Messages in this thread | | | Subject | Re: [PATCH v4 19/22] arm64: capabilities: Handle shared entries | From | Suzuki K Poulose <> | Date | Thu, 22 Mar 2018 16:43:28 +0000 |
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On 13/03/18 11:51, 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 by maintaining list of matches + cpu_enable callbacks. > To avoid complicating the prototypes for the "matches()", we use > arm64_cpu_capabilities maintain the list and we ignore all the other > fields except the matches & cpu_enable. > > This ensures : > > 1) The capabilitiy is set when at least one of the entry detects > 2) Action is only taken for the entries that "matches". > > This avoids explicit checks in the cpu_enable() take some action. > The only constraint here is that, all the entries should have the > same "type" (i.e, scope and conflict rules). > > If a cpu_enable() method is associated with multiple matches for a > single capability, care should be taken that either the match criteria > are mutually exclusive, or that the method is robust against being > called multiple times. > > This also reverts the changes introduced by commit 67948af41f2e6818ed > ("arm64: capabilities: Handle duplicate entries for a capability"). > > Cc: Robin Murphy <robin.murphy@arm.com> > Reviewed-by: Dave Martin <dave.martin@arm.com> > Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Lost changelog:
Changes since v3 - Rename cap_list => match_list - Address other comments from Dave - Added Reviewed-by from Dave
Cheers Suzuki
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