Bus bridge device

• US 20050256998A1
• Filed: 07/21/2005
• Published: 11/17/2005
• Est. Priority Date: 03/31/2003
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Arataki, Nina
• Granted Patent: US 7,415,555 B2
• Time in Patent Office: Days
• US Class Current: 711/110
• CPC Class Codes: G06F 13/4027 using bus bridges G06F13/4022 takes precedence

Abstract

A bus bridge device, which connects a first device executing a first process and a second device executing a second process in response to a request from the first device, includes a notifying unit that notifies, when a result of the second process is received from the second device, the result to the first device. The first device executes, after sending the request, a third process until the result is notified from the notifying unit.

Claims

1. A bus bridge device that connects a first device executing a first process and a second device executing a second process in response to a request from the first device, the bus bridge device comprising a notifying unit that notifies, when a result of the second process is received from the second device, the result to the first device, wherein

the first device executes, after sending the request, a third process until the result is notified from the notifying unit.

2. The bus bridge device according to claim 1, wherein the notifying unit notifies, when receiving an inquiry about the second process from the first device before receiving the result from the second device, the first device that the second process is being executed.

3. The bus bridge device according to claim 1, wherein the notifying unit notifies the result to the first device by writing the result in a predetermined memory area of the first device.

4. The bus bridge device according to claim 1, wherein the notifying unit notifies the result to the first device by generating an interrupt with respect to the first device.

5. The bus bridge device according to claim 1, wherein the first device and the second device are connected by means of a peripheral-component-interconnect bus.

6. The bus bridge device according to claim 5, wherein

the first device is a storage controller that controls a storage system,

the second device is a cache controller that provides a fast access to the storage system, and

the request is a write-data request from the storage controller to the cache controller.

7. A bus bridge device that connects a first device executing a first process and a second device executing a second process in response to a request from the first device, the bus bridge device comprising:

a first notifying unit that notifies, when receiving an inquiry about the second process from the first device before receiving a result of the second process from the second device, the first device that the second process is being executed;

a second notifying unit that notifies, when receiving the result from the second device, the result to the first device by writing the result in a predetermined memory area of the first device;

a third notifying unit that notifies, when receiving the result from the second device, the result to the first device by generating an interrupt with respect to the first device; and

a selecting unit that selects, based on a specification by the first device, any one of the first notifying unit, the second notifying unit, and the third notifying unit.

8. The bus bridge device according to claim 7, wherein the first device and the second device are connected by means of a peripheral-component-interconnect bus.

9. The bus bridge device according to claim 8, wherein

the first device is a storage controller that controls a storage system,

the second device is a cache controller that provides a fast access to the storage system, and

the request is a write-data request from the storage controller to the cache controller.

10. A method for controlling a bus bridge device that connects a first device executing a first process and a second device executing a second process in response to a request from the first device, the method comprising notifying, when a result of the second process is received from the second device, the result to the first device, wherein

the first device executes, after sending the request, a third process until the result is notified from the notifying unit.

11. The method according to claim 10, wherein the notifying includes notifying, when receiving an inquiry about the second process from the first device before receiving the result from the second device, the first device that the second process is being executed.

12. The method according to claim 10, wherein the notifying includes notifying the result to the first device by writing the result in a predetermined memory area of the first device.

13. The method according to claim 10, wherein the notifying includes notifying the result to the first device by generating an interrupt with respect to the first device.