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>

drivers/nfc/pn533.c

@@ -1194,8 +1194,8 @@ static int pn533_activate_target_nfcdep(struct pn533 *dev)
 	return rc;
 }
 
-static int pn533_activate_target(struct nfc_dev *nfc_dev, u32 target_idx,
-								u32 protocol)
+static int pn533_activate_target(struct nfc_dev *nfc_dev,
+				 struct nfc_target *target, u32 protocol)
 {
 	struct pn533 *dev = nfc_get_drvdata(nfc_dev);
 	int rc;
@@ -1243,7 +1243,8 @@ static int pn533_activate_target(struct nfc_dev *nfc_dev, u32 target_idx,
 	return 0;
 }
 
-static void pn533_deactivate_target(struct nfc_dev *nfc_dev, u32 target_idx)
+static void pn533_deactivate_target(struct nfc_dev *nfc_dev,
+				    struct nfc_target *target)
 {
 	struct pn533 *dev = nfc_get_drvdata(nfc_dev);
 	u8 tg;
@@ -1351,7 +1352,7 @@ static int pn533_in_dep_link_up_complete(struct pn533 *dev, void *arg,
 	return 0;
 }
 
-static int pn533_dep_link_up(struct nfc_dev *nfc_dev, int target_idx,
+static int pn533_dep_link_up(struct nfc_dev *nfc_dev, struct nfc_target *target,
 			     u8 comm_mode, u8* gb, size_t gb_len)
 {
 	struct pn533 *dev = nfc_get_drvdata(nfc_dev);
@@ -1552,10 +1553,9 @@ error:
 	return 0;
 }
 
-static int pn533_data_exchange(struct nfc_dev *nfc_dev, u32 target_idx,
-						struct sk_buff *skb,
-						data_exchange_cb_t cb,
-						void *cb_context)
+static int pn533_data_exchange(struct nfc_dev *nfc_dev,
+			       struct nfc_target *target, struct sk_buff *skb,
+			       data_exchange_cb_t cb, void *cb_context)
 {
 	struct pn533 *dev = nfc_get_drvdata(nfc_dev);
 	struct pn533_frame *out_frame, *in_frame;

include/net/nfc/nfc.h

@@ -48,26 +48,28 @@ struct nfc_dev;
 typedef void (*data_exchange_cb_t)(void *context, struct sk_buff *skb,
 								int err);
 
+struct nfc_target;
+
 struct nfc_ops {
 	int (*dev_up)(struct nfc_dev *dev);
 	int (*dev_down)(struct nfc_dev *dev);
 	int (*start_poll)(struct nfc_dev *dev, u32 protocols);
 	void (*stop_poll)(struct nfc_dev *dev);
-	int (*dep_link_up)(struct nfc_dev *dev, int target_idx, u8 comm_mode,
-			   u8 *gb, size_t gb_len);
+	int (*dep_link_up)(struct nfc_dev *dev, struct nfc_target *target,
+			   u8 comm_mode, u8 *gb, size_t gb_len);
 	int (*dep_link_down)(struct nfc_dev *dev);
-	int (*activate_target)(struct nfc_dev *dev, u32 target_idx,
+	int (*activate_target)(struct nfc_dev *dev, struct nfc_target *target,
 			       u32 protocol);
-	void (*deactivate_target)(struct nfc_dev *dev, u32 target_idx);
-	int (*data_exchange)(struct nfc_dev *dev, u32 target_idx,
+	void (*deactivate_target)(struct nfc_dev *dev,
+				  struct nfc_target *target);
+	int (*data_exchange)(struct nfc_dev *dev, struct nfc_target *target,
 			     struct sk_buff *skb, data_exchange_cb_t cb,
 			     void *cb_context);
-	int (*check_presence)(struct nfc_dev *dev, u32 target_idx);
+	int (*check_presence)(struct nfc_dev *dev, struct nfc_target *target);
 };
 
 #define NFC_TARGET_IDX_ANY -1
 #define NFC_MAX_GT_LEN 48
-#define NFC_TARGET_IDX_NONE 0xffffffff
 
 struct nfc_target {
 	u32 idx;
@@ -99,7 +101,7 @@ struct nfc_dev {
 	struct device dev;
 	bool dev_up;
 	bool polling;
-	u32 activated_target_idx;
+	struct nfc_target *active_target;
 	bool dep_link_up;
 	u32 dep_rf_mode;
 	struct nfc_genl_data genl_data;

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);

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:

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");