crypto: qce - switch to using a mutex

Having switched to workqueue from tasklet, we are no longer limited to
atomic APIs and can now convert the spinlock to a mutex. This, along
with the conversion from tasklet to workqueue grants us ~15% improvement
in cryptsetup benchmarks for AES encryption.

While at it: use guards to simplify locking code.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/qce/core.c b/drivers/crypto/qce/core.c
index 6de9f1e23e2820cfedf9718bdb65ef799e6c7e46..e95e84486d9aefe4b9af09a27631f0f9e7ad231f 100644 (file)
--- a/drivers/crypto/qce/core.c
+++ b/drivers/crypto/qce/core.c
@@ -3,6 +3,7 @@
  * Copyright (c) 2010-2014, The Linux Foundation. All rights reserved.
  */
 
+#include <linux/cleanup.h>
 #include <linux/clk.h>
 #include <linux/device.h>
 #include <linux/dma-mapping.h>
@@ -11,7 +12,6 @@
 #include <linux/module.h>
 #include <linux/mod_devicetable.h>
 #include <linux/platform_device.h>
-#include <linux/spinlock.h>
 #include <linux/types.h>
 #include <crypto/algapi.h>
 #include <crypto/internal/hash.h>
@@ -89,34 +89,28 @@ static int qce_handle_queue(struct qce_device *qce,
                            struct crypto_async_request *req)
 {
        struct crypto_async_request *async_req, *backlog;
-       unsigned long flags;
        int ret = 0, err;
 
-       spin_lock_irqsave(&qce->lock, flags);
+       scoped_guard(mutex, &qce->lock) {
+               if (req)
+                       ret = crypto_enqueue_request(&qce->queue, req);
 
-       if (req)
-               ret = crypto_enqueue_request(&qce->queue, req);
+               /* busy, do not dequeue request */
+               if (qce->req)
+                       return ret;
 
-       /* busy, do not dequeue request */
-       if (qce->req) {
-               spin_unlock_irqrestore(&qce->lock, flags);
-               return ret;
+               backlog = crypto_get_backlog(&qce->queue);
+               async_req = crypto_dequeue_request(&qce->queue);
+               if (async_req)
+                       qce->req = async_req;
        }
 
-       backlog = crypto_get_backlog(&qce->queue);
-       async_req = crypto_dequeue_request(&qce->queue);
-       if (async_req)
-               qce->req = async_req;
-
-       spin_unlock_irqrestore(&qce->lock, flags);
-
        if (!async_req)
                return ret;
 
        if (backlog) {
-               spin_lock_bh(&qce->lock);
-               crypto_request_complete(backlog, -EINPROGRESS);
-               spin_unlock_bh(&qce->lock);
+               scoped_guard(mutex, &qce->lock)
+                       crypto_request_complete(backlog, -EINPROGRESS);
        }
 
        err = qce_handle_request(async_req);
@@ -133,12 +127,11 @@ static void qce_req_done_work(struct work_struct *work)
        struct qce_device *qce = container_of(work, struct qce_device,
                                              done_work);
        struct crypto_async_request *req;
-       unsigned long flags;
 
-       spin_lock_irqsave(&qce->lock, flags);
-       req = qce->req;
-       qce->req = NULL;
-       spin_unlock_irqrestore(&qce->lock, flags);
+       scoped_guard(mutex, &qce->lock) {
+               req = qce->req;
+               qce->req = NULL;
+       }
 
        if (req)
                crypto_request_complete(req, qce->result);
@@ -243,7 +236,10 @@ static int qce_crypto_probe(struct platform_device *pdev)
        if (ret)
                return ret;
 
-       spin_lock_init(&qce->lock);
+       ret = devm_mutex_init(qce->dev, &qce->lock);
+       if (ret)
+               return ret;
+
        INIT_WORK(&qce->done_work, qce_req_done_work);
        crypto_init_queue(&qce->queue, QCE_QUEUE_LENGTH);
 

diff --git a/drivers/crypto/qce/core.h b/drivers/crypto/qce/core.h
index 39e75a75a4293278b1d0d9e60b67ce9c012fd993..eb6fa7a8b64a81daf9ad5304a3ae4e5e597a70b8 100644 (file)
--- a/drivers/crypto/qce/core.h
+++ b/drivers/crypto/qce/core.h
@@ -6,6 +6,7 @@
 #ifndef _CORE_H_
 #define _CORE_H_
 
+#include <linux/mutex.h>
 #include <linux/workqueue.h>
 
 #include "dma.h"
@@ -30,7 +31,7 @@
  */
 struct qce_device {
        struct crypto_queue queue;
-       spinlock_t lock;
+       struct mutex lock;
        struct work_struct done_work;
        struct crypto_async_request *req;
        int result;