hotplugged CPUs for missing mandatory features. However there is no explicit helper available for this in the kernel. There is sys_caps_initialised, which is not exposed. The other closest one we have is the jump_label arm64_const_caps_ready which denotes that the capabilities are set and the capability checks could use the individual jump_labels for fast path. This is performed before setting the ELF Hwcaps, which must be checked against the new CPUs. We also perform some of the other initialization e.g, SVE setup, which is important for the use of FP/SIMD where SVE is supported. Normally userspace doesn't get to run before we finish this. However the in-kernel users may potentially start using the neon mode. So, we need to reject uses of neon mode before we are set. Instead of defining a new marker for the completion of SVE setup, we could simply reuse the arm64_const_caps_ready and enable it once we have finished all the setup. Also we could expose this to the various users as "system_capabilities_finalized()" to make it more meaningful than "const_caps_ready". Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will@kernel.org> |
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| .. | ||
| boot | ||
| configs | ||
| crypto | ||
| include | ||
| kernel | ||
| kvm | ||
| lib | ||
| mm | ||
| net | ||
| xen | ||
| Kbuild | ||
| Kconfig | ||
| Kconfig.debug | ||
| Kconfig.platforms | ||
| Makefile | ||