arm64: cpufeature: Fix the type of no FP/SIMD capability
authorSuzuki K Poulose <suzuki.poulose@arm.com>
Mon, 13 Jan 2020 23:30:19 +0000 (23:30 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 14 Feb 2020 21:33:26 +0000 (16:33 -0500)
commit12e2dca1f224fde0ec1dec10a3c6e178c6dd8a7a
tree0bc525693f550b99c45bb9eafff5d151afb7da88
parentf1025b2f75a0e2ad037e1d875e43d996aed78dfb
arm64: cpufeature: Fix the type of no FP/SIMD capability

commit 449443c03d8cfdacf7313e17779a2594ebf87e6d upstream.

The NO_FPSIMD capability is defined with scope SYSTEM, which implies
that the "absence" of FP/SIMD on at least one CPU is detected only
after all the SMP CPUs are brought up. However, we use the status
of this capability for every context switch. So, let us change
the scope to LOCAL_CPU to allow the detection of this capability
as and when the first CPU without FP is brought up.

Also, the current type allows hotplugged CPU to be brought up without
FP/SIMD when all the current CPUs have FP/SIMD and we have the userspace
up. Fix both of these issues by changing the capability to
BOOT_RESTRICTED_LOCAL_CPU_FEATURE.

Fixes: 82e0191a1aa11abf ("arm64: Support systems without FP/ASIMD")
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/arm64/kernel/cpufeature.c