Merge branch 'for-6.18/cxl-update-access-coordinates' into cxl-for-next

Update the CXL memory hotplug notifier to update the NUMA node access
coordinates directly rather than go through the HMAT memory hotplug
notifier.

Author: davejiang

drivers/acpi/numa/hmat.c

@@ -74,7 +74,6 @@ struct memory_target {
 	struct node_cache_attrs cache_attrs;
 	u8 gen_port_device_handle[ACPI_SRAT_DEVICE_HANDLE_SIZE];
 	bool registered;
-	bool ext_updated;	/* externally updated */
 };
 
 struct memory_initiator {
@@ -368,35 +367,6 @@ static void hmat_update_target_access(struct memory_target *target,
 	}
 }
 
-int hmat_update_target_coordinates(int nid, struct access_coordinate *coord,
-				   enum access_coordinate_class access)
-{
-	struct memory_target *target;
-	int pxm;
-
-	if (nid == NUMA_NO_NODE)
-		return -EINVAL;
-
-	pxm = node_to_pxm(nid);
-	guard(mutex)(&target_lock);
-	target = find_mem_target(pxm);
-	if (!target)
-		return -ENODEV;
-
-	hmat_update_target_access(target, ACPI_HMAT_READ_LATENCY,
-				  coord->read_latency, access);
-	hmat_update_target_access(target, ACPI_HMAT_WRITE_LATENCY,
-				  coord->write_latency, access);
-	hmat_update_target_access(target, ACPI_HMAT_READ_BANDWIDTH,
-				  coord->read_bandwidth, access);
-	hmat_update_target_access(target, ACPI_HMAT_WRITE_BANDWIDTH,
-				  coord->write_bandwidth, access);
-	target->ext_updated = true;
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(hmat_update_target_coordinates);
-
 static __init void hmat_add_locality(struct acpi_hmat_locality *hmat_loc)
 {
 	struct memory_locality *loc;
@@ -773,10 +743,6 @@ static void hmat_update_target_attrs(struct memory_target *target,
 	u32 best = 0;
 	int i;
 
-	/* Don't update if an external agent has changed the data.  */
-	if (target->ext_updated)
-		return;
-
 	/* Don't update for generic port if there's no device handle */
 	if ((access == NODE_ACCESS_CLASS_GENPORT_SINK_LOCAL ||
 	     access == NODE_ACCESS_CLASS_GENPORT_SINK_CPU) &&

drivers/base/node.c

@@ -248,6 +248,44 @@ void node_set_perf_attrs(unsigned int nid, struct access_coordinate *coord,
 }
 EXPORT_SYMBOL_GPL(node_set_perf_attrs);
 
+/**
+ * node_update_perf_attrs - Update the performance values for given access class
+ * @nid: Node identifier to be updated
+ * @coord: Heterogeneous memory performance coordinates
+ * @access: The access class for the given attributes
+ */
+void node_update_perf_attrs(unsigned int nid, struct access_coordinate *coord,
+			    enum access_coordinate_class access)
+{
+	struct node_access_nodes *access_node;
+	struct node *node;
+	int i;
+
+	if (WARN_ON_ONCE(!node_online(nid)))
+		return;
+
+	node = node_devices[nid];
+	list_for_each_entry(access_node, &node->access_list, list_node) {
+		if (access_node->access != access)
+			continue;
+
+		access_node->coord = *coord;
+		for (i = 0; access_attrs[i]; i++) {
+			sysfs_notify(&access_node->dev.kobj,
+				     NULL, access_attrs[i]->name);
+		}
+		break;
+	}
+
+	/* When setting CPU access coordinates, update mempolicy */
+	if (access != ACCESS_COORDINATE_CPU)
+		return;
+
+	if (mempolicy_set_node_perf(nid, coord))
+		pr_info("failed to set mempolicy attrs for node %d\n", nid);
+}
+EXPORT_SYMBOL_GPL(node_update_perf_attrs);
+
 /**
  * struct node_cache_info - Internal tracking for memory node caches
  * @dev:	Device represeting the cache level

drivers/cxl/core/cdat.c

@@ -1075,14 +1075,3 @@ void cxl_region_perf_data_calculate(struct cxl_region *cxlr,
 		cxlr->coord[i].write_bandwidth += perf->coord[i].write_bandwidth;
 	}
 }
-
-int cxl_update_hmat_access_coordinates(int nid, struct cxl_region *cxlr,
-				       enum access_coordinate_class access)
-{
-	return hmat_update_target_coordinates(nid, &cxlr->coord[access], access);
-}
-
-bool cxl_need_node_perf_attrs_update(int nid)
-{
-	return !acpi_node_backed_by_real_pxm(nid);
-}

drivers/cxl/core/core.h

@@ -141,9 +141,6 @@ bool cxl_memdev_has_poison_cmd(struct cxl_memdev *cxlmd,
 
 long cxl_pci_get_latency(struct pci_dev *pdev);
 int cxl_pci_get_bandwidth(struct pci_dev *pdev, struct access_coordinate *c);
-int cxl_update_hmat_access_coordinates(int nid, struct cxl_region *cxlr,
-				       enum access_coordinate_class access);
-bool cxl_need_node_perf_attrs_update(int nid);
 int cxl_port_get_switch_dport_bandwidth(struct cxl_port *port,
 					struct access_coordinate *c);
 

drivers/cxl/core/region.c

@@ -32,6 +32,12 @@
  * 3. Decoder targets
  */
 
+/*
+ * nodemask that sets per node when the access_coordinates for the node has
+ * been updated by the CXL memory hotplug notifier.
+ */
+static nodemask_t nodemask_region_seen = NODE_MASK_NONE;
+
 static struct cxl_region *to_cxl_region(struct device *dev);
 
 #define __ACCESS_ATTR_RO(_level, _name) {				\
@@ -2442,14 +2448,8 @@ static bool cxl_region_update_coordinates(struct cxl_region *cxlr, int nid)
 
 	for (int i = 0; i < ACCESS_COORDINATE_MAX; i++) {
 		if (cxlr->coord[i].read_bandwidth) {
-			rc = 0;
-			if (cxl_need_node_perf_attrs_update(nid))
-				node_set_perf_attrs(nid, &cxlr->coord[i], i);
-			else
-				rc = cxl_update_hmat_access_coordinates(nid, cxlr, i);
-
-			if (rc == 0)
-				cset++;
+			node_update_perf_attrs(nid, &cxlr->coord[i], i);
+			cset++;
 		}
 	}
 
@@ -2487,6 +2487,10 @@ static int cxl_region_perf_attrs_callback(struct notifier_block *nb,
 	if (nid != region_nid)
 		return NOTIFY_DONE;
 
+	/* No action needed if node bit already set */
+	if (node_test_and_set(nid, nodemask_region_seen))
+		return NOTIFY_DONE;
+
 	if (!cxl_region_update_coordinates(cxlr, nid))
 		return NOTIFY_DONE;
 

include/linux/acpi.h

@@ -1595,18 +1595,6 @@ static inline void acpi_use_parent_companion(struct device *dev)
 	ACPI_COMPANION_SET(dev, ACPI_COMPANION(dev->parent));
 }
 
-#ifdef CONFIG_ACPI_HMAT
-int hmat_update_target_coordinates(int nid, struct access_coordinate *coord,
-				   enum access_coordinate_class access);
-#else
-static inline int hmat_update_target_coordinates(int nid,
-						 struct access_coordinate *coord,
-						 enum access_coordinate_class access)
-{
-	return -EOPNOTSUPP;
-}
-#endif
-
 #ifdef CONFIG_ACPI_NUMA
 bool acpi_node_backed_by_real_pxm(int nid);
 #else

include/linux/memory.h

@@ -115,13 +115,13 @@ struct notifier_block;
 struct mem_section;
 
 /*
- * Priorities for the hotplug memory callback routines (stored in decreasing
- * order in the callback chain)
+ * Priorities for the hotplug memory callback routines. Invoked from
+ * high to low. Higher priorities correspond to higher numbers.
  */
 #define DEFAULT_CALLBACK_PRI	0
 #define SLAB_CALLBACK_PRI	1
-#define HMAT_CALLBACK_PRI	2
 #define CXL_CALLBACK_PRI	5
+#define HMAT_CALLBACK_PRI	6
 #define MM_COMPUTE_BATCH_PRI	10
 #define CPUSET_CALLBACK_PRI	10
 #define MEMTIER_HOTPLUG_PRI	100

include/linux/node.h

@@ -85,6 +85,8 @@ struct node_cache_attrs {
 void node_add_cache(unsigned int nid, struct node_cache_attrs *cache_attrs);
 void node_set_perf_attrs(unsigned int nid, struct access_coordinate *coord,
 			 enum access_coordinate_class access);
+void node_update_perf_attrs(unsigned int nid, struct access_coordinate *coord,
+			    enum access_coordinate_class access);
 #else
 static inline void node_add_cache(unsigned int nid,
 				  struct node_cache_attrs *cache_attrs)
@@ -96,6 +98,12 @@ static inline void node_set_perf_attrs(unsigned int nid,
 				       enum access_coordinate_class access)
 {
 }
+
+static inline void node_update_perf_attrs(unsigned int nid,
+					  struct access_coordinate *coord,
+					  enum access_coordinate_class access)
+{
+}
 #endif
 
 struct node {