mirrors/linux
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-12-27 11:06:41 -05:00
Code Issues Packages Projects Releases Wiki Activity

cxl: Add helper to detect top of CXL device topology

Browse Source 
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>
This commit is contained in:
Dave Jiang
2025-08-29 11:09:19 -07:00
parent 8f5ae30d69
commit 4fde89539a
1 changed files with 11 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
drivers/cxl/core/port.c
View File

@@ -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 @@ int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd)
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;