cxl/region: Move find_cxl_root() to cxl_add_to_region()

When adding an endpoint to a region, the root port is determined
first. Move this directly into cxl_add_to_region(). This is in
preparation of the initialization of endpoints that iterates the port
hierarchy from the endpoint up to the root port.

As a side-effect the root argument is removed from the argument lists
of cxl_add_to_region() and related functions. Now, the endpoint is the
only parameter to add a region. This simplifies the function
interface.

Signed-off-by: Robert Richter <rrichter@amd.com>
Reviewed-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: "Fabio M. De Francesco" <fabio.m.de.francesco@linux.intel.com>
Tested-by: Gregory Price <gourry@gourry.net>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Link: https://patch.msgid.link/20250509150700.2817697-8-rrichter@amd.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index efa5953df4492b43552cb2a911827b34ef6d6108..b78f195194697c427c140955ba51b70592d0da30 100644 (file)
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -3382,9 +3382,11 @@ static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd,
        return cxlr;
 }
 
-int cxl_add_to_region(struct cxl_port *root, struct cxl_endpoint_decoder *cxled)
+int cxl_add_to_region(struct cxl_endpoint_decoder *cxled)
 {
        struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
+       struct cxl_port *port = cxled_to_port(cxled);
+       struct cxl_root *cxl_root __free(put_cxl_root) = find_cxl_root(port);
        struct range *hpa = &cxled->cxld.hpa_range;
        struct cxl_decoder *cxld = &cxled->cxld;
        struct device *cxlrd_dev, *region_dev;
@@ -3394,7 +3396,7 @@ int cxl_add_to_region(struct cxl_port *root, struct cxl_endpoint_decoder *cxled)
        bool attach = false;
        int rc;
 
-       cxlrd_dev = device_find_child(&root->dev, &cxld->hpa_range,
+       cxlrd_dev = device_find_child(&cxl_root->port.dev, &cxld->hpa_range,
                                      match_root_decoder_by_range);
        if (!cxlrd_dev) {
                dev_err(cxlmd->dev.parent,

diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 14e20b44f2f459b4a642a37c4a2969635593f44f..3266be2fe5ea63c6b2ea60571e60ce1ebf86352a 100644 (file)
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -857,8 +857,7 @@ struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct cxl_port *port);
 #ifdef CONFIG_CXL_REGION
 bool is_cxl_pmem_region(struct device *dev);
 struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev);
-int cxl_add_to_region(struct cxl_port *root,
-                     struct cxl_endpoint_decoder *cxled);
+int cxl_add_to_region(struct cxl_endpoint_decoder *cxled);
 struct cxl_dax_region *to_cxl_dax_region(struct device *dev);
 u64 cxl_port_get_spa_cache_alias(struct cxl_port *endpoint, u64 spa);
 #else
@@ -870,8 +869,7 @@ static inline struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev)
 {
        return NULL;
 }
-static inline int cxl_add_to_region(struct cxl_port *root,
-                                   struct cxl_endpoint_decoder *cxled)
+static inline int cxl_add_to_region(struct cxl_endpoint_decoder *cxled)
 {
        return 0;
 }

diff --git a/drivers/cxl/port.c b/drivers/cxl/port.c
index a35fc55528459813d45427401d22d359174aa6b6..fe4b593331da050bab9503063a334c12149ac25f 100644 (file)
--- a/drivers/cxl/port.c
+++ b/drivers/cxl/port.c
@@ -30,7 +30,7 @@ static void schedule_detach(void *cxlmd)
        schedule_cxl_memdev_detach(cxlmd);
 }
 
-static int discover_region(struct device *dev, void *root)
+static int discover_region(struct device *dev, void *unused)
 {
        struct cxl_endpoint_decoder *cxled;
        int rc;
@@ -49,7 +49,7 @@ static int discover_region(struct device *dev, void *root)
         * Region enumeration is opportunistic, if this add-event fails,
         * continue to the next endpoint decoder.
         */
-       rc = cxl_add_to_region(root, cxled);
+       rc = cxl_add_to_region(cxled);
        if (rc)
                dev_dbg(dev, "failed to add to region: %#llx-%#llx\n",
                        cxled->cxld.hpa_range.start, cxled->cxld.hpa_range.end);
@@ -95,7 +95,6 @@ static int cxl_endpoint_port_probe(struct cxl_port *port)
        struct cxl_memdev *cxlmd = to_cxl_memdev(port->uport_dev);
        struct cxl_dev_state *cxlds = cxlmd->cxlds;
        struct cxl_hdm *cxlhdm;
-       struct cxl_port *root;
        int rc;
 
        rc = cxl_dvsec_rr_decode(cxlds, &info);
@@ -126,19 +125,11 @@ static int cxl_endpoint_port_probe(struct cxl_port *port)
        if (rc)
                return rc;
 
-       /*
-        * This can't fail in practice as CXL root exit unregisters all
-        * descendant ports and that in turn synchronizes with cxl_port_probe()
-        */
-       struct cxl_root *cxl_root __free(put_cxl_root) = find_cxl_root(port);
-
-       root = &cxl_root->port;
-
        /*
         * Now that all endpoint decoders are successfully enumerated, try to
         * assemble regions from committed decoders
         */
-       device_for_each_child(&port->dev, root, discover_region);
+       device_for_each_child(&port->dev, NULL, discover_region);
 
        return 0;
 }