pciehp: use delayed_work private data to pass pending events

euler inclusion
category: bugfix
bugzilla: NA
CVE: NA
---------------------------

We use 'work_struct' private data to pass the pending events when we
schedule a 'delayed_work' in the following commit.
764cafd9875e ("pciehp: fix a race between pciehp and removing operations
by sysfs")
But workqueue framework will use this member, such as workqueue core
function 'set_work_pool_and_keep_pending()'. This patch add a new member
in 'struct delayed_work' and use this member to pass the pending events.
This patch also add more debug info.

Fixes: 764cafd9875e ("pciehp: fix a race between pciehp and removing
operations by sysfs")
Signed-off-by: NXiongfeng Wang <wangxiongfeng2@huawei.com>
Reviewed-by: NYao Hongbo <yaohongbo@huawei.com>
Reviewed-by: NHanjun Guo <guohanjun@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/pci/hotplug/pciehp_ctrl.c

@@ -145,8 +145,7 @@ void pciehp_queue_pushbutton_work(struct work_struct *work)
 {
 	struct slot *p_slot = container_of(work, struct slot, work.work);
 	struct controller *ctrl = p_slot->ctrl;
-	int events = atomic_long_read(&work->data) & (PCI_EXP_SLTSTA_PDC |
-			PCI_EXP_SLTSTA_DLLSC | DISABLE_SLOT);
+	int events = p_slot->work.data;
 
 	mutex_lock(&p_slot->lock);
 	switch (p_slot->state) {
@@ -188,7 +187,7 @@ void pciehp_handle_button_press(struct slot *p_slot)
 		/* blink green LED and turn off amber */
 		pciehp_green_led_blink(p_slot);
 		pciehp_set_attention_status(p_slot, 0);
-		atomic_long_set(&p_slot->work.work.data, 0);
+		p_slot->work.data = 0;
 		schedule_delayed_work(&p_slot->work, 5 * HZ);
 		break;
 	case BLINKINGOFF_STATE:

drivers/pci/hotplug/pciehp_hpc.c

@@ -693,18 +693,22 @@ static irqreturn_t pciehp_ist(int irq, void *dev_id)
 					slot->state == BLINKINGON_STATE)
 				pciehp_handle_disable_request(slot);
 			else {
+				ctrl_info(ctrl, "Slot(%s): DISABLE_SLOT event in remove or rescan process!\n",
+						slot_name(slot));
 				/*
 				 * we use the work_struct private data to store
 				 * the event type
 				 */
-				atomic_long_set(&slot->work.work.data,
-						DISABLE_SLOT);
+				slot->work.data = DISABLE_SLOT;
 				/*
 				 * If 'work.timer' is pending, schedule the work will
 				 * cause BUG_ON().
 				 */
 				if (!timer_pending(&slot->work.timer))
 					schedule_delayed_work(&slot->work, 3 * HZ);
+				else
+					ctrl_info(ctrl, "Slot(%s): Didn't schedule delayed_work because timer is pending!\n",
+						slot_name(slot));
 			}
 		}
 	} else if (events & (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC)) {
@@ -723,11 +727,12 @@ static irqreturn_t pciehp_ist(int irq, void *dev_id)
 				 */
 				ctrl_info(ctrl, "Slot(%s): Surprise link down/up in remove or rescan process!\n",
 						slot_name(slot));
-				atomic_long_set(&slot->work.work.data,
-						events & (PCI_EXP_SLTSTA_PDC |
-							PCI_EXP_SLTSTA_DLLSC));
+				slot->work.data = events & (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC);
 				if (!timer_pending(&slot->work.timer))
 					schedule_delayed_work(&slot->work, 3 * HZ);
+				else
+					ctrl_info(ctrl, "Slot(%s): Didn't schedule delayed_work because timer is pending!\n",
+						slot_name(slot));
 			}
 		}
 	}

include/linux/workqueue.h

@@ -125,6 +125,8 @@ struct delayed_work {
 	/* target workqueue and CPU ->timer uses to queue ->work */
 	struct workqueue_struct *wq;
 	int cpu;
+	/* delayed_work private data, only used in pciehp now */
+	unsigned long data;
 
 	KABI_RESERVE(1)
 	KABI_RESERVE(2)