On 2021/8/5 7:52, Bjorn Helgaas wrote:
On Wed, Aug 04, 2021 at 09:47:06PM +0800, Dongdong Liu wrote:
PCIe spec 5.0 r1.0 section 2.2.6.2 says that if an Endpoint supports
sending Requests to other Endpoints (as opposed to host memory), the
Endpoint must not send 10-Bit Tag Requests to another given Endpoint
unless an implementation-specific mechanism determines that the Endpoint
supports 10-Bit Tag Completer capability. Add a 10bit_tag sysfs file,
write 0 to disable 10-Bit Tag Requester when the driver does not bind
the device if the peer device does not support the 10-Bit Tag Completer.
This will make P2P traffic safe. the 10bit_tag file content indicate
current 10-Bit Tag Requester Enable status.
Signed-off-by: Dongdong Liu <liudongdong3@xxxxxxxxxx>
+ The file is also writeable, the value only accept by write 0
+ to disable 10-Bit Tag Requester when the driver does not bind
+ the deivce. The typical use case is for p2pdma when the peer
+ device does not support 10-BIT Tag Completer.
s/10-BIT/10-Bit/
Will fix and will check other place.
Thank,
Dongdong
.
