crypto: sahara - don't sleep when in softirq

Function of sahara_aes_crypt maybe could be called by function
of crypto_skcipher_encrypt during the rx softirq, so it is not
allowed to use mutex lock.

Fixes: c0c3c89a ("crypto: sahara - replace tasklets with...")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/sahara.c

@@ -26,10 +26,10 @@
 #include <linux/kernel.h>
 #include <linux/kthread.h>
 #include <linux/module.h>
-#include <linux/mutex.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
+#include <linux/spinlock.h>
 
 #define SHA_BUFFER_LEN		PAGE_SIZE
 #define SAHARA_MAX_SHA_BLOCK_SIZE	SHA256_BLOCK_SIZE
@@ -196,7 +196,7 @@ struct sahara_dev {
 	void __iomem		*regs_base;
 	struct clk		*clk_ipg;
 	struct clk		*clk_ahb;
-	struct mutex		queue_mutex;
+	spinlock_t		queue_spinlock;
 	struct task_struct	*kthread;
 	struct completion	dma_completion;
 
@@ -642,9 +642,9 @@ static int sahara_aes_crypt(struct skcipher_request *req, unsigned long mode)
 
 	rctx->mode = mode;
 
-	mutex_lock(&dev->queue_mutex);
+	spin_lock_bh(&dev->queue_spinlock);
 	err = crypto_enqueue_request(&dev->queue, &req->base);
-	mutex_unlock(&dev->queue_mutex);
+	spin_unlock_bh(&dev->queue_spinlock);
 
 	wake_up_process(dev->kthread);
 
@@ -1043,10 +1043,10 @@ static int sahara_queue_manage(void *data)
 	do {
 		__set_current_state(TASK_INTERRUPTIBLE);
 
-		mutex_lock(&dev->queue_mutex);
+		spin_lock_bh(&dev->queue_spinlock);
 		backlog = crypto_get_backlog(&dev->queue);
 		async_req = crypto_dequeue_request(&dev->queue);
-		mutex_unlock(&dev->queue_mutex);
+		spin_unlock_bh(&dev->queue_spinlock);
 
 		if (backlog)
 			backlog->complete(backlog, -EINPROGRESS);
@@ -1092,9 +1092,9 @@ static int sahara_sha_enqueue(struct ahash_request *req, int last)
 		rctx->first = 1;
 	}
 
-	mutex_lock(&dev->queue_mutex);
+	spin_lock_bh(&dev->queue_spinlock);
 	ret = crypto_enqueue_request(&dev->queue, &req->base);
-	mutex_unlock(&dev->queue_mutex);
+	spin_unlock_bh(&dev->queue_spinlock);
 
 	wake_up_process(dev->kthread);
 
@@ -1449,7 +1449,7 @@ static int sahara_probe(struct platform_device *pdev)
 
 	crypto_init_queue(&dev->queue, SAHARA_QUEUE_LENGTH);
 
-	mutex_init(&dev->queue_mutex);
+	spin_lock_init(&dev->queue_spinlock);
 
 	dev_ptr = dev;