2020-01-27 22:18:08

by Iuliana Prodan

[permalink] [raw]
Subject: [PATCH] crypto: engine - support for parallel requests

Added support for executing multiple requests, in parallel,
for crypto engine.
A new callback is added, can_enqueue_hardware, which asks the
driver if the hardware has free space, to enqueue a new request.
The new crypto_engine_alloc_init_and_set function, initialize
crypto-engine, sets the maximum size for crypto-engine software
queue (not hardcoded anymore) and the can_enqueue_hardware callback.
On crypto_pump_requests, if can_enqueue_hardware callback returns true,
a new request is send to hardware, until there is no space and the
callback returns false.

Signed-off-by: Iuliana Prodan <[email protected]>

---
Changes since V0 (RFC):
- removed max_no_req and no_req, as the number of request that
can be processed in parallel;
- added a new callback, can_enqueue_hardware, to check whether
the hardware can process a new request.
---

crypto/crypto_engine.c | 105 ++++++++++++++++++++++++++++++------------------
include/crypto/engine.h | 10 +++--
2 files changed, 71 insertions(+), 44 deletions(-)

diff --git a/crypto/crypto_engine.c b/crypto/crypto_engine.c
index eb029ff..ee3a610 100644
--- a/crypto/crypto_engine.c
+++ b/crypto/crypto_engine.c
@@ -22,32 +22,18 @@
* @err: error number
*/
static void crypto_finalize_request(struct crypto_engine *engine,
- struct crypto_async_request *req, int err)
+ struct crypto_async_request *req, int err)
{
- unsigned long flags;
- bool finalize_cur_req = false;
int ret;
struct crypto_engine_ctx *enginectx;

- spin_lock_irqsave(&engine->queue_lock, flags);
- if (engine->cur_req == req)
- finalize_cur_req = true;
- spin_unlock_irqrestore(&engine->queue_lock, flags);
-
- if (finalize_cur_req) {
- enginectx = crypto_tfm_ctx(req->tfm);
- if (engine->cur_req_prepared &&
- enginectx->op.unprepare_request) {
- ret = enginectx->op.unprepare_request(engine, req);
- if (ret)
- dev_err(engine->dev, "failed to unprepare request\n");
- }
- spin_lock_irqsave(&engine->queue_lock, flags);
- engine->cur_req = NULL;
- engine->cur_req_prepared = false;
- spin_unlock_irqrestore(&engine->queue_lock, flags);
+ enginectx = crypto_tfm_ctx(req->tfm);
+ if (enginectx->op.prepare_request &&
+ enginectx->op.unprepare_request) {
+ ret = enginectx->op.unprepare_request(engine, req);
+ if (ret)
+ dev_err(engine->dev, "failed to unprepare request\n");
}
-
req->complete(req, err);

kthread_queue_work(engine->kworker, &engine->pump_requests);
@@ -73,10 +59,6 @@ static void crypto_pump_requests(struct crypto_engine *engine,

spin_lock_irqsave(&engine->queue_lock, flags);

- /* Make sure we are not already running a request */
- if (engine->cur_req)
- goto out;
-
/* If another context is idling then defer */
if (engine->idling) {
kthread_queue_work(engine->kworker, &engine->pump_requests);
@@ -108,13 +90,18 @@ static void crypto_pump_requests(struct crypto_engine *engine,
goto out;
}

+start_request:
+ /* If hw is busy, do not send any request */
+ if (engine->can_enqueue_hardware &&
+ !engine->can_enqueue_hardware(engine->dev))
+ goto out;
+
/* Get the fist request from the engine queue to handle */
backlog = crypto_get_backlog(&engine->queue);
async_req = crypto_dequeue_request(&engine->queue);
if (!async_req)
goto out;

- engine->cur_req = async_req;
if (backlog)
backlog->complete(backlog, -EINPROGRESS);

@@ -130,7 +117,7 @@ static void crypto_pump_requests(struct crypto_engine *engine,
ret = engine->prepare_crypt_hardware(engine);
if (ret) {
dev_err(engine->dev, "failed to prepare crypt hardware\n");
- goto req_err;
+ goto req_err_2;
}
}

@@ -141,26 +128,38 @@ static void crypto_pump_requests(struct crypto_engine *engine,
if (ret) {
dev_err(engine->dev, "failed to prepare request: %d\n",
ret);
- goto req_err;
+ goto req_err_2;
}
- engine->cur_req_prepared = true;
}
if (!enginectx->op.do_one_request) {
dev_err(engine->dev, "failed to do request\n");
ret = -EINVAL;
- goto req_err;
+ goto req_err_1;
}
+
ret = enginectx->op.do_one_request(engine, async_req);
if (ret) {
dev_err(engine->dev, "Failed to do one request from queue: %d\n", ret);
- goto req_err;
+ goto req_err_1;
}
- return;

-req_err:
- crypto_finalize_request(engine, async_req, ret);
- return;
+ goto retry;
+
+req_err_1:
+ if (enginectx->op.unprepare_request) {
+ ret = enginectx->op.unprepare_request(engine, async_req);
+ if (ret)
+ dev_err(engine->dev, "failed to unprepare request\n");
+ }
+req_err_2:
+ async_req->complete(async_req, ret);

+retry:
+ if (engine->can_enqueue_hardware) {
+ spin_lock_irqsave(&engine->queue_lock, flags);
+ goto start_request;
+ }
+ return;
out:
spin_unlock_irqrestore(&engine->queue_lock, flags);
}
@@ -386,15 +385,25 @@ int crypto_engine_stop(struct crypto_engine *engine)
EXPORT_SYMBOL_GPL(crypto_engine_stop);

/**
- * crypto_engine_alloc_init - allocate crypto hardware engine structure and
- * initialize it.
+ * crypto_engine_alloc_init_and_set - allocate crypto hardware engine structure
+ * and initialize it by setting the maximum number of entries in the software
+ * crypto-engine queue.
* @dev: the device attached with one hardware engine
+ * @cbk: pointer to a callback function to be invoked when pumping requests
+ * to check whether the hardware can process a new request.
+ * This has the form:
+ * callback(struct device *dev)
+ * where:
+ * @dev: contains the device that processed this response.
* @rt: whether this queue is set to run as a realtime task
+ * @qlen: maximum size of the crypto-engine queue
*
* This must be called from context that can sleep.
* Return: the crypto engine structure on success, else NULL.
*/
-struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt)
+struct crypto_engine *crypto_engine_alloc_init_and_set(struct device *dev,
+ bool (*cbk)(struct device *dev),
+ bool rt, int qlen)
{
struct sched_param param = { .sched_priority = MAX_RT_PRIO / 2 };
struct crypto_engine *engine;
@@ -411,12 +420,12 @@ struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt)
engine->running = false;
engine->busy = false;
engine->idling = false;
- engine->cur_req_prepared = false;
engine->priv_data = dev;
+ engine->can_enqueue_hardware = cbk;
snprintf(engine->name, sizeof(engine->name),
"%s-engine", dev_name(dev));

- crypto_init_queue(&engine->queue, CRYPTO_ENGINE_MAX_QLEN);
+ crypto_init_queue(&engine->queue, qlen);
spin_lock_init(&engine->queue_lock);

engine->kworker = kthread_create_worker(0, "%s", engine->name);
@@ -433,6 +442,22 @@ struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt)

return engine;
}
+EXPORT_SYMBOL_GPL(crypto_engine_alloc_init_and_set);
+
+/**
+ * crypto_engine_alloc_init - allocate crypto hardware engine structure and
+ * initialize it.
+ * @dev: the device attached with one hardware engine
+ * @rt: whether this queue is set to run as a realtime task
+ *
+ * This must be called from context that can sleep.
+ * Return: the crypto engine structure on success, else NULL.
+ */
+struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt)
+{
+ return crypto_engine_alloc_init_and_set(dev, NULL, rt,
+ CRYPTO_ENGINE_MAX_QLEN);
+}
EXPORT_SYMBOL_GPL(crypto_engine_alloc_init);

/**
diff --git a/include/crypto/engine.h b/include/crypto/engine.h
index e29cd67..15d1150 100644
--- a/include/crypto/engine.h
+++ b/include/crypto/engine.h
@@ -24,7 +24,6 @@
* @idling: the engine is entering idle state
* @busy: request pump is busy
* @running: the engine is on working
- * @cur_req_prepared: current request is prepared
* @list: link with the global crypto engine list
* @queue_lock: spinlock to syncronise access to request queue
* @queue: the crypto queue of the engine
@@ -35,17 +34,17 @@
* @unprepare_crypt_hardware: there are currently no more requests on the
* queue so the subsystem notifies the driver that it may relax the
* hardware by issuing this call
+ * @can_enqueue_hardware: callback to check whether the hardware can process
+ * a new request
* @kworker: kthread worker struct for request pump
* @pump_requests: work struct for scheduling work to the request pump
* @priv_data: the engine private data
- * @cur_req: the current request which is on processing
*/
struct crypto_engine {
char name[ENGINE_NAME_LEN];
bool idling;
bool busy;
bool running;
- bool cur_req_prepared;

struct list_head list;
spinlock_t queue_lock;
@@ -56,12 +55,12 @@ struct crypto_engine {

int (*prepare_crypt_hardware)(struct crypto_engine *engine);
int (*unprepare_crypt_hardware)(struct crypto_engine *engine);
+ bool (*can_enqueue_hardware)(struct device *dev);

struct kthread_worker *kworker;
struct kthread_work pump_requests;

void *priv_data;
- struct crypto_async_request *cur_req;
};

/*
@@ -102,6 +101,9 @@ void crypto_finalize_skcipher_request(struct crypto_engine *engine,
int crypto_engine_start(struct crypto_engine *engine);
int crypto_engine_stop(struct crypto_engine *engine);
struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt);
+struct crypto_engine *crypto_engine_alloc_init_and_set(struct device *dev,
+ bool (*cbk)(struct device *dev),
+ bool rt, int qlen);
int crypto_engine_exit(struct crypto_engine *engine);

#endif /* _CRYPTO_ENGINE_H */
--
2.1.0


2020-01-28 11:02:22

by Iuliana Prodan

[permalink] [raw]
Subject: Re: [PATCH] crypto: engine - support for parallel requests

On 1/28/2020 10:58 AM, Corentin Labbe wrote:
> On Tue, Jan 28, 2020 at 12:17:05AM +0200, Iuliana Prodan wrote:
>> Added support for executing multiple requests, in parallel,
>> for crypto engine.
>> A new callback is added, can_enqueue_hardware, which asks the
>> driver if the hardware has free space, to enqueue a new request.
>> The new crypto_engine_alloc_init_and_set function, initialize
>> crypto-engine, sets the maximum size for crypto-engine software
>> queue (not hardcoded anymore) and the can_enqueue_hardware callback.
>> On crypto_pump_requests, if can_enqueue_hardware callback returns true,
>> a new request is send to hardware, until there is no space and the
>> callback returns false.
>>
>> Signed-off-by: Iuliana Prodan <[email protected]>
>>
>> ---
>> Changes since V0 (RFC):
>> - removed max_no_req and no_req, as the number of request that
>> can be processed in parallel;
>> - added a new callback, can_enqueue_hardware, to check whether
>> the hardware can process a new request.
>> ---
>>
>> crypto/crypto_engine.c | 105 ++++++++++++++++++++++++++++++------------------
>> include/crypto/engine.h | 10 +++--
>> 2 files changed, 71 insertions(+), 44 deletions(-)
>>
>> diff --git a/crypto/crypto_engine.c b/crypto/crypto_engine.c
>> index eb029ff..ee3a610 100644
>> --- a/crypto/crypto_engine.c
>> +++ b/crypto/crypto_engine.c
>> @@ -22,32 +22,18 @@
>> * @err: error number
>> */
>> static void crypto_finalize_request(struct crypto_engine *engine,
>> - struct crypto_async_request *req, int err)
>> + struct crypto_async_request *req, int err)
>> {
>> - unsigned long flags;
>> - bool finalize_cur_req = false;
>> int ret;
>> struct crypto_engine_ctx *enginectx;
>>
>> - spin_lock_irqsave(&engine->queue_lock, flags);
>> - if (engine->cur_req == req)
>> - finalize_cur_req = true;
>> - spin_unlock_irqrestore(&engine->queue_lock, flags);
>> -
>> - if (finalize_cur_req) {
>> - enginectx = crypto_tfm_ctx(req->tfm);
>> - if (engine->cur_req_prepared &&
>> - enginectx->op.unprepare_request) {
>> - ret = enginectx->op.unprepare_request(engine, req);
>> - if (ret)
>> - dev_err(engine->dev, "failed to unprepare request\n");
>> - }
>> - spin_lock_irqsave(&engine->queue_lock, flags);
>> - engine->cur_req = NULL;
>> - engine->cur_req_prepared = false;
>> - spin_unlock_irqrestore(&engine->queue_lock, flags);
>> + enginectx = crypto_tfm_ctx(req->tfm);
>> + if (enginectx->op.prepare_request &&
>> + enginectx->op.unprepare_request) {
>> + ret = enginectx->op.unprepare_request(engine, req);
>> + if (ret)
>> + dev_err(engine->dev, "failed to unprepare request\n");
>> }
>> -
>> req->complete(req, err);
>>
>> kthread_queue_work(engine->kworker, &engine->pump_requests);
>> @@ -73,10 +59,6 @@ static void crypto_pump_requests(struct crypto_engine *engine,
>>
>> spin_lock_irqsave(&engine->queue_lock, flags);
>>
>> - /* Make sure we are not already running a request */
>> - if (engine->cur_req)
>> - goto out;
>> -
>> /* If another context is idling then defer */
>> if (engine->idling) {
>> kthread_queue_work(engine->kworker, &engine->pump_requests);
>> @@ -108,13 +90,18 @@ static void crypto_pump_requests(struct crypto_engine *engine,
>> goto out;
>> }
>>
>> +start_request:
>> + /* If hw is busy, do not send any request */
>> + if (engine->can_enqueue_hardware &&
>> + !engine->can_enqueue_hardware(engine->dev))
>> + goto out;
>> +
>> /* Get the fist request from the engine queue to handle */
>> backlog = crypto_get_backlog(&engine->queue);
>> async_req = crypto_dequeue_request(&engine->queue);
>> if (!async_req)
>> goto out;
>>
>> - engine->cur_req = async_req;
>> if (backlog)
>> backlog->complete(backlog, -EINPROGRESS);
>>
>> @@ -130,7 +117,7 @@ static void crypto_pump_requests(struct crypto_engine *engine,
>> ret = engine->prepare_crypt_hardware(engine);
>> if (ret) {
>> dev_err(engine->dev, "failed to prepare crypt hardware\n");
>> - goto req_err;
>> + goto req_err_2;
>> }
>> }
>>
>> @@ -141,26 +128,38 @@ static void crypto_pump_requests(struct crypto_engine *engine,
>> if (ret) {
>> dev_err(engine->dev, "failed to prepare request: %d\n",
>> ret);
>> - goto req_err;
>> + goto req_err_2;
>> }
>> - engine->cur_req_prepared = true;
>> }
>> if (!enginectx->op.do_one_request) {
>> dev_err(engine->dev, "failed to do request\n");
>> ret = -EINVAL;
>> - goto req_err;
>> + goto req_err_1;
>> }
>> +
>> ret = enginectx->op.do_one_request(engine, async_req);
>> if (ret) {
>> dev_err(engine->dev, "Failed to do one request from queue: %d\n", ret);
>> - goto req_err;
>> + goto req_err_1;
>> }
>> - return;
>>
>> -req_err:
>> - crypto_finalize_request(engine, async_req, ret);
>> - return;
>> + goto retry;
>> +
>> +req_err_1:
>> + if (enginectx->op.unprepare_request) {
>> + ret = enginectx->op.unprepare_request(engine, async_req);
>> + if (ret)
>> + dev_err(engine->dev, "failed to unprepare request\n");
>> + }
>> +req_err_2:
>> + async_req->complete(async_req, ret);
>>
>> +retry:
>> + if (engine->can_enqueue_hardware) {
>> + spin_lock_irqsave(&engine->queue_lock, flags);
>> + goto start_request;
>> + }
>> + return;
>> out:
>> spin_unlock_irqrestore(&engine->queue_lock, flags);
>> }
>> @@ -386,15 +385,25 @@ int crypto_engine_stop(struct crypto_engine *engine)
>> EXPORT_SYMBOL_GPL(crypto_engine_stop);
>>
>> /**
>> - * crypto_engine_alloc_init - allocate crypto hardware engine structure and
>> - * initialize it.
>> + * crypto_engine_alloc_init_and_set - allocate crypto hardware engine structure
>> + * and initialize it by setting the maximum number of entries in the software
>> + * crypto-engine queue.
>> * @dev: the device attached with one hardware engine
>> + * @cbk: pointer to a callback function to be invoked when pumping requests
>> + * to check whether the hardware can process a new request.
>> + * This has the form:
>> + * callback(struct device *dev)
>> + * where:
>> + * @dev: contains the device that processed this response.
>> * @rt: whether this queue is set to run as a realtime task
>> + * @qlen: maximum size of the crypto-engine queue
>> *
>> * This must be called from context that can sleep.
>> * Return: the crypto engine structure on success, else NULL.
>> */
>> -struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt)
>> +struct crypto_engine *crypto_engine_alloc_init_and_set(struct device *dev,
>> + bool (*cbk)(struct device *dev),
>> + bool rt, int qlen)
>> {
>> struct sched_param param = { .sched_priority = MAX_RT_PRIO / 2 };
>> struct crypto_engine *engine;
>> @@ -411,12 +420,12 @@ struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt)
>> engine->running = false;
>> engine->busy = false;
>> engine->idling = false;
>> - engine->cur_req_prepared = false;
>> engine->priv_data = dev;
>> + engine->can_enqueue_hardware = cbk;
>> snprintf(engine->name, sizeof(engine->name),
>> "%s-engine", dev_name(dev));
>>
>> - crypto_init_queue(&engine->queue, CRYPTO_ENGINE_MAX_QLEN);
>> + crypto_init_queue(&engine->queue, qlen);
>> spin_lock_init(&engine->queue_lock);
>>
>> engine->kworker = kthread_create_worker(0, "%s", engine->name);
>> @@ -433,6 +442,22 @@ struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt)
>>
>> return engine;
>> }
>> +EXPORT_SYMBOL_GPL(crypto_engine_alloc_init_and_set);
>> +
>> +/**
>> + * crypto_engine_alloc_init - allocate crypto hardware engine structure and
>> + * initialize it.
>> + * @dev: the device attached with one hardware engine
>> + * @rt: whether this queue is set to run as a realtime task
>> + *
>> + * This must be called from context that can sleep.
>> + * Return: the crypto engine structure on success, else NULL.
>> + */
>> +struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt)
>> +{
>> + return crypto_engine_alloc_init_and_set(dev, NULL, rt,
>> + CRYPTO_ENGINE_MAX_QLEN);
>> +}
>> EXPORT_SYMBOL_GPL(crypto_engine_alloc_init);
>>
>> /**
>> diff --git a/include/crypto/engine.h b/include/crypto/engine.h
>> index e29cd67..15d1150 100644
>> --- a/include/crypto/engine.h
>> +++ b/include/crypto/engine.h
>> @@ -24,7 +24,6 @@
>> * @idling: the engine is entering idle state
>> * @busy: request pump is busy
>> * @running: the engine is on working
>> - * @cur_req_prepared: current request is prepared
>> * @list: link with the global crypto engine list
>> * @queue_lock: spinlock to syncronise access to request queue
>> * @queue: the crypto queue of the engine
>> @@ -35,17 +34,17 @@
>> * @unprepare_crypt_hardware: there are currently no more requests on the
>> * queue so the subsystem notifies the driver that it may relax the
>> * hardware by issuing this call
>> + * @can_enqueue_hardware: callback to check whether the hardware can process
>> + * a new request
>> * @kworker: kthread worker struct for request pump
>> * @pump_requests: work struct for scheduling work to the request pump
>> * @priv_data: the engine private data
>> - * @cur_req: the current request which is on processing
>> */
>> struct crypto_engine {
>> char name[ENGINE_NAME_LEN];
>> bool idling;
>> bool busy;
>> bool running;
>> - bool cur_req_prepared;
>>
>> struct list_head list;
>> spinlock_t queue_lock;
>> @@ -56,12 +55,12 @@ struct crypto_engine {
>>
>> int (*prepare_crypt_hardware)(struct crypto_engine *engine);
>> int (*unprepare_crypt_hardware)(struct crypto_engine *engine);
>> + bool (*can_enqueue_hardware)(struct device *dev);
>>
>> struct kthread_worker *kworker;
>> struct kthread_work pump_requests;
>>
>> void *priv_data;
>> - struct crypto_async_request *cur_req;
>> };
>>
>> /*
>> @@ -102,6 +101,9 @@ void crypto_finalize_skcipher_request(struct crypto_engine *engine,
>> int crypto_engine_start(struct crypto_engine *engine);
>> int crypto_engine_stop(struct crypto_engine *engine);
>> struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt);
>> +struct crypto_engine *crypto_engine_alloc_init_and_set(struct device *dev,
>> + bool (*cbk)(struct device *dev),
>> + bool rt, int qlen);
>> int crypto_engine_exit(struct crypto_engine *engine);
>>
>> #endif /* _CRYPTO_ENGINE_H */
>> --
>> 2.1.0
>>
>
>
> Hello
>
> For someone which said "I'm planning to improve crypto-engine incrementally", this is lot of change in one.
> You could have used my first 4 patchs which clean crypto_engine (for getting rid of cur_req_prepared/cur_req for example).
>

The number of patches is something debatable!
Your first patches were already in my RFC!
This patch adds support for independent requests by adding a check for
hardware availability. Removing current request (cur_req) means we need
to add something else to break from the loop we have in pump_requests().
I didn't see how I could split it in several commits, but I don't see
this as a big deal.
We can split it any way we/Herbert agree on.

> Furthermore, the callback should not be registred at init, but should be part of the struct crypto_engine_op.

We need to check if we can enqueue a new request before dequeuing the
request from crypto-engine's queue.

> And the callback need to have the crypto engine itself as parameter, in case the driver own more than one crypto engine.
I can add crypto-engine as argument if you consider it useful.

> In my serie I added also the current request for giving more hint on the current state and let the driver do the right decision.
>
If you refer to linked requests, this is something specific for your
case/driver. I'm not handling this case, here.
But, for sure, is not correct to do do_one_request, only on the first
request. This breaks the current API and doesn't scale to supporting
multiple independent requests.

2020-01-28 13:28:43

by Corentin Labbe

[permalink] [raw]
Subject: Re: [PATCH] crypto: engine - support for parallel requests

On Tue, Jan 28, 2020 at 11:01:13AM +0000, Iuliana Prodan wrote:
> On 1/28/2020 10:58 AM, Corentin Labbe wrote:
> > On Tue, Jan 28, 2020 at 12:17:05AM +0200, Iuliana Prodan wrote:
> >> Added support for executing multiple requests, in parallel,
> >> for crypto engine.
> >> A new callback is added, can_enqueue_hardware, which asks the
> >> driver if the hardware has free space, to enqueue a new request.
> >> The new crypto_engine_alloc_init_and_set function, initialize
> >> crypto-engine, sets the maximum size for crypto-engine software
> >> queue (not hardcoded anymore) and the can_enqueue_hardware callback.
> >> On crypto_pump_requests, if can_enqueue_hardware callback returns true,
> >> a new request is send to hardware, until there is no space and the
> >> callback returns false.
> >>
> >> Signed-off-by: Iuliana Prodan <[email protected]>
> >>
> >> ---
> >> Changes since V0 (RFC):
> >> - removed max_no_req and no_req, as the number of request that
> >> can be processed in parallel;
> >> - added a new callback, can_enqueue_hardware, to check whether
> >> the hardware can process a new request.
> >> ---
> >>
> >> crypto/crypto_engine.c | 105 ++++++++++++++++++++++++++++++------------------
> >> include/crypto/engine.h | 10 +++--
> >> 2 files changed, 71 insertions(+), 44 deletions(-)
> >>
> >> diff --git a/crypto/crypto_engine.c b/crypto/crypto_engine.c
> >> index eb029ff..ee3a610 100644
> >> --- a/crypto/crypto_engine.c
> >> +++ b/crypto/crypto_engine.c
> >> @@ -22,32 +22,18 @@
> >> * @err: error number
> >> */
> >> static void crypto_finalize_request(struct crypto_engine *engine,
> >> - struct crypto_async_request *req, int err)
> >> + struct crypto_async_request *req, int err)
> >> {
> >> - unsigned long flags;
> >> - bool finalize_cur_req = false;
> >> int ret;
> >> struct crypto_engine_ctx *enginectx;
> >>
> >> - spin_lock_irqsave(&engine->queue_lock, flags);
> >> - if (engine->cur_req == req)
> >> - finalize_cur_req = true;
> >> - spin_unlock_irqrestore(&engine->queue_lock, flags);
> >> -
> >> - if (finalize_cur_req) {
> >> - enginectx = crypto_tfm_ctx(req->tfm);
> >> - if (engine->cur_req_prepared &&
> >> - enginectx->op.unprepare_request) {
> >> - ret = enginectx->op.unprepare_request(engine, req);
> >> - if (ret)
> >> - dev_err(engine->dev, "failed to unprepare request\n");
> >> - }
> >> - spin_lock_irqsave(&engine->queue_lock, flags);
> >> - engine->cur_req = NULL;
> >> - engine->cur_req_prepared = false;
> >> - spin_unlock_irqrestore(&engine->queue_lock, flags);
> >> + enginectx = crypto_tfm_ctx(req->tfm);
> >> + if (enginectx->op.prepare_request &&
> >> + enginectx->op.unprepare_request) {
> >> + ret = enginectx->op.unprepare_request(engine, req);
> >> + if (ret)
> >> + dev_err(engine->dev, "failed to unprepare request\n");
> >> }
> >> -
> >> req->complete(req, err);
> >>
> >> kthread_queue_work(engine->kworker, &engine->pump_requests);
> >> @@ -73,10 +59,6 @@ static void crypto_pump_requests(struct crypto_engine *engine,
> >>
> >> spin_lock_irqsave(&engine->queue_lock, flags);
> >>
> >> - /* Make sure we are not already running a request */
> >> - if (engine->cur_req)
> >> - goto out;
> >> -
> >> /* If another context is idling then defer */
> >> if (engine->idling) {
> >> kthread_queue_work(engine->kworker, &engine->pump_requests);
> >> @@ -108,13 +90,18 @@ static void crypto_pump_requests(struct crypto_engine *engine,
> >> goto out;
> >> }
> >>
> >> +start_request:
> >> + /* If hw is busy, do not send any request */
> >> + if (engine->can_enqueue_hardware &&
> >> + !engine->can_enqueue_hardware(engine->dev))
> >> + goto out;
> >> +
> >> /* Get the fist request from the engine queue to handle */
> >> backlog = crypto_get_backlog(&engine->queue);
> >> async_req = crypto_dequeue_request(&engine->queue);
> >> if (!async_req)
> >> goto out;
> >>
> >> - engine->cur_req = async_req;
> >> if (backlog)
> >> backlog->complete(backlog, -EINPROGRESS);
> >>
> >> @@ -130,7 +117,7 @@ static void crypto_pump_requests(struct crypto_engine *engine,
> >> ret = engine->prepare_crypt_hardware(engine);
> >> if (ret) {
> >> dev_err(engine->dev, "failed to prepare crypt hardware\n");
> >> - goto req_err;
> >> + goto req_err_2;
> >> }
> >> }
> >>
> >> @@ -141,26 +128,38 @@ static void crypto_pump_requests(struct crypto_engine *engine,
> >> if (ret) {
> >> dev_err(engine->dev, "failed to prepare request: %d\n",
> >> ret);
> >> - goto req_err;
> >> + goto req_err_2;
> >> }
> >> - engine->cur_req_prepared = true;
> >> }
> >> if (!enginectx->op.do_one_request) {
> >> dev_err(engine->dev, "failed to do request\n");
> >> ret = -EINVAL;
> >> - goto req_err;
> >> + goto req_err_1;
> >> }
> >> +
> >> ret = enginectx->op.do_one_request(engine, async_req);
> >> if (ret) {
> >> dev_err(engine->dev, "Failed to do one request from queue: %d\n", ret);
> >> - goto req_err;
> >> + goto req_err_1;
> >> }
> >> - return;
> >>
> >> -req_err:
> >> - crypto_finalize_request(engine, async_req, ret);
> >> - return;
> >> + goto retry;
> >> +
> >> +req_err_1:
> >> + if (enginectx->op.unprepare_request) {
> >> + ret = enginectx->op.unprepare_request(engine, async_req);
> >> + if (ret)
> >> + dev_err(engine->dev, "failed to unprepare request\n");
> >> + }
> >> +req_err_2:
> >> + async_req->complete(async_req, ret);
> >>
> >> +retry:
> >> + if (engine->can_enqueue_hardware) {
> >> + spin_lock_irqsave(&engine->queue_lock, flags);
> >> + goto start_request;
> >> + }
> >> + return;
> >> out:
> >> spin_unlock_irqrestore(&engine->queue_lock, flags);
> >> }
> >> @@ -386,15 +385,25 @@ int crypto_engine_stop(struct crypto_engine *engine)
> >> EXPORT_SYMBOL_GPL(crypto_engine_stop);
> >>
> >> /**
> >> - * crypto_engine_alloc_init - allocate crypto hardware engine structure and
> >> - * initialize it.
> >> + * crypto_engine_alloc_init_and_set - allocate crypto hardware engine structure
> >> + * and initialize it by setting the maximum number of entries in the software
> >> + * crypto-engine queue.
> >> * @dev: the device attached with one hardware engine
> >> + * @cbk: pointer to a callback function to be invoked when pumping requests
> >> + * to check whether the hardware can process a new request.
> >> + * This has the form:
> >> + * callback(struct device *dev)
> >> + * where:
> >> + * @dev: contains the device that processed this response.
> >> * @rt: whether this queue is set to run as a realtime task
> >> + * @qlen: maximum size of the crypto-engine queue
> >> *
> >> * This must be called from context that can sleep.
> >> * Return: the crypto engine structure on success, else NULL.
> >> */
> >> -struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt)
> >> +struct crypto_engine *crypto_engine_alloc_init_and_set(struct device *dev,
> >> + bool (*cbk)(struct device *dev),
> >> + bool rt, int qlen)
> >> {
> >> struct sched_param param = { .sched_priority = MAX_RT_PRIO / 2 };
> >> struct crypto_engine *engine;
> >> @@ -411,12 +420,12 @@ struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt)
> >> engine->running = false;
> >> engine->busy = false;
> >> engine->idling = false;
> >> - engine->cur_req_prepared = false;
> >> engine->priv_data = dev;
> >> + engine->can_enqueue_hardware = cbk;
> >> snprintf(engine->name, sizeof(engine->name),
> >> "%s-engine", dev_name(dev));
> >>
> >> - crypto_init_queue(&engine->queue, CRYPTO_ENGINE_MAX_QLEN);
> >> + crypto_init_queue(&engine->queue, qlen);
> >> spin_lock_init(&engine->queue_lock);
> >>
> >> engine->kworker = kthread_create_worker(0, "%s", engine->name);
> >> @@ -433,6 +442,22 @@ struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt)
> >>
> >> return engine;
> >> }
> >> +EXPORT_SYMBOL_GPL(crypto_engine_alloc_init_and_set);
> >> +
> >> +/**
> >> + * crypto_engine_alloc_init - allocate crypto hardware engine structure and
> >> + * initialize it.
> >> + * @dev: the device attached with one hardware engine
> >> + * @rt: whether this queue is set to run as a realtime task
> >> + *
> >> + * This must be called from context that can sleep.
> >> + * Return: the crypto engine structure on success, else NULL.
> >> + */
> >> +struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt)
> >> +{
> >> + return crypto_engine_alloc_init_and_set(dev, NULL, rt,
> >> + CRYPTO_ENGINE_MAX_QLEN);
> >> +}
> >> EXPORT_SYMBOL_GPL(crypto_engine_alloc_init);
> >>
> >> /**
> >> diff --git a/include/crypto/engine.h b/include/crypto/engine.h
> >> index e29cd67..15d1150 100644
> >> --- a/include/crypto/engine.h
> >> +++ b/include/crypto/engine.h
> >> @@ -24,7 +24,6 @@
> >> * @idling: the engine is entering idle state
> >> * @busy: request pump is busy
> >> * @running: the engine is on working
> >> - * @cur_req_prepared: current request is prepared
> >> * @list: link with the global crypto engine list
> >> * @queue_lock: spinlock to syncronise access to request queue
> >> * @queue: the crypto queue of the engine
> >> @@ -35,17 +34,17 @@
> >> * @unprepare_crypt_hardware: there are currently no more requests on the
> >> * queue so the subsystem notifies the driver that it may relax the
> >> * hardware by issuing this call
> >> + * @can_enqueue_hardware: callback to check whether the hardware can process
> >> + * a new request
> >> * @kworker: kthread worker struct for request pump
> >> * @pump_requests: work struct for scheduling work to the request pump
> >> * @priv_data: the engine private data
> >> - * @cur_req: the current request which is on processing
> >> */
> >> struct crypto_engine {
> >> char name[ENGINE_NAME_LEN];
> >> bool idling;
> >> bool busy;
> >> bool running;
> >> - bool cur_req_prepared;
> >>
> >> struct list_head list;
> >> spinlock_t queue_lock;
> >> @@ -56,12 +55,12 @@ struct crypto_engine {
> >>
> >> int (*prepare_crypt_hardware)(struct crypto_engine *engine);
> >> int (*unprepare_crypt_hardware)(struct crypto_engine *engine);
> >> + bool (*can_enqueue_hardware)(struct device *dev);
> >>
> >> struct kthread_worker *kworker;
> >> struct kthread_work pump_requests;
> >>
> >> void *priv_data;
> >> - struct crypto_async_request *cur_req;
> >> };
> >>
> >> /*
> >> @@ -102,6 +101,9 @@ void crypto_finalize_skcipher_request(struct crypto_engine *engine,
> >> int crypto_engine_start(struct crypto_engine *engine);
> >> int crypto_engine_stop(struct crypto_engine *engine);
> >> struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt);
> >> +struct crypto_engine *crypto_engine_alloc_init_and_set(struct device *dev,
> >> + bool (*cbk)(struct device *dev),
> >> + bool rt, int qlen);
> >> int crypto_engine_exit(struct crypto_engine *engine);
> >>
> >> #endif /* _CRYPTO_ENGINE_H */
> >> --
> >> 2.1.0
> >>
> >
> >
> > Hello
> >
> > For someone which said "I'm planning to improve crypto-engine incrementally", this is lot of change in one.
> > You could have used my first 4 patchs which clean crypto_engine (for getting rid of cur_req_prepared/cur_req for example).
> >
>
> The number of patches is something debatable!
> Your first patches were already in my RFC!
> This patch adds support for independent requests by adding a check for
> hardware availability. Removing current request (cur_req) means we need
> to add something else to break from the loop we have in pump_requests().
> I didn't see how I could split it in several commits, but I don't see
> this as a big deal.
> We can split it any way we/Herbert agree on.
>
> > Furthermore, the callback should not be registred at init, but should be part of the struct crypto_engine_op.
>
> We need to check if we can enqueue a new request before dequeuing the
> request from crypto-engine's queue.
>
> > And the callback need to have the crypto engine itself as parameter, in case the driver own more than one crypto engine.
> I can add crypto-engine as argument if you consider it useful.
>
> > In my serie I added also the current request for giving more hint on the current state and let the driver do the right decision.
> >
> If you refer to linked requests, this is something specific for your
> case/driver. I'm not handling this case, here.

That's the point, while I am trying to bring the change to support every case, you continue other each iteration to support only yours.

So I will stop here and wait to see what Herbert will think.

Regards