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path: root/drivers/xen/xen-pciback/pciback_ops.c
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Diffstat (limited to 'drivers/xen/xen-pciback/pciback_ops.c')
-rw-r--r--drivers/xen/xen-pciback/pciback_ops.c48
1 files changed, 38 insertions, 10 deletions
diff --git a/drivers/xen/xen-pciback/pciback_ops.c b/drivers/xen/xen-pciback/pciback_ops.c
index e11a7438e1a2..3fbc21466a93 100644
--- a/drivers/xen/xen-pciback/pciback_ops.c
+++ b/drivers/xen/xen-pciback/pciback_ops.c
@@ -276,26 +276,41 @@ int xen_pcibk_disable_msix(struct xen_pcibk_device *pdev,
return 0;
}
#endif
+
+static inline bool xen_pcibk_test_op_pending(struct xen_pcibk_device *pdev)
+{
+ return test_bit(_XEN_PCIF_active,
+ (unsigned long *)&pdev->sh_info->flags) &&
+ !test_and_set_bit(_PDEVF_op_active, &pdev->flags);
+}
+
/*
* Now the same evtchn is used for both pcifront conf_read_write request
* as well as pcie aer front end ack. We use a new work_queue to schedule
* xen_pcibk conf_read_write service for avoiding confict with aer_core
* do_recovery job which also use the system default work_queue
*/
-void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev)
+static void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev)
{
+ bool eoi = true;
+
/* Check that frontend is requesting an operation and that we are not
* already processing a request */
- if (test_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags)
- && !test_and_set_bit(_PDEVF_op_active, &pdev->flags)) {
+ if (xen_pcibk_test_op_pending(pdev)) {
schedule_work(&pdev->op_work);
+ eoi = false;
}
/*_XEN_PCIB_active should have been cleared by pcifront. And also make
sure xen_pcibk is waiting for ack by checking _PCIB_op_pending*/
if (!test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags)
&& test_bit(_PCIB_op_pending, &pdev->flags)) {
wake_up(&xen_pcibk_aer_wait_queue);
+ eoi = false;
}
+
+ /* EOI if there was nothing to do. */
+ if (eoi)
+ xen_pcibk_lateeoi(pdev, XEN_EOI_FLAG_SPURIOUS);
}
/* Performing the configuration space reads/writes must not be done in atomic
@@ -303,10 +318,8 @@ void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev)
* use of semaphores). This function is intended to be called from a work
* queue in process context taking a struct xen_pcibk_device as a parameter */
-void xen_pcibk_do_op(struct work_struct *data)
+static void xen_pcibk_do_one_op(struct xen_pcibk_device *pdev)
{
- struct xen_pcibk_device *pdev =
- container_of(data, struct xen_pcibk_device, op_work);
struct pci_dev *dev;
struct xen_pcibk_dev_data *dev_data = NULL;
struct xen_pci_op *op = &pdev->op;
@@ -379,16 +392,31 @@ void xen_pcibk_do_op(struct work_struct *data)
smp_mb__before_atomic(); /* /after/ clearing PCIF_active */
clear_bit(_PDEVF_op_active, &pdev->flags);
smp_mb__after_atomic(); /* /before/ final check for work */
+}
- /* Check to see if the driver domain tried to start another request in
- * between clearing _XEN_PCIF_active and clearing _PDEVF_op_active.
- */
- xen_pcibk_test_and_schedule_op(pdev);
+void xen_pcibk_do_op(struct work_struct *data)
+{
+ struct xen_pcibk_device *pdev =
+ container_of(data, struct xen_pcibk_device, op_work);
+
+ do {
+ xen_pcibk_do_one_op(pdev);
+ } while (xen_pcibk_test_op_pending(pdev));
+
+ xen_pcibk_lateeoi(pdev, 0);
}
irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id)
{
struct xen_pcibk_device *pdev = dev_id;
+ bool eoi;
+
+ /* IRQs might come in before pdev->evtchn_irq is written. */
+ if (unlikely(pdev->evtchn_irq != irq))
+ pdev->evtchn_irq = irq;
+
+ eoi = test_and_set_bit(_EOI_pending, &pdev->flags);
+ WARN(eoi, "IRQ while EOI pending\n");
xen_pcibk_test_and_schedule_op(pdev);