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>

1 files changed, 61 insertions, 20 deletions

diff --git a/net/nfc/core.c b/net/nfc/core.c
index 3192c3f589e..7df28ad4727 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);