General input/output architecture, protocol and related methods to implement flow control

An apparatus comprising:

• logic to:
• assemble a transaction layer packet to include an indication of a traffic class associated with the packet;
• and
• send the packet to a device over a differential, point-to-point serial data link, wherein the packet is to be associated with a particular one of a plurality of virtual channels based at least in part on the traffic class.

An apparatus comprising:

• a root complex to:
• identify a traffic class of a packet from transaction layer information of the packet;
• use a virtual channel capability structure to identify a particular virtual channel associated with the traffic class, wherein the particular virtual channel is to be included in a set of at least eight supported virtual channels, the set of virtual channels to include a default virtual channel, and wherein each virtual channel is to comprise a respective one of a plurality of independent logical data flows for a differential, point-to-point serial data link;
• assemble physical layer information for the packet to include an identification of the particular virtual channel;
• and
• send the packet, to include transaction layer information to identify the traffic class and the physical layer information, over the link to a device.

A method comprising:

• receiving a packet over a differential, point-to-point serial data link;
• identifying a traffic class associated with the packet;
• identifying a virtual channel associated with the traffic class;
• and
• sending the packet using the virtual channel.

A system comprising:

• an interconnect;
• a first device;
• and
• a second device communicatively coupled to the first device using the interconnect, the second device to:
• identify a traffic class associated with the packet;
• identify a virtual channel associated with the traffic class;
• and
• send the packet to the first device using the virtual channel.

An apparatus comprising:

• logic to:
• assemble a transaction layer packet to include:
• a type field to indicate a type for the packet;
• a traffic class field to indicate a traffic class for the transaction layer packet;
• an attribute field to identify an attribute of the packet;
• a length field to indicate a length of a data, payload for the packet;
• and
• send the translation layer packet to a device over a differential, point-to-point serial data link, wherein the packet is to be associated with a particular one of a plurality of virtual channels based at least in part on the traffic class to be identified in the traffic class field.

An apparatus comprising:

• logic to receive a transaction layer packet, the transaction layer packet to include:
• a type field to indicate a type for the packet;
• a traffic class field to indicate a traffic class for the transaction layer packet;
• an attribute field to identify an attribute of the packet;
• a length field to indicate a length of a data payload for the packet;
• logic to map the transaction layer packet to a virtual channel based on the traffic class to be indicated in the traffic class field;
• logic to indicate the virtual channel in the transaction layer packet;
• and
• logic to send the translation layer packet to a device over a differential, point-to-point serial data link responsive to the virtual channel to be indicated in the transactional layer packet.