Memory protection mechanism for a distributed shared memory multiprocessor with integrated message passing support

A method for memory protection in a distributed shared memory multiprocessor system with integrated message passing, comprising:

• providing a first processor node including a processor, a shareable memory sub-system, a mesh coherence unit (MCU) and a bus for the communicative coupling thereof;
• providing a second processor node including a processor, a shareable memory sub-system, an MCU and a bus for the communicative coupling thereof;
• communicatively connecting the first processor node and the second processor node by an interconnection coupled to the MCU of the first processor node and to the MCU of the second processor node;
• the first processor node generating a lock value and storing the lock value in the MCU of the first processor node;
• the first processor node computing a key value as a function of the lock value and of a memory address, and communicating the key value and the memory address to the second processor node;
• the second processor node initiating a request for memory access by communicating to the first processor node the key value and the memory address;
• the first processor node computing a temp value as the function of the lock value and the memory address;
• and
• the first processor node permitting the second processor node access to the memory address if the temp value matches the key value.

A method for protecting memory in a multi processor-node computer system including an initiator node and a target node, comprising:

• the target node generating and storing a lock value;
• the target node using the lock value and a memory address of a shareable memory of the target node to calculate a key value;
• the initiator node receiving the key value and the memory address;
• the initiator node subsequently sending the key value and the memory address to the target node;
• the target node receiving the key value and the memory address;
• the target node using the received memory address and stored lock value to calculate a temp value;
• and
• the target node comparing the temp value and the received key value and granting the initiator node access rights to the shareable memory at the received memory address if the temp value matches the received key value.