cnss2: record timestamps in smmu fault cb handler

Record timestamps in smmu fault cb handler.

Change-Id: I96042ffdc81fcca8069d16bf74899412cf04183c
CRs-Fixed: 3487738

cnss2/debug.c

@@ -914,6 +914,39 @@ static const struct file_operations cnss_dynamic_feature_fops = {
 	.llseek = seq_lseek,
 };
 
+static int cnss_smmu_fault_timestamp_show(struct seq_file *s, void *data)
+{
+	struct cnss_plat_data *plat_priv = s->private;
+	struct cnss_pci_data *pci_priv = plat_priv->bus_priv;
+
+	if (!pci_priv)
+		return -ENODEV;
+
+	seq_printf(s, "smmu irq cb entry timestamp : %llu ns\n",
+		   pci_priv->smmu_fault_timestamp[SMMU_CB_ENTRY]);
+	seq_printf(s, "smmu irq cb before doorbell ring timestamp : %llu ns\n",
+		   pci_priv->smmu_fault_timestamp[SMMU_CB_DOORBELL_RING]);
+	seq_printf(s, "smmu irq cb after doorbell ring timestamp : %llu ns\n",
+		   pci_priv->smmu_fault_timestamp[SMMU_CB_EXIT]);
+
+	return 0;
+}
+
+static int cnss_smmu_fault_timestamp_open(struct inode *inode,
+					  struct file *file)
+{
+	return single_open(file, cnss_smmu_fault_timestamp_show,
+			   inode->i_private);
+}
+
+static const struct file_operations cnss_smmu_fault_timestamp_fops = {
+	.read = seq_read,
+	.release = single_release,
+	.open = cnss_smmu_fault_timestamp_open,
+	.owner = THIS_MODULE,
+	.llseek = seq_lseek,
+};
+
 #ifdef CONFIG_DEBUG_FS
 #ifdef CONFIG_CNSS2_DEBUG
 static int cnss_create_debug_only_node(struct cnss_plat_data *plat_priv)
@@ -932,6 +965,8 @@ static int cnss_create_debug_only_node(struct cnss_plat_data *plat_priv)
 			    &cnss_control_params_debug_fops);
 	debugfs_create_file("dynamic_feature", 0600, root_dentry, plat_priv,
 			    &cnss_dynamic_feature_fops);
+	debugfs_create_file("cnss_smmu_fault_timestamp", 0600, root_dentry,
+			    plat_priv, &cnss_smmu_fault_timestamp_fops);
 
 	return 0;
 }

cnss2/pci.c

@@ -909,12 +909,23 @@ void cnss_mhi_controller_set_base(struct cnss_pci_data *pci_priv,
 
 #ifdef CONFIG_CNSS2_SMMU_DB_SUPPORT
 #define CNSS_MHI_WAKE_TIMEOUT		500000
+
+static void cnss_record_smmu_fault_timestamp(struct cnss_pci_data *pci_priv,
+					     enum cnss_smmu_fault_time id)
+{
+	if (id >= SMMU_CB_MAX)
+		return;
+
+	pci_priv->smmu_fault_timestamp[id] = sched_clock();
+}
+
 static void cnss_pci_smmu_fault_handler_irq(struct iommu_domain *domain,
 					    void *handler_token)
 {
 	struct cnss_pci_data *pci_priv = handler_token;
 	int ret = 0;
 
+	cnss_record_smmu_fault_timestamp(pci_priv, SMMU_CB_ENTRY);
 	ret = cnss_mhi_device_get_sync_atomic(pci_priv,
 					      CNSS_MHI_WAKE_TIMEOUT, true);
 	if (ret < 0) {
@@ -922,9 +933,12 @@ static void cnss_pci_smmu_fault_handler_irq(struct iommu_domain *domain,
 		return;
 	}
 
+	cnss_record_smmu_fault_timestamp(pci_priv, SMMU_CB_DOORBELL_RING);
 	ret = cnss_mhi_host_notify_db_disable_trace(pci_priv);
 	if (ret < 0)
 		cnss_pr_err("Fail to notify wlan fw to stop trace collection, ret %d\n", ret);
+
+	cnss_record_smmu_fault_timestamp(pci_priv, SMMU_CB_EXIT);
 }
 
 void cnss_register_iommu_fault_handler_irq(struct cnss_pci_data *pci_priv)

cnss2/pci.h

@@ -19,6 +19,7 @@
 #endif
 #include <linux/of_reserved_mem.h>
 #include <linux/pci.h>
+#include <linux/sched_clock.h>
 
 #include "main.h"
 
@@ -72,6 +73,13 @@ enum cnss_pci_reg_dev_mask {
 	REG_MASK_PEACH,
 };
 
+enum cnss_smmu_fault_time {
+	SMMU_CB_ENTRY,
+	SMMU_CB_DOORBELL_RING,
+	SMMU_CB_EXIT,
+	SMMU_CB_MAX,
+};
+
 struct cnss_msi_user {
 	char *name;
 	int num_vectors;
@@ -169,6 +177,7 @@ struct cnss_pci_data {
 	u8 iommu_geometry;
 	bool drv_supported;
 	bool is_smmu_fault;
+	unsigned long long smmu_fault_timestamp[SMMU_CB_MAX];
 };
 
 static inline void cnss_set_pci_priv(struct pci_dev *pci_dev, void *data)