Bluetooth: Use LE buffers for LE traffic

Bluetooth chips may have separate buffers for LE traffic.
This patch add support to use LE buffers provided by the chip.

Signed-off-by: Ville Tervo <ville.tervo@nokia.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>

3 files changed, 108 insertions, 4 deletions

diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index d0c470c18f9d..aecd78e6cceb 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -326,6 +326,11 @@ int hci_conn_del(struct hci_conn *conn)
 
                 /* Unacked frames */
                 hdev->acl_cnt += conn->sent;
+        } else if (conn->type == LE_LINK) {
+                if (hdev->le_pkts)
+                        hdev->le_cnt += conn->sent;
+                else
+                        hdev->acl_cnt += conn->sent;
         } else {
                 struct hci_conn *acl = conn->link;
                 if (acl) {
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 2f003224d2ea..92960532dea4 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -263,6 +263,14 @@ static void hci_init_req(struct hci_dev *hdev, unsigned long opt)
         hci_send_cmd(hdev, HCI_OP_DELETE_STORED_LINK_KEY, sizeof(cp), &cp);
 }
 
+static void hci_le_init_req(struct hci_dev *hdev, unsigned long opt)
+{
+        BT_DBG("%s", hdev->name);
+
+        /* Read LE buffer size */
+        hci_send_cmd(hdev, HCI_OP_LE_READ_BUFFER_SIZE, 0, NULL);
+}
+
 static void hci_scan_req(struct hci_dev *hdev, unsigned long opt)
 {
         __u8 scan = opt;
@@ -529,6 +537,10 @@ int hci_dev_open(__u16 dev)
                 ret = __hci_request(hdev, hci_init_req, 0,
                                         msecs_to_jiffies(HCI_INIT_TIMEOUT));
 
+                if (lmp_le_capable(hdev))
+                        ret = __hci_request(hdev, hci_le_init_req, 0,
+                                        msecs_to_jiffies(HCI_INIT_TIMEOUT));
+
                 clear_bit(HCI_INIT, &hdev->flags);
         }
 
@@ -671,7 +683,7 @@ int hci_dev_reset(__u16 dev)
                 hdev->flush(hdev);
 
         atomic_set(&hdev->cmd_cnt, 1);
-        hdev->acl_cnt = 0; hdev->sco_cnt = 0;
+        hdev->acl_cnt = 0; hdev->sco_cnt = 0; hdev->le_cnt = 0;
 
         if (!test_bit(HCI_RAW, &hdev->flags))
                 ret = __hci_request(hdev, hci_reset_req, 0,
@@ -1672,8 +1684,25 @@ static inline struct hci_conn *hci_low_sent(struct hci_dev *hdev, __u8 type, int
         }
 
         if (conn) {
-                int cnt = (type == ACL_LINK ? hdev->acl_cnt : hdev->sco_cnt);
-                int q = cnt / num;
+                int cnt, q;
+
+                switch (conn->type) {
+                case ACL_LINK:
+                        cnt = hdev->acl_cnt;
+                        break;
+                case SCO_LINK:
+                case ESCO_LINK:
+                        cnt = hdev->sco_cnt;
+                        break;
+                case LE_LINK:
+                        cnt = hdev->le_mtu ? hdev->le_cnt : hdev->acl_cnt;
+                        break;
+                default:
+                        cnt = 0;
+                        BT_ERR("Unknown link type");
+                }
+
+                q = cnt / num;
                 *quote = q ? q : 1;
         } else
                 *quote = 0;
@@ -1772,6 +1801,40 @@ static inline void hci_sched_esco(struct hci_dev *hdev)
         }
 }
 
+static inline void hci_sched_le(struct hci_dev *hdev)
+{
+        struct hci_conn *conn;
+        struct sk_buff *skb;
+        int quote, cnt;
+
+        BT_DBG("%s", hdev->name);
+
+        if (!test_bit(HCI_RAW, &hdev->flags)) {
+                /* LE tx timeout must be longer than maximum
+                 * link supervision timeout (40.9 seconds) */
+                if (!hdev->le_cnt &&
+                                time_after(jiffies, hdev->le_last_tx + HZ * 45))
+                        hci_acl_tx_to(hdev);
+        }
+
+        cnt = hdev->le_pkts ? hdev->le_cnt : hdev->acl_cnt;
+        while (cnt && (conn = hci_low_sent(hdev, LE_LINK, &quote))) {
+                while (quote-- && (skb = skb_dequeue(&conn->data_q))) {
+                        BT_DBG("skb %p len %d", skb, skb->len);
+
+                        hci_send_frame(skb);
+                        hdev->le_last_tx = jiffies;
+
+                        cnt--;
+                        conn->sent++;
+                }
+        }
+        if (hdev->le_pkts)
+                hdev->le_cnt = cnt;
+        else
+                hdev->acl_cnt = cnt;
+}
+
 static void hci_tx_task(unsigned long arg)
 {
         struct hci_dev *hdev = (struct hci_dev *) arg;
@@ -1779,7 +1842,8 @@ static void hci_tx_task(unsigned long arg)
 
         read_lock(&hci_task_lock);
 
-        BT_DBG("%s acl %d sco %d", hdev->name, hdev->acl_cnt, hdev->sco_cnt);
+        BT_DBG("%s acl %d sco %d le %d", hdev->name, hdev->acl_cnt,
+                hdev->sco_cnt, hdev->le_cnt);
 
         /* Schedule queues and send stuff to HCI driver */
 
@@ -1789,6 +1853,8 @@ static void hci_tx_task(unsigned long arg)
 
         hci_sched_esco(hdev);
 
+        hci_sched_le(hdev);
+
         /* Send next queued raw (unknown type) packet */
         while ((skb = skb_dequeue(&hdev->raw_q)))
                 hci_send_frame(skb);
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 47c6e9316ce8..3155ad588076 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -776,6 +776,25 @@ static void hci_cc_pin_code_neg_reply(struct hci_dev *hdev, struct sk_buff *skb)
                 mgmt_pin_code_neg_reply_complete(hdev->id, &rp->bdaddr,
                                                                 rp->status);
 }
+static void hci_cc_le_read_buffer_size(struct hci_dev *hdev,
+                                       struct sk_buff *skb)
+{
+        struct hci_rp_le_read_buffer_size *rp = (void *) skb->data;
+
+        BT_DBG("%s status 0x%x", hdev->name, rp->status);
+
+        if (rp->status)
+                return;
+
+        hdev->le_mtu = __le16_to_cpu(rp->le_mtu);
+        hdev->le_pkts = rp->le_max_pkt;
+
+        hdev->le_cnt = hdev->le_pkts;
+
+        BT_DBG("%s le mtu %d:%d", hdev->name, hdev->le_mtu, hdev->le_pkts);
+
+        hci_req_complete(hdev, HCI_OP_LE_READ_BUFFER_SIZE, rp->status);
+}
 
 static inline void hci_cs_inquiry(struct hci_dev *hdev, __u8 status)
 {
@@ -1704,6 +1723,10 @@ static inline void hci_cmd_complete_evt(struct hci_dev *hdev, struct sk_buff *sk
                 hci_cc_pin_code_neg_reply(hdev, skb);
                 break;
 
+        case HCI_OP_LE_READ_BUFFER_SIZE:
+                hci_cc_le_read_buffer_size(hdev, skb);
+                break;
+
         default:
                 BT_DBG("%s opcode 0x%x", hdev->name, opcode);
                 break;
@@ -1849,6 +1872,16 @@ static inline void hci_num_comp_pkts_evt(struct hci_dev *hdev, struct sk_buff *s
                                 hdev->acl_cnt += count;
                                 if (hdev->acl_cnt > hdev->acl_pkts)
                                         hdev->acl_cnt = hdev->acl_pkts;
+                        } else if (conn->type == LE_LINK) {
+                                if (hdev->le_pkts) {
+                                        hdev->le_cnt += count;
+                                        if (hdev->le_cnt > hdev->le_pkts)
+                                                hdev->le_cnt = hdev->le_pkts;
+                                } else {
+                                        hdev->acl_cnt += count;
+                                        if (hdev->acl_cnt > hdev->acl_pkts)
+                                                hdev->acl_cnt = hdev->acl_pkts;
+                                }
                         } else {
                                 hdev->sco_cnt += count;
                                 if (hdev->sco_cnt > hdev->sco_pkts)