1 files changed, 162 insertions, 8 deletions

diff --git a/drivers/hwtracing/ptt/hisi_ptt.c b/drivers/hwtracing/ptt/hisi_ptt.c
index 548cfef51ace..31471488fc91 100644
--- a/drivers/hwtracing/ptt/hisi_ptt.c
+++ b/drivers/hwtracing/ptt/hisi_ptt.c
@@ -357,24 +357,42 @@ static int hisi_ptt_register_irq(struct hisi_ptt *hisi_ptt)
 static void hisi_ptt_del_free_filter(struct hisi_ptt *hisi_ptt,
 				      struct hisi_ptt_filter_desc *filter)
 {
+	if (filter->is_port)
+		hisi_ptt->port_mask &= ~hisi_ptt_get_filter_val(filter->devid, true);
+
 	list_del(&filter->list);
+	kfree(filter->name);
 	kfree(filter);
 }
 
 static struct hisi_ptt_filter_desc *
-hisi_ptt_alloc_add_filter(struct hisi_ptt *hisi_ptt, struct pci_dev *pdev)
+hisi_ptt_alloc_add_filter(struct hisi_ptt *hisi_ptt, u16 devid, bool is_port)
 {
 	struct hisi_ptt_filter_desc *filter;
+	u8 devfn = devid & 0xff;
+	char *filter_name;
+
+	filter_name = kasprintf(GFP_KERNEL, "%04x:%02x:%02x.%d", pci_domain_nr(hisi_ptt->pdev->bus),
+				 PCI_BUS_NUM(devid), PCI_SLOT(devfn), PCI_FUNC(devfn));
+	if (!filter_name) {
+		pci_err(hisi_ptt->pdev, "failed to allocate name for filter %04x:%02x:%02x.%d\n",
+			pci_domain_nr(hisi_ptt->pdev->bus), PCI_BUS_NUM(devid),
+			PCI_SLOT(devfn), PCI_FUNC(devfn));
+		return NULL;
+	}
 
 	filter = kzalloc(sizeof(*filter), GFP_KERNEL);
 	if (!filter) {
 		pci_err(hisi_ptt->pdev, "failed to add filter for %s\n",
-			pci_name(pdev));
+			filter_name);
+		kfree(filter_name);
 		return NULL;
 	}
 
-	filter->devid = PCI_DEVID(pdev->bus->number, pdev->devfn);
-	filter->is_port = pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT;
+	filter->name = filter_name;
+	filter->is_port = is_port;
+	filter->devid = devid;
+
 	if (filter->is_port) {
 		list_add_tail(&filter->list, &hisi_ptt->port_filters);
 
@@ -387,6 +405,102 @@ hisi_ptt_alloc_add_filter(struct hisi_ptt *hisi_ptt, struct pci_dev *pdev)
 	return filter;
 }
 
+static void hisi_ptt_update_filters(struct work_struct *work)
+{
+	struct delayed_work *delayed_work = to_delayed_work(work);
+	struct hisi_ptt_filter_update_info info;
+	struct hisi_ptt_filter_desc *filter;
+	struct hisi_ptt *hisi_ptt;
+
+	hisi_ptt = container_of(delayed_work, struct hisi_ptt, work);
+
+	if (!mutex_trylock(&hisi_ptt->filter_lock)) {
+		schedule_delayed_work(&hisi_ptt->work, HISI_PTT_WORK_DELAY_MS);
+		return;
+	}
+
+	while (kfifo_get(&hisi_ptt->filter_update_kfifo, &info)) {
+		if (info.is_add) {
+			/*
+			 * Notify the users if failed to add this filter, others
+			 * still work and available. See the comments in
+			 * hisi_ptt_init_filters().
+			 */
+			filter = hisi_ptt_alloc_add_filter(hisi_ptt, info.devid, info.is_port);
+			if (!filter)
+				continue;
+		} else {
+			struct hisi_ptt_filter_desc *tmp;
+			struct list_head *target_list;
+
+			target_list = info.is_port ? &hisi_ptt->port_filters :
+				      &hisi_ptt->req_filters;
+
+			list_for_each_entry_safe(filter, tmp, target_list, list)
+				if (filter->devid == info.devid) {
+					hisi_ptt_del_free_filter(hisi_ptt, filter);
+					break;
+				}
+		}
+	}
+
+	mutex_unlock(&hisi_ptt->filter_lock);
+}
+
+/*
+ * A PCI bus notifier is used here for dynamically updating the filter
+ * list.
+ */
+static int hisi_ptt_notifier_call(struct notifier_block *nb, unsigned long action,
+				  void *data)
+{
+	struct hisi_ptt *hisi_ptt = container_of(nb, struct hisi_ptt, hisi_ptt_nb);
+	struct hisi_ptt_filter_update_info info;
+	struct pci_dev *pdev, *root_port;
+	struct device *dev = data;
+	u32 port_devid;
+
+	pdev = to_pci_dev(dev);
+	root_port = pcie_find_root_port(pdev);
+	if (!root_port)
+		return 0;
+
+	port_devid = PCI_DEVID(root_port->bus->number, root_port->devfn);
+	if (port_devid < hisi_ptt->lower_bdf ||
+	    port_devid > hisi_ptt->upper_bdf)
+		return 0;
+
+	info.is_port = pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT;
+	info.devid = PCI_DEVID(pdev->bus->number, pdev->devfn);
+
+	switch (action) {
+	case BUS_NOTIFY_ADD_DEVICE:
+		info.is_add = true;
+		break;
+	case BUS_NOTIFY_DEL_DEVICE:
+		info.is_add = false;
+		break;
+	default:
+		return 0;
+	}
+
+	/*
+	 * The FIFO size is 16 which is sufficient for almost all the cases,
+	 * since each PCIe core will have most 8 Root Ports (typically only
+	 * 1~4 Root Ports). On failure log the failed filter and let user
+	 * handle it.
+	 */
+	if (kfifo_in_spinlocked(&hisi_ptt->filter_update_kfifo, &info, 1,
+				&hisi_ptt->filter_update_lock))
+		schedule_delayed_work(&hisi_ptt->work, 0);
+	else
+		pci_warn(hisi_ptt->pdev,
+			 "filter update fifo overflow for target %s\n",
+			 pci_name(pdev));
+
+	return 0;
+}
+
 static int hisi_ptt_init_filters(struct pci_dev *pdev, void *data)
 {
 	struct pci_dev *root_port = pcie_find_root_port(pdev);
@@ -407,7 +521,8 @@ static int hisi_ptt_init_filters(struct pci_dev *pdev, void *data)
 	 * should be partial initialized and users would know which filter fails
 	 * through the log. Other functions of PTT device are still available.
 	 */
-	filter = hisi_ptt_alloc_add_filter(hisi_ptt, pdev);
+	filter = hisi_ptt_alloc_add_filter(hisi_ptt, PCI_DEVID(pdev->bus->number, pdev->devfn),
+					    pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT);
 	if (!filter)
 		return -ENOMEM;
 
@@ -466,8 +581,13 @@ static int hisi_ptt_init_ctrls(struct hisi_ptt *hisi_ptt)
 	int ret;
 	u32 reg;
 
+	INIT_DELAYED_WORK(&hisi_ptt->work, hisi_ptt_update_filters);
+	INIT_KFIFO(hisi_ptt->filter_update_kfifo);
+	spin_lock_init(&hisi_ptt->filter_update_lock);
+
 	INIT_LIST_HEAD(&hisi_ptt->port_filters);
 	INIT_LIST_HEAD(&hisi_ptt->req_filters);
+	mutex_init(&hisi_ptt->filter_lock);
 
 	ret = hisi_ptt_config_trace_buf(hisi_ptt);
 	if (ret)
@@ -620,6 +740,7 @@ static int hisi_ptt_trace_valid_filter(struct hisi_ptt *hisi_ptt, u64 config)
 {
 	unsigned long val, port_mask = hisi_ptt->port_mask;
 	struct hisi_ptt_filter_desc *filter;
+	int ret = 0;
 
 	hisi_ptt->trace_ctrl.is_port = FIELD_GET(HISI_PTT_PMU_FILTER_IS_PORT, config);
 	val = FIELD_GET(HISI_PTT_PMU_FILTER_VAL_MASK, config);
@@ -633,16 +754,20 @@ static int hisi_ptt_trace_valid_filter(struct hisi_ptt *hisi_ptt, u64 config)
 	 * For Requester ID filters, walk the available filter list to see
 	 * whether we have one matched.
 	 */
+	mutex_lock(&hisi_ptt->filter_lock);
 	if (!hisi_ptt->trace_ctrl.is_port) {
 		list_for_each_entry(filter, &hisi_ptt->req_filters, list) {
 			if (val == hisi_ptt_get_filter_val(filter->devid, filter->is_port))
-				return 0;
+				goto out;
 		}
 	} else if (bitmap_subset(&val, &port_mask, BITS_PER_LONG)) {
-		return 0;
+		goto out;
 	}
 
-	return -EINVAL;
+	ret = -EINVAL;
+out:
+	mutex_unlock(&hisi_ptt->filter_lock);
+	return ret;
 }
 
 static void hisi_ptt_pmu_init_configs(struct hisi_ptt *hisi_ptt, struct perf_event *event)
@@ -916,6 +1041,31 @@ static int hisi_ptt_register_pmu(struct hisi_ptt *hisi_ptt)
 					&hisi_ptt->hisi_ptt_pmu);
 }
 
+static void hisi_ptt_unregister_filter_update_notifier(void *data)
+{
+	struct hisi_ptt *hisi_ptt = data;
+
+	bus_unregister_notifier(&pci_bus_type, &hisi_ptt->hisi_ptt_nb);
+
+	/* Cancel any work that has been queued */
+	cancel_delayed_work_sync(&hisi_ptt->work);
+}
+
+/* Register the bus notifier for dynamically updating the filter list */
+static int hisi_ptt_register_filter_update_notifier(struct hisi_ptt *hisi_ptt)
+{
+	int ret;
+
+	hisi_ptt->hisi_ptt_nb.notifier_call = hisi_ptt_notifier_call;
+	ret = bus_register_notifier(&pci_bus_type, &hisi_ptt->hisi_ptt_nb);
+	if (ret)
+		return ret;
+
+	return devm_add_action_or_reset(&hisi_ptt->pdev->dev,
+					hisi_ptt_unregister_filter_update_notifier,
+					hisi_ptt);
+}
+
 /*
  * The DMA of PTT trace can only use direct mappings due to some
  * hardware restriction. Check whether there is no IOMMU or the
@@ -987,6 +1137,10 @@ static int hisi_ptt_probe(struct pci_dev *pdev,
 		return ret;
 	}
 
+	ret = hisi_ptt_register_filter_update_notifier(hisi_ptt);
+	if (ret)
+		pci_warn(pdev, "failed to register filter update notifier, ret = %d", ret);
+
 	ret = hisi_ptt_register_pmu(hisi_ptt);
 	if (ret) {
 		pci_err(pdev, "failed to register PMU device, ret = %d", ret);