Multiple I/O bus virtual broadcast of programmed I/O instructions

Claim 1

A method for performing an input/output process containing a programmed input/output instruction in a multiprocessor system including at least two processors, each of said processors being coupled to an I/O bus with one or more I/O devices connected thereto, said multiprocessor system including an operating system having process scheduling means for executing processes on said processors according to assigned priority, said process scheduling means including a process control block containing scheduling information for each of said processes said method comprising the steps of: establishing a global device location table accessible by each of said processors in which a unique I/O device address and a corresponding I/O bus location are stored for each I/O device in said multiprocessor system; when starting a programmed input/output instruction, determining the unique address of a referenced I/O device; reading the corresponding I/O bus location of the referenced I/O device from the global device location table; determining whether the referenced I/O device is connected to the local I/O bus, and when the referenced I/O device is connected to the local I/O bus, executing the input/output process on the local processor, when the referenced I/O device is connected to a prescribed remote I/O bus, placing a locked descriptor in the process control block for the input/output process indicating that the input/output process can be performed only on the remote processor coupled with the prescribed remote I/O bus, saving the registers of the input/output process in its process control block, scheduling the input/output process on the remote processor coupled with the prescribed remote I/O bus in accordance with the priority assigned to the I/O process by the operating system, and executing the input/output process on the remote processor coupled with the prescribed remote I/O bus.

Claim 2

A method for performing an input/output process containing a programmed input/output instruction in a multiprocessor system including at least two processors, each of said processors being coupled to an I/O bus with one or more I/O devices connected thereto, said multiprocessor system including an operating system having process scheduling means for executing processes on said processors according to assigned priority, said process scheduling means including a process control block containing scheduling information for each of said processes said method comprising the steps of: establishing a global device location table accessible by each of said processors in which a unique I/O device address and a corresponding I/O bus location are stored for each I/O device in said multiprocessor system; when starting a programmed input/output instruction, determining the unique address of a referenced I/O device; reading the corresponding I/O bus location of the referenced I/O device from the global device location table; determining whether the referenced I/O device is connected to the local I/O bus, and when the referenced I/O device is connected to the local I/O bus, executing the input/output process on the local processor, when the referenced I/O device is connected to a prescribed remote I/O bus, placing a locked descriptor in the process control block for the input/output process indicating that the input/output process can be performed only on the remote processor coupled with the prescribed remote I/O bus, saving the registers of the input/output process in its process control block, scheduling the input/output process on the remote processor coupled with the prescribed remote I/O bus in accordance with the priority assigned to the I/O process by the operating system, and executing the input/output process on the remote processor coupled with the prescribed remote I/O bus.

Claim 4

A method for performing an input/output process containing a programmed input/output instruction in a multiprocessor system including at least two processors, each of said processors coupled to an I/O bus with one or more I/O devices connected thereto, and further including an operating system having process scheduling means for executing processes on said processors according to assigned priority, said process scheduling means including a process control block for each of said processors, said method comprising the steps of: storing a unique I/O device address and a corresponding I/O bus location for each I/O device of the multiprocessor system in a global device location table accessible by each of said processors; determining the unique address of a referenced I/O device prior to performing the programmed input/output instruction; reading the corresponding I/O bus location of the referenced I/O device from the global device location table; executing the input/output process on the local processor when the referenced I/O device is connected to the local I/O bus, and when the referenced I/O device is connected to a prescribed remote I/O bus, placing a locked descriptor in the process control block for the input/output process indicating that the input/output process can be performed only on the remote processor coupled with the prescribed remote I/O bus; saving the registers of the input/output process in its process control block, scheduling the input/output process on the remote processor coupled with the prescribed remote I/O bus in accordance with the priority assigned to the I/O process by the operating system, and executing the input/output process on the remote processor coupled with the prescribed remote I/O bus.

Claim 5

A method for performing an input/output process containing a programmed input/output instruction in a multiprocessor system including at least two processors, each of said processors coupled to an I/O bus with one or more I/O devices connected thereto, and further including an operating system having process scheduling means for executing processes on said processors according to assigned priority, said process scheduling means including a process control block for each of said processors, said method comprising the steps of: storing a unique I/O device address and a corresponding I/O bus location for each I/O device of the multiprocessor system in a global device location table accessible by each of said processors; determining the unique address of a referenced I/O device prior to performing the programmed input/output instruction; reading the corresponding I/O bus location of the referenced I/O device from the global device location table; executing the input/output process on the local processor when the referenced I/O device is connected to the local I/O bus, and when the referenced I/O device is connected to a prescribed remote I/O bus, placing a locked descriptor in the process control block for the input/output process indicating that the input/output process can be performed only on the remote processor coupled with the prescribed remote I/O bus; saving the registers of the input/output process in its process control block, scheduling the input/output process on the remote processor coupled with the prescribed remote I/O bus in accordance with the priority assigned to the I/O process by the operating system, and executing the input/output process on the remote processor coupled with the prescribed remote I/O bus.

Claim 7

An apparatus for performing an input/output process containing a programmed input/output (PIO) instruction comprising: at least two processors, each of said processors capable of executing programmed input/output instructions; at least two I/O busses, each of said I/O busses coupled to one of said processors, each of said I/O busses having one or more I/O devices connected thereto; a shared memory means accessible by each of said processors and defining a global device location table, said global device location table containing a unique I/O device address and a corresponding I/O bus location for each I/O device attached to said I/O busses; means for determining the unique address of a reference I/o device for performing the PIO instruction; means for reading the corresponding I/O bus location of the reference I/O device from the global device location table; an operating system having process scheduling means for executing input/output processes on said processors according to priority assigned to said processes by said operating system, said process scheduling means further includes a process control block for each of said I/O processes, said process control block including a locked descriptor indicating that the I/O process is executable only on the processor to which the referenced I/O bus is coupled; and means for executing an I/O process on the processor coupled with the I/O bus on which the referenced I/O device is located.

Claim 8

An apparatus for performing an input/output process containing a programmed input/output (PIO) instruction comprising: at least two processors, each of said processors capable of executing programmed input/output instructions; at least two I/O busses, each of said I/O busses coupled to one of said processors, each of said I/O busses having one or more I/O devices connected thereto; a shared memory means accessible by each of said processors and defining a global device location table, said global device location table containing a unique I/O device address and a corresponding I/O bus location for each I/O device attached to said I/O busses; means for determining the unique address of a reference I/o device for performing the PIO instruction; means for reading the corresponding I/O bus location of the reference I/O device from the global device location table; an operating system having process scheduling means for executing input/output processes on said processors according to priority assigned to said processes by said operating system, said process scheduling means further includes a process control block for each of said I/O processes, said process control block including a locked descriptor indicating that the I/O process is executable only on the processor to which the referenced I/O bus is coupled; and means for executing an I/O process on the processor coupled with the I/O bus on which the referenced I/O device is located.