pciehp: Event handling rework

The event handler of PCIEHP driver is unnecessarily very complex. In
addition, current event handler can only a fixed number of events at
the same time, and some of events would be lost if several number of
events happened at the same time.

This patch simplify the event handler using 'work queue', and it also
fix the above-mentioned issue.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 23 insertions, 11 deletions

diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index fbc64aa2dd68..9aac6a87eb53 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -71,6 +71,8 @@
 #define DBG_LEAVE_ROUTINE
 #endif                          /* DEBUG */
 
+static atomic_t pciehp_num_controllers = ATOMIC_INIT(0);
+
 struct ctrl_reg {
         u8 cap_id;
         u8 nxt_ptr;
@@ -219,10 +221,7 @@ static inline int pciehp_writel(struct controller *ctrl, int reg, u32 value)
 #define EMI_STATE               0x0080
 #define EMI_STATUS_BIT          7
 
-static spinlock_t hpc_event_lock;
-
 DEFINE_DBG_BUFFER               /* Debug string buffer for entire HPC defined here */
-static int ctlr_seq_num = 0;    /* Controller sequence # */
 
 static irqreturn_t pcie_isr(int irq, void *dev_id);
 static void start_int_poll_timer(struct controller *ctrl, int sec);
@@ -656,6 +655,13 @@ static void hpc_release_ctlr(struct controller *ctrl)
         else
                 free_irq(ctrl->pci_dev->irq, ctrl);
 
+        /*
+         * If this is the last controller to be released, destroy the
+         * pciehp work queue
+         */
+        if (atomic_dec_and_test(&pciehp_num_controllers))
+                destroy_workqueue(pciehp_wq);
+
         DBG_LEAVE_ROUTINE
 }
 
@@ -1152,7 +1158,6 @@ int pciehp_acpi_get_hp_hw_control_from_firmware(struct pci_dev *dev)
 int pcie_init(struct controller * ctrl, struct pcie_device *dev)
 {
         int rc;
-        static int first = 1;
         u16 temp_word;
         u16 cap_reg;
         u16 intr_enable = 0;
@@ -1221,11 +1226,6 @@ int pcie_init(struct controller * ctrl, struct pcie_device *dev)
         dbg("%s: SLOTCTRL offset %x slot_ctrl %x\n",
             __FUNCTION__, ctrl->cap_base + SLOTCTRL, slot_ctrl);
 
-        if (first) {
-                spin_lock_init(&hpc_event_lock);
-                first = 0;
-        }
-
         for ( rc = 0; rc < DEVICE_COUNT_RESOURCE; rc++)
                 if (pci_resource_len(pdev, rc) > 0)
                         dbg("pci resource[%d] start=0x%llx(len=0x%llx)\n", rc,
@@ -1286,7 +1286,8 @@ int pcie_init(struct controller * ctrl, struct pcie_device *dev)
                 rc = request_irq(ctrl->pci_dev->irq, pcie_isr, IRQF_SHARED,
                                  MY_NAME, (void *)ctrl);
                 dbg("%s: request_irq %d for hpc%d (returns %d)\n",
-                    __FUNCTION__, ctrl->pci_dev->irq, ctlr_seq_num, rc);
+                    __FUNCTION__, ctrl->pci_dev->irq,
+                    atomic_read(&pciehp_num_controllers), rc);
                 if (rc) {
                         err("Can't get irq %d for the hotplug controller\n",
                             ctrl->pci_dev->irq);
@@ -1296,6 +1297,18 @@ int pcie_init(struct controller * ctrl, struct pcie_device *dev)
         dbg("pciehp ctrl b:d:f:irq=0x%x:%x:%x:%x\n", pdev->bus->number,
                 PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn), dev->irq);
 
+        /*
+         * If this is the first controller to be initialized,
+         * initialize the pciehp work queue
+         */
+        if (atomic_add_return(1, &pciehp_num_controllers) == 1) {
+                pciehp_wq = create_singlethread_workqueue("pciehpd");
+                if (!pciehp_wq) {
+                        rc = -ENOMEM;
+                        goto abort_free_irq;
+                }
+        }
+
         rc = pciehp_readw(ctrl, SLOTCTRL, &temp_word);
         if (rc) {
                 err("%s: Cannot read SLOTCTRL register\n", __FUNCTION__);
@@ -1349,7 +1362,6 @@ int pcie_init(struct controller * ctrl, struct pcie_device *dev)
                         goto abort_disable_intr;
         }
 
-        ctlr_seq_num++;
         ctrl->hpc_ops = &pciehp_hpc_ops;
 
         DBG_LEAVE_ROUTINE