RDMA/bnxt_re: Add a debugfs entry for CQE coalescing tuning

This patch adds debugfs interfaces that allows the user to
enable/disable the RoCE CQ coalescing and fine tune certain
CQ coalescing parameters which would be helpful during debug.

Signed-off-by: Damodharam Ammepalli <damodharam.ammepalli@broadcom.com>
Reviewed-by: Hongguang Gao <hongguang.gao@broadcom.com>
Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Link: https://patch.msgid.link/20251103043425.234846-1-kalesh-anakkur.purayil@broadcom.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

drivers/infiniband/hw/bnxt_re/bnxt_re.h

@@ -224,6 +224,8 @@ struct bnxt_re_dev {
 	struct workqueue_struct		*dcb_wq;
 	struct dentry                   *cc_config;
 	struct bnxt_re_dbg_cc_config_params *cc_config_params;
+	struct dentry			*cq_coal_cfg;
+	struct bnxt_re_dbg_cq_coal_params *cq_coal_cfg_params;
 #define BNXT_VPD_FLD_LEN		32
 	char board_partno[BNXT_VPD_FLD_LEN];
 	/* RoCE mirror */

drivers/infiniband/hw/bnxt_re/debugfs.c

@@ -23,6 +23,14 @@
 
 static struct dentry *bnxt_re_debugfs_root;
 
+static const char * const bnxt_re_cq_coal_str[] = {
+	"buf_maxtime",
+	"normal_maxbuf",
+	"during_maxbuf",
+	"en_ring_idle_mode",
+	"enable",
+};
+
 static const char * const bnxt_re_cc_gen0_name[] = {
 	"enable_cc",
 	"run_avg_weight_g",
@@ -349,6 +357,123 @@ static void bnxt_re_debugfs_add_info(struct bnxt_re_dev *rdev)
 	debugfs_create_file("info", 0400, rdev->dbg_root, rdev, &info_fops);
 }
 
+static ssize_t cq_coal_cfg_write(struct file *file,
+				 const char __user *buf,
+				 size_t count, loff_t *pos)
+{
+	struct seq_file *s = file->private_data;
+	struct bnxt_re_cq_coal_param *param = s->private;
+	struct bnxt_re_dev *rdev = param->rdev;
+	int offset = param->offset;
+	char lbuf[16] = { };
+	u32 val;
+
+	if (count > sizeof(lbuf))
+		return -EINVAL;
+
+	if (copy_from_user(lbuf, buf, count))
+		return -EFAULT;
+
+	lbuf[sizeof(lbuf) - 1] = '\0';
+
+	if (kstrtou32(lbuf, 0, &val))
+		return -EINVAL;
+
+	switch (offset) {
+	case BNXT_RE_COAL_CQ_BUF_MAXTIME:
+		if (val < 1 || val > BNXT_QPLIB_CQ_COAL_MAX_BUF_MAXTIME)
+			return -EINVAL;
+		rdev->cq_coalescing.buf_maxtime = val;
+		break;
+	case BNXT_RE_COAL_CQ_NORMAL_MAXBUF:
+		if (val < 1 || val > BNXT_QPLIB_CQ_COAL_MAX_NORMAL_MAXBUF)
+			return -EINVAL;
+		rdev->cq_coalescing.normal_maxbuf = val;
+		break;
+	case BNXT_RE_COAL_CQ_DURING_MAXBUF:
+		if (val < 1 || val > BNXT_QPLIB_CQ_COAL_MAX_DURING_MAXBUF)
+			return -EINVAL;
+		rdev->cq_coalescing.during_maxbuf = val;
+		break;
+	case BNXT_RE_COAL_CQ_EN_RING_IDLE_MODE:
+		if (val > BNXT_QPLIB_CQ_COAL_MAX_EN_RING_IDLE_MODE)
+			return -EINVAL;
+		rdev->cq_coalescing.en_ring_idle_mode = val;
+		break;
+	case BNXT_RE_COAL_CQ_ENABLE:
+		if (val > 1)
+			return -EINVAL;
+		rdev->cq_coalescing.enable = val;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return  count;
+}
+
+static int cq_coal_cfg_show(struct seq_file *s, void *unused)
+{
+	struct bnxt_re_cq_coal_param *param = s->private;
+	struct bnxt_re_dev *rdev = param->rdev;
+	int offset = param->offset;
+	u32 val = 0;
+
+	switch (offset) {
+	case BNXT_RE_COAL_CQ_BUF_MAXTIME:
+		val = rdev->cq_coalescing.buf_maxtime;
+		break;
+	case BNXT_RE_COAL_CQ_NORMAL_MAXBUF:
+		val = rdev->cq_coalescing.normal_maxbuf;
+		break;
+	case BNXT_RE_COAL_CQ_DURING_MAXBUF:
+		val = rdev->cq_coalescing.during_maxbuf;
+		break;
+	case BNXT_RE_COAL_CQ_EN_RING_IDLE_MODE:
+		val = rdev->cq_coalescing.en_ring_idle_mode;
+		break;
+	case BNXT_RE_COAL_CQ_ENABLE:
+		val = rdev->cq_coalescing.enable;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	seq_printf(s, "%u\n", val);
+	return 0;
+}
+DEFINE_SHOW_STORE_ATTRIBUTE(cq_coal_cfg);
+
+static void bnxt_re_cleanup_cq_coal_debugfs(struct bnxt_re_dev *rdev)
+{
+	debugfs_remove_recursive(rdev->cq_coal_cfg);
+	kfree(rdev->cq_coal_cfg_params);
+}
+
+static void bnxt_re_init_cq_coal_debugfs(struct bnxt_re_dev *rdev)
+{
+	struct bnxt_re_dbg_cq_coal_params *dbg_cq_coal_params;
+	int i;
+
+	if (_is_cq_coalescing_supported(rdev->dev_attr->dev_cap_flags2))
+		return;
+
+	dbg_cq_coal_params = kzalloc(sizeof(*dbg_cq_coal_params), GFP_KERNEL);
+	if (!dbg_cq_coal_params)
+		return;
+
+	rdev->cq_coal_cfg = debugfs_create_dir("cq_coal_cfg", rdev->dbg_root);
+	rdev->cq_coal_cfg_params = dbg_cq_coal_params;
+
+	for (i = 0; i < BNXT_RE_COAL_CQ_MAX; i++) {
+		dbg_cq_coal_params->params[i].offset = i;
+		dbg_cq_coal_params->params[i].rdev = rdev;
+		debugfs_create_file(bnxt_re_cq_coal_str[i],
+				    0600, rdev->cq_coal_cfg,
+				    &dbg_cq_coal_params->params[i],
+				    &cq_coal_cfg_fops);
+	}
+}
+
 void bnxt_re_debugfs_add_pdev(struct bnxt_re_dev *rdev)
 {
 	struct pci_dev *pdev = rdev->en_dev->pdev;
@@ -374,10 +499,13 @@ void bnxt_re_debugfs_add_pdev(struct bnxt_re_dev *rdev)
 							 rdev->cc_config, tmp_params,
 							 &bnxt_re_cc_config_ops);
 	}
+
+	bnxt_re_init_cq_coal_debugfs(rdev);
 }
 
 void bnxt_re_debugfs_rem_pdev(struct bnxt_re_dev *rdev)
 {
+	bnxt_re_cleanup_cq_coal_debugfs(rdev);
 	debugfs_remove_recursive(rdev->qp_debugfs);
 	debugfs_remove_recursive(rdev->cc_config);
 	kfree(rdev->cc_config_params);

drivers/infiniband/hw/bnxt_re/debugfs.h

@@ -33,4 +33,23 @@ struct bnxt_re_cc_param {
 struct bnxt_re_dbg_cc_config_params {
 	struct bnxt_re_cc_param	gen0_parms[BNXT_RE_CC_PARAM_GEN0];
 };
+
+struct bnxt_re_cq_coal_param {
+	struct bnxt_re_dev	*rdev;
+	u32			offset;
+};
+
+enum bnxt_re_cq_coal_types {
+	BNXT_RE_COAL_CQ_BUF_MAXTIME,
+	BNXT_RE_COAL_CQ_NORMAL_MAXBUF,
+	BNXT_RE_COAL_CQ_DURING_MAXBUF,
+	BNXT_RE_COAL_CQ_EN_RING_IDLE_MODE,
+	BNXT_RE_COAL_CQ_ENABLE,
+	BNXT_RE_COAL_CQ_MAX
+
+};
+
+struct bnxt_re_dbg_cq_coal_params {
+	struct bnxt_re_cq_coal_param	params[BNXT_RE_COAL_CQ_MAX];
+};
 #endif

drivers/infiniband/hw/bnxt_re/main.c

@@ -1453,6 +1453,7 @@ static struct bnxt_re_dev *bnxt_re_dev_add(struct auxiliary_device *adev,
 	atomic_set(&rdev->stats.res.pd_count, 0);
 	rdev->cosq[0] = 0xFFFF;
 	rdev->cosq[1] = 0xFFFF;
+	rdev->cq_coalescing.enable = 1;
 	rdev->cq_coalescing.buf_maxtime = BNXT_QPLIB_CQ_COAL_DEF_BUF_MAXTIME;
 	if (bnxt_re_chip_gen_p7(en_dev->chip_num)) {
 		rdev->cq_coalescing.normal_maxbuf = BNXT_QPLIB_CQ_COAL_DEF_NORMAL_MAXBUF_P7;

drivers/infiniband/hw/bnxt_re/qplib_fp.c

@@ -2226,7 +2226,8 @@ int bnxt_qplib_create_cq(struct bnxt_qplib_res *res, struct bnxt_qplib_cq *cq)
 	req.cq_handle = cpu_to_le64(cq->cq_handle);
 	req.cq_size = cpu_to_le32(cq->max_wqe);
 
-	if (_is_cq_coalescing_supported(res->dattr->dev_cap_flags2)) {
+	if (_is_cq_coalescing_supported(res->dattr->dev_cap_flags2) &&
+	    cq->coalescing->enable) {
 		req.flags |= cpu_to_le16(CMDQ_CREATE_CQ_FLAGS_COALESCING_VALID);
 		coalescing |= ((cq->coalescing->buf_maxtime <<
 				CMDQ_CREATE_CQ_BUF_MAXTIME_SFT) &

drivers/infiniband/hw/bnxt_re/qplib_fp.h

@@ -395,6 +395,7 @@ struct bnxt_qplib_cq_coal_param {
 	u8 normal_maxbuf;
 	u8 during_maxbuf;
 	u8 en_ring_idle_mode;
+	u8 enable;
 };
 
 #define BNXT_QPLIB_CQ_COAL_DEF_BUF_MAXTIME		0x1