摘要:
The present invention provides for asynchronous DMA command completion notification in a computer system. A command tag, associated with a plurality DMA command is generated. A DMA data movement command having the command tag is grouped with another DMA data movement command having the command tag. DMA commands belonging to the same tag group are monitored to see whether all DMA commands of the same tag group are completed.
摘要:
The present invention provides for a system comprising a DMA queue configured to receive a DMA command comprising a tag, wherein the tag belongs to one of a plurality of tag groups. A counter couples to the DMA queue and is configured to increment a tag group count of the tag group to which the tag belongs upon receipt of the DMA command by the DMA queue and to decrement the tag group count upon execution of the DMA command. A tag group count status register couples to the counter and is configured to store the tag group count for each of the plurality of tag groups. And the tag group count status register is further configured to receive a request for a tag group status and to respond to the request for the tag group status.
摘要:
The present invention provides for selectively overwriting sets of a cache as a function of a replacement management table and a least recently used function. A class identifier is created as a function of an address miss. A replacement management table is employable to read the class identifier to create a tag replacement control indicia. The cache, comprising a plurality of sets, is employable to disable the replacement of at least one of the plurality of sets as a function of the tag replacement control indicia.
摘要:
Disclosed is a coherent cache system that operates in conjunction with non-homogeneous processing units. A set of processing units of a first configuration has conventional cache and directly accesses common or shared system physical and virtual address memory through the use of a conventional MMU (Memory Management Unit). Additional processors of a different configuration and/or other devices that need to access system memory are configured to store accessed data in compatible caches. Each of the caches is compatible with a given protocol coherent memory management bus interspersed between the caches and the system memory.
摘要:
Memory management in a computer system is improved by preventing a subset of address translation information from being replaced with other types of address translation information in a cache memory reserved for storing such address translation information for faster access by a CPU. This way, the CPU can identify the subset of address translation information stored in the cache.
摘要:
A system and a method are provided for improving memory management in a multiprocessor system. A direct memory access (DMA) operation is set up for a first processor. A DMA effective address is translated to a virtual address. The virtual address is translated to a physical address, which is used to access a memory hierarchy of the multiprocessor system.
摘要:
The present invention provides for atomic update primitives in an asymmetric single-chip heterogeneous multiprocessor computer system having a shared memory with DMA transfers. At least one lock line command is generated from a set comprising a get lock line command with reservation, a put lock line conditional command, and a put lock line unconditional command.
摘要:
The present invention provides for atomic update primitives in an asymmetric single-chip heterogeneous multiprocessor computer system having a shared memory with DMA transfers. At least one lock line command is generated from a set comprising a get lock line command with reservation, a put lock line conditional command, and a put lock line unconditional command.
摘要:
The present invention provides a system for managing cache replacement eligibility. A first address register is configured to request an address from an L1 cache. An L1 cache is configured to determine whether a requested address is in the L1 cache and, in response to a determination that a requested address is not in the L1 cache, is further configured to transmit the requested address to a range register coupled to the L1 cache. The range register is configured to generate a class identifier in response to a received requested address and to transmit the requested address and class identifier to a replacement management table coupled to the range register. The replacement management table is configured to generate L2 tag replacement control indicia in response to a received requested address and class identifier. An L2 address register is coupled to the first address register and configured to request an address from an L2 cache. An L2 cache is coupled to the L2 address register and the replacement management table and is configured to determine whether a requested address is in the L2 cache and is further configured to assign replacement eligibility of at least one set of cache lines in the L2 cache in response to received L2 tag replacement control indicia. In response to a determination that a requested address is not in the L2 cache, the L2 cache is further configured to overwrite a cache line within a set of the L2 cache as a function of the replacement eligibility.
摘要:
A component of a microprocessor-based data processing system, which includes features for regulating power consumption in snoopable components and has gating off memory coherency properties, is determined to be in a relatively inactive state and is transitioned to a non-snoopable low power mode. Then, when a snoop request occurs, a retry protocol is sent in response to the snoop request. In conjunction with the retry protocol, a signal is sent to bring the component into snoopable mode. When the retry snoop is requested, the component is in full power mode and can properly respond to the snoop request. After the snoop request has been satisfied, the component again enters into a low power mode. Therefore, the component is able to enter into a low power mode in between snoops