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.h b/drivers/infiniband/hw/qib/qib.h
index 1946101419a31c0c3066c72d90401639a474d3e3..f044430ed98eb1f8b549543a368b310e66d5f382 100644 (file)
--- a/drivers/infiniband/hw/qib/qib.h
+++ b/drivers/infiniband/hw/qib/qib.h
@@ -868,8 +868,10 @@ struct qib_devdata {
        /* last buffer for user use */
        u32 lastctxt_piobuf;
 
-       /* saturating counter of (non-port-specific) device interrupts */
-       u32 int_counter;
+       /* reset value */
+       u64 z_int_counter;
+       /* percpu intcounter */
+       u64 __percpu *int_counter;
 
        /* pio bufs allocated per ctxt */
        u32 pbufsctxt;
@@ -1449,6 +1451,10 @@ void qib_nomsi(struct qib_devdata *);
 void qib_nomsix(struct qib_devdata *);
 void qib_pcie_getcmd(struct qib_devdata *, u16 *, u8 *, u8 *);
 void qib_pcie_reenable(struct qib_devdata *, u16, u8, u8);
+/* interrupts for device */
+u64 qib_int_counter(struct qib_devdata *);
+/* interrupt for all devices */
+u64 qib_sps_ints(void);
 
 /*
  * dma_addr wrappers - all 0's invalid for hw

diff --git a/drivers/infiniband/hw/qib/qib_fs.c b/drivers/infiniband/hw/qib/qib_fs.c
index c61e2a92b3c115b4ab0b6c3ceb3f52d0d49a10ea..cab610ccd50e3d2cdf5efaf220dfd8ad5a95cc06 100644 (file)
--- a/drivers/infiniband/hw/qib/qib_fs.c
+++ b/drivers/infiniband/hw/qib/qib_fs.c
@@ -105,6 +105,7 @@ static int create_file(const char *name, umode_t mode,
 static ssize_t driver_stats_read(struct file *file, char __user *buf,
                                 size_t count, loff_t *ppos)
 {
+       qib_stats.sps_ints = qib_sps_ints();
        return simple_read_from_buffer(buf, count, ppos, &qib_stats,
                                       sizeof qib_stats);
 }

diff --git a/drivers/infiniband/hw/qib/qib_iba6120.c b/drivers/infiniband/hw/qib/qib_iba6120.c
index 84e593d6007b5c31a3ef0cc080c243697de10027..b9bea2ebfd4a625c610ba6975eeb491348c4253f 100644 (file)
--- a/drivers/infiniband/hw/qib/qib_iba6120.c
+++ b/drivers/infiniband/hw/qib/qib_iba6120.c
@@ -1634,9 +1634,7 @@ static irqreturn_t qib_6120intr(int irq, void *data)
                goto bail;
        }
 
-       qib_stats.sps_ints++;
-       if (dd->int_counter != (u32) -1)
-               dd->int_counter++;
+       this_cpu_inc(*dd->int_counter);
 
        if (unlikely(istat & (~QLOGIC_IB_I_BITSEXTANT |
                              QLOGIC_IB_I_GPIO | QLOGIC_IB_I_ERROR)))
@@ -1808,7 +1806,8 @@ static int qib_6120_setup_reset(struct qib_devdata *dd)
         * isn't set.
         */
        dd->flags &= ~(QIB_INITTED | QIB_PRESENT);
-       dd->int_counter = 0; /* so we check interrupts work again */
+       /* so we check interrupts work again */
+       dd->z_int_counter = qib_int_counter(dd);
        val = dd->control | QLOGIC_IB_C_RESET;
        writeq(val, &dd->kregbase[kr_control]);
        mb(); /* prevent compiler re-ordering around actual reset */

diff --git a/drivers/infiniband/hw/qib/qib_iba7220.c b/drivers/infiniband/hw/qib/qib_iba7220.c
index 454c2e7668fe71815f80cdabed08bacb35863ec0..28063d4c225bbb02da45e934eadd8cca04827927 100644 (file)
--- a/drivers/infiniband/hw/qib/qib_iba7220.c
+++ b/drivers/infiniband/hw/qib/qib_iba7220.c
@@ -1962,10 +1962,7 @@ static irqreturn_t qib_7220intr(int irq, void *data)
                goto bail;
        }
 
-       qib_stats.sps_ints++;
-       if (dd->int_counter != (u32) -1)
-               dd->int_counter++;
-
+       this_cpu_inc(*dd->int_counter);
        if (unlikely(istat & (~QLOGIC_IB_I_BITSEXTANT |
                              QLOGIC_IB_I_GPIO | QLOGIC_IB_I_ERROR)))
                unlikely_7220_intr(dd, istat);
@@ -2120,7 +2117,8 @@ static int qib_setup_7220_reset(struct qib_devdata *dd)
         * isn't set.
         */
        dd->flags &= ~(QIB_INITTED | QIB_PRESENT);
-       dd->int_counter = 0; /* so we check interrupts work again */
+       /* so we check interrupts work again */
+       dd->z_int_counter = qib_int_counter(dd);
        val = dd->control | QLOGIC_IB_C_RESET;
        writeq(val, &dd->kregbase[kr_control]);
        mb(); /* prevent compiler reordering around actual reset */

diff --git a/drivers/infiniband/hw/qib/qib_iba7322.c b/drivers/infiniband/hw/qib/qib_iba7322.c
index d1bd21319d7d2ec128442042448ce101111938a3..8441579decd98cc13eef225635d3d17bf51151b3 100644 (file)
--- a/drivers/infiniband/hw/qib/qib_iba7322.c
+++ b/drivers/infiniband/hw/qib/qib_iba7322.c
@@ -3115,9 +3115,7 @@ static irqreturn_t qib_7322intr(int irq, void *data)
                goto bail;
        }
 
-       qib_stats.sps_ints++;
-       if (dd->int_counter != (u32) -1)
-               dd->int_counter++;
+       this_cpu_inc(*dd->int_counter);
 
        /* handle "errors" of various kinds first, device ahead of port */
        if (unlikely(istat & (~QIB_I_BITSEXTANT | QIB_I_GPIO |
@@ -3186,9 +3184,7 @@ static irqreturn_t qib_7322pintr(int irq, void *data)
                 */
                return IRQ_HANDLED;
 
-       qib_stats.sps_ints++;
-       if (dd->int_counter != (u32) -1)
-               dd->int_counter++;
+       this_cpu_inc(*dd->int_counter);
 
        /* Clear the interrupt bit we expect to be set. */
        qib_write_kreg(dd, kr_intclear, ((1ULL << QIB_I_RCVAVAIL_LSB) |
@@ -3215,9 +3211,7 @@ static irqreturn_t qib_7322bufavail(int irq, void *data)
                 */
                return IRQ_HANDLED;
 
-       qib_stats.sps_ints++;
-       if (dd->int_counter != (u32) -1)
-               dd->int_counter++;
+       this_cpu_inc(*dd->int_counter);
 
        /* Clear the interrupt bit we expect to be set. */
        qib_write_kreg(dd, kr_intclear, QIB_I_SPIOBUFAVAIL);
@@ -3248,9 +3242,7 @@ static irqreturn_t sdma_intr(int irq, void *data)
                 */
                return IRQ_HANDLED;
 
-       qib_stats.sps_ints++;
-       if (dd->int_counter != (u32) -1)
-               dd->int_counter++;
+       this_cpu_inc(*dd->int_counter);
 
        /* Clear the interrupt bit we expect to be set. */
        qib_write_kreg(dd, kr_intclear, ppd->hw_pidx ?
@@ -3277,9 +3269,7 @@ static irqreturn_t sdma_idle_intr(int irq, void *data)
                 */
                return IRQ_HANDLED;
 
-       qib_stats.sps_ints++;
-       if (dd->int_counter != (u32) -1)
-               dd->int_counter++;
+       this_cpu_inc(*dd->int_counter);
 
        /* Clear the interrupt bit we expect to be set. */
        qib_write_kreg(dd, kr_intclear, ppd->hw_pidx ?
@@ -3306,9 +3296,7 @@ static irqreturn_t sdma_progress_intr(int irq, void *data)
                 */
                return IRQ_HANDLED;
 
-       qib_stats.sps_ints++;
-       if (dd->int_counter != (u32) -1)
-               dd->int_counter++;
+       this_cpu_inc(*dd->int_counter);
 
        /* Clear the interrupt bit we expect to be set. */
        qib_write_kreg(dd, kr_intclear, ppd->hw_pidx ?
@@ -3336,9 +3324,7 @@ static irqreturn_t sdma_cleanup_intr(int irq, void *data)
                 */
                return IRQ_HANDLED;
 
-       qib_stats.sps_ints++;
-       if (dd->int_counter != (u32) -1)
-               dd->int_counter++;
+       this_cpu_inc(*dd->int_counter);
 
        /* Clear the interrupt bit we expect to be set. */
        qib_write_kreg(dd, kr_intclear, ppd->hw_pidx ?
@@ -3723,7 +3709,8 @@ static int qib_do_7322_reset(struct qib_devdata *dd)
        dd->pport->cpspec->ibsymdelta = 0;
        dd->pport->cpspec->iblnkerrdelta = 0;
        dd->pport->cpspec->ibmalfdelta = 0;
-       dd->int_counter = 0; /* so we check interrupts work again */
+       /* so we check interrupts work again */
+       dd->z_int_counter = qib_int_counter(dd);
 
        /*
         * Keep chip from being accessed until we are ready.  Use

diff --git a/drivers/infiniband/hw/qib/qib_init.c b/drivers/infiniband/hw/qib/qib_init.c
index 76c3e177164dcdd4f654c33bce9008bea8fe843a..6d2629990cb30905050de57990915e0ef31618b3 100644 (file)
--- a/drivers/infiniband/hw/qib/qib_init.c
+++ b/drivers/infiniband/hw/qib/qib_init.c
@@ -525,6 +525,7 @@ static void enable_chip(struct qib_devdata *dd)
 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 @@ static void verify_interrupt(unsigned long opaque)
         * 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 @@ void qib_free_devdata(struct qib_devdata *dd)
 #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 @@ struct qib_devdata *qib_alloc_devdata(struct pci_dev *pdev, size_t extra)
                              "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();