International Business Machines Corporation

Jonathan James DeMent

Ronald P Hall

Christopher Michael Abernathy

Jason Nathaniel Dale

David James Shippy

Clark M O'Niell

Robert Alan Philhower

Thuong Quang Truong

Steven Leonard Roberts

Sang Hoo Dhong

Albert James Van Norstrand, Jr

Gilles Gervais

Christopher John Spandikow

Brian King Flachs

Kurt Alan Feiste

Gavin Balfour Meil

Adam P Burns

Kerey Michelle Tassin

Kevin C Stelzer

Charles Ray Johns

Kirk David Peterson

Cedric Lichtenau

Alain F Loiseau

Michael Norman Day

Peichun Peter Liu

Michael Fan Wang

Makoto Aikawa

John Samuel Liberty

Robert Walter Berry, Jr

Kimberly Marie Fernsler

Alvan Wing Ng

Iwao Takiguchi

Tetsuji Tamura

Rolf B Hilgendorf

Roy Moonseuk Kim

Douglas Hooker Bradley

Yoichi Nishino

Brian Patrick Hanley

John L Sinchak

Kevin Stelzer

A system, method, and program product are provided that identifies a cache set using Translation LookAside Buffer (TLB) attributes. When a virtual address is requested, the method, system, and program product identifies a cache set using buffer attributes. When a virtual address is received, an attempt is made to load the received virtual address from a cache. When the attempt results in a cache miss, a page is identified within a Translation LookAside Buffer that includes the virtual address. A class identifier is then retrieved from the identified page, with the class identifier identifying a cache set that is selected from the cache.

System and method for cache-locking mechanism using translation table attributes for replacement class ID determination

A method for electronically fused encryption key security includes inserting a plurality of inverters between a bank of security fuses and a fuse sense logic module. The method also includes sensing an activated set of the bank of security fuses and the plurality of inverters. The method further includes comparing the sensed activated set of the bank of security fuses and the plurality of inverters with a software key to determine whether at least a substantial match is made.

Method for security in electronically fused encryption keys

A system, method, and program product are provided that identifies a cache set using Segment LookAside Buffer attributes. When an effective address is requested, an attempt is made to load the received effective address from an L2 cache. When this attempt results in a cache miss, the system identifies a segment within the Segment LookAside Buffer that includes the effective address. A class identifier is retrieved from the identified segment within the Segment LookAside Buffer. This class identifier identifies a cache set selected from the cache for replacement. Data is then reloaded into the cache set of the cache by using the retrieved class identifier that corresponds to the effective address.

System and method for cache-locking mechanism using segment table attributes for replacement class ID determination

One of the processors of a multiprocessor system is chosen to be a boot processor. The other processors of the multiprocessor system execute masking code that generates electromagnetic and/or thermal signatures that mask the electromagnetic and/or thermal signatures of the actual boot processor. Such masking may involve running the same boot code as the boot processor but without obtaining access to security information, such as the security key for accessing the system. The electromagnetic and/or thermal signatures generated by the execution of the masking code preferably approximate the electromagnetic and/or thermal signatures of the actual boot code executing on the boot processor. In this way, it is difficult to distinguish which processor is the actual boot processor.

Masking a hardware boot sequence

Boot code is partitioned into a plurality of boot code partitions. Processors of a multiprocessor system are selected to be boot processors and are each provided with a boot code partition to execute in a predetermined boot code sequence. Each processor executes its boot code partition in accordance with the boot code sequence and signals to a next processor the successful and uncompromised execution of its boot code partition. If any of the processors does not signal successful completion and/or uncompromised execution of its boot code partition, the boot operation fails. The processors may be arranged, with regard to the boot operation, in a daisy chain, ring, or master/slave arrangement, for example.

Secure boot across a plurality of processors

Pervasive logic is provided that includes a random event generator. The random event generator randomly selects which processor of a plurality of processors in the multiprocessor system is to be a boot processor for the multiprocessor system. A corresponding configuration bit for the randomly selected processor is set to identify the processor as a boot processor. Based on the setting of the configuration bits for each processor in the plurality of processors, a selection of a security key is made. The security key is then used to decrypt the boot code for booting the multiprocessor system. Only the randomly selected boot processor is able to select the correct security key for correctly decrypting the boot code, which it then executes to bring the system to an operational state.

Selecting a random processor to boot on a multiprocessor system

A method, system and processor for improving the performance of an in-order processor. A processor may include an execution unit with an execution pipeline that includes a backup pipeline and a regular pipeline. The backup pipeline may store a copy of the instructions issued to the regular pipeline. The execution pipeline may include logic for allowing instructions to flow from the backup pipeline to the regular pipeline following the flushing of the instructions younger than the exception detected in the regular pipeline. By maintaining a backup copy of the instructions issued to the regular pipeline, instructions may not need to be flushed from separate execution pipelines and re-fetched. As a result, one may complete the results of the execution units to the architected state out of order thereby allowing the completion point to vary among the different execution pipelines.

Performance of an in-order processor by no longer requiring a uniform completion point across different execution pipelines

Mechanisms for generating a worst case current waveform for testing of integrated circuit devices are provided. Architectural analysis of an integrated circuit device is first performed to determine an initial worst case power workload to be applied to the integrated circuit device. Thereafter, the derived worst case power workload is applied to a model and is simulated to generate a worst case current waveform that is input to an electrical model of the integrated circuit device to generate a worst case noise budget value. The worst case noise budget value is then compared to measured noise from application of the worst case power workload to a hardware implemented integrated circuit device. The worst case current waveform may be selected for future testing of integrated circuit devices or modifications to the simulation models may be performed and the process repeated based on the results of the comparison.

Generating a worst case current waveform for testing of integrated circuit devices

Tracking the order of issued instructions using a counter is presented. In one embodiment, a saturating, decrementing counter is used. The counter is initialized to a value that corresponds to the processor's commit point. Instructions are issued from a first issue queue to one or more execution units and one or more second issue queues. After being issued by the first issue queue, the counter associated with each instruction is decremented during each instruction cycle until the instruction is executed by one of the execution units. Once the counter reaches zero it will be completed by the execution unit. If a flush condition occurs, instructions with counters equal to zero are maintained (i.e., not flushed or invalidated), while other instructions in the pipeline are invalidated based upon their counter values.

Time-of-life counter for handling instruction flushes from a queue

A write-through cache scheme is created. A store data command is sent to a cache line of a cache array from a processing unit. It is then determined whether the address of the store data is valid, wherein the original data from the store's address has been previously loaded into the cache. A write-through command is sent to a system bus as a function of whether the address of the store data is valid. The bus controller is employed to sense the write-through command. If the write-through command is sensed, a clean command is generated by the bus controller. If the write-through command is sensed, the store data is written into the cache array, and the data is marked as modified. If the write-through command is sensed, the clean command is sent onto the system bus by the bus controller, thereby causing modified data to be written to memory.

Bus controller initiated write-through mechanism with hardware automatically generated clean command

A processor includes a general purpose (GP) unit adapted to receive and configured to execute GP instructions; and includes a single instruction multiple data (SIMD) unit adapted to receive and configured to execute SIMD instructions. An instruction unit comprises a first logic unit coupled to the GP unit and a second logic unit coupled to the SIMD unit, wherein SIMD instructions are processed subsequent to GP instructions. In the first logic unit a GP instruction with unresolved dependencies unconditionally causes subsequent SIMD instructions to stall, and an SIMD instruction with unresolved dependencies does not cause subsequent GP instructions to stall. The first logic unit resolves dependencies in GP instructions, provides dependency-free instructions to the GP unit, and provides SIMD instructions to the second logic unit. The second logic unit resolves dependencies in SIMD instructions and provides dependency-free instructions to the SIMD unit.

Queue design system supporting dependency checking and issue for SIMD instructions within a general purpose processor

A mechanism is provided for booting a multiprocessor device based on selection of encryption keys to be provided to the processors. With the mechanism, a security key and one or more randomly generated key values are provided to a selector mechanism of each processor of the multiprocessor device. A random selection mechanism is provided in pervasive logic that randomly selects one of the processors to be a boot processor and thereby, provides a select signal to the selector of the boot processor such that the boot processor selects the security key. All other processors select one of the one or more randomly generated key values. As a result, only the randomly selected boot processor is able to use the proper security key to decrypt the boot code for execution.

Booting a multiprocessor device based on selection of encryption keys to be provided to processors

A mechanism is provided for masking a boot sequence by providing a dummy processor. With the mechanism, one of the processors of a multiprocessor system is chosen to be a boot processor. The other processors of the multiprocessor system execute masking code that generates electromagnetic and/or thermal signatures that mask the electromagnetic and/or thermal signatures of the actual boot processor. The execution of the masking code on the non-boot processors preferably generates electromagnetic and/or thermal signatures that approximate the signatures of the actual boot code execution on the boot processor. One of the non-boot processors is selected to execute masking code that is different from the other masking code sequence to thereby generate a electromagnetic and/or thermal signature that appears to be unique from an external monitoring perspective.

Masking a boot sequence by providing a dummy processor

Masking a boot sequence by providing a dummy processor is provided. One of the processors of a multiprocessor system is chosen to be a boot processor. The other processors of the multiprocessor system execute masking code that generates electromagnetic and/or thermal signatures that mask the electromagnetic and/or thermal signatures of the actual boot processor. The execution of the masking code on the non-boot processors preferably generates electromagnetic and/or thermal signatures that approximate the signatures of the actual boot code execution on the boot processor. One of the non-boot processors is selected to execute masking code that is different from the other masking code sequence to thereby generate an electromagnetic and/or thermal signature that appears to be unique from an external monitoring perspective.

A voltage identifier (VID) sorting system is provided that optimizes processor power and operating voltage guardband at a constant processor frequency. The VID sorting system determines a voltage versus current curve for the processor. The VID sorting system then uses the voltage versus current characteristics to calculate the power for each VID to determine an acceptable range of VIDs within the maximum power criteria. The VID sorting system then tests VIDs in the range and selects a VID from the range to optimize for minimum power and/or maximum voltage guardband at a constant processor frequency.

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Austin, TX, United States of America

Jonathan James DeMent