- The message queue is replaced with standard Linux linked list
 - kmem_cache is used for list members
 - A check for return value of receive method is added
 - GFP_ATOMIC is changed to GFP_KERNEL
 - A few other related minor changes

Signed-off-by: Chandra S Gorentla <csgoren...@gmail.com>
---
 - Comments of Dan Carpenter are taken care
   - If receive method return value not checked, case statement for previous
     message may get executed if not done
   - Indication of usage of 'kmem_cache' is added to the description
   - Memory allocation donw outside spin_lock; GFP_ATOMIC replaced
     with GFP_KERNEL
   - spin_lock, spin_unlock are matched
   - goto statements removed
   - Unrelated changes moved to a different patch
   - PRINT_ERR can be taken up in a seperate patch

 drivers/staging/wilc1000/host_interface.c |  7 ++-
 drivers/staging/wilc1000/wilc_msgqueue.c  | 73 +++++++++++++------------------
 drivers/staging/wilc1000/wilc_platform.h  |  5 ++-
 3 files changed, 40 insertions(+), 45 deletions(-)

diff --git a/drivers/staging/wilc1000/host_interface.c 
b/drivers/staging/wilc1000/host_interface.c
index 62f4a8a..954656d 100644
--- a/drivers/staging/wilc1000/host_interface.c
+++ b/drivers/staging/wilc1000/host_interface.c
@@ -4304,11 +4304,16 @@ static int hostIFthread(void *pvArg)
        u32 u32Ret;
        struct host_if_msg msg;
        tstrWILC_WFIDrv *pstrWFIDrv;
+       int ret;
 
        memset(&msg, 0, sizeof(struct host_if_msg));
 
        while (1) {
-               wilc_mq_recv(&gMsgQHostIF, &msg, sizeof(struct host_if_msg), 
&u32Ret);
+               ret = wilc_mq_recv(&gMsgQHostIF, &msg,
+                                       sizeof(struct host_if_msg), &u32Ret);
+               if (ret)
+                       continue;
+
                pstrWFIDrv = (tstrWILC_WFIDrv *)msg.drvHandler;
                if (msg.id == HOST_IF_MSG_EXIT) {
                        PRINT_D(GENERIC_DBG, "THREAD: Exiting HostIfThread\n");
diff --git a/drivers/staging/wilc1000/wilc_msgqueue.c 
b/drivers/staging/wilc1000/wilc_msgqueue.c
index 869736a..a01ada4 100644
--- a/drivers/staging/wilc1000/wilc_msgqueue.c
+++ b/drivers/staging/wilc1000/wilc_msgqueue.c
@@ -12,9 +12,15 @@
  */
 int wilc_mq_create(WILC_MsgQueueHandle *pHandle)
 {
+       pHandle->msg_cache = kmem_cache_create("wilc_message_queue",
+                                               sizeof(Message),
+                                               0, SLAB_POISON, NULL);
+       if (!pHandle->msg_cache)
+               return -ENOMEM;
+
        spin_lock_init(&pHandle->strCriticalSection);
        sema_init(&pHandle->hSem, 0);
-       pHandle->pstrMessageList = NULL;
+       INIT_LIST_HEAD(&pHandle->msg_list_head);
        pHandle->u32ReceiversCount = 0;
        pHandle->bExiting = false;
        return 0;
@@ -28,6 +34,7 @@ int wilc_mq_create(WILC_MsgQueueHandle *pHandle)
  */
 int wilc_mq_destroy(WILC_MsgQueueHandle *pHandle)
 {
+       Message *msg;
        pHandle->bExiting = true;
 
        /* Release any waiting receiver thread. */
@@ -36,13 +43,16 @@ int wilc_mq_destroy(WILC_MsgQueueHandle *pHandle)
                pHandle->u32ReceiversCount--;
        }
 
-       while (pHandle->pstrMessageList) {
-               Message *pstrMessge = pHandle->pstrMessageList->pstrNext;
-
-               kfree(pHandle->pstrMessageList);
-               pHandle->pstrMessageList = pstrMessge;
+       while (!list_empty(&pHandle->msg_list_head)) {
+               msg = list_first_entry(&pHandle->msg_list_head,
+                                       Message, link);
+               list_del(&msg->link);
+               kfree(msg->pvBuffer);
+               kmem_cache_free(pHandle->msg_cache, msg);
        }
 
+       kmem_cache_destroy(pHandle->msg_cache);
+
        return 0;
 }
 
@@ -55,61 +65,40 @@ int wilc_mq_destroy(WILC_MsgQueueHandle *pHandle)
 int wilc_mq_send(WILC_MsgQueueHandle *pHandle,
                             const void *pvSendBuffer, u32 u32SendBufferSize)
 {
-       int result = 0;
        unsigned long flags;
        Message *pstrMessage = NULL;
 
        if ((!pHandle) || (u32SendBufferSize == 0) || (!pvSendBuffer)) {
                PRINT_ER("pHandle or pvSendBuffer is null\n");
-               result = -EFAULT;
-               goto ERRORHANDLER;
+               return -EFAULT;
        }
 
        if (pHandle->bExiting) {
                PRINT_ER("pHandle fail\n");
-               result = -EFAULT;
-               goto ERRORHANDLER;
+               return -EFAULT;
        }
 
-       spin_lock_irqsave(&pHandle->strCriticalSection, flags);
-
        /* construct a new message */
-       pstrMessage = kmalloc(sizeof(Message), GFP_ATOMIC);
+       pstrMessage = kmem_cache_zalloc(pHandle->msg_cache, GFP_KERNEL);
        if (!pstrMessage)
                return -ENOMEM;
+
        pstrMessage->u32Length = u32SendBufferSize;
-       pstrMessage->pstrNext = NULL;
-       pstrMessage->pvBuffer = kmalloc(u32SendBufferSize, GFP_ATOMIC);
+       pstrMessage->pvBuffer = kmalloc(u32SendBufferSize, GFP_KERNEL);
        if (!pstrMessage->pvBuffer) {
-               result = -ENOMEM;
-               goto ERRORHANDLER;
+               kmem_cache_free(pHandle->msg_cache, pstrMessage);
+               return -ENOMEM;
        }
        memcpy(pstrMessage->pvBuffer, pvSendBuffer, u32SendBufferSize);
 
        /* add it to the message queue */
-       if (!pHandle->pstrMessageList) {
-               pHandle->pstrMessageList  = pstrMessage;
-       } else {
-               Message *pstrTailMsg = pHandle->pstrMessageList;
-
-               while (pstrTailMsg->pstrNext)
-                       pstrTailMsg = pstrTailMsg->pstrNext;
-
-               pstrTailMsg->pstrNext = pstrMessage;
-       }
-
+       spin_lock_irqsave(&pHandle->strCriticalSection, flags);
+       list_add_tail(&pstrMessage->link, &pHandle->msg_list_head);
        spin_unlock_irqrestore(&pHandle->strCriticalSection, flags);
 
        up(&pHandle->hSem);
 
-ERRORHANDLER:
-       /* error occured, free any allocations */
-       if (pstrMessage) {
-               kfree(pstrMessage->pvBuffer);
-               kfree(pstrMessage);
-       }
-
-       return result;
+       return 0;
 }
 
 /*!
@@ -156,12 +145,13 @@ int wilc_mq_recv(WILC_MsgQueueHandle *pHandle,
 
        spin_lock_irqsave(&pHandle->strCriticalSection, flags);
 
-       pstrMessage = pHandle->pstrMessageList;
-       if (!pstrMessage) {
+       if (list_empty(&pHandle->msg_list_head)) {
                spin_unlock_irqrestore(&pHandle->strCriticalSection, flags);
                PRINT_ER("pstrMessage is null\n");
                return -EFAULT;
        }
+
+       pstrMessage = list_first_entry(&pHandle->msg_list_head, Message, link);
        /* check buffer size */
        if (u32RecvBufferSize < pstrMessage->u32Length) {
                spin_unlock_irqrestore(&pHandle->strCriticalSection, flags);
@@ -175,10 +165,9 @@ int wilc_mq_recv(WILC_MsgQueueHandle *pHandle,
        memcpy(pvRecvBuffer, pstrMessage->pvBuffer, pstrMessage->u32Length);
        *pu32ReceivedLength = pstrMessage->u32Length;
 
-       pHandle->pstrMessageList = pstrMessage->pstrNext;
-
+       list_del(&pstrMessage->link);
        kfree(pstrMessage->pvBuffer);
-       kfree(pstrMessage);
+       kmem_cache_free(pHandle->msg_cache, pstrMessage);
 
        spin_unlock_irqrestore(&pHandle->strCriticalSection, flags);
 
diff --git a/drivers/staging/wilc1000/wilc_platform.h 
b/drivers/staging/wilc1000/wilc_platform.h
index b763616..3871658 100644
--- a/drivers/staging/wilc1000/wilc_platform.h
+++ b/drivers/staging/wilc1000/wilc_platform.h
@@ -20,7 +20,7 @@
 typedef struct __Message_struct {
        void *pvBuffer;
        u32 u32Length;
-       struct __Message_struct *pstrNext;
+       struct list_head link;
 } Message;
 
 typedef struct __MessageQueue_struct {
@@ -28,7 +28,8 @@ typedef struct __MessageQueue_struct {
        spinlock_t strCriticalSection;
        bool bExiting;
        u32 u32ReceiversCount;
-       Message *pstrMessageList;
+       struct list_head msg_list_head;
+       struct kmem_cache *msg_cache;
 } WILC_MsgQueueHandle;
 
 
-- 
2.1.4

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