PCI: pciehp: Handle events synchronously

Up until now, pciehp's IRQ handler schedules a work item for each event,
which in turn schedules a work item to enable or disable the slot.  This
double indirection was necessary because sleeping wasn't allowed in the
IRQ handler.

However it is now that pciehp has been converted to threaded IRQ handling
and polling, so handle events synchronously in pciehp_ist() and remove
the work item infrastructure (with the exception of work items to handle
a button press after the 5 second delay).

For link or presence change events, move the register read to determine
the current link or presence state behind acquisition of the slot lock
to prevent it from becoming stale while the lock is contended.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

1 files changed, 4 insertions, 16 deletions

diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h
index 9f11360e3318..82ff77cc92f5 100644
--- a/drivers/pci/hotplug/pciehp.h
+++ b/drivers/pci/hotplug/pciehp.h
@@ -69,8 +69,7 @@ do {									\
  *	protects scheduling, execution and cancellation of @work
  * @hotplug_lock: serializes calls to pciehp_enable_slot() and
  *	pciehp_disable_slot()
- * @wq: work queue on which @work is scheduled;
- *	also used to queue interrupt events and slot enablement and disablement
+ * @wq: work queue on which @work is scheduled
  */
 struct slot {
 	u8 state;
@@ -82,12 +81,6 @@ struct slot {
 	struct workqueue_struct *wq;
 };
 
-struct event_info {
-	u32 event_type;
-	struct slot *p_slot;
-	struct work_struct work;
-};
-
 /**
  * struct controller - PCIe hotplug controller
  * @ctrl_lock: serializes writes to the Slot Control register
@@ -131,13 +124,6 @@ struct controller {
 	atomic_t pending_events;
 };
 
-#define INT_PRESENCE_ON			1
-#define INT_PRESENCE_OFF		2
-#define INT_POWER_FAULT			3
-#define INT_BUTTON_PRESS		4
-#define INT_LINK_UP			5
-#define INT_LINK_DOWN			6
-
 #define STATIC_STATE			0
 #define BLINKINGON_STATE		1
 #define BLINKINGOFF_STATE		2
@@ -156,7 +142,9 @@ struct controller {
 
 int pciehp_sysfs_enable_slot(struct slot *slot);
 int pciehp_sysfs_disable_slot(struct slot *slot);
-void pciehp_queue_interrupt_event(struct slot *slot, u32 event_type);
+void pciehp_handle_button_press(struct slot *slot);
+void pciehp_handle_link_change(struct slot *slot);
+void pciehp_handle_presence_change(struct slot *slot);
 int pciehp_configure_device(struct slot *p_slot);
 void pciehp_unconfigure_device(struct slot *p_slot);
 void pciehp_queue_pushbutton_work(struct work_struct *work);