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 <alison.schofi...@intel.com> Cc: Vishal Verma <vishal.l.ve...@intel.com> Cc: Ira Weiny <ira.we...@intel.com> Cc: Ben Widawsky <ben.widaw...@intel.com> Reviewed-by: Dave Jiang <dave.ji...@intel.com> Reviewed-by: Kevin Tian <kevin.t...@intel.com> Signed-off-by: Dan Williams <dan.j.willi...@intel.com> --- 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))