Executing a Kernel Device Driver as a User Space Process

• US 20120131375A1
• Filed: 11/18/2010
• Published: 05/24/2012
• Est. Priority Date: 11/18/2010
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Adda, Michael, Aloni, Dan, Braverman, Avner
• Granted Patent: US 8,806,511 B2
• Time in Patent Office: Days
• US Class Current: 714/2
• CPC Class Codes: G06F 11/0715 in a system implementing multitasking multitasking per se G06F9/46
• CPC Class Codes: G06F 11/0793 Remedial or corrective actions recovery from an exception in an instruction pipeline G06F9/3861; by retry G06F11/1402; for recovering from a failure of a protocol instance or entity H04L69/40
• CPC Class Codes: G06F 11/1402 Saving, restoring, recovering or retrying
• CPC Class Codes: G06F 13/102 where the programme performs an interfacing function, e.g. device driver G06F13/105 takes precedence; scheduling within device drivers G06F9/52; contention policies within device drivers G06F9/4881
• CPC Class Codes: G06F 13/24 using interrupt G06F13/32 takes precedence
• CPC Class Codes: G06F 13/28 using burst mode transfer, e.g. direct memory access DMA, cycle steal G06F13/32 takes precedence
• CPC Class Codes: G06F 13/4282 on a serial bus, e.g. I2C bus, SPI bus on daisy chain buses G06F13/4247
• CPC Class Codes: G06F 9/4843 by program, e.g. task dispatcher, supervisor, operating system
• CPC Class Codes: G06F 9/541 via adapters, e.g. between incompatible applications
• CPC Class Codes: G06F 9/545 where tasks reside in different layers, e.g. user- and kernel-space

Abstract

A method, including receiving, by a user space driver framework (UDF) library executing from a user space of a memory over a monolithic operating system kernel, a kernel application programming interface (API) call from a device driver executing from the user space. The UDF library then performs an operation corresponding to the kernel API call.

Claims

1. A method, comprising:

receiving, by a user space driver framework (UDF) library executing from a user space of a memory over a monolithic operating system kernel, a kernel application programming interface (API) call from a device driver executing from the user space; and

performing, by the UDF library, an operation corresponding to the kernel API call.

2. The method according to claim 1, wherein the operation comprises a non-privileged operation.

3. The method according to claim 2, wherein the non-privileged operation is selected from a group of operations comprising maintaining a list, maintaining a timer, and maintaining a process scheduler.

4. The method according to claim 1, and comprising:

determining that the operation comprises a privileged operation;

conveying, via a file descriptor, the API call to a UDF kernel module executing from a kernel space of the memory over the monolithic operating system kernel; and

performing, by the kernel space emulation module, the privileged operation.

5. The method according to claim 4, wherein the privileged operation is selected from a group of operations comprising catching an interrupt, allocating direct memory access (DMA) memory, and mapping input/output (I/O) memory addresses.

6. The method according to claim 1, wherein the device driver comprises a Peripheral Component Interconnect (PCI) device driver.

7. A computer program product, the computer program product comprising:

a non-transitory computer readable storage medium having computer readable program code embodied therewith, the computer readable program code comprising;

computer readable program code configured to receive, by a user space driver framework (UDF) library executing from a user space of a memory over a monolithic operating system kernel, a kernel application programming interface (API) call from a device driver executing from the user space; and

computer readable program code configured to perform, by the UDF library, an operation corresponding to the kernel API call.

8. The computer program product according to claim 7, wherein the operation comprises a non-privileged operation.

9. The computer program product according to claim 8, wherein the computer readable program code is configured to select the non-privileged operation from a group of operations comprising maintaining a list, maintaining a timer, and maintaining a process scheduler.

10. The computer program product according to claim 7, and comprising:

computer readable program code configured to determine that the operation comprises a privileged operation;

computer readable program code configured to convey, via a file descriptor, the API call to a UDF kernel module executing from a kernel space of the memory over the monolithic operating system kernel; and

computer readable program code configured to perform, by the kernel space emulation module, the privileged operation.

11. The computer program product according to claim 10, wherein the computer readable program code is configured to select the privileged operation from a group of operations comprising catching an interrupt, allocating direct memory access (DMA) memory, and mapping input/output (I/O) memory addresses.

12. The computer program product according to claim 7, wherein the device driver comprises a Peripheral Component Interconnect (PCI) device driver.

13. A method, comprising:

identifying two or more ports of a same type in a computer;

initiating a separate device driver process for each of the identified ports; and

establishing a one-to-one correspondence between each of the ports and each of the device driver processes.

14. The method according to claim 13, wherein the separate device driver processes comprise identical device drivers executing from unique addresses in a memory.

15. The method according to claim 13, wherein establishing a one-to-one correspondence comprises coupling the separate device driver processes to respective ports.

16. The method according to claim 13, wherein the two or more ports are positioned on one or more devices.

17. The method according to claim 13, and comprising:

detecting a failure of one of the device driver processes;

identifying the port associated with the failed device driver process;

re-launching the failed device driver process; and

coupling the re-launched device driver process to the identified port.

18. A computer program product, the computer program product comprising:

a non-transitory computer readable storage medium having computer readable program code embodied therewith, the computer readable program code comprising;

computer readable program code configured to identify two or more ports of a same type in a computer;

computer readable program code configured to initiate a separate device driver process for each of the identified ports; and

computer readable program code configured to establish a one-to-one correspondence between each of the ports and each of the device driver processes.

19. The computer program product according to claim 18, wherein the separate device driver processes comprise identical device drivers executing from unique addresses in a memory.

20. The computer program product according to claim 18, wherein the computer readable program code configured to establish a one-to-one correspondence by coupling the separate device driver processes to respective ports.

21. The computer program product according to claim 18, wherein the two or more ports are positioned on one or more devices.

22. The computer program product according to claim 18, and comprising:

computer readable program code configured to detect a failure of one of the device driver processes;

computer readable program code configured to identify the port associated with the failed device driver process;

computer readable program code configured to re-launch the failed device driver process; and

computer readable program code configured to couple the re-launched device driver process to the identified port.