iwmc3200wifi: protect rx_tickets and rx_packets[] lists

Protect rx_tickets and rx_packets[] lists with spinlocks to fix the
race condition for concurrent list operations. In iwmc3200wifi both
sdio_isr_worker and rx_worker workqueues can access the rx ticket
and packets lists at the same time under high rx load.

Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

4 files changed, 30 insertions, 5 deletions

diff --git a/drivers/net/wireless/iwmc3200wifi/debugfs.c b/drivers/net/wireless/iwmc3200wifi/debugfs.c
index 6ac5c8dbe051..48930c1a0f76 100644
--- a/drivers/net/wireless/iwmc3200wifi/debugfs.c
+++ b/drivers/net/wireless/iwmc3200wifi/debugfs.c
@@ -280,6 +280,7 @@ static ssize_t iwm_debugfs_rx_ticket_read(struct file *filp,
         if (!buf)
                 return -ENOMEM;
 
+        spin_lock(&iwm->ticket_lock);
         list_for_each_entry(ticket, &iwm->rx_tickets, node) {
                 len += snprintf(buf + len, buf_len - len, "Ticket #%d\n",
                                 ticket->ticket->id);
@@ -288,6 +289,7 @@ static ssize_t iwm_debugfs_rx_ticket_read(struct file *filp,
                 len += snprintf(buf + len, buf_len - len, "\tflags:  0x%x\n",
                                 ticket->ticket->flags);
         }
+        spin_unlock(&iwm->ticket_lock);
 
         for (i = 0; i < IWM_RX_ID_HASH; i++) {
                 struct iwm_rx_packet *packet;
@@ -296,6 +298,7 @@ static ssize_t iwm_debugfs_rx_ticket_read(struct file *filp,
                 if (!list_empty(pkt_list)) {
                         len += snprintf(buf + len, buf_len - len,
                                         "Packet hash #%d\n", i);
+                        spin_lock(&iwm->packet_lock[i]);
                         list_for_each_entry(packet, pkt_list, node) {
                                 len += snprintf(buf + len, buf_len - len,
                                                 "\tPacket id:     %d\n",
@@ -304,6 +307,7 @@ static ssize_t iwm_debugfs_rx_ticket_read(struct file *filp,
                                                 "\tPacket length: %lu\n",
                                                 packet->pkt_size);
                         }
+                        spin_unlock(&iwm->packet_lock[i]);
                 }
         }
 
diff --git a/drivers/net/wireless/iwmc3200wifi/iwm.h b/drivers/net/wireless/iwmc3200wifi/iwm.h
index 9ad5b3c22eb2..13266c3842f8 100644
--- a/drivers/net/wireless/iwmc3200wifi/iwm.h
+++ b/drivers/net/wireless/iwmc3200wifi/iwm.h
@@ -269,7 +269,9 @@ struct iwm_priv {
 
         struct sk_buff_head rx_list;
         struct list_head rx_tickets;
+        spinlock_t ticket_lock;
         struct list_head rx_packets[IWM_RX_ID_HASH];
+        spinlock_t packet_lock[IWM_RX_ID_HASH];
         struct workqueue_struct *rx_wq;
         struct work_struct rx_worker;
 
diff --git a/drivers/net/wireless/iwmc3200wifi/main.c b/drivers/net/wireless/iwmc3200wifi/main.c
index 90519600a947..3a3510a6223a 100644
--- a/drivers/net/wireless/iwmc3200wifi/main.c
+++ b/drivers/net/wireless/iwmc3200wifi/main.c
@@ -276,8 +276,11 @@ int iwm_priv_init(struct iwm_priv *iwm)
 
         skb_queue_head_init(&iwm->rx_list);
         INIT_LIST_HEAD(&iwm->rx_tickets);
-        for (i = 0; i < IWM_RX_ID_HASH; i++)
+        spin_lock_init(&iwm->ticket_lock);
+        for (i = 0; i < IWM_RX_ID_HASH; i++) {
                 INIT_LIST_HEAD(&iwm->rx_packets[i]);
+                spin_lock_init(&iwm->packet_lock[i]);
+        }
 
         INIT_WORK(&iwm->rx_worker, iwm_rx_worker);
 
diff --git a/drivers/net/wireless/iwmc3200wifi/rx.c b/drivers/net/wireless/iwmc3200wifi/rx.c
index 38d950b0f24b..c8a31be16885 100644
--- a/drivers/net/wireless/iwmc3200wifi/rx.c
+++ b/drivers/net/wireless/iwmc3200wifi/rx.c
@@ -344,10 +344,15 @@ static struct iwm_rx_packet *iwm_rx_packet_get(struct iwm_priv *iwm, u16 id)
         u8 id_hash = IWM_RX_ID_GET_HASH(id);
         struct iwm_rx_packet *packet;
 
+        spin_lock(&iwm->packet_lock[id_hash]);
         list_for_each_entry(packet, &iwm->rx_packets[id_hash], node)
-                if (packet->id == id)
+                if (packet->id == id) {
+                        list_del(&packet->node);
+                        spin_unlock(&iwm->packet_lock[id_hash]);
                         return packet;
+                }
 
+        spin_unlock(&iwm->packet_lock[id_hash]);
         return NULL;
 }
 
@@ -385,18 +390,22 @@ void iwm_rx_free(struct iwm_priv *iwm)
         struct iwm_rx_packet *packet, *np;
         int i;
 
+        spin_lock(&iwm->ticket_lock);
         list_for_each_entry_safe(ticket, nt, &iwm->rx_tickets, node) {
                 list_del(&ticket->node);
                 iwm_rx_ticket_node_free(ticket);
         }
+        spin_unlock(&iwm->ticket_lock);
 
         for (i = 0; i < IWM_RX_ID_HASH; i++) {
+                spin_lock(&iwm->packet_lock[i]);
                 list_for_each_entry_safe(packet, np, &iwm->rx_packets[i],
                                          node) {
                         list_del(&packet->node);
                         kfree_skb(packet->skb);
                         kfree(packet);
                 }
+                spin_unlock(&iwm->packet_lock[i]);
         }
 }
 
@@ -424,7 +433,9 @@ static int iwm_ntf_rx_ticket(struct iwm_priv *iwm, u8 *buf,
                                    ticket->action ==  IWM_RX_TICKET_RELEASE ?
                                    "RELEASE" : "DROP",
                                    ticket->id);
+                        spin_lock(&iwm->ticket_lock);
                         list_add_tail(&ticket_node->node, &iwm->rx_tickets);
+                        spin_unlock(&iwm->ticket_lock);
 
                         /*
                          * We received an Rx ticket, most likely there's
@@ -457,6 +468,7 @@ static int iwm_ntf_rx_packet(struct iwm_priv *iwm, u8 *buf,
         struct iwm_rx_packet *packet;
         u16 id, buf_offset;
         u32 packet_size;
+        u8 id_hash;
 
         IWM_DBG_RX(iwm, DBG, "\n");
 
@@ -474,7 +486,10 @@ static int iwm_ntf_rx_packet(struct iwm_priv *iwm, u8 *buf,
         if (IS_ERR(packet))
                 return PTR_ERR(packet);
 
-        list_add_tail(&packet->node, &iwm->rx_packets[IWM_RX_ID_GET_HASH(id)]);
+        id_hash = IWM_RX_ID_GET_HASH(id);
+        spin_lock(&iwm->packet_lock[id_hash]);
+        list_add_tail(&packet->node, &iwm->rx_packets[id_hash]);
+        spin_unlock(&iwm->packet_lock[id_hash]);
 
         /* We might (unlikely) have received the packet _after_ the ticket */
         queue_work(iwm->rx_wq, &iwm->rx_worker);
@@ -1664,6 +1679,7 @@ void iwm_rx_worker(struct work_struct *work)
          * We stop whenever a ticket is missing its packet, as we're
          * supposed to send the packets in order.
          */
+        spin_lock(&iwm->ticket_lock);
         list_for_each_entry_safe(ticket, next, &iwm->rx_tickets, node) {
                 struct iwm_rx_packet *packet =
                         iwm_rx_packet_get(iwm, le16_to_cpu(ticket->ticket->id));
@@ -1672,12 +1688,12 @@ void iwm_rx_worker(struct work_struct *work)
                         IWM_DBG_RX(iwm, DBG, "Skip rx_work: Wait for ticket %d "
                                    "to be handled first\n",
                                    le16_to_cpu(ticket->ticket->id));
-                        return;
+                        break;
                 }
 
                 list_del(&ticket->node);
-                list_del(&packet->node);
                 iwm_rx_process_packet(iwm, packet, ticket);
         }
+        spin_unlock(&iwm->ticket_lock);
 }