drm/amdkfd: Add perf counters to topology

For hardware blocks whose performance counters are accessed via MMIO
registers, KFD provides the support for those privileged blocks.

IOMMU is one of those privileged blocks. Most performance counter properties
required by Thunk are available at /sys/bus/event_source/devices/amd_iommu.

This patch adds properties to topology in KFD sysfs for information not
available in /sys/bus/event_source/devices/amd_iommu. They are shown at
/sys/devices/virtual/kfd/kfd/topology/nodes/0/perf/iommu/ formatted as
/sys/devices/virtual/kfd/kfd/topology/nodes/0/perf/<block>/<property>, i.e.
/sys/devices/virtual/kfd/kfd/topology/nodes/0/perf/iommu/max_concurrent.

For dGPUs, who don't have IOMMU, nothing appears under
/sys/devices/virtual/kfd/kfd/topology/nodes/0/perf.

Signed-off-by: Amber Lin <Amber.Lin@amd.com>
Signed-off-by: Kent Russell <kent.russell@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>

drivers/gpu/drm/amd/amdkfd/kfd_topology.c

@@ -104,6 +104,7 @@ static void kfd_release_topology_device(struct kfd_topology_device *dev)
 	struct kfd_mem_properties *mem;
 	struct kfd_cache_properties *cache;
 	struct kfd_iolink_properties *iolink;
+	struct kfd_perf_properties *perf;
 
 	list_del(&dev->list);
 
@@ -128,6 +129,13 @@ static void kfd_release_topology_device(struct kfd_topology_device *dev)
 		kfree(iolink);
 	}
 
+	while (dev->perf_props.next != &dev->perf_props) {
+		perf = container_of(dev->perf_props.next,
+				struct kfd_perf_properties, list);
+		list_del(&perf->list);
+		kfree(perf);
+	}
+
 	kfree(dev);
 }
 
@@ -162,6 +170,7 @@ struct kfd_topology_device *kfd_create_topology_device(
 	INIT_LIST_HEAD(&dev->mem_props);
 	INIT_LIST_HEAD(&dev->cache_props);
 	INIT_LIST_HEAD(&dev->io_link_props);
+	INIT_LIST_HEAD(&dev->perf_props);
 
 	list_add_tail(&dev->list, device_list);
 
@@ -328,6 +337,39 @@ static struct kobj_type cache_type = {
 	.sysfs_ops = &cache_ops,
 };
 
+/****** Sysfs of Performance Counters ******/
+
+struct kfd_perf_attr {
+	struct kobj_attribute attr;
+	uint32_t data;
+};
+
+static ssize_t perf_show(struct kobject *kobj, struct kobj_attribute *attrs,
+			char *buf)
+{
+	struct kfd_perf_attr *attr;
+
+	buf[0] = 0;
+	attr = container_of(attrs, struct kfd_perf_attr, attr);
+	if (!attr->data) /* invalid data for PMC */
+		return 0;
+	else
+		return sysfs_show_32bit_val(buf, attr->data);
+}
+
+#define KFD_PERF_DESC(_name, _data)			\
+{							\
+	.attr  = __ATTR(_name, 0444, perf_show, NULL),	\
+	.data = _data,					\
+}
+
+static struct kfd_perf_attr perf_attr_iommu[] = {
+	KFD_PERF_DESC(max_concurrent, 0),
+	KFD_PERF_DESC(num_counters, 0),
+	KFD_PERF_DESC(counter_ids, 0),
+};
+/****************************************/
+
 static ssize_t node_show(struct kobject *kobj, struct attribute *attr,
 		char *buffer)
 {
@@ -452,6 +494,7 @@ static void kfd_remove_sysfs_node_entry(struct kfd_topology_device *dev)
 	struct kfd_iolink_properties *iolink;
 	struct kfd_cache_properties *cache;
 	struct kfd_mem_properties *mem;
+	struct kfd_perf_properties *perf;
 
 	if (dev->kobj_iolink) {
 		list_for_each_entry(iolink, &dev->io_link_props, list)
@@ -488,6 +531,16 @@ static void kfd_remove_sysfs_node_entry(struct kfd_topology_device *dev)
 		dev->kobj_mem = NULL;
 	}
 
+	if (dev->kobj_perf) {
+		list_for_each_entry(perf, &dev->perf_props, list) {
+			kfree(perf->attr_group);
+			perf->attr_group = NULL;
+		}
+		kobject_del(dev->kobj_perf);
+		kobject_put(dev->kobj_perf);
+		dev->kobj_perf = NULL;
+	}
+
 	if (dev->kobj_node) {
 		sysfs_remove_file(dev->kobj_node, &dev->attr_gpuid);
 		sysfs_remove_file(dev->kobj_node, &dev->attr_name);
@@ -504,8 +557,10 @@ static int kfd_build_sysfs_node_entry(struct kfd_topology_device *dev,
 	struct kfd_iolink_properties *iolink;
 	struct kfd_cache_properties *cache;
 	struct kfd_mem_properties *mem;
+	struct kfd_perf_properties *perf;
 	int ret;
-	uint32_t i;
+	uint32_t i, num_attrs;
+	struct attribute **attrs;
 
 	if (WARN_ON(dev->kobj_node))
 		return -EEXIST;
@@ -534,6 +589,10 @@ static int kfd_build_sysfs_node_entry(struct kfd_topology_device *dev,
 	if (!dev->kobj_iolink)
 		return -ENOMEM;
 
+	dev->kobj_perf = kobject_create_and_add("perf", dev->kobj_node);
+	if (!dev->kobj_perf)
+		return -ENOMEM;
+
 	/*
 	 * Creating sysfs files for node properties
 	 */
@@ -611,7 +670,33 @@ static int kfd_build_sysfs_node_entry(struct kfd_topology_device *dev,
 		if (ret < 0)
 			return ret;
 		i++;
-}
+	}
+
+	/* All hardware blocks have the same number of attributes. */
+	num_attrs = sizeof(perf_attr_iommu)/sizeof(struct kfd_perf_attr);
+	list_for_each_entry(perf, &dev->perf_props, list) {
+		perf->attr_group = kzalloc(sizeof(struct kfd_perf_attr)
+			* num_attrs + sizeof(struct attribute_group),
+			GFP_KERNEL);
+		if (!perf->attr_group)
+			return -ENOMEM;
+
+		attrs = (struct attribute **)(perf->attr_group + 1);
+		if (!strcmp(perf->block_name, "iommu")) {
+		/* Information of IOMMU's num_counters and counter_ids is shown
+		 * under /sys/bus/event_source/devices/amd_iommu. We don't
+		 * duplicate here.
+		 */
+			perf_attr_iommu[0].data = perf->max_concurrent;
+			for (i = 0; i < num_attrs; i++)
+				attrs[i] = &perf_attr_iommu[i].attr.attr;
+		}
+		perf->attr_group->name = perf->block_name;
+		perf->attr_group->attrs = attrs;
+		ret = sysfs_create_group(dev->kobj_perf, perf->attr_group);
+		if (ret < 0)
+			return ret;
+	}
 
 	return 0;
 }
@@ -778,6 +863,29 @@ static void find_system_memory(const struct dmi_header *dm,
 		}
 	}
 }
+
+/*
+ * Performance counters information is not part of CRAT but we would like to
+ * put them in the sysfs under topology directory for Thunk to get the data.
+ * This function is called before updating the sysfs.
+ */
+static int kfd_add_perf_to_topology(struct kfd_topology_device *kdev)
+{
+	struct kfd_perf_properties *props;
+
+	if (amd_iommu_pc_supported()) {
+		props = kfd_alloc_struct(props);
+		if (!props)
+			return -ENOMEM;
+		strcpy(props->block_name, "iommu");
+		props->max_concurrent = amd_iommu_pc_get_max_banks(0) *
+			amd_iommu_pc_get_max_counters(0); /* assume one iommu */
+		list_add_tail(&props->list, &kdev->perf_props);
+	}
+
+	return 0;
+}
+
 /* kfd_add_non_crat_information - Add information that is not currently
  *	defined in CRAT but is necessary for KFD topology
  * @dev - topology device to which addition info is added
@@ -860,6 +968,10 @@ int kfd_topology_init(void)
 		}
 	}
 
+	kdev = list_first_entry(&temp_topology_device_list,
+				struct kfd_topology_device, list);
+	kfd_add_perf_to_topology(kdev);
+
 	down_write(&topology_lock);
 	kfd_topology_update_device_list(&temp_topology_device_list,
 					&topology_device_list);

drivers/gpu/drm/amd/amdkfd/kfd_topology.h

@@ -134,6 +134,13 @@ struct kfd_iolink_properties {
 	struct attribute	attr;
 };
 
+struct kfd_perf_properties {
+	struct list_head	list;
+	char			block_name[16];
+	uint32_t		max_concurrent;
+	struct attribute_group	*attr_group;
+};
+
 struct kfd_topology_device {
 	struct list_head		list;
 	uint32_t			gpu_id;
@@ -144,11 +151,13 @@ struct kfd_topology_device {
 	struct list_head		cache_props;
 	uint32_t			io_link_count;
 	struct list_head		io_link_props;
+	struct list_head		perf_props;
 	struct kfd_dev			*gpu;
 	struct kobject			*kobj_node;
 	struct kobject			*kobj_mem;
 	struct kobject			*kobj_cache;
 	struct kobject			*kobj_iolink;
+	struct kobject			*kobj_perf;
 	struct attribute		attr_gpuid;
 	struct attribute		attr_name;
 	struct attribute		attr_props;
@@ -173,4 +182,8 @@ struct kfd_topology_device *kfd_create_topology_device(
 		struct list_head *device_list);
 void kfd_release_topology_device_list(struct list_head *device_list);
 
+extern bool amd_iommu_pc_supported(void);
+extern u8 amd_iommu_pc_get_max_banks(u16 devid);
+extern u8 amd_iommu_pc_get_max_counters(u16 devid);
+
 #endif /* __KFD_TOPOLOGY_H__ */