MAX_LOCKDEP_SUBCLASSES limits the depth of the CXL topology that can be
validated by lockdep. Given that the cxl_test topology is already at
this limit collapse some of the levels and clamp the max depth.
Cc: Alison Schofield <[email protected]>
Cc: Vishal Verma <[email protected]>
Cc: Ira Weiny <[email protected]>
Cc: Ben Widawsky <[email protected]>
Reviewed-by: Dave Jiang <[email protected]>
Reviewed-by: Kevin Tian <[email protected]>
Signed-off-by: Dan Williams <[email protected]>
---
drivers/cxl/cxl.h | 25 +++++++++++++++++++++----
1 file changed, 21 insertions(+), 4 deletions(-)
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index a6c1a027e389..b86aac8cde4f 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -410,20 +410,37 @@ enum cxl_lock_class {
CXL_ANON_LOCK,
CXL_NVDIMM_LOCK,
CXL_NVDIMM_BRIDGE_LOCK,
- CXL_PORT_LOCK,
+ /*
+ * Collapse the compatible port and nvdimm-bridge lock classes
+ * to save space
+ */
+ CXL_PORT_LOCK = CXL_NVDIMM_BRIDGE_LOCK,
/*
* Be careful to add new lock classes here, CXL_PORT_LOCK is
* extended by the port depth, so a maximum CXL port topology
- * depth would need to be defined first.
+ * depth would need to be defined first. Also, the max
+ * validation depth is limited by MAX_LOCKDEP_SUBCLASSES.
*/
};
+static inline int clamp_lock_class(struct device *dev, int lock_class)
+{
+ if (lock_class >= MAX_LOCKDEP_SUBCLASSES) {
+ dev_warn_once(dev,
+ "depth: %d, disabling lockdep for this device\n",
+ lock_class);
+ return -1;
+ }
+
+ return lock_class;
+}
+
static inline int cxl_lock_class(struct device *dev)
{
if (is_cxl_port(dev)) {
struct cxl_port *port = to_cxl_port(dev);
- return CXL_PORT_LOCK + port->depth;
+ return clamp_lock_class(dev, CXL_PORT_LOCK + port->depth);
} else if (is_cxl_decoder(dev)) {
struct cxl_port *port = to_cxl_port(dev->parent);
@@ -431,7 +448,7 @@ static inline int cxl_lock_class(struct device *dev)
* A decoder is the immediate child of a port, so set
* its lock class equal to other child device siblings.
*/
- return CXL_PORT_LOCK + port->depth + 1;
+ return clamp_lock_class(dev, CXL_PORT_LOCK + port->depth + 1);
} else if (is_cxl_nvdimm_bridge(dev))
return CXL_NVDIMM_BRIDGE_LOCK;
else if (is_cxl_nvdimm(dev))