caif: Bugfix - use standard Linux lists

Discovered bug when running high number of parallel connect requests.
Replace buggy home brewed list with linux/list.h.

Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 28 insertions, 68 deletions

diff --git a/include/net/caif/cfctrl.h b/include/net/caif/cfctrl.h
index 997603f2bf4c..9402543fc20d 100644
--- a/include/net/caif/cfctrl.h
+++ b/include/net/caif/cfctrl.h
@@ -94,8 +94,8 @@ struct cfctrl_request_info {
         enum cfctrl_cmd cmd;
         u8 channel_id;
         struct cfctrl_link_param param;
-        struct cfctrl_request_info *next;
         struct cflayer *client_layer;
+        struct list_head list;
 };
 
 struct cfctrl {
@@ -103,7 +103,7 @@ struct cfctrl {
         struct cfctrl_rsp res;
         atomic_t req_seq_no;
         atomic_t rsp_seq_no;
-        struct cfctrl_request_info *first_req;
+        struct list_head list;
         /* Protects from simultaneous access to first_req list */
         spinlock_t info_list_lock;
 #ifndef CAIF_NO_LOOP
diff --git a/net/caif/cfctrl.c b/net/caif/cfctrl.c
index 0ffe1e1ce901..fcfda98a5e6d 100644
--- a/net/caif/cfctrl.c
+++ b/net/caif/cfctrl.c
@@ -44,13 +44,14 @@ struct cflayer *cfctrl_create(void)
         dev_info.id = 0xff;
         memset(this, 0, sizeof(*this));
         cfsrvl_init(&this->serv, 0, &dev_info);
-        spin_lock_init(&this->info_list_lock);
         atomic_set(&this->req_seq_no, 1);
         atomic_set(&this->rsp_seq_no, 1);
         this->serv.layer.receive = cfctrl_recv;
         sprintf(this->serv.layer.name, "ctrl");
         this->serv.layer.ctrlcmd = cfctrl_ctrlcmd;
         spin_lock_init(&this->loop_linkid_lock);
+        spin_lock_init(&this->info_list_lock);
+        INIT_LIST_HEAD(&this->list);
         this->loop_linkid = 1;
         return &this->serv.layer;
 }
@@ -112,20 +113,10 @@ bool cfctrl_req_eq(struct cfctrl_request_info *r1,
 void cfctrl_insert_req(struct cfctrl *ctrl,
                               struct cfctrl_request_info *req)
 {
-        struct cfctrl_request_info *p;
         spin_lock(&ctrl->info_list_lock);
-        req->next = NULL;
         atomic_inc(&ctrl->req_seq_no);
         req->sequence_no = atomic_read(&ctrl->req_seq_no);
-        if (ctrl->first_req == NULL) {
-                ctrl->first_req = req;
-                spin_unlock(&ctrl->info_list_lock);
-                return;
-        }
-        p = ctrl->first_req;
-        while (p->next != NULL)
-                p = p->next;
-        p->next = req;
+        list_add_tail(&req->list, &ctrl->list);
         spin_unlock(&ctrl->info_list_lock);
 }
 
@@ -133,46 +124,28 @@ void cfctrl_insert_req(struct cfctrl *ctrl,
 struct cfctrl_request_info *cfctrl_remove_req(struct cfctrl *ctrl,
                                               struct cfctrl_request_info *req)
 {
-        struct cfctrl_request_info *p;
-        struct cfctrl_request_info *ret;
+        struct cfctrl_request_info *p, *tmp, *first;
 
         spin_lock(&ctrl->info_list_lock);
-        if (ctrl->first_req == NULL) {
-                spin_unlock(&ctrl->info_list_lock);
-                return NULL;
-        }
-
-        if (cfctrl_req_eq(req, ctrl->first_req)) {
-                ret = ctrl->first_req;
-                caif_assert(ctrl->first_req);
-                atomic_set(&ctrl->rsp_seq_no,
-                                 ctrl->first_req->sequence_no);
-                ctrl->first_req = ctrl->first_req->next;
-                spin_unlock(&ctrl->info_list_lock);
-                return ret;
-        }
+        first = list_first_entry(&ctrl->list, struct cfctrl_request_info, list);
 
-        p = ctrl->first_req;
-
-        while (p->next != NULL) {
-                if (cfctrl_req_eq(req, p->next)) {
-                        pr_warning("CAIF: %s(): Requests are not "
+        list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
+                if (cfctrl_req_eq(req, p)) {
+                        if (p != first)
+                                pr_warning("CAIF: %s(): Requests are not "
                                         "received in order\n",
                                         __func__);
-                        ret = p->next;
+
                         atomic_set(&ctrl->rsp_seq_no,
-                                        p->next->sequence_no);
-                        p->next = p->next->next;
-                        spin_unlock(&ctrl->info_list_lock);
-                        return ret;
+                                         p->sequence_no);
+                        list_del(&p->list);
+                        goto out;
                 }
-                p = p->next;
         }
+        p = NULL;
+out:
         spin_unlock(&ctrl->info_list_lock);
-
-        pr_warning("CAIF: %s(): Request does not match\n",
-                   __func__);
-        return NULL;
+        return p;
 }
 
 struct cfctrl_rsp *cfctrl_get_respfuncs(struct cflayer *layer)
@@ -388,31 +361,18 @@ void cfctrl_getstartreason_req(struct cflayer *layer)
 
 void cfctrl_cancel_req(struct cflayer *layr, struct cflayer *adap_layer)
 {
-        struct cfctrl_request_info *p, *req;
+        struct cfctrl_request_info *p, *tmp;
         struct cfctrl *ctrl = container_obj(layr);
         spin_lock(&ctrl->info_list_lock);
-
-        if (ctrl->first_req == NULL) {
-                spin_unlock(&ctrl->info_list_lock);
-                return;
-        }
-
-        if (ctrl->first_req->client_layer == adap_layer) {
-
-                req = ctrl->first_req;
-                ctrl->first_req = ctrl->first_req->next;
-                kfree(req);
-        }
-
-        p = ctrl->first_req;
-        while (p != NULL && p->next != NULL) {
-                if (p->next->client_layer == adap_layer) {
-
-                        req = p->next;
-                        p->next = p->next->next;
-                        kfree(p->next);
+        pr_warning("CAIF: %s(): enter\n", __func__);
+
+        list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
+                if (p->client_layer == adap_layer) {
+                        pr_warning("CAIF: %s(): cancel req :%d\n", __func__,
+                                        p->sequence_no);
+                        list_del(&p->list);
+                        kfree(p);
                 }
-                p = p->next;
         }
 
         spin_unlock(&ctrl->info_list_lock);
@@ -634,7 +594,7 @@ static void cfctrl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
         case _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND:
         case CAIF_CTRLCMD_FLOW_OFF_IND:
                 spin_lock(&this->info_list_lock);
-                if (this->first_req != NULL) {
+                if (!list_empty(&this->list)) {
                         pr_debug("CAIF: %s(): Received flow off in "
                                    "control layer", __func__);
                 }