摘要:
In a method and apparatus that ensures data consistency between an I/O channel and a processor, system software issues an instruction which causes the issuance of a transaction when notification of a DMA completion is received. The transaction instructs the I/O channel to enforce coherency and then responds back only after coherency has been ensured. Specifically, a DMA.sub.-- SYNC transaction is broadcast to all I/O channels in the system. Responsive thereto, each I/O channel writes back to memory any modified lines in its cache that might contain DMA data for a DMA sequence that was reported by the system as completed. The I/O channels have a reporting means to indicate when this transaction is completed, so that the DMA.sub.-- SYNC transaction does not have to complete in pipeline order. Thus, the I/O channel can issue new transactions before responding to the DMA.sub.-- SYNC transaction.
摘要:
A distributed-memory multi-processor system includes a plurality of cells communicatively coupled to each other and collectively including a plurality of processors, caches, main memories, and cell controllers. Each of the cells includes at least one of the processors, at least one of the caches, one of the main memories, and one of the cell controllers. Each of the cells is configured to perform memory migration functions for migrating memory from a first one of the main memories to a second one of the main memories in a manner that is invisible to an operating system of the system.
摘要:
A method of accessing a plurality of memories in an interleaved manner using a contiguous logical address space includes providing at least one map table. The at least one map table includes a plurality of entries. Each entry includes a plurality of entry items. Each entry item identifies one of the memories. A first logical address is received. The first logical address includes a plurality of address bits. The plurality of address bits includes a first set of address bits corresponding to a first set of entries in the at least one map table. A first entry in the first set of entries is identified based on the first set and a second set of the address bits. A first entry item in the first entry is identified based on a third set of the address bits. The memory identified by the first entry item is accessed.
摘要:
A shared bus system having a bus and a set of client modules coupled to the bus. Each client module is capable of sending transactions on the bus to other client modules and receiving transactions on the bus from other client modules for processing. Each module has a queue for storing transactions received by the module for processing. A bus controller limits the types of transactions that can be sent on the bus to prevent any module's queue from overflowing.
摘要:
Apparatus and method for efficiently sharing data in support of hardware he coherency and coordinated in software with semaphore instructions. Accordingly, a new instruction called "Load-Bias" which, in addition to normal load operations, requests a private copy of the data, and hints to the hardware cache to try to maintain ownership until the next memory reference from that processor. When used with the Cmpxchg instruction semaphore operation, the Load-Bias instruction will reduce coherency traffic, and minimize the possibility of coherency ping-ponging or system deadlock that causes the condition in which no processor is getting useful work done.
摘要:
A new instruction that ensures that the effects of a control register write will be observed at a well defined time is introduced. Specifically, the present invention introduces the concept of a serialization fence instruction. The serialization fence instruction ensures that after a control register in a computer has been modified, all subsequent instructions will observe the effects of the control register modification. Two different serialization fence instructions are illustrated: a data memory reference serialization fence instruction (SRLZ.d) and an instruction fetch serialization fence instruction (SRLZ.i). The data memory reference serialization fence instruction ensures that subsequent instruction executions and data memory references will observe the effects of the control register write. The instruction fetch serialization fence instruction ensures that the entire machine pipeline, starting at the initial instruction fetch stage, will observe the effects of the control register write.
摘要:
A bus system having a bus arbitration scheme. The bus system includes a bus and a plurality of client modules coupled to the bus. Each of the client modules is capable of transmitting information on the bus to another of client module, and only one client module is entitled to transmit information on the bus at any time. A module entitled to transmit information on the bus has control of the bus for a minimum period of time defining a cycle. To determine which module is entitled to use the bus, each client module generates an arbitration signal when it seeks to transmit information on the bus. Each client module has an arbitration signal processor responsive to the arbitration signals for determining whether the module is entitled to transmit information on said bus. The system preferably also contains a host module that informs the client modules what types of transactions allowed on the bus in a given cycle. Each arbitration signal processor preferably is also responsive to the client option signals sent by the host module during an earlier cycle.
摘要:
A computing system includes a memory bus, a main memory, an I/O adapter and a processor. The main memory, the I/O adapter and the processor are connected to the bus. The I/O adapter includes a translation map. The translation map maps I/O page numbers to memory address page numbers. The translation map includes coherence indices. The processor includes a cache and an instruction execution means. The instruction execution means generates coherence indices to be stored in the translation map. The instruction execution means performs in hardware a hash operation to generate the coherence indices.
摘要:
A shared bus system having a bus and a set of client modules coupled to the bus. Each client module is capable of sending transactions on the bus to other client modules and receiving transactions on the bus from other client modules for processing. Each module has a queue for storing transactions received by the module for processing. A bus controller limits the types of transactions that can be sent on the bus to prevent any module's queue from overflowing.
摘要:
A method and apparatus for implementing a page table walker that uses at least one of a default page size and a page size selected for a virtual address space to position a sliding field in a virtual address. According to one aspect of the invention, an apparatus for use in a computer system is provided that includes a page size storage area and a page table walker. The page size storage area is used to store a number of page sizes each selected for translating a different set of virtual addresses. The page table walker includes a selection unit coupled to the page size storage area, as well as a page entry address generator coupled to the selection unit. For each of the virtual address received, the selection unit positions a field in that virtual address based on the page size selected for translating the set of virtual addresses to which that virtual address belongs. In response to receiving the bits in the field identified for each of the virtual addresses, the page entry address generator identifies an entry in a page table based on those bits.