The PCIe devices supported by the PTT trace can be removed/rescanned
by hotplug or through sysfs. Add support for dynamically updating
the available filter list by registering a PCI bus notifier block.
Then user can always get latest information about available tracing
filters and driver can block the invalid filters of which related
devices no longer exist in the system.
Signed-off-by: Yicong Yang
---
drivers/hwtracing/ptt/hisi_ptt.c | 138 ---
drivers/hwtracing/ptt/hisi_ptt.h | 34
2 files changed, 160 insertions(+), 12 deletions(-)
diff --git a/drivers/hwtracing/ptt/hisi_ptt.c b/drivers/hwtracing/ptt/hisi_ptt.c
index c2b6f8aa9f1e..50193a331faa 100644
--- a/drivers/hwtracing/ptt/hisi_ptt.c
+++ b/drivers/hwtracing/ptt/hisi_ptt.c
@@ -269,25 +269,118 @@ static int hisi_ptt_register_irq(struct hisi_ptt
*hisi_ptt)
return 0;
}
-static int hisi_ptt_init_filters(struct pci_dev *pdev, void *data)
+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 = data;
struct list_head *target_list;
+ struct hisi_ptt *hisi_ptt;
- target_list = pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT ?
- _ptt->port_filters : _ptt->req_filters;
+ hisi_ptt = container_of(delayed_work, struct hisi_ptt, work);
- filter = kzalloc(sizeof(*filter), GFP_KERNEL);
- if (!filter)
- return -ENOMEM;
+ if (!mutex_trylock(_ptt->mutex)) {
+ schedule_delayed_work(_ptt->work, HISI_PTT_WORK_DELAY_MS);
+ return;
+ }
- filter->pdev = pdev;
- list_add_tail(>list, target_list);
+ while (kfifo_get(_ptt->filter_update_kfifo, )) {
+ bool is_port = pci_pcie_type(info.pdev) ==
PCI_EXP_TYPE_ROOT_PORT;
+ u16 val = hisi_ptt_get_filter_val(info.pdev);
+
+ target_list = is_port ? _ptt->port_filters :
_ptt->req_filters;
+
+ if (info.is_add) {
+ filter = kzalloc(sizeof(*filter), GFP_KERNEL);
+ if (!filter)
+ continue;
+
+ filter->pdev = info.pdev;
+ list_add_tail(>list, target_list);
+ } else {
+ list_for_each_entry(filter, target_list, list)
+ if (hisi_ptt_get_filter_val(filter->pdev) ==
val) {
+ list_del(>list);
+ kfree(filter);
+ break;
+ }
+ }
- /* Update the available port mask */
- if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT)
- hisi_ptt->port_mask |= hisi_ptt_get_filter_val(pdev);
+ /* Update the available port mask */
+ if (!is_port)
+ continue;
+
+ if (info.is_add)
+ hisi_ptt->port_mask |= val;
+ else
+ hisi_ptt->port_mask &= ~val;
+ }
+
+ mutex_unlock(_ptt->mutex);
+}
+
+static void hisi_ptt_update_fifo_in(struct hisi_ptt *hisi_ptt,
+ struct hisi_ptt_filter_update_info *info)
+{
+ struct pci_dev *root_port = pcie_find_root_port(info->pdev);
+ u32 port_devid;
+
+ if (!root_port)
+ return;
+
+ port_devid = PCI_DEVID(root_port->bus->number, root_port->devfn);
+ if (port_devid < hisi_ptt->lower ||
+ port_devid > hisi_ptt->upper)
+ return;
+
+ if (kfifo_in_spinlocked(_ptt->filter_update_kfifo, info, 1,
+ _ptt->filter_update_lock))
+ schedule_delayed_work(_ptt->work, 0);
+ else
+ pci_warn(hisi_ptt->pdev,
+"filter update fifo overflow for target %s\n",
+pci_name(info->pdev));
+}
+
+/*
+ * 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 device *dev = data;
+ struct pci_dev *pdev = to_pci_dev(dev);
+
+ info.pdev = pdev;
+
+ 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;
+ }
+
+ hisi_ptt_update_fifo_in(hisi_ptt, );
+
+ return 0;
+}
+
+static int
