Apple Inc.

International Business Machines Corporation

Christopher Colletti

David Edward Kroesche

Sreevathsa Ramachandra

Ronald P Hall

James Nolan Hardage

Brett Stanley Feero

Bryan Glen Hickerson

Jonathan Y Tong

Matthew C Stone

So Min Song

Michael Joseph Schiffli

Jonathan Ying Fai Tong

Gagan Anand

Techniques are disclosed relating to managing storage array invalidations. A computer system may comprise a processor core configured to operate in an idle state and operate in a run state in which the processor core executes instructions. The computer system may further comprise a power management circuit that is configured to receive, while the processor core is in the idle state, a set of invalidation requests directed to the processor core to invalidate a set of entries of a storage array of the processor core. The power management circuit may store invalidation information indicative of the set of invalidation requests. The power management circuit may determine that the processor core has received a request to transition to the run state. Prior to the processor core operating in the run state, the power management circuit may invalidate the set of entries of the storage array based on the invalidation information.

Storage array invalidation maintenance

A processor with reduced interrupt latency is disclosed. An apparatus includes a processor core and a cache subsystem having a cache controller and a cache. The processor core is configured to submit, to the cache controller, requests for access to the cache, wherein a given request for access to the cache specifies whether the given request is abandonable or non-abandonable in an event of an interrupt request. In response to a particular interrupt request, the processor core may provide an indication to cause the cache controller to abandon requests for access to the cache identified as abandonable. After receiving an acknowledgement from the cache controller that the abandonable requests have been abandoned, the processor core may begin execution of an interrupt handler in order to service the interrupt request.

Processor with reduced interrupt latency

A system and method for efficiently handling maintenance requests among multiple processors. In various embodiments, a given processor of multiple processors receives a maintenance request. If maintenance requests are not currently being blocked, then the given processor determines a type of the maintenance request and updates one or more maintenance type counters based on the type. If one or more counters exceed a threshold, an indication is generated specifying maintenance requests received at a later time are to be held. The received maintenance request is processed. Different types of maintenance requests are used for invalidating entries in the instruction cache, for invalidating entries in a TLB and for synchronizing page table updates. Afterward, software applications continue processing. Forward progress of the software applications is measured using one or more metrics. If forward progress has been achieved, then one or more maintenance type counters are reset.

Method to ensure forward progress of a processor in the presence of persistent external cache/TLB maintenance requests

A processor receives an instruction operation (OP) code from a verification system. The instruction OP code includes instruction bits and forced event bits. The processor identifies a forced event based upon the forced event bits, which is unrelated to an instruction that corresponds to the instruction bits. In turn, the processor executes the forced event.

Generating hardware events via the instruction stream for microprocessor verification

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Austin, TX, United States of America

Christopher Colletti