diff options
| author | Dave Jiang <dave.jiang@intel.com> | 2025-08-29 11:09:19 -0700 |
|---|---|---|
| committer | Dave Jiang <dave.jiang@intel.com> | 2025-09-17 08:49:50 -0700 |
| commit | 4fde89539a18d39169a511fda00db65eeba1a8e0 (patch) | |
| tree | a4bd192256a0a83decfafc62b218e659fb441c17 | |
| parent | 8f5ae30d69d7543eee0d70083daf4de8fe15d585 (diff) | |
cxl: Add helper to detect top of CXL device topology
Add a helper to replace the open code detection of CXL device hierarchy
root, or the host bridge. The helper will be used for delayed downstream
port (dport) creation.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Li Ming <ming.li@zohomail.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Robert Richter <rrichter@amd.com>
Tested-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
| -rw-r--r-- | drivers/cxl/core/port.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index 29197376b18e..855623cebd7d 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -33,6 +33,15 @@ static DEFINE_IDA(cxl_port_ida); static DEFINE_XARRAY(cxl_root_buses); +/* + * The terminal device in PCI is NULL and @platform_bus + * for platform devices (for cxl_test) + */ +static bool is_cxl_host_bridge(struct device *dev) +{ + return (!dev || dev == &platform_bus); +} + int cxl_num_decoders_committed(struct cxl_port *port) { lockdep_assert_held(&cxl_rwsem.region); @@ -1541,7 +1550,7 @@ static int add_port_attach_ep(struct cxl_memdev *cxlmd, resource_size_t component_reg_phys; int rc; - if (!dparent) { + if (is_cxl_host_bridge(dparent)) { /* * The iteration reached the topology root without finding the * CXL-root 'cxl_port' on a previous iteration, fail for now to @@ -1629,11 +1638,7 @@ retry: struct device *uport_dev; struct cxl_dport *dport; - /* - * The terminal "grandparent" in PCI is NULL and @platform_bus - * for platform devices - */ - if (!dport_dev || dport_dev == &platform_bus) + if (is_cxl_host_bridge(dport_dev)) return 0; uport_dev = dport_dev->parent; |