net/enic: fix counter action

- track whether counter DMAs are active or not so they can be stopped if
  needed before DMA memory is freed
- fix counter DMA shut-down by changing vnic_dev_counter_dma_cfg() to
  take the number of counters to DMA instead of high counter index and
  use num counters = 0 to shut off DMAs
- remove unnecessary checks that DMA counter memory is valid and that
  counter DMAs are in use
- change the minimum DMA period to match what 1400 series adapter is
  capable of
- fix comments and change a couple variable names to make more sense

Fixes: 86df6c4e2f ("net/enic: support flow counter action")

Signed-off-by: John Daley <johndale@cisco.com>
Reviewed-by: Hyong Youb Kim <hyonkim@cisco.com>

drivers/net/enic/base/vnic_dev.c

@@ -59,6 +59,7 @@ struct vnic_dev {
 		dma_addr_t dma_handle);
 	struct vnic_counter_counts *flow_counters;
 	dma_addr_t flow_counters_pa;
+	u8 flow_counters_dma_active;
 };
 
 #define VNIC_MAX_RES_HDR_SIZE \
@@ -618,18 +619,30 @@ int vnic_dev_stats_dump(struct vnic_dev *vdev, struct vnic_stats **stats)
 /*
  * Configure counter DMA
  */
-int vnic_dev_counter_dma_cfg(struct vnic_dev *vdev, u32 period, u32 counter_idx)
+int vnic_dev_counter_dma_cfg(struct vnic_dev *vdev, u32 period,
+			     u32 num_counters)
 {
 	u64 args[3];
 	int wait = 1000;
+	int err;
 
-	if (!vdev->flow_counters || counter_idx >= VNIC_MAX_FLOW_COUNTERS)
+	if (num_counters > VNIC_MAX_FLOW_COUNTERS)
 		return -ENOMEM;
+	if (period > 0 && (period < VNIC_COUNTER_DMA_MIN_PERIOD ||
+	    num_counters == 0))
+		return -EINVAL;
 
-	args[0] = counter_idx + 1;
+	args[0] = num_counters;
 	args[1] = vdev->flow_counters_pa;
 	args[2] = period;
-	return vnic_dev_cmd_args(vdev, CMD_COUNTER_DMA_CONFIG, args, 3, wait);
+	err =  vnic_dev_cmd_args(vdev, CMD_COUNTER_DMA_CONFIG, args, 3, wait);
+
+	/* record if DMAs need to be stopped on close */
+	if (!err)
+		vdev->flow_counters_dma_active = (num_counters != 0 &&
+						  period != 0);
+
+	return err;
 }
 
 int vnic_dev_close(struct vnic_dev *vdev)
@@ -974,6 +987,7 @@ int vnic_dev_alloc_counter_mem(struct vnic_dev *vdev)
 					     * VNIC_MAX_FLOW_COUNTERS,
 					     &vdev->flow_counters_pa,
 					     (u8 *)name);
+	vdev->flow_counters_dma_active = 0;
 	return vdev->flow_counters == NULL ? -ENOMEM : 0;
 }
 
@@ -991,7 +1005,8 @@ void vnic_dev_unregister(struct vnic_dev *vdev)
 				vdev->stats, vdev->stats_pa);
 		if (vdev->flow_counters) {
 			/* turn off counter DMAs before freeing memory */
-			vnic_dev_counter_dma_cfg(vdev, 0, 0);
+			if (vdev->flow_counters_dma_active)
+				vnic_dev_counter_dma_cfg(vdev, 0, 0);
 
 			vdev->free_consistent(vdev->priv,
 				sizeof(struct vnic_counter_counts)
@@ -1171,19 +1186,16 @@ bool vnic_dev_counter_query(struct vnic_dev *vdev, uint32_t idx,
 	u64 a1 = reset ? 1 : 0;
 	int wait = 1000;
 
-	if (vdev->flow_counters) {
-		/* Using counter DMA API, so counters avail in host memory */
-		*packets = vdev->flow_counters[idx].vcc_packets;
-		*bytes = vdev->flow_counters[idx].vcc_bytes;
-		if (reset)
-			if (vnic_dev_cmd(vdev, CMD_COUNTER_QUERY, &a0, &a1,
-			    wait))
-				return false;
-	} else {
+	if (reset) {
+		/* query/reset returns updated counters */
 		if (vnic_dev_cmd(vdev, CMD_COUNTER_QUERY, &a0, &a1, wait))
 			return false;
 		*packets = a0;
 		*bytes = a1;
+	} else {
+		/* Get values DMA'd from the adapter */
+		*packets = vdev->flow_counters[idx].vcc_packets;
+		*bytes = vdev->flow_counters[idx].vcc_bytes;
 	}
 	return true;
 }

drivers/net/enic/base/vnic_dev.h

@@ -119,7 +119,7 @@ int vnic_dev_spec(struct vnic_dev *vdev, unsigned int offset, size_t size,
 int vnic_dev_stats_clear(struct vnic_dev *vdev);
 int vnic_dev_stats_dump(struct vnic_dev *vdev, struct vnic_stats **stats);
 int vnic_dev_counter_dma_cfg(struct vnic_dev *vdev, u32 period,
-			     u32 counter_idx);
+			     u32 num_counters);
 int vnic_dev_hang_notify(struct vnic_dev *vdev);
 int vnic_dev_packet_filter(struct vnic_dev *vdev, int directed, int multicast,
 	int broadcast, int promisc, int allmulti);

drivers/net/enic/base/vnic_devcmd.h

@@ -634,6 +634,7 @@ enum vnic_devcmd_cmd {
 	 *     (u32) a2 = DMA period in milliseconds (0 to disable)
 	 */
 	CMD_COUNTER_DMA_CONFIG = _CMDC(_CMD_DIR_WRITE, _CMD_VTYPE_ENET, 88),
+#define VNIC_COUNTER_DMA_MIN_PERIOD 500
 
 	/*
 	 * Clear all counters on a vnic

drivers/net/enic/enic.h

@@ -38,7 +38,9 @@
 #define ENIC_PAGE_SIZE          4096
 #define PAGE_ROUND_UP(x) \
 	((((unsigned long)(x)) + ENIC_PAGE_SIZE-1) & (~(ENIC_PAGE_SIZE-1)))
-#define VNIC_FLOW_COUNTER_UPDATE_MSECS 100
+
+/* must be >= VNIC_COUNTER_DMA_MIN_PERIOD */
+#define VNIC_FLOW_COUNTER_UPDATE_MSECS 500
 
 #define ENICPMD_VFIO_PATH          "/dev/vfio/vfio"
 /*#define ENIC_DESC_COUNT_MAKE_ODD (x) do{if ((~(x)) & 1) { (x)--; } }while(0)*/

drivers/net/enic/enic_flow.c

@@ -1444,7 +1444,7 @@ enic_flow_add_filter(struct enic *enic, struct filter_v2 *enic_filter,
 		if (ctr_idx > enic->max_flow_counter) {
 			err = vnic_dev_counter_dma_cfg(enic->vdev,
 						 VNIC_FLOW_COUNTER_UPDATE_MSECS,
-						 ctr_idx);
+						 ctr_idx + 1);
 			if (err) {
 				rte_flow_error_set(error, -err,
 					   RTE_FLOW_ERROR_TYPE_ACTION_CONF,
@@ -1477,7 +1477,7 @@ enic_flow_add_filter(struct enic *enic, struct filter_v2 *enic_filter,
 		/* reduce counter DMA size */
 		vnic_dev_counter_dma_cfg(enic->vdev,
 					 VNIC_FLOW_COUNTER_UPDATE_MSECS,
-					 last_max_flow_ctr);
+					 last_max_flow_ctr + 1);
 		enic->max_flow_counter = last_max_flow_ctr;
 	}
 unwind_ctr_alloc:

drivers/net/enic/enic_main.c

@@ -1766,7 +1766,7 @@ int enic_probe(struct enic *enic)
 
 	/*
 	 * Allocate the consistent memory for stats and counters upfront so
-	 * both primary and secondary processes can dump stats.
+	 * both primary and secondary processes can access them.
 	 */
 	err = vnic_dev_alloc_stats_mem(enic->vdev);
 	if (err) {