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    SubjectRe: [PATCH v2 16/20] arm64: Handle shared capability entries
    On Wed, Jan 31, 2018 at 06:28:03PM +0000, Suzuki K Poulose wrote:
    > Some capabilities have different criteria for detection and associated
    > actions based on the matching criteria, even though they all share the
    > same capability bit. So far we have used multiple entries with the same
    > capability bit to handle this. This is prone to errors, as the
    > cpu_enable is invoked for each entry, irrespective of whether the
    > detection rule applies to the CPU or not. And also this complicates
    > other helpers, e.g, __this_cpu_has_cap.
    >
    > This patch adds a wrapper entry to cover all the possible variations
    > of a capability and ensures :
    > 1) The capabilitiy is set when at least one of the entry detects
    > 2) Action is only taken for the entries that detects.
    >
    > This avoids explicit checks in the call backs. The only constraint
    > here is that, all the entries should have the same "type".
    >
    > Cc: Dave Martin <dave.martin@arm.com>
    > Cc: Will Deacon <will.deacon@arm.com>
    > Cc: Mark Rutland <mark.rutland@arm.com>
    > Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
    > ---

    [...]

    > diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c

    [...]

    > @@ -1275,7 +1274,7 @@ static bool __verify_local_cpu_caps(const struct arm64_cpu_capabilities *caps_li
    > if (!(caps->type & scope_mask))
    > continue;
    >
    > - cpu_has_cap = __this_cpu_has_cap(caps_list, caps->capability);
    > + cpu_has_cap = caps->matches(caps, SCOPE_LOCAL_CPU);

    One other minor thing: the original caps_list argument seems no longer
    to be needed in this function after this change.

    Can we rename the caps_list argument to "caps" and remove the local
    variable of the same name?

    Cheers
    ---Dave

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