soc: fsl: dpio: add Net DIM integration

Use the generic dynamic interrupt moderation (dim) framework to
implement adaptive interrupt coalescing on Rx. With the per-packet
interrupt scheme, a high interrupt rate has been noted for moderate
traffic flows leading to high CPU utilization.

The dpio driver exports new functions to enable/disable adaptive IRQ
coalescing on a DPIO object, to query the state or to update Net DIM
with a new set of bytes and frames dequeued.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/soc/fsl/Kconfig b/drivers/soc/fsl/Kconfig
index 4df32bc..07d52ca 100644 (file)
--- a/drivers/soc/fsl/Kconfig
+++ b/drivers/soc/fsl/Kconfig
@@ -24,6 +24,7 @@ config FSL_MC_DPIO
         tristate "QorIQ DPAA2 DPIO driver"
         depends on FSL_MC_BUS
         select SOC_BUS
+        select DIMLIB
         help
          Driver for the DPAA2 DPIO object.  A DPIO provides queue and
          buffer management facilities for software to interact with

diff --git a/drivers/soc/fsl/dpio/dpio-service.c b/drivers/soc/fsl/dpio/dpio-service.c
index 44fafed..3fd0d08 100644 (file)
--- a/drivers/soc/fsl/dpio/dpio-service.c
+++ b/drivers/soc/fsl/dpio/dpio-service.c
@@ -12,6 +12,7 @@
 #include <linux/platform_device.h>
 #include <linux/interrupt.h>
 #include <linux/dma-mapping.h>
+#include <linux/dim.h>
 #include <linux/slab.h>
 
 #include "dpio.h"
@@ -28,6 +29,14 @@ struct dpaa2_io {
        spinlock_t lock_notifications;
        struct list_head notifications;
        struct device *dev;
+
+       /* Net DIM */
+       struct dim rx_dim;
+       /* protect against concurrent Net DIM updates */
+       spinlock_t dim_lock;
+       u16 event_ctr;
+       u64 bytes;
+       u64 frames;
 };
 
 struct dpaa2_io_store {
@@ -100,6 +109,17 @@ struct dpaa2_io *dpaa2_io_service_select(int cpu)
 }
 EXPORT_SYMBOL_GPL(dpaa2_io_service_select);
 
+static void dpaa2_io_dim_work(struct work_struct *w)
+{
+       struct dim *dim = container_of(w, struct dim, work);
+       struct dim_cq_moder moder =
+               net_dim_get_rx_moderation(dim->mode, dim->profile_ix);
+       struct dpaa2_io *d = container_of(dim, struct dpaa2_io, rx_dim);
+
+       dpaa2_io_set_irq_coalescing(d, moder.usec);
+       dim->state = DIM_START_MEASURE;
+}
+
 /**
  * dpaa2_io_create() - create a dpaa2_io object.
  * @desc: the dpaa2_io descriptor
@@ -147,6 +167,7 @@ struct dpaa2_io *dpaa2_io_create(const struct dpaa2_io_desc *desc,
        INIT_LIST_HEAD(&obj->node);
        spin_lock_init(&obj->lock_mgmt_cmd);
        spin_lock_init(&obj->lock_notifications);
+       spin_lock_init(&obj->dim_lock);
        INIT_LIST_HEAD(&obj->notifications);
 
        /* For now only enable DQRR interrupts */
@@ -164,6 +185,12 @@ struct dpaa2_io *dpaa2_io_create(const struct dpaa2_io_desc *desc,
 
        obj->dev = dev;
 
+       memset(&obj->rx_dim, 0, sizeof(obj->rx_dim));
+       INIT_WORK(&obj->rx_dim.work, dpaa2_io_dim_work);
+       obj->event_ctr = 0;
+       obj->bytes = 0;
+       obj->frames = 0;
+
        return obj;
 }
 
@@ -203,6 +230,8 @@ irqreturn_t dpaa2_io_irq(struct dpaa2_io *obj)
        struct qbman_swp *swp;
        u32 status;
 
+       obj->event_ctr++;
+
        swp = obj->swp;
        status = qbman_swp_interrupt_read_status(swp);
        if (!status)
@@ -817,3 +846,53 @@ void dpaa2_io_get_irq_coalescing(struct dpaa2_io *d, u32 *irq_holdoff)
        qbman_swp_get_irq_coalescing(swp, NULL, irq_holdoff);
 }
 EXPORT_SYMBOL(dpaa2_io_get_irq_coalescing);
+
+/**
+ * dpaa2_io_set_adaptive_coalescing() - Enable/disable adaptive coalescing
+ * @d: the given DPIO object
+ * @use_adaptive_rx_coalesce: adaptive coalescing state
+ */
+void dpaa2_io_set_adaptive_coalescing(struct dpaa2_io *d,
+                                     int use_adaptive_rx_coalesce)
+{
+       d->swp->use_adaptive_rx_coalesce = use_adaptive_rx_coalesce;
+}
+EXPORT_SYMBOL(dpaa2_io_set_adaptive_coalescing);
+
+/**
+ * dpaa2_io_get_adaptive_coalescing() - Query adaptive coalescing state
+ * @d: the given DPIO object
+ *
+ * Return 1 when adaptive coalescing is enabled on the DPIO object and 0
+ * otherwise.
+ */
+int dpaa2_io_get_adaptive_coalescing(struct dpaa2_io *d)
+{
+       return d->swp->use_adaptive_rx_coalesce;
+}
+EXPORT_SYMBOL(dpaa2_io_get_adaptive_coalescing);
+
+/**
+ * dpaa2_io_update_net_dim() - Update Net DIM
+ * @d: the given DPIO object
+ * @frames: how many frames have been dequeued by the user since the last call
+ * @bytes: how many bytes have been dequeued by the user since the last call
+ */
+void dpaa2_io_update_net_dim(struct dpaa2_io *d, __u64 frames, __u64 bytes)
+{
+       struct dim_sample dim_sample = {};
+
+       if (!d->swp->use_adaptive_rx_coalesce)
+               return;
+
+       spin_lock(&d->dim_lock);
+
+       d->bytes += bytes;
+       d->frames += frames;
+
+       dim_update_sample(d->event_ctr, d->frames, d->bytes, &dim_sample);
+       net_dim(&d->rx_dim, dim_sample);
+
+       spin_unlock(&d->dim_lock);
+}
+EXPORT_SYMBOL(dpaa2_io_update_net_dim);

diff --git a/drivers/soc/fsl/dpio/qbman-portal.h b/drivers/soc/fsl/dpio/qbman-portal.h
index 4ea2dd9..b23883d 100644 (file)
--- a/drivers/soc/fsl/dpio/qbman-portal.h
+++ b/drivers/soc/fsl/dpio/qbman-portal.h
@@ -162,6 +162,7 @@ struct qbman_swp {
        /* Interrupt coalescing */
        u32 irq_threshold;
        u32 irq_holdoff;
+       int use_adaptive_rx_coalesce;
 };
 
 /* Function pointers */

diff --git a/include/soc/fsl/dpaa2-io.h b/include/soc/fsl/dpaa2-io.h
index 9bff280..4bf62de 100644 (file)
--- a/include/soc/fsl/dpaa2-io.h
+++ b/include/soc/fsl/dpaa2-io.h
@@ -134,5 +134,8 @@ int dpaa2_io_query_bp_count(struct dpaa2_io *d, u16 bpid,
 
 int dpaa2_io_set_irq_coalescing(struct dpaa2_io *d, u32 irq_holdoff);
 void dpaa2_io_get_irq_coalescing(struct dpaa2_io *d, u32 *irq_holdoff);
-
+void dpaa2_io_set_adaptive_coalescing(struct dpaa2_io *d,
+                                     int use_adaptive_rx_coalesce);
+int dpaa2_io_get_adaptive_coalescing(struct dpaa2_io *d);
+void dpaa2_io_update_net_dim(struct dpaa2_io *d, __u64 frames, __u64 bytes);
 #endif /* __FSL_DPAA2_IO_H */