[RFC,6/6] docs: cxl: Add example commandline for MCTP CXL CCIs

Commit Message

Jonathan Cameron May 25, 2023, 4:08 p.m. UTC

A lot more needed here on what these are for and what can be done
with them.

Signed-off-by: Jonathan Cameron <[e-mail]>
---
 docs/system/devices/cxl.rst | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

Patch

diff --git a/docs/system/devices/cxl.rst b/docs/system/devices/cxl.rst
index f12011e230..5374b44f43 100644
--- a/docs/system/devices/cxl.rst
+++ b/docs/system/devices/cxl.rst
@@ -406,6 +406,33 @@  OS management of CXL memory devices as described here.
 * CONFIG_CXL_PORT
 * CONFIG_CXL_REGION
 
+
+CCI access via MCTP over I2C
+----------------------------
+
+TODO: Add some more info here on what this actually is.
+
+Both CXL switches and CXL Type 3 devices support configuration via
+MCTP access to Component Command Interfaces (CCIs) on the devices.
+
+Example configuration:
+
+ -device cxl-upstream,port=33,bus=root_port0,id=us0,multifunction=on,addr=0.0,sn=12345678 \
+ -device cxl-downstream,port=0,bus=us0,id=swport0,chassis=0,slot=4 \
+ -device cxl-downstream,port=1,bus=us0,id=swport1,chassis=0,slot=5 \
+ -device cxl-downstream,port=2,bus=us0,id=swport2,chassis=0,slot=6 \
+ -device cxl-type3,bus=swport0,persistent-memdev=cxl-mem1,id=cxl-pmem0,lsa=cxl-lsa1,sn=3 \
+ -device cxl-type3,bus=swport1,persistent-memdev=cxl-mem2,id=cxl-pmem1,lsa=cxl-lsa2,sn=4 \
+ -device cxl-type3,bus=swport2,persistent-memdev=cxl-mem3,id=cxl-pmem2,lsa=cxl-lsa3,sn=5 \
+ -machine cxl-fmw.0.targets.0=cxl.1,cxl-fmw.0.size=4G,cxl-fmw.0.interleave-granularity=1k \
+ -device i2c_mctp_cxl,bus=aspeed.i2c.bus.0,address=4,target=us0 \
+ -device i2c_mctp_cxl,bus=aspeed.i2c.bus.0,address=5,target=cxl-pmem0 \
+ -device i2c_mctp_cxl,bus=aspeed.i2c.bus.0,address=6,target=cxl-pmem1 \
+ -device i2c_mctp_cxl,bus=aspeed.i2c.bus.0,address=7,target=cxl-pmem2
+
+Communication with the MCTP CCI can then be established using standard MCTP configuration
+tools.
+
 References
 ----------