Add BCM_VK_QSTATS Kconfig option to allow for enabling debug VK
queue statistics.

These statistics keep track of max, abs_max, and average for the
messages queues.

Co-developed-by: Desmond Yan <desmond....@broadcom.com>
Signed-off-by: Desmond Yan <desmond....@broadcom.com>
Signed-off-by: Scott Branden <scott.bran...@broadcom.com>
---
 drivers/misc/bcm-vk/Kconfig      | 14 +++++++++
 drivers/misc/bcm-vk/bcm_vk_dev.c |  9 ++++++
 drivers/misc/bcm-vk/bcm_vk_msg.c | 52 +++++++++++++++++++++++++++++++-
 drivers/misc/bcm-vk/bcm_vk_msg.h | 12 ++++++++
 4 files changed, 86 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/bcm-vk/Kconfig b/drivers/misc/bcm-vk/Kconfig
index 2272e47655ed..a3a020b19e3b 100644
--- a/drivers/misc/bcm-vk/Kconfig
+++ b/drivers/misc/bcm-vk/Kconfig
@@ -13,3 +13,17 @@ config BCM_VK
          accelerators via /dev/bcm-vk.N devices.
 
          If unsure, say N.
+
+if BCM_VK
+
+config BCM_VK_QSTATS
+       bool "VK Queue Statistics"
+       help
+         Turn on to enable Queue Statistics.
+         These are useful for debugging purposes.
+         Some performance loss by enabling this debug config.
+         For properly operating PCIe hardware no need to enable this.
+
+         If unsure, say N.
+
+endif
diff --git a/drivers/misc/bcm-vk/bcm_vk_dev.c b/drivers/misc/bcm-vk/bcm_vk_dev.c
index 718badb53100..6c2370723e0a 100644
--- a/drivers/misc/bcm-vk/bcm_vk_dev.c
+++ b/drivers/misc/bcm-vk/bcm_vk_dev.c
@@ -1097,6 +1097,15 @@ static int bcm_vk_trigger_reset(struct bcm_vk *vk)
        vkwrite32(vk, 0, BAR_0, BAR_INTF_VER);
        memset(&vk->host_alert, 0, sizeof(vk->host_alert));
        memset(&vk->peer_alert, 0, sizeof(vk->peer_alert));
+#if defined(CONFIG_BCM_VK_QSTATS)
+       /* clear qstats */
+       for (i = 0; i < VK_MSGQ_MAX_NR; i++) {
+               memset(&vk->to_v_msg_chan.qstats[i].qcnts, 0,
+                      sizeof(vk->to_v_msg_chan.qstats[i].qcnts));
+               memset(&vk->to_h_msg_chan.qstats[i].qcnts, 0,
+                      sizeof(vk->to_h_msg_chan.qstats[i].qcnts));
+       }
+#endif
        /* clear 4096 bits of bitmap */
        bitmap_clear(vk->bmap, 0, VK_MSG_ID_BITMAP_SIZE);
 
diff --git a/drivers/misc/bcm-vk/bcm_vk_msg.c b/drivers/misc/bcm-vk/bcm_vk_msg.c
index e31d41400199..6ba0a7a94dcc 100644
--- a/drivers/misc/bcm-vk/bcm_vk_msg.c
+++ b/drivers/misc/bcm-vk/bcm_vk_msg.c
@@ -91,6 +91,44 @@ u32 msgq_avail_space(const struct bcm_vk_msgq __iomem *msgq,
        return (qinfo->q_size - msgq_occupied(msgq, qinfo) - 1);
 }
 
+#if defined(CONFIG_BCM_VK_QSTATS)
+
+/* Use default value of 20000 rd/wr per update */
+#if !defined(BCM_VK_QSTATS_ACC_CNT)
+#define BCM_VK_QSTATS_ACC_CNT 20000
+#endif
+
+static void bcm_vk_update_qstats(struct bcm_vk *vk,
+                                const char *tag,
+                                struct bcm_vk_qstats *qstats,
+                                u32 occupancy)
+{
+       struct bcm_vk_qs_cnts *qcnts = &qstats->qcnts;
+
+       if (occupancy > qcnts->max_occ) {
+               qcnts->max_occ = occupancy;
+               if (occupancy > qcnts->max_abs)
+                       qcnts->max_abs = occupancy;
+       }
+
+       qcnts->acc_sum += occupancy;
+       if (++qcnts->cnt >= BCM_VK_QSTATS_ACC_CNT) {
+               /* log average and clear counters */
+               dev_dbg(&vk->pdev->dev,
+                       "%s[%d]: Max: [%3d/%3d] Acc %d num %d, Aver %d\n",
+                       tag, qstats->q_num,
+                       qcnts->max_occ, qcnts->max_abs,
+                       qcnts->acc_sum,
+                       qcnts->cnt,
+                       qcnts->acc_sum / qcnts->cnt);
+
+               qcnts->cnt = 0;
+               qcnts->max_occ = 0;
+               qcnts->acc_sum = 0;
+       }
+}
+#endif
+
 /* number of retries when enqueue message fails before returning EAGAIN */
 #define BCM_VK_H2VK_ENQ_RETRY 10
 #define BCM_VK_H2VK_ENQ_RETRY_DELAY_MS 50
@@ -495,8 +533,12 @@ static int bcm_vk_msg_chan_init(struct bcm_vk_msg_chan 
*chan)
 
        mutex_init(&chan->msgq_mutex);
        spin_lock_init(&chan->pendq_lock);
-       for (i = 0; i < VK_MSGQ_MAX_NR; i++)
+       for (i = 0; i < VK_MSGQ_MAX_NR; i++) {
                INIT_LIST_HEAD(&chan->pendq[i]);
+#if defined(CONFIG_BCM_VK_QSTATS)
+               chan->qstats[i].q_num = i;
+#endif
+       }
 
        return 0;
 }
@@ -605,6 +647,10 @@ static int bcm_to_v_msg_enqueue(struct bcm_vk *vk, struct 
bcm_vk_wkent *entry)
 
        avail = msgq_avail_space(msgq, qinfo);
 
+#if defined(CONFIG_BCM_VK_QSTATS)
+       bcm_vk_update_qstats(vk, "to_v", &chan->qstats[q_num],
+                            qinfo->q_size - avail);
+#endif
        /* if not enough space, return EAGAIN and let app handles it */
        retry = 0;
        while ((avail < entry->to_v_blks) &&
@@ -818,6 +864,10 @@ s32 bcm_to_h_msg_dequeue(struct bcm_vk *vk)
                                goto idx_err;
                        }
 
+#if defined(CONFIG_BCM_VK_QSTATS)
+                       bcm_vk_update_qstats(vk, "to_h", &chan->qstats[q_num],
+                                            msgq_occupied(msgq, qinfo));
+#endif
                        num_blks = src_size + 1;
                        data = kzalloc(num_blks * VK_MSGQ_BLK_SIZE, GFP_KERNEL);
                        if (data) {
diff --git a/drivers/misc/bcm-vk/bcm_vk_msg.h b/drivers/misc/bcm-vk/bcm_vk_msg.h
index 637c5d662eb7..d00d9707bd01 100644
--- a/drivers/misc/bcm-vk/bcm_vk_msg.h
+++ b/drivers/misc/bcm-vk/bcm_vk_msg.h
@@ -125,6 +125,14 @@ struct bcm_vk_qs_cnts {
        u32 max_abs; /* the abs max since reset */
 };
 
+#if defined(CONFIG_BCM_VK_QSTATS)
+/* stats structure */
+struct bcm_vk_qstats {
+       u32 q_num;
+       struct bcm_vk_qs_cnts qcnts;
+};
+#endif
+
 /* control channel structure for either to_v or to_h communication */
 struct bcm_vk_msg_chan {
        u32 q_nr;
@@ -138,6 +146,10 @@ struct bcm_vk_msg_chan {
        struct list_head pendq[VK_MSGQ_MAX_NR];
        /* static queue info from the sync */
        struct bcm_vk_sync_qinfo sync_qinfo[VK_MSGQ_MAX_NR];
+#if defined(CONFIG_BCM_VK_QSTATS)
+       /* qstats */
+       struct bcm_vk_qstats qstats[VK_MSGQ_MAX_NR];
+#endif
 };
 
 /* total number of supported ctx, 32 ctx each for 5 components */
-- 
2.17.1

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