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[PATCH 4/4] crypto: s5p-sss - Use mutex instead of spinlock




Driver uses threaded interrupt handler so there is no real need for
using spinlocks for synchronization.  Mutexes would do fine and are
friendlier for overall system preemptivness and real-time behavior.

Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
---
 drivers/crypto/s5p-sss.c | 35 ++++++++++++++++-------------------
 1 file changed, 16 insertions(+), 19 deletions(-)

diff --git a/drivers/crypto/s5p-sss.c b/drivers/crypto/s5p-sss.c
index 7ac657f46d15..1893cf5dedc0 100644
--- a/drivers/crypto/s5p-sss.c
+++ b/drivers/crypto/s5p-sss.c
@@ -21,6 +21,7 @@
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/scatterlist.h>
@@ -214,7 +215,7 @@ struct s5p_aes_dev {
 	struct tasklet_struct		tasklet;
 	struct crypto_queue		queue;
 	bool				busy;
-	spinlock_t			lock;
+	struct mutex			lock;
 };
 
 static struct s5p_aes_dev *s5p_dev;
@@ -443,11 +444,10 @@ static irqreturn_t s5p_aes_interrupt(int irq, void *dev_id)
 	int err_dma_tx = 0;
 	int err_dma_rx = 0;
 	bool tx_end = false;
-	unsigned long flags;
 	uint32_t status;
 	int err;
 
-	spin_lock_irqsave(&dev->lock, flags);
+	mutex_lock(&dev->lock);
 
 	/*
 	 * Handle rx or tx interrupt. If there is still data (scatterlist did not
@@ -481,7 +481,7 @@ static irqreturn_t s5p_aes_interrupt(int irq, void *dev_id)
 	if (tx_end) {
 		s5p_sg_done(dev);
 
-		spin_unlock_irqrestore(&dev->lock, flags);
+		mutex_unlock(&dev->lock);
 
 		s5p_aes_complete(dev, 0);
 		/* Device is still busy */
@@ -498,7 +498,7 @@ static irqreturn_t s5p_aes_interrupt(int irq, void *dev_id)
 		if (err_dma_rx == 1)
 			s5p_set_dma_indata(dev, dev->sg_src);
 
-		spin_unlock_irqrestore(&dev->lock, flags);
+		mutex_unlock(&dev->lock);
 	}
 
 	return IRQ_HANDLED;
@@ -506,7 +506,7 @@ static irqreturn_t s5p_aes_interrupt(int irq, void *dev_id)
 error:
 	s5p_sg_done(dev);
 	dev->busy = false;
-	spin_unlock_irqrestore(&dev->lock, flags);
+	mutex_unlock(&dev->lock);
 	s5p_aes_complete(dev, err);
 
 	return IRQ_HANDLED;
@@ -599,7 +599,6 @@ static void s5p_aes_crypt_start(struct s5p_aes_dev *dev, unsigned long mode)
 {
 	struct ablkcipher_request *req = dev->req;
 	uint32_t aes_control;
-	unsigned long flags;
 	int err;
 
 	aes_control = SSS_AES_KEY_CHANGE_MODE;
@@ -625,7 +624,7 @@ static void s5p_aes_crypt_start(struct s5p_aes_dev *dev, unsigned long mode)
 		    |  SSS_AES_BYTESWAP_KEY
 		    |  SSS_AES_BYTESWAP_CNT;
 
-	spin_lock_irqsave(&dev->lock, flags);
+	mutex_lock(&dev->lock);
 
 	SSS_WRITE(dev, FCINTENCLR,
 		  SSS_FCINTENCLR_BTDMAINTENCLR | SSS_FCINTENCLR_BRDMAINTENCLR);
@@ -648,7 +647,7 @@ static void s5p_aes_crypt_start(struct s5p_aes_dev *dev, unsigned long mode)
 	SSS_WRITE(dev, FCINTENSET,
 		  SSS_FCINTENSET_BTDMAINTENSET | SSS_FCINTENSET_BRDMAINTENSET);
 
-	spin_unlock_irqrestore(&dev->lock, flags);
+	mutex_unlock(&dev->lock);
 
 	return;
 
@@ -658,7 +657,7 @@ static void s5p_aes_crypt_start(struct s5p_aes_dev *dev, unsigned long mode)
 indata_error:
 	s5p_sg_done(dev);
 	dev->busy = false;
-	spin_unlock_irqrestore(&dev->lock, flags);
+	mutex_unlock(&dev->lock);
 	s5p_aes_complete(dev, err);
 }
 
@@ -667,18 +666,17 @@ static void s5p_tasklet_cb(unsigned long data)
 	struct s5p_aes_dev *dev = (struct s5p_aes_dev *)data;
 	struct crypto_async_request *async_req, *backlog;
 	struct s5p_aes_reqctx *reqctx;
-	unsigned long flags;
 
-	spin_lock_irqsave(&dev->lock, flags);
+	mutex_lock(&dev->lock);
 	backlog   = crypto_get_backlog(&dev->queue);
 	async_req = crypto_dequeue_request(&dev->queue);
 
 	if (!async_req) {
 		dev->busy = false;
-		spin_unlock_irqrestore(&dev->lock, flags);
+		mutex_unlock(&dev->lock);
 		return;
 	}
-	spin_unlock_irqrestore(&dev->lock, flags);
+	mutex_unlock(&dev->lock);
 
 	if (backlog)
 		backlog->complete(backlog, -EINPROGRESS);
@@ -693,18 +691,17 @@ static void s5p_tasklet_cb(unsigned long data)
 static int s5p_aes_handle_req(struct s5p_aes_dev *dev,
 			      struct ablkcipher_request *req)
 {
-	unsigned long flags;
 	int err;
 
-	spin_lock_irqsave(&dev->lock, flags);
+	mutex_lock(&dev->lock);
 	err = ablkcipher_enqueue_request(&dev->queue, req);
 	if (dev->busy) {
-		spin_unlock_irqrestore(&dev->lock, flags);
+		mutex_unlock(&dev->lock);
 		goto exit;
 	}
 	dev->busy = true;
 
-	spin_unlock_irqrestore(&dev->lock, flags);
+	mutex_unlock(&dev->lock);
 
 	tasklet_schedule(&dev->tasklet);
 
@@ -856,7 +853,7 @@ static int s5p_aes_probe(struct platform_device *pdev)
 		return err;
 	}
 
-	spin_lock_init(&pdata->lock);
+	mutex_init(&pdata->lock);
 
 	pdata->aes_ioaddr = pdata->ioaddr + variant->aes_offset;
 
-- 
2.9.3