In preparation for upleveling device_lock() lockdep annotation support into the core, provide a helper to retrieve the lock class. This lock_class will be used with device_set_lock_class() to idenify the CXL nested locking rules.
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> Signed-off-by: Dan Williams <dan.j.willi...@intel.com> --- drivers/cxl/cxl.h | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 5486fb6aebd4..ca8a61a623b7 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -509,13 +509,12 @@ enum cxl_lock_class { */ }; -static inline void cxl_nested_lock(struct device *dev) +static inline int cxl_lock_class(struct device *dev) { if (is_cxl_port(dev)) { struct cxl_port *port = to_cxl_port(dev); - mutex_lock_nested(&dev->lockdep_mutex, - CXL_PORT_LOCK + port->depth); + return CXL_PORT_LOCK + port->depth; } else if (is_cxl_decoder(dev)) { struct cxl_port *port = to_cxl_port(dev->parent); @@ -523,14 +522,18 @@ static inline void cxl_nested_lock(struct device *dev) * A decoder is the immediate child of a port, so set * its lock class equal to other child device siblings. */ - mutex_lock_nested(&dev->lockdep_mutex, - CXL_PORT_LOCK + port->depth + 1); + return CXL_PORT_LOCK + port->depth + 1; } else if (is_cxl_nvdimm_bridge(dev)) - mutex_lock_nested(&dev->lockdep_mutex, CXL_NVDIMM_BRIDGE_LOCK); + return CXL_NVDIMM_BRIDGE_LOCK; else if (is_cxl_nvdimm(dev)) - mutex_lock_nested(&dev->lockdep_mutex, CXL_NVDIMM_LOCK); + return CXL_NVDIMM_LOCK; else - mutex_lock_nested(&dev->lockdep_mutex, CXL_ANON_LOCK); + return CXL_ANON_LOCK; +} + +static inline void cxl_nested_lock(struct device *dev) +{ + mutex_lock_nested(&dev->lockdep_mutex, cxl_lock_class(dev)); } static inline void cxl_nested_unlock(struct device *dev)