NFC: Cache the core NFC active target pointer instead of its index

The NFC Core now caches the active nfc target pointer, thereby avoiding
the need to lookup the target table for each invocation of a driver ops.
Consequently, pn533, HCI and NCI now directly receive an nfc_target
pointer instead of a target index.

Cc: Ilan Elias <ilane@ti.com>
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 81 insertions, 63 deletions

diff --git a/net/nfc/core.c b/net/nfc/core.c
index 3192c3f..7df28ad 100644
--- a/net/nfc/core.c
+++ b/net/nfc/core.c
@@ -97,7 +97,7 @@ int nfc_dev_down(struct nfc_dev *dev)
 		goto error;
 	}
 
-	if (dev->polling || dev->activated_target_idx != NFC_TARGET_IDX_NONE) {
+	if (dev->polling || dev->active_target) {
 		rc = -EBUSY;
 		goto error;
 	}
@@ -183,11 +183,27 @@ error:
 	return rc;
 }
 
+static struct nfc_target *nfc_find_target(struct nfc_dev *dev, u32 target_idx)
+{
+	int i;
+
+	if (dev->n_targets == 0)
+		return NULL;
+
+	for (i = 0; i < dev->n_targets ; i++) {
+		if (dev->targets[i].idx == target_idx)
+			return &dev->targets[i];
+	}
+
+	return NULL;
+}
+
 int nfc_dep_link_up(struct nfc_dev *dev, int target_index, u8 comm_mode)
 {
 	int rc = 0;
 	u8 *gb;
 	size_t gb_len;
+	struct nfc_target *target;
 
 	pr_debug("dev_name=%s comm %d\n", dev_name(&dev->dev), comm_mode);
 
@@ -212,9 +228,15 @@ int nfc_dep_link_up(struct nfc_dev *dev, int target_index, u8 comm_mode)
 		goto error;
 	}
 
-	rc = dev->ops->dep_link_up(dev, target_index, comm_mode, gb, gb_len);
+	target = nfc_find_target(dev, target_index);
+	if (target == NULL) {
+		rc = -ENOTCONN;
+		goto error;
+	}
+
+	rc = dev->ops->dep_link_up(dev, target, comm_mode, gb, gb_len);
 	if (!rc)
-		dev->activated_target_idx = target_index;
+		dev->active_target = target;
 
 error:
 	device_unlock(&dev->dev);
@@ -250,7 +272,7 @@ int nfc_dep_link_down(struct nfc_dev *dev)
 	rc = dev->ops->dep_link_down(dev);
 	if (!rc) {
 		dev->dep_link_up = false;
-		dev->activated_target_idx = NFC_TARGET_IDX_NONE;
+		dev->active_target = NULL;
 		nfc_llcp_mac_is_down(dev);
 		nfc_genl_dep_link_down_event(dev);
 	}
@@ -282,6 +304,7 @@ EXPORT_SYMBOL(nfc_dep_link_is_up);
 int nfc_activate_target(struct nfc_dev *dev, u32 target_idx, u32 protocol)
 {
 	int rc;
+	struct nfc_target *target;
 
 	pr_debug("dev_name=%s target_idx=%u protocol=%u\n",
 		 dev_name(&dev->dev), target_idx, protocol);
@@ -293,9 +316,20 @@ int nfc_activate_target(struct nfc_dev *dev, u32 target_idx, u32 protocol)
 		goto error;
 	}
 
-	rc = dev->ops->activate_target(dev, target_idx, protocol);
+	if (dev->active_target) {
+		rc = -EBUSY;
+		goto error;
+	}
+
+	target = nfc_find_target(dev, target_idx);
+	if (target == NULL) {
+		rc = -ENOTCONN;
+		goto error;
+	}
+
+	rc = dev->ops->activate_target(dev, target, protocol);
 	if (!rc) {
-		dev->activated_target_idx = target_idx;
+		dev->active_target = target;
 
 		if (dev->ops->check_presence)
 			mod_timer(&dev->check_pres_timer, jiffies +
@@ -327,11 +361,21 @@ int nfc_deactivate_target(struct nfc_dev *dev, u32 target_idx)
 		goto error;
 	}
 
+	if (dev->active_target == NULL) {
+		rc = -ENOTCONN;
+		goto error;
+	}
+
+	if (dev->active_target->idx != target_idx) {
+		rc = -ENOTCONN;
+		goto error;
+	}
+
 	if (dev->ops->check_presence)
 		del_timer_sync(&dev->check_pres_timer);
 
-	dev->ops->deactivate_target(dev, target_idx);
-	dev->activated_target_idx = NFC_TARGET_IDX_NONE;
+	dev->ops->deactivate_target(dev, dev->active_target);
+	dev->active_target = NULL;
 
 error:
 	device_unlock(&dev->dev);
@@ -365,13 +409,13 @@ int nfc_data_exchange(struct nfc_dev *dev, u32 target_idx, struct sk_buff *skb,
 		goto error;
 	}
 
-	if (dev->activated_target_idx == NFC_TARGET_IDX_NONE) {
+	if (dev->active_target == NULL) {
 		rc = -ENOTCONN;
 		kfree_skb(skb);
 		goto error;
 	}
 
-	if (target_idx != dev->activated_target_idx) {
+	if (dev->active_target->idx != target_idx) {
 		rc = -EADDRNOTAVAIL;
 		kfree_skb(skb);
 		goto error;
@@ -380,7 +424,8 @@ int nfc_data_exchange(struct nfc_dev *dev, u32 target_idx, struct sk_buff *skb,
 	if (dev->ops->check_presence)
 		del_timer_sync(&dev->check_pres_timer);
 
-	rc = dev->ops->data_exchange(dev, target_idx, skb, cb, cb_context);
+	rc = dev->ops->data_exchange(dev, dev->active_target, skb, cb,
+				     cb_context);
 
 	if (!rc && dev->ops->check_presence)
 		mod_timer(&dev->check_pres_timer, jiffies +
@@ -514,7 +559,7 @@ int nfc_target_lost(struct nfc_dev *dev, u32 target_idx)
 
 	dev->targets_generation++;
 	dev->n_targets--;
-	dev->activated_target_idx = NFC_TARGET_IDX_NONE;
+	dev->active_target = NULL;
 
 	if (dev->n_targets) {
 		memcpy(&dev->targets[i], &dev->targets[i + 1],
@@ -556,15 +601,14 @@ static void nfc_check_pres_work(struct work_struct *work)
 
 	device_lock(&dev->dev);
 
-	if (dev->activated_target_idx != NFC_TARGET_IDX_NONE &&
-	    timer_pending(&dev->check_pres_timer) == 0) {
-		rc = dev->ops->check_presence(dev, dev->activated_target_idx);
+	if (dev->active_target && timer_pending(&dev->check_pres_timer) == 0) {
+		rc = dev->ops->check_presence(dev, dev->active_target);
 		if (!rc) {
 			mod_timer(&dev->check_pres_timer, jiffies +
 				  msecs_to_jiffies(NFC_CHECK_PRES_FREQ_MS));
 		} else {
-			nfc_target_lost(dev, dev->activated_target_idx);
-			dev->activated_target_idx = NFC_TARGET_IDX_NONE;
+			nfc_target_lost(dev, dev->active_target->idx);
+			dev->active_target = NULL;
 		}
 	}
 
@@ -643,8 +687,6 @@ struct nfc_dev *nfc_allocate_device(struct nfc_ops *ops,
 	/* first generation must not be 0 */
 	dev->targets_generation = 1;
 
-	dev->activated_target_idx = NFC_TARGET_IDX_NONE;
-
 	if (ops->check_presence) {
 		char name[32];
 		init_timer(&dev->check_pres_timer);
@@ -662,7 +704,6 @@ struct nfc_dev *nfc_allocate_device(struct nfc_ops *ops,
 		}
 	}
 
-
 	return dev;
 }
 EXPORT_SYMBOL(nfc_allocate_device);
diff --git a/net/nfc/hci/core.c b/net/nfc/hci/core.c
index 86fd00d..545c19f 100644
--- a/net/nfc/hci/core.c
+++ b/net/nfc/hci/core.c
@@ -520,50 +520,26 @@ static void hci_stop_poll(struct nfc_dev *nfc_dev)
 	}
 }
 
-static struct nfc_target *hci_find_target(struct nfc_hci_dev *hdev,
-					  u32 target_idx)
+static int hci_activate_target(struct nfc_dev *nfc_dev,
+			       struct nfc_target *target, u32 protocol)
 {
-	int i;
-	if (hdev->poll_started == false || hdev->targets == NULL)
-		return NULL;
-
-	for (i = 0; i < hdev->target_count; i++) {
-		if (hdev->targets[i].idx == target_idx)
-			return &hdev->targets[i];
-	}
-
-	return NULL;
-}
-
-static int hci_activate_target(struct nfc_dev *nfc_dev, u32 target_idx,
-			       u32 protocol)
-{
-	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
-
-	if (hci_find_target(hdev, target_idx) == NULL)
-		return -ENOMEDIUM;
-
 	return 0;
 }
 
-static void hci_deactivate_target(struct nfc_dev *nfc_dev, u32 target_idx)
+static void hci_deactivate_target(struct nfc_dev *nfc_dev,
+				  struct nfc_target *target)
 {
 }
 
-static int hci_data_exchange(struct nfc_dev *nfc_dev, u32 target_idx,
+static int hci_data_exchange(struct nfc_dev *nfc_dev, struct nfc_target *target,
 			     struct sk_buff *skb, data_exchange_cb_t cb,
 			     void *cb_context)
 {
 	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
 	int r;
-	struct nfc_target *target;
 	struct sk_buff *res_skb = NULL;
 
-	pr_debug("target_idx=%d\n", target_idx);
-
-	target = hci_find_target(hdev, target_idx);
-	if (target == NULL)
-		return -ENOMEDIUM;
+	pr_debug("target_idx=%d\n", target->idx);
 
 	switch (target->hci_reader_gate) {
 	case NFC_HCI_RF_READER_A_GATE:
diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index 8737c20..d560e6f 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -436,16 +436,16 @@ static void nci_stop_poll(struct nfc_dev *nfc_dev)
 		    msecs_to_jiffies(NCI_RF_DEACTIVATE_TIMEOUT));
 }
 
-static int nci_activate_target(struct nfc_dev *nfc_dev, __u32 target_idx,
-			       __u32 protocol)
+static int nci_activate_target(struct nfc_dev *nfc_dev,
+			       struct nfc_target *target, __u32 protocol)
 {
 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
 	struct nci_rf_discover_select_param param;
-	struct nfc_target *target = NULL;
+	struct nfc_target *nci_target = NULL;
 	int i;
 	int rc = 0;
 
-	pr_debug("target_idx %d, protocol 0x%x\n", target_idx, protocol);
+	pr_debug("target_idx %d, protocol 0x%x\n", target->idx, protocol);
 
 	if ((atomic_read(&ndev->state) != NCI_W4_HOST_SELECT) &&
 	    (atomic_read(&ndev->state) != NCI_POLL_ACTIVE)) {
@@ -459,25 +459,25 @@ static int nci_activate_target(struct nfc_dev *nfc_dev, __u32 target_idx,
 	}
 
 	for (i = 0; i < ndev->n_targets; i++) {
-		if (ndev->targets[i].idx == target_idx) {
-			target = &ndev->targets[i];
+		if (ndev->targets[i].idx == target->idx) {
+			nci_target = &ndev->targets[i];
 			break;
 		}
 	}
 
-	if (!target) {
+	if (!nci_target) {
 		pr_err("unable to find the selected target\n");
 		return -EINVAL;
 	}
 
-	if (!(target->supported_protocols & (1 << protocol))) {
+	if (!(nci_target->supported_protocols & (1 << protocol))) {
 		pr_err("target does not support the requested protocol 0x%x\n",
 		       protocol);
 		return -EINVAL;
 	}
 
 	if (atomic_read(&ndev->state) == NCI_W4_HOST_SELECT) {
-		param.rf_discovery_id = target->logical_idx;
+		param.rf_discovery_id = nci_target->logical_idx;
 
 		if (protocol == NFC_PROTO_JEWEL)
 			param.rf_protocol = NCI_RF_PROTOCOL_T1T;
@@ -501,11 +501,12 @@ static int nci_activate_target(struct nfc_dev *nfc_dev, __u32 target_idx,
 	return rc;
 }
 
-static void nci_deactivate_target(struct nfc_dev *nfc_dev, __u32 target_idx)
+static void nci_deactivate_target(struct nfc_dev *nfc_dev,
+				  struct nfc_target *target)
 {
 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
 
-	pr_debug("target_idx %d\n", target_idx);
+	pr_debug("target_idx %d\n", target->idx);
 
 	if (!ndev->target_active_prot) {
 		pr_err("unable to deactivate target, no active target\n");
@@ -520,14 +521,14 @@ static void nci_deactivate_target(struct nfc_dev *nfc_dev, __u32 target_idx)
 	}
 }
 
-static int nci_data_exchange(struct nfc_dev *nfc_dev, __u32 target_idx,
+static int nci_data_exchange(struct nfc_dev *nfc_dev, struct nfc_target *target,
 			     struct sk_buff *skb,
 			     data_exchange_cb_t cb, void *cb_context)
 {
 	struct nci_dev *ndev = nfc_get_drvdata(nfc_dev);
 	int rc;
 
-	pr_debug("target_idx %d, len %d\n", target_idx, skb->len);
+	pr_debug("target_idx %d, len %d\n", target->idx, skb->len);
 
 	if (!ndev->target_active_prot) {
 		pr_err("unable to exchange data, no active target\n");