[PATCH 1/2] drivers: staging: wilc1000: Replace message queue with standard Linux lists
Chandra S Gorentla
csgorentla at gmail.com
Mon Sep 28 18:13:55 UTC 2015
- 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 <csgorentla at 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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