IB/qib: Add percpu counter replacing qib_devdata int_counter
This patch replaces the dd->int_counter with a percpu counter.
The maintanance of qib_stats.sps_ints and int_counter are
combined into the new counter.
There are two new functions added to read the counter:
- qib_int_counter (for a particular qib_devdata)
- qib_sps_ints (for all HCAs)
A z_int_counter is added to allow the interrupt detection logic
to determine if interrupts have occured since z_int_counter
was "reset".
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/infiniband/hw/qib/qib_init.c b/drivers/infiniband/hw/qib/qib_init.c
index 76c3e17..6d26299 100644
--- a/drivers/infiniband/hw/qib/qib_init.c
+++ b/drivers/infiniband/hw/qib/qib_init.c
@@ -525,6 +525,7 @@
static void verify_interrupt(unsigned long opaque)
{
struct qib_devdata *dd = (struct qib_devdata *) opaque;
+ u64 int_counter;
if (!dd)
return; /* being torn down */
@@ -533,7 +534,8 @@
* If we don't have a lid or any interrupts, let the user know and
* don't bother checking again.
*/
- if (dd->int_counter == 0) {
+ int_counter = qib_int_counter(dd) - dd->z_int_counter;
+ if (int_counter == 0) {
if (!dd->f_intr_fallback(dd))
dev_err(&dd->pcidev->dev,
"No interrupts detected, not usable.\n");
@@ -1079,9 +1081,34 @@
#ifdef CONFIG_DEBUG_FS
qib_dbg_ibdev_exit(&dd->verbs_dev);
#endif
+ free_percpu(dd->int_counter);
ib_dealloc_device(&dd->verbs_dev.ibdev);
}
+u64 qib_int_counter(struct qib_devdata *dd)
+{
+ int cpu;
+ u64 int_counter = 0;
+
+ for_each_possible_cpu(cpu)
+ int_counter += *per_cpu_ptr(dd->int_counter, cpu);
+ return int_counter;
+}
+
+u64 qib_sps_ints(void)
+{
+ unsigned long flags;
+ struct qib_devdata *dd;
+ u64 sps_ints = 0;
+
+ spin_lock_irqsave(&qib_devs_lock, flags);
+ list_for_each_entry(dd, &qib_dev_list, list) {
+ sps_ints += qib_int_counter(dd);
+ }
+ spin_unlock_irqrestore(&qib_devs_lock, flags);
+ return sps_ints;
+}
+
/*
* Allocate our primary per-unit data structure. Must be done via verbs
* allocator, because the verbs cleanup process both does cleanup and
@@ -1119,6 +1146,13 @@
"Could not allocate unit ID: error %d\n", -ret);
goto bail;
}
+ dd->int_counter = alloc_percpu(u64);
+ if (!dd->int_counter) {
+ ret = -ENOMEM;
+ qib_early_err(&pdev->dev,
+ "Could not allocate per-cpu int_counter\n");
+ goto bail;
+ }
if (!qib_cpulist_count) {
u32 count = num_online_cpus();